Getting Causes from Powers

STEPHEN MU MFORD

AND

RANI LILL ANJUM

OXFORD UNIVERSITY PRESS

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essential parts of this book's backwards causal cone

1

PREFACE

We heard a joke. A team of fundamental physicists had produced a Inodel for predicting the outcomes of horse races. They were asked why they were not rich. 'Ah,' they explained: 'You sec, the model only works on two assumptions. One is that the horses are perfectly spherical; alld the other is that they move without friction.' Though we heard the joke relatively late in the composition of this book, it neatly sums up the noason we wrote it. The world is a messy place. The exisling theories of r;!lIsation tend to ignore this, or at least abstract away from it. But slIlIlcthing can be lost if we do so. We wanted a theory that could deal wilh causal complexity and there are not many theories that offer us that. Al1d, although we thought we needed a theory for a messy world, we didll'l want a messy theory for the world, as causal plurallsm gives us.

There are many books on causation already and we didn't want to lmnlcn the world with another one unless it offered something new. What is new about this one? We are offering what we hope is a novel and positive account of causation, though with historical antecedents in Whitehead, J. S. M.iIl, Aquinas and Aristotle. Recent decades have llHlIlght what we take to be a wrong tum in the philosophy of causation. ()Ui' aim was to get it back on track. Among analytic philosophers, a n ltllltcrfactual dependence view of causation now seems the most pOPlllar. What-causes-what then becomes a matter of facts about occur­lI'IIlTS at vaIious possible worlds. We wanted to do causation without possihle worlds. Our knowledge and intuitions concerning those worlds :11 i', we think, determined entirely by ow· knowledge of and theories .111(1111 this world. This is the only world we know and our theory of ( allsatinl1 is limited to its resources. A possible-worlds theorist may ;I~;s('rl Ihat there is at least one Hurne-world, in which causation is Ilolliillg mOfe than constant conjunction. We deny this. How is there .IIIY l';msation in that world? Only if one already believes that constant nl1ljllllclion is a viable theory can one say that such a world is a I'0~;sihilily. So henceforth we will be dispensing with possible-worlds Ldt.;. ()111" theory of causation should be an entirely this-worldly theory.

I'hl' world is a world of powers. Not everyone believes this and this hook is l10L the place in which we argue for it. Our concem here is, 111~,h.:HI, what the theory of causation should look like if it were based on

.-----------... ~-

viii Preface

the reality of powers. A number of others have suggested that if one adopts a metaphysics of powers or real dispositions, one of the benefits would be a theory of causation. But we do not think it has been shown correctly or in enough detail what such a theory of causation would look like. We try to do that but we think that some of the main features of a dispositional theory of causation have been overlooked. We offer some ilUlovations. First we offer a new way of modelling causal situa­tions: using vectors instead of neuron diagrams. TIns allows us to show multiple causal factors at work. If we abstract away from that complex­Ity we WIll omIt various important features of causation. Causes can be thwarted, for instance, and this should show that they never guarantee their. effects, even when they succeed in producing them. Causal pro­duction should not, therefore, be confiated with causal necessitation. We attempt to account for the former without the latter. A second innovation follows this - or at least the reasseltion of a very old innovation. Causation involves what we call a dispositional modality. Causes dis­pose towards their effects, whcre disposing towards something involves :111 irreducible sui generis modality. The modality is something between plln' cOllllllgCIlCY and pure necessity and is rcducible to neither. This :,("('IIlS [0 us [lie key feature that a dispositional theory of causation :,hnult! haw, ;ulCl il is HillS a surprise that it has been so neglected. j',"lw\'lally :UI1l1I1j', [host' l'oJlll'llIporary metaphysicians who favour dis-1'(1, .. 110tl~, 'I'll\' idl';! oi" S(lIIH'tliillg irreducibly tending towards certain 1111[(,0111(':'; ha~; 1101 allral'll'd IlJaIlY adherents in modern philosophy even [holll',h, II WI' an' right, it is for causal agents the core modal notion. (jivclI Ih:llcausalion is taken to involve a primitive dispositional modal­ity, it might be wondered how we come to acquire an idea of it. Causation is perceivable, we will argue, through our roles as causal agents and patients, and the dispositional modality is thus known inti­mately by us.

There is a further key commitment that we develop in this book. Most philosophical work on causation builds upon the groundwork laid by Hume. Even those who consider themselves anti-Humean, we find, nevertheless follow the general terms in which he framed the discussion. We are looking to reappraise some of the basic features of the I-Iumean view - features that are so often taken for granted. Cause and effect for Hume, are distinct events standing in vmious contingent relations. The cause must temporally precede the effect, for instance, and all events of the same kind as the cause must be constantly conjoined with events of the samc kind as the effect. Few have challenged all these Humean

Preface ix

orthodoxies. If one is a dispositionalist, however, they really should be rejected. Rather than depicting causation as a relation that stands h~tween two whol1y distinct relata, we argue that it should instead be secn as a single unfolding process that occurs when a number (any lIumber) of mutual manifestation partners mcet. Whitehead (J92 9) had suggested a metaphysics like this, but not sufficiently clearly for our purposes and it did not have everything we want. Since such a pro.e~ss hegins at exactly the time an such partners are together, and ends eltner when the process has run its course or been interrupted, then causes and crfects are best understood as simultaneous. We try to meet the chal­kllge of explaining how causation and causal chains can take time.

What we are offering may be thought of as a radical departure. We have nevertheless tried to relate it to some of the existing debates, 10 provide an anchor for those who already study causation. We accept Ihat these debates provide for us a focus: a set of issues that we have to H'solve. We discuss whether there can be causation by absence, for Ulslance, and whether causalion should be thought of as transitive. We ,,!low that there is a distinction between the cause and effect, and thus IltallY of the questions that arise [Tom it being relational - such as ',ynlmetry and transitivity - still remain. But we dislike the way t?at \'IIUSI0 and effect are carved asunder by many of the popular theones. I'hal makes the key issue one of finding the relevant tie that joins them Ilack logcther. Instead, we see cause and effect as far more inti~ately 1 oll11l'cted, where one merges into the other in a more-than-contmgent pi on'.SS. The cause is then that about the process that ~s productive; the d kcl IS that aboul the process that is produced. RelatIOn-talk has Lo be I1l1tinslood within this context. We also speak frequently of those causes 111111 dlccis as being events. They often arc. But that does not tell the full !;ItIlY. They arc causes and effects derivatively because they ~ontain powns: and it is the powers that do the work. By employmg the IUlll

t,lIage of events from time to time we arc, however, able to engage

wll\I till' contemporary discussions. . Many thanks are due. Research for this book was conducted WIth

1IIIIIIIciai support, for which we are grateful. Stephen Mumford was p(1I1 IIi" Ihe AHRC-funded Metaphysics of Science project that, ~ogether Willi ll1Slilutional study leave [rom the lJniversity of Nottmgham, plllvl,lnl all extended spell of research leave. At the same time, Rani I III AlljUIll had a Norwegian Research Council (NFR)-funded thn:e­yl'll! I'Wjl'c\ on Dispositions and Causation, which contained a period as

~II

1

II

I'

1

I.

[I

x Preface

visiting research fellow in Nottingham. It was through the convergence of these two projects that the book was written.

While at Nottingham, we benefited from the weekly meetings of its Dispositions Group. The core members of this group consisted in, as well as the authors, Charlotte Matheson, Markus Schrenk and Matthew Tugby. Other regular participants included David Armstrong, Stephen Barker and Svein Anders Noer Lie, and we had visits from Hilan Bensusan and Kristina Engelhard. Various stages of the different parts of the book were discussed in these group meetings and we thank all the contributors for their input.

Our thanks also to the collaborators on the NJ-iR Dispositions and Causation project who pruticipated in the annual workshops at the University of Troms¢. These included Johan Aml Myrstad, Svein Anders Noer Lie, Sigurd Tonnessen, Thomas BOhn, Tcrje Traavik, Trond Skaftncsmo and Petter Omtvedt.

The material from the book was presented at a number of seminars and conferences away from Nottingham. We thank audiences for their time and comments at Aachen, Aarhus, Athens, Belfast, Bergen, Bristol, Buffalo, Cambridge (the Serious Metaphysics club), Cardiff, Durham, Essen, Granada, Grenoble, Halifax Nova Scotia, Hertfordshire, Istanbul Bogazici, Kent, Koln, Lancaster, Lisbon, London School of Economics, Lund, Madrid, Melbourne, Munster, Oslo, Oxford, Paris Sorbonne 4, Saskatchewan, St. Louis, Tampere, Troms0, Trondheuu NTNU, Turku, Valparaiso, Warsaw, and As UMB.

A number of other people have providcd useful comments and advicc on various parts of the book. We thank Markku Keinanen and Dagfinn DOh! Dygvig, as well as the anonymous Readers for Oxford University Press. We also thank Peter Momtehiloff for his support of the project. Thomas Bohn and John Armour gave helpful feedhack on the causal role of genes that we were able to use in chapter IO. Thanks also to our followers on Twitter for thcir discussions, support and great enthusiasm for the book. A special thanks goes to our families, Jon Henrik, Maggie, William, Oliver and Charlie. Finally, it was Bcn Curtis who told us the joke about the fundamental physicists and horse racing, though he says he heard it first from Philip Percival.

CONTENTS

Passing Powers Around

1 I ('<llIses and powers I _, ('ausal primitivism I \ Millian causes

,I Particular and general causal claims " The attack on causation

1 Mo,h-Iling Causes as Vectors

I Thl~ neuron and the vector Neuron diagrams

\ Till' vector and the quality space .1 ('uIHposition of causes and vector addition

, 'r What the vector model explains: standard cases 'h Mlltual manifestation and single powers , I I<l'alism about component powers '11 Mlliti-dimensional cases '., . All things are vectors'

i\I',jIIIIS[ Necessity

\ I I:,xplaining the familiar by the obscure . Thl'l"l' is a necessary eonnexion to be taken into "( IIIsi. leration'

\ \ '1'111' l':ISC for causal necessitarianism \ I 11Ih'l'krence and prevention \ '1 AII[l'l~edcnt strengthening I (, (11111'1' anti-necessitarians \ I I~, addition just subtraction in disguise? \ ti Wlta1 if there is no interferer? \ q ,'lhIHlldll', we just include more?

xv

7 II

13 T5

T9

19 20

23 27 30

34 38

44 45

47

47

. __ .

l xii Contents Contents xiii

3. 10 Can we exclude all inteIferers? 67 7·5 Prevention, induction and ceteris paribus clauses 165 3·II How can there be causal production without 7·6 Transitivity 167

necessitation? 70 7·7 Context-sensitivity 174 3·12 What if determinism is true? 74 3.13 Probabilistic causation and multi-directional powers 77 8. Primitive Modality 175 3·14 The new necessitarianism 81 8.1 Something in between 175 3.15 Causal necessitarianism jettisoned 84 8.2 Dispositions and necessity 176

8.3 What if everything is necessary? 178

'I 4· Reductionism, Holism and Emergence 86 8-4 Dispositions and possibility 179

I 4. 1 The composition of causes 86 8·S Dispositionality as natural possibility 181

III 4.2 Alleged problem cases for tbe vector mode! 88 8.6 Dispositionality and nonnativity 183 4·3 Some possible replies 92 8·7 Dispositionality and intentionality T85 4·4 What type of emergence do we have when 8.8 Intentionality and nonnativity are dispositional notions 186

I! powers collide? 103 8·9 DisposWonality as a selection function 189 4·5 Emergent powers 104 8.10 The conditional analysis 190

I! 8.Il Dispositional ity is the most basic modality 193

I

S· Simultaneity 106 5. 1 The causal relation 106 9· Perceiving Causes 195 5. 2 Temporal priority 107 9. 1 Primitive but empilicaUy grounded 195 5·.1 Prohlt'llls with temporal priority 108 9.2 Causal judgements and perceptions 196 ,.~ Silllllitalicity of cause and effect I T3 9·3 Where can we find the causal connection? T98

I ".) ()bjcctiolls to simultancous causation ll5 9-4 Bodily perception 201

! 5.6 J\ swcet solution 12 T Constant conjunction between willing and acting? 203 9·5

9.6 A reunificationist account of agency 204 6. Explanation, Absences and Countcrfactuals T30 9·7 The sense of proprioception 207 6. I Epistcmology and metaphysics T30 9.8 Perception and the dispositional modality 209 6.2 Explanation 131 9·9 Dispositional modality is the best known 212 6·3 Prediction 13S 6-4 Models 136 TO. A Biologically Disposed Theory of Causation 214 6·5 i\nti-deductivism 137 10.1 A reflective equilibrium 214 6.6 Inductive inference 140 10.2 Why not physics? 21 5 6·7 Causation by absence 143 10·3 The central features of causal dispositionalism 218 6.8 Causal coullterfaetuals 148 lOA Powers in biological explanation 21 9

to.S Complexity, polygeny and pleiotropy 22l 7· The Logic of Causation 156 10.6 Context-sensitivity, plasticity and flexibility 224

7·1. Relating cause to effect 156 10·7 Thresholds in biology 226 7.2 Distinguishing causal claims IS7 10.8 Emcrgence, holism and non-linearity 229 7·3 Some causal and non-causal claims 159 10·9 Simultaneity 232 7·4 Hypothetical versus categorical 163

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xiv Contents

10.10 Defeasible prediction 10.1 I Dispositional modality In. ] 2 Causation and science

Conclusion of This Book

Bibliography Index

233 234 235 LIST OF FIGURES

2.1 A neuron diagram

2.2 An inhibited neuron

2.3 A one-dimensional quality space

2.4 A disposition towards F

2.5 Multiple powers

2.6 A simple vector addition for figure 2.5

2.7 A zero resultant vector or equilibrium

2.8 A 'lonely' power

2.9 Counterbalanced powers

2.10 Component powers and their resultant R

1. 1 1 Mill's example of a resultant force

2.12 An example not considered by Mill

2.13 Vectors within a two-dimensional quality space

2.14 Vectors within a multi-dimensional quality space

3. T Interference

3.2 Prevention

3.3 Subtractive interference

3.4 Additive interference

20

21

23

25

28

29

29

36

37

39 40

40

45

45

54

55 62

62

3.5 The threshold for e is met 73

3.6 The threshold for e is not met 73

3.7 A probabilistic case with two possible, equally likely, outcomes 79

3.8 A probabilistic case wilh six possible, equally likely, outcomes 79

4.1 A non-linear function relating wealth and happiness

4.2 An antipathetic case

4.3 Plant moisture equilibrium

404 Non-linear composition for area

5.1 A simultaneous but temporally extended causal process

5.2 Overlapping causal processes

5.3 The backwards causal cone

54 The forwards causal cone

123 u6

127

128

II' ~ II I

II

Ii

XVl List of Figures

6.T 'Causation by absence'

6.2 Overdeterrnination

7.T Transitivity of classification

7.2 A causal chain

7.3 A case of transitivity failure

147

153

168

169

172

I

Passing Powers Around

J . I Causes and powers

Only philosophers worry about it but everyone else believes in causa­tion. And, even among philosophers, it is rare to find anyone who openly denies there is such a thing. The question of what causation consists in is, however, an altogether different matter.

Let us start with a simple example. We place a bag of apples on some weighing scales. The pointer on the scales moves. This is causation. The appJes caused the pointer's movement. We know, of course, that it might not really be a genuine case of causation. The pointer may have moved for some other, unexpected, reason. Philosophers pride them­selves on being able to contrive such cases. But all they show is that our causal knowledge and expectation is defeasible. They don't really affect the issue of what causation is. Let us assume that the apples on the scale tmIy did cause the pointer to move.

We now alTeady have a number of metaphysical questions before us. \¥hat exactly was the cause of the pointer's movement? Was it the apples? Was it the fact that the apples were on the scales? 'Vas it the event of the apples being placed on the scales? These options in turn suggest that objects, facts and events are the relata of causal relations. In this book, we defend another view. It is properties that do the causal work, and they do so because they are powerful.

Nevertheless, objects, facts and events can all be involved in causa­tion, on our view. But they arc involved because ohhe powerful proper­ties that they contain. The apples indeed moved the scales, but only because they had a property that was capable of moving the scales. More precisely, it was the weight or mass that was the causally active prop­erty, not the colour of the apples, nor their shape. These other properties could be involved in other causal transactions, but not this one.

Properties do not, however. float around freely in the world. They aTe properties of things. Weight has to be the weight of something. So it is quite reasonable to say that the apples moved the scales. They did so

2 Passing Powers Around

uecause they had a causally powerful property. There is, thus, something in substance causation. But it does not tell the whole story, OJ a precise enough story_It is a something about the substance that docs its causal work.

Both Armstrong (r99T ch. r4) and Mellor ([995), in contrast, take facts to be the causal relata. In Annstrong's metaphysics, a fact is a particular-bearing-a-propclty. Again, such facts can indeed be involved in causation. But we can say once more that it is the propclty involved in such a fact that does its causal work. Which particular bears that property may well be an important matter, and it may dictate the where and the when causation occurs. But it will always be the property doing the causing.

Events are the favoured causal relata of many, especially the fol­lowers of Hume (I739) and Lewis ([973). Much of our ordinary causal talk is couched in tenm, of events, they might point out. It is the placing of the apples on the scales that causes the pointer to move, we are encouraged to think, the putting of sugar in tea that causes it to dissolve, the throwing of the rock that breaks the window, and smoking that causes cancer. We do not deny that events can be causal. But why are lhl~y'? Sll1okin& causes cancer when it is the smoking of a carcinogen. Smoking herbal cigarettes, or smoldng rolled-up seaweed, would not cause cancn, as far as we know. So it is not the event of smoking as such that docs the work: it is that the thing smoked has the power to cause this response when inhaled.

When we speak of events as causes (and effects), it often works as a causal story precisely because of our background knowledge of causal powers. When we speak of smoking, we know that we usually mean tobacco smoking. When we speak of tin-owing a rock at a window, we know that we are speaking of something hard, massive and with a velocity. Throwing a sponge at a window doesn't break it. And when we speak of it being thrown at a window, we know that to be something made of glass, hence fragile. The properties of mass, velocity, fragility and so on are thus vital in the truthmaking of the causal truth.

We do not deny that there are events. We have an explanation of them. Events will be produced by powers at work: at least the events that are caused will be (whether some events are uncaused, we leave open). Events will be the changes produced when powers exercise themselves. AmI some of these changes will then push other powers together. The exercising of one power may put sugar into tea, for instance. When suitably partnered powers are pushed together, they will in tum manifest

Causes and potvers 3

themselves. And so it goes 011. When we talk of events in causation, we are mainly talking about how the empowered properties got together­how the mass met the fragility or how the sugar met the lea - but it is the partnered properties that do the causing. Understood this way, we are happy to talk in tenns of events as causes.

We have said, nevertheless, that it is properties doing the causal work. This suggests that there is a close connection between properties and powers. What is this and why is it? Our answer is based 011 a the~r~ of what a property is. Properties just are clusters of causal powers. ThIS IS a theory ventured by Shoemaker ([980). though one that he has subse­quently abandoned. He now thinks that properties bestow their bearers with causal powers (Shoemaker j 999: 297) instead of being simply constituted by them. Either theory would suffice to establish the intimate connection between properties and powers, but it is the original theory that we prefer. If we take properties just to be causal powers, then we have a more parsimonious ontology than that in which there are proper­ties as well as the powers they bestow. We also have no need to give an account of the relation of bestowal (Mumford 2008: 146). And the revised Shoemaker theory would tell us no longer what a properly is. We stick with the original Shoemaker theory, therefore, and apply it to all properties (Mumford 2004: ch. TO), which gives us the position of pandispositionalism. All properties are clusters of. causal pOVl'~rs, 110t just the overtly powerlul ones such as being explOSive or corroSIve.

It is argued by many, however, that at least some properties are non­dispositional or categorical (see Armstrong 2005, for instance). ~t is not often said what is meant by categorical, but shape i::; usuall y comadcred a paradigm (see Prior 1982). 1\ pandispositionalist has to defend the view, therefore, that even a property such as sphericity is in reality a duster of causal powers. This is not easy because the property term does not wc~r its powers on its sleeve. But even this, the pandispositionalist say~, IS

covertly dispositional. Something that is spherical is disposed to roll II1 a straioht line down an inclined plane. Something that is cubical, in con;ast, is not. It may be countered that there are spherical things that do not roll in a straight line, even if on an inclined plane. A soap bubble sticks to the surface,l a bowls ball may have a weight in one side that causes it to roll in a curved line, and a non-rigid sphere might squash fiat (Unger 2006: 269). But these examples do not show us spherical things

I This example was suggested to LIS by E. J. I "owe.

I

4 Passin!? Powers Around

that lack the disposition to TOll in a straight line. They only show us examples of spheres that don't manifest their disposition to roll in straight lines and one crucial mark of a disposition is that it can exist unmanifested. The soap bubble is indeed disposed to roll in a straight line in virtue of being spherjcal and the reason it doesn't is because it has a countervailing power of stickiness that is stronger than its rolling power. Similarly, the crooked weight of the bowls ball countervails its power to roll in a straight line, and the non-rigid sphere has the power to roll as long as it is spherical, though, of course, as soon as it loses its shape, it ceases to have that power.

A further task is to explain what powers are and defend the ontologi­cal commItment to them. The reader wlll not be too disappointed, we hope, to hear that we will not be attempting to complete that task here. Others have done so with varying degrees of detail and success (Weissman 1965; Tuomela 1978; Prior 1985; Harre aod Madden 1975; Cartwnght 1989; Mumford [998, 2004; Ellis 200 [; Molnar 2003; Bird 2007; and Martin 2008, for instance). The main task in this book IS

something different. Many of the above authors have suggested that one o~ the ad:antages of a theory of powers is that it would give us a theory of causatIOn (for example, Molnar 2003: ch. 12). None have shown this to our satisfaction. however. In this book, we will simply assume that the world is a world containing real powers and our job instead is to show what the theory of causation would look like, given that assumption.

We.still have to say something about our assumption, however, given that Vlews of what powers are vary. One crucial point is that we are using the terms 'power' and 'disposition' as equivalent. Not everyone does. Fara (2005), for instance, reserves the term 'disposition' for powers that tend to he manifested. On this tendential view, something can have a power to F, even if it is not disposed to F. You may have a ~ower to speak Gennan, for instance, but not be disposed to do so if, for mstance, you are also shy. Our use of disposition is non-tendential. Just as one can reasonably say that something has a power to act, though it rarely does so, similarly we can use the term' disposition' in that same way. Indeed, fragility is often taken as a paradigm disposition, though an object that has it may never manifest it. Dispositions such as this are manifested onCe only, if at all, because manifestation leads to destruc­tion of the bearer, so the tcndential reading of beinx disposed seems to a degree artificial.

A disposition or power we take, therefore. to be something that has possible manifestations, though it may nevertheless still exist

Causes and powers 5

unmanifested. This commits us to realism and, for reasons we will give much later (§8. 10), we do not accept that there is a reductive analysis of disposition ascription. OUT dispositional vocabulary is, however, a rich one. We thus have terms for dispositions that reliably and frequently manifest (tendency), dispositions it is an advantage to have (abilities), dispositions it is a disadvantage to have (liabilities), and so on. We will set aside these linguistic distinctions because the basic dispositions present us with all we need to explain the dispositional theory of

causation. Dispositions have sometimes been classified as types of propelties.

We do not say that because, as has already been stated, we take proper­ties themselves to be just clusters of powers. Nevertheless, a type-token distinction clearly applies to dispositions. Hence, a particular object may have a token power to F, but we can also speak of the type of power to F (Mumford 2008: 150), which makes the power property-like.

Talk of the power to F makes it clear that a disposition must have a type of manifestation: to F, to G, to I-I, and so on. The manifestation type detennines the identity of the disposition. The disposition whose mani­festation is dissolving is solubility, the disposition whose manifestation is stretching when pulled is elasticity, and so on. We wi1l see that this plays a role later in the theory, as we have to maintain the correspon­dence between manifestation type and disposition type in accounting for effects whose causes are complex.

It should be clear from what has been stated so far that the manifesta­tion of a power will, for any pandispositionalist, be itself a further power or cluster of powers. Dispositions manifest themselves in properties. Fragility manifests itself in being broken, for instance. But being bro­ken, for a pandispositionalist, is itself a cluster of powers. This is thought by some to raise a major problem for a pandispositionalist theory of causation. Annstrong has articulated the problem like so: 'Causality becomes the mere passing around of powers from particulars to further particulars' (Armstrong 2005: 314). Rather than attempt a defensive strategy, however, and fight off Annstrong's attack, our approach is to tum the tables. On reflection, the idea of causation as a passing around of powers, especially for a pandispositionalist, starts to look extremely attractive (Mumford 2009). Some examples will illus­

trate this. You come in from the cold and sit by the fire. You sit by the fire

because it is hot, which for the pandispositionalist means that it has the power to wann your body. This shows the significance of the connection

6 Passing Powers Around

between properties and causal powers. The fire being hot would mean nothing to you if it didn't mean that it had the power to heat. Causation occurs when powers exercise themselves. In this case, causation occurs when the fire warms your body, changing it from cold to hot. Armstrong retorts that such causation, for pandispositionalism, consists in the mere passing around of powers. In the present case, that would mean that the heat of the fire, which consisted in 11 having the power to wann some other object, has been passed on to you. But that sounds quite right. Your body was cold and now it is hot. And, being hot, it now also has the power to warm some other thing, such as the body of anyone who wants to come and cuddle. And, if they do, the power to warm something else will be passed on to their body, and so on. (We know in practice that there will be ~ome energy going elsewhere, or heat loss, so the power is passed not just to the person you cuddle but to other things in the immediate environment.) Armstrong has other worries, because he is committed to categorical ism - that all real properties are categorical and non-dispositi(\nal - and so thinks that if heat is just a power to wann something else, then it is not real enough. We are assuming, however, lhat powers arc as real as anything. The power to warm something is rl~;tl, ('veil if it is not manifesting itself in actually warming something \'ISl'. Again, we are not arguing for such a realism here. We are merely assllilling it. The assumption is, however, that powers are not 'mere' potelltialities (If 'pure possibilities' but as actual as any properties we assume to exist, whether they are manifested or not.

A second example comes from Hume's famous billiard table, which he calls the perfect instance of causation (Hume 1740: 137). A ball rolls across the surface. It has momentum - a disposition to movement _ which it manifests in rolling. It strikes a second ball which then moves along the table while the tirst ball stops. The power of momentum has been passed from the first ball to the second, and could be transferred to a third or fourth (though again with a caveat that some of the power is lost because of the friction between the ball and the cloth).

It is not, however, always the same power that is passed on from cause to effect. Tn the cases of heat and momentum, the same power in the cause is passed on to the effect, which acquires the power. But in many cases the change brought about in the effect is acquisition of a different set of powers to the powers of the cause. The third exanlple is an instance. We have a fragile glass that manifests its disposition when it is dropped and breaks. Wc take this as a case of causation, though we have yet to spell out exactly what is going on and why this counts as

Causal primitivism 7

causation. That will come in due course. The effect is that the glass is broken into many pieces. The glass (or at. least its pieces) now has a power, to cut, for instance, that it did not have before the causation occurred. Then the glass had a different power - to hold liquid - which it no longer has now that it is broken. Now its pieces have sharp, rigid edges. Some new properties are instantiated, and older ones relin­quished, at the time of causation. And with the appearance of new properties, for the pandispositionaIist, there arise new powers. The case can be understood as new, different powers being passed from cause to effect.

This gives the simple essence of the dispositional theory of causation. Effects are brought about by powers manifesting themselves. We will develop this position, which we call causal dispositionalisrn, in the rest of the book. We will have to give much more detail if we are to persuade any philosopher that the theory is viable. But if we succeed we will have contributed to the attraction of a general dispositional ontology. As Molnar (2003: 186) has said, one of the chief arguments for an ontology of real powers is the work such powers can do in one's metaphysics, work thaI includes t.he theory of causation.

J.2 Causal primitivism

Many other theories of causation are offered also as reductive analyses of causation. Causal dispositionalism is not. It docs not offer to replace causation with something else. Burne had such a project, for instance, arguing that when event a causes event b it means simply that a occurs before h. is contiguous with b, and that every a-like thing is followed by a b-like thing. Causation in his theory is thus reduced to the non-causal notions of temporal pliority, spatial contiguity and constant conjunction. But there are two reasons why causal dispositionalism cannot be offered as a reductive analysis. In the first place, the notions of power or disposition are already causally laden notions and it can thus reasonably be argued that unless onc already has a grasp of causation, one cannot have a grasp of power. Powers, indeed, are often called causal powers (Harre and Madden 1975). Second, there is good reason for scepticism whether any analysis of causation is possible given that the existing proposed analyses all havc known weaknesses that lead to the produc­tion of counterexamples. We will not be cataloguing those weaknesses in this book as others have already done that. job: for example, Moore

,II' I '

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II

11\

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8 Passing Powers Around

(zooy), who is also a primitivist and outlines the weaknesses of the VariOllS reductive analyses.

Causal dispositionalism is a theory, therefore, but not an analysis of causation. We can say more. Powers, we maintain, arc productive of their manifestations, and production is clearly itself a causal notion. We cannot, therefore, analyse causation in tenns of an already causal notion of production. This we accept. Not evclyone believes that powers produce their manifestations, it ought to be added, despite that being prima facie intuitive. It has been alleged that the causal base of the disposition does a11 the work and dispositions are impotent (Prior, Pargetter and Jackson 198z). Moliere's virtu.\' dormitiva objection to powers (1682: 328) would be one reason one might want to say this. Other views have it that a disposition ascription is merely an assertion of a conditional (a view associated, though only through oversimplifica­tion, with Ryle 1949: 127) or a tacit argument (Mackie comes closest to this in 1973: ch. 4), which may have inductive warrant but contains no commitment to causal productivity. Even though such views could. if suitahly presented, open up the possibility of a non-trivial dispositional ;Illalysis or cau~ation. we do not follow them. They would do more hann to the IIIl'1aphysics or dispositions than good (Mumford 1998: ch. 3; Moillar .W{l.I: XJ 94; Bini 200]: eh. 2). Powers would have lost their jlo1l'HCY alld lIll1s would no longer be any use in explaining how one thing hrought nhout another unless, of course, it really is possible to analyse the causal into the non-causal, which we have already indicated we deny.

We accept, therefore, that powers involve some notion of cause and cannot be used in a non-circular analysis. But circularity is only one of the reasons a proposed analysis would fail. The other way is by being false, which is what we say about the existing putatively non-circular analyses. It is not our aim to demonstrate this in any detail, however, as a review of all the existing putative analyses of causation, to any satisfac­tory depth, would take up the whole of at least onc book. Our primary aim is to offer a new theory, rather than criticize old ones (it will nevertheless be made clear during the book why certain altemative accounts are rejected). Our general diagnosis of the problem is that, to be non-circular, causation must be analysed in terms of something entirely non-causal. Dispositions? it seems, are not fit for that task. But then whenever we have a non-circular analysis of what it is for a to cause h, a case can be found that satisfies the analysis without being causation, or there can bc a case of causation that does not satisfy the

Causal primitivism 9

analysis. To take the simplest theory - a naive constant conjunction account - we can quickly see thai there can be constant conjunction without causation (coincidences) and causation without constant con­junction (smoking causing cancer). Similar problems are found for the counterfactual dependence view of causation, if it is offered as an analysis. We can then try, as many have tried, to refine the analysis. such as by saying that causes are constant conjunctions that are empiri­cally well-confinned, or some such. But the problem remains that, unless the analysis employs causal terms, and collapses into triviality because of that, there remains a conceptual gap between analysis and analysandum. It is then a matter of time before some counterexamples are found to the new analysis. This is not simply an application of G. E. Moore's paradox of analysis (first invoked in Moore '90 3: 7)· Some analyses can succeed, we allow. When a putative analysis fails. however, despite a number of epicycles of ad hoc repair and further counterexamples, then it could indicate that the analysis is a degenerat­ing research programme.

In addition to this admittedly inconclusive diagnosis we have a general theoretical reason for doubting the prospects of any proposed reduction. Locke (1690: Book 1I) argued that there were both simple and complex ideas, the simple ones being acquired directly from experience and the complex ones being built out of the simple. The assumption that causation can be analysed rests on an assumption that it is essentially complex: built of simpler ideas. Hume's project, for instance, was to find the simpler ideas from which our notion of cause was gained. Bul was this assumption safe? Do we really build a concept of cause out of simpler materials? Or does it come to us directly and immediately? Hume doubted the latter, challenging us to show the simple idea that would give us the concept of calise and we will concede that it is no easy matter to so do. But we can now make the opposite challenge: show Uf.

the complex ideas in which the concept. of cause consists, or from which we could ever know that one thing caused another. Hume answers this question, in terms of priority, contiguity and constant conjuIlction, but we have already said that we think this analysis fails, as do others. For our concepts to be empirically grounded, and empiricism is appealing: when it prescribes that all valid concepts should be so grounded, we need at least some of them to be directly and immediately gained from experience. Might not causation, then, be one such concept? Perhaps no satisfactory account has been produced of what it is directly to perceive causes, an issue we tackle in chapter 9, but on the other hand no

10 Passing Powers Around

satisfactory analysis of causation has been produced either. That causa­tion has no analysis remains, thus, a live option. Instead of continuing that search, we will be looking instead at whether causation is something we can know directly from our experience.

In that case, we can return to the point that dispositions seem a non­starter for any analysis because they are already causally laden notjons. But, we have argued, anything that can truly describe causation should be causally laden. That raises a further question, which we need to answer: how c(ln something that is said truly of causation, if 1t must involve causation, be useful to hear'? In answer, we can point out that there are many things that are informative that seem trivial, such as many of the truths of mathematics. In this particular case, however, we will be offering what we take to be a number of ways in which under­standing causation in terms of dispositions will be useful. One such way is that it allows us to see something that has been overlooked, namely, that causation involves an irreducible dispositional modality. Causes dispose towards their effects in a way that is more than purely contin­gent but less than purely necessaIY (see chapter 8, below). In addition to such a reminder, however, there are reasons why it is causes that are illtllilinakd in terms of powers, rather than vice versa. There is interest ill the powers metaphysics hecause powers CaIl explain a broad range of isslit's illillctapllysics, not just causation. Properties (Shoemaker 1980), callses, modality (Moinar 2003: ch. 12.2), events, and perhaps even particulars Cl:ln all be explained in terms of powers.

EvelY philosophical enquiry faces a problem. How do we begin? Arc we just articulating our intuitions about the problem at hand? And, if so, what right do we then have to reject or challcnge those intuitions? What gives us a basis for that? The answer we give for this particular enquiry into causation, and which we think applies to the whole of philosophy, is essentially a Socratic one. Socrates gave us the Meno paradox (Plato Menu Sod I-4). In order to enquire into some subject philosophically, mustn't we already know it, otherwise we wouldn't know where to st.mt? But then what is the point of the enquiry if we already know the subject? Rather than support the doctrine of recollection, which was Plato's immediate solution of the Meno paradox, we instead prefer to follow the wider example set by Socrates. We start with a working knowledge of our subject matter. But as we rel1ect upon it, and various problems that arise, we are sometimes prepared to throw out our initial, unconsid­ered and vulgar intuitions if t.hey clash with our more considered intui­tions. We are prepared to be revisionary jf we need to he (this answer is

Millian causes II

also -inspired by Suits 2005: Appendix A, and indeed almost the whole of post-Socratic philosophy). Our theory of causation, therefore, is one that is both revisionary and, we maintain, in accord with our considered common-sense intuitions. Later, we will reject causation by absence and transitivity of causation, for instance. Such features of causation might be allowed by our initial intuitions but, we will argue (§6.7), afteI due reflection we realize that we cannot accept them in a worked-out theory.

To sum up this section, we are offering a theory of causation in terms of real dispositions or powers; we me not offering a reductive analysis. Causal dispositionalism -is a version of causal primitivism, based on sceptiCIsm [or the prospects of reductive analyses. Analyses arc based on an assumption that causat.ion is a complex idea, of which the simple aspects can be found. But there has been nothing so far to provc this view for causation, other than that the search for a simple idea of causation has also not yet succeeded. Neither side of this debate can claim victory, so there is nothing to stop us developing the view that causation is primitive.

1.3 Millian causes

Lewis claimed that there had been improvements in our understanding of causation since the time of Hume. One such improvement he listed was that 'we allow a cause to be only one indispensable pmt, not the whole, of the total situation that is followed by the effect in accor­dance with a law' (1973: 159). Lewis docs not, however, give an argument for why this should be taken as an improvement, although we can see that such a notion of cause - as one indispensable part, not the whole - is more suited to a counterfactual dependence theory of causation, of the kind he is developing.

What Lewis is railing against is presumably the MiIIian notion of cause. Mill dcfined cause so:

The cause, then, philosophically speaking, is the sum total of the conditions positive and negative taken together; the whole of the contingencies of eve?, description, which being realized, the consequent invm:iably follows. (Mill r843: 217)

In chapter 3, we will criticize the latter part. of Mill's account: that effects follow causes invariably. But the former part of his definition, which we may call the total cause, is a notion that we wish to defend

I2 Passing Powers Around

against Lewis's asse~~ment. According to the dispositional account, there are certain important feahlres of causation that are misscd if we concentrate on just one causal factor in the production of an effect. The counterfactual dependence view indeed concentrates on such factors, one at a time. The claim that a caused b amounts to a being one of the causes of b, such that b would not have occurred had a not occurred. But this is to ignore the important point that, in virtually every case, a cause is complex, consisting in many different factors working together. We will argue in ch<1pter 4 that in some cases of causation there are mutual manifestation partnerings of dispositions that are interactive: where being involved together in a causal transaction issues in a transfonnation of the causes. Treating the causes in singular isolation would overlook this point, so we need to look back at the Millian notion of a total cause.

Apart from this feature of causation, which Molnar (2003: 194) calls polygeny, being important for its own sake, we also think of it as a key that unlocks many other insights. Seeing that there arc numerous factors at work suggests that we should model causes as vectors (chapter 2,

helow), for instance, rather than neuron diagrams. Neuron diagrams are sej lip in such a way that only one cause per effect can be represented: allY Hlol"(' wOllld 1I1Hknninc the coumerlactual dependence of the effcct (Ill rill' callSt'o So lleuron diagrams are an immediately limited tool. And (lilt"\" we Sl"C !luI powers work together, we also see that they can work ;Igains( cadi other. This shows us that a natural process can be interfered with and thus that a cause never neccssitates its effect (chapter 3). Mill accepted (he point about interference and prevention and it was a mistake, in our view, that he persisted with the idea of the cause producing the effect invariably. In place of invariability, we will go on in chapter 8 to offer dispositionality as the required modality of causa­tioo. In chapter 4 we will tackle questions of how the various causal factors compose, sometimes to produce novel phenomena, and we will also be showing how causal explanation works and how it can solve the problems of causation by absence and eounterfactuals (chapter 6). Without the Millian notion of total cause, many of these points could be missed.

But are we right to opt for Mill's notion of tot a! cause over Lewis's in the first place? It is hard to deny the basic motivation of the total cause notion; indeed, Lewis concedes that there is such a notion. He merely states that he wishes to concentrate on an indispensable part of the total situation. The distinction can still then be drawn between a cause of an effect - which is one among many - and the cause of an effect which

Particular and general causal claims 13

will be all (he individual contributing factors taken together. The account (hat we develop will be a theory of both these things. W c can say what it is to be a cause, but we can also explain what it is to be the (total) cause. The vector model of chapter 2 will do this. Lewis's theory, in contrast, is only about being a cause and we thus maintain that it misses at least half of the picture, especially those features listed above that emerge only once we consider total causes.

There may be an objection that Mill's notion of cause includes too much. Might every previous event in the universe count as a cause of evelY later effect, or at least everything in an event's backwards light cone? Surely our notion of cause is more restrictive than that. Causal disposi­tionalism, howcver, has some resources for limiting the causes of an effect. We will see in chapter 7 that there are some limits on the transitivity of causation, for instance. We count only as a cause of an effect something that disposes towards it and not every(hing in the backwards light cone will have done this. If you speed up your walking, for instance, there will be many factors in the past that simply did not bear on it: they had no disposition to increase or slow down your walking. Causes can be big, therefore, as M.iJl's notion suggests, without being 100 big.

I -4 Particular and general causal claims

Some causal claims concern particular incidents, such as that a paJ1icu­lar bullet killed Kennedy, or that this cue ball, hit at this particular time, caused the black ball to sink and win the game. Particular causal claims are of great interest to us. If you get an illness, for instance, you might want to know what caused it in your individual case. Other things that cause the same illness, in other circumstances, might be of only a passing interest to you. Similarly, if a building collapses, then we will want to know what. in this specific case, was the cause. What has caused other buildings to collapse, at other times and places, w.ill not be our direct. concern. Where these particular or token causal claims arc being discussed in the abstract, we will use lower-case letters as an indicator; for example, where we say c causes, caused or will cause e.

General causal claims can also be important to us, however, especially for causal predictions where we do not yet know the exact palticuiar circumstances. Any complete theory of causation should say something about those too. We may say, for instance, that smoking causes cancer, that drought causes famine, or that friends cause happiness. Our theory

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14 Passing Pmvers Around

allows these as truths, even though it is the properties or powers in virtue of which they arc truc. To know such generalities is to be anned for future actions. They can help us decide what to do when choices are presented to us. Where we are discussing a general causal truth, we will lISC upper-case letters as an indicator; for example, C causes E. Distin­guishing tenses for general causal claims is less impOltant as one may think of type causal claims as atemporal in import.

While acknowledging that there are both particular and general causal truths, we ought to say something about the relation between them. Does either have priority. for instance. either epistemologically or metaphysi­cally? The approach in this book will be to favour particular causal claims epistemologically while being more neutral on matters of meta­physical priority. Regarding epistemology, we win be arguing in chapter 9 that we gain knowledge of particular powers through experience, as those powers act on our perception. Metaphysically, we are also at­tracted by the idea that particular causal transactions come first. On the other hand. there is some strength in the idea promoted by Armstrong (1983: ell. 6) and Lowe (2006: eh. 8) that universals can play the metaphysical lead role. If, however, this is interpreted as meaning that type-causal claims are tantamount to laws of nature, that detennine or govenl particular causal transactions, then the view is not accepted. There is no plausible account of how such laws could govern their instances (see Mumford 2004, in particular, 102-3). For Lewis. it is the particular causes that are of interest (and indeed any nominalist would prioritize the particular), but he then ventures that causal general­izations will simply be quantifications over particular causes (Lewis 1973: 162). We do not want to go that way either. General causal claims, as we interpret them within dispositionalism, mean that C disposes towards E only, but this does not mean for us that every particular c will produce an e. The latter would mean that everything with the disposition to E successfully manifests it. There is no reason to believe that this is the case and some reasons to believe that it is not the easc. Hence, there may be a singular causal tmth that a's smoking caused a's cancer, ami there can be a general causal truth that smoking causes cancer, but the latter does not mean that everyone who smokes will thereby get cancer. Tn our account, the general causal claim just means that smoking disposes towards cancer and whether it manifest"> that disposition in any particular case is a context-dependent matter.

What relation is proposed between particular and general causal claims, then? The suggestion we find most plausible is that this is simply

The attack on causation 15

an application of the token-type distinction, which can apply to powers as much as anything else (Mumford 2008: 150). Particular causal claulls concenl disposition tokens and general causal claims concern their types. Types and tokens come together. A token has to be of a type and each type exists in its tokens, which is why we do not want to give metaphysical priority to either the particular or general causal claims. You can't have one without the other. Given that the particular-general distinction is explained in tenns of the token-type distinction, however, we ensure an identity that runs through the many, as in Annstrong's Aristotelian or immanent realism about universals (Annstrong 1978). Dispositions of the same lype must all be for the same manifestation. Hence, where there is a type causal truth that smoking disposes towards cancer, it does mean that each instance disposes towards cancer, even if not every instance successfully manifests itself in cancer.

This brings us finally to one significant way in which t.ype and token causal claims can differ. Many particular causal claims ulVolve a tacit assertion of success. If I say that wcak rivets caused the bli.dge to collapse 1 am saying not just that the weak rivets disposed towards the bridge'S collapse but that they actually succeeded: they manifested their disposition in the bridge collapsing. The idea can also be expressed by saying that the token causal truths are factive. A similar success claim can be made in present-and future-tense causal claims. If I say that installing a cheap component will cause the engine to fail, I am claiming that its disposition towards engine failure will manifest -itself. General causal claims, however, do not contain this element of success. To say that smoking causes cancer clearly does not entail that every instance of smoking causes an instance of cancer (Mellor 1995: ch. 2; Anscombe 1971). The notion of disposition can thus unify the general and particu­lar. Both kinds of claim arc about one thing disposing towards another: types in one case, tokens in the other. The only difference is that token causal claims typically will contain an additional factive component that the disposition successfully manifested, whi1c general causal claims do

not carry this implicature.

1.5 The attack on causation

But should we be bothering with the notion of cause at all? 'fhere is a famous attack that suggests we should not. At the start of this chapter, we said it was rare to find a philosopher who denied completely that

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16 Passing Powers Around

there was causation. But, back in 1913, Russell wrote: 'the word "cause" is so inextricably bound up with misleading associations as to make its complete extrusion from the philosophical vocabulary desirable' (1913: 193)·

Physics, Russell infomls us, has discovered that there is no such thino b

as causation. In place of causes, fundamental physics deals only in equations, showing functional relations between sets of detenninants. Allegedly. the description of the world given by fundamental physics makes no reference to causes and indeed depicts a world in which nothing has the asymmetry we associate with causation. Causes produce effects, we think, rather than the other way round. But the equations of physics are symmetrical, and can be run either way. Speaking of the world in causal terms is thus, according to the Russellian aHack, unsci­entific. Exactly the same charge can bc made against powers, of course. Powers produce their manifestations, rather than the other way, so they are putative asymmetrical phenomena in a world that fundamental physics tel1s us is essentially symmetrical.

Is there any defence of causation that can be mounted against Russell's eliminativism? Causal republicanism is one such defem:e. As Price and Corry (2007) suggest, just because we cannot find causation in physics need not mean that we reject it outright. They offer what they call a republican option in which 'although the notion of causation is useful, perhaps indispensable, in our dealings with the world, it is a category provided neither by God nor physics, but rather constructed by us' (20070 2). We do not have the space to engage fully with this view but it is not the option we will take. One version of the view could be projectivism (Beebee 2007); another could be a neo-Kantian per­spectivalism (Price 2007). All such views, howcver, make causation to an extent mind-dependent and not an objective feature of the mind­independent reality. In their place, we stand by realism: that causation is a feature of the world and not just our thinking about it.

What then can we say about fundamental physics? Do wc challenge the Russellian claim that it has dispensed with causation? Suppose we agree it has. Does that mean that there is no causation in the world? There is a further option. Might causation still be a feature of the world even ifit were not to be found at the fundamental level? Physics of this kind deals primarily in symbols and nmnbers. It offers a mathematical description of the world. which is why Martin (1997) referred to it as a Pythagorean world. Thus fundamental physics contains no colours, sounds, solidity, people, tables or chairs. Does that mean that no such

The attack on causation

things exist? Or might it be instead that funJamental physics describes the world at too Iowa level for those things to show up? This might then illustrate one danger of reductionism: not all of nature's phenomena are to be found at its presumably lowest level of description, but that does not mean that such things do not exist. It might mean that these things are relatively macro-level phenomena, and that is another thing. The repuhlican option, in these cases, would tell us that colours, sounds and solid objects are constructed by us. rather than given by the physical world, but Russell's argument no more forces us to accept this than it

forces us to accept it of causation. We also wish to avoid rushing into a sparse theory of properties as

advocated. for instance. by Armstrong (1978). We do not say. as in Bird (2007). that the only real powers arc fundamental. Higher·level proper­ties, such as being fragile, may be messier in a scientific sense, but we need a better reason than that to ignore them. Does physics provide a

good enough reason? We have general reservations about letting physics (or philosophers'

interpretations of physics) do our metaphysics for us? Physics offers just one description of the world. and not a complete onc. A complete description might not even be possible. And Schaffer (2003) argues that there is no conclusive evidence that there actually is a fundamentallcvel in physics and that infinite descent is at least a metaphysical possibility. In such a metaphysics, he says, alllcveis would be ontoiogically equal:

Infinhe descent yields an egalitarian ontological attitude which is at home in the macroworld precisely because everything is macro. Mesons, molecules, minds, and mountains are in every sense ontologically equal. Because there can be no privileged locus for the causal powers, and because they must be somewhere. they arc everywhere. So infinite descent yields an egalitarian metaphYSics which dignifies and empowers the whole of nature. (Schaffer 2003: 512- 13)

Although we Hnd this an attractive view, we will not go fmther into this discussion of whether there might be a fundamental level of physics. For even if there is a level of description in physics where there is no causation, but only equations, this does not rule out there being further levels above that do contain powers and causes.

:! This paraphrases from memory the remark with which Hugh Mellor ended his Cha~r.'s comments for the 1993 Joint Session symposium between Graham MtcDonald and Philip

Pettit on the nature of nahnalism.

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r8 Passing Powers Around

Physic~ becomes interesting and relevant to us only if the symbols in the equatIOns ~Te about something: a force; a mass, an acceleration. Alld once ~e consld~r those things we see that without them being causally powerful, even If they arc powerful only at relatively high levels, then they ar~ of no mterest to us. Pandispositionalism maintains that all propertIes .are powcIful and this, it is claimed, is true also [or properties such as spm, charge ~d mass as well as macro-level properties. But if such causal power dIsappears at a certain level of description, this should Il?t lead us to say that there is no such thing as power in the whole of nature. Rather. we might ask what significance such a level could have in our ontology.

We h.ave stated our position more than defended it, but it already s~ems. t.lme ~o move on and develop the positive parl of the caus~l chSposltlOnahst theory, having set out enough of its basic assumptions to do so. .

2

Modelling Causes as Vectors

2. T The neuron and the vectur

When you sit by the fire, it causes your body to heat up. We have seen in chapter I how this can be understood as the power of heat being passed around, from the flame to your body. If anything is an example of causation at work, this is. The aim now is to take a closer look at such cases of causation and also to find the right model by which to represent

them. The example of the fire is one where a change is caused. J t is a human

body that undergoes the change while the change undergone involves the replacemeIlt of one property with another. The body had the property of being cold, but the effect of the causation is that the body becomes first wann and then eventually hoL The basic idea of the theory heing advanced in this book is that a cause should be understood as something that disposes towards an effect. In the example, then, fire should be understood as having a disposition to wann a human body, among other things. This could be true in general, in that all fire has a disposition to warm any human body, but it can also be defended in the particular case. where this particular fire disposes to the wanning of this particular body that is in its vicinity. How should we then understand such disposing towards an effect? And can we find a way of repres~nting causation thal displays its most important features and perhaps even allows us tc

discover new things about it? Since the influential work of Lewis on causation (Lewis 1973), there

has been a dominant convention of representing particular causal situa­tions in the foml of neuron diagrams (for example, figure 2. I). Hitch cock (2006) reports how widespread this convention has become Many if not most academic talks on causation now involve neuror diagrams being presented and discussed. But, as Hitchcock says, 'tht way in which we choose to represent some phenomenon can shape ttll way in which we think about that phenomenon' (Hitchcock 2006: 69) Neuron diagrams were originally offered within the context of Lewis':

20 Modelling Causes as Vectors

cuuntcrfactual dependence theory of causation but they have now become the standard mode of representing causal sct-ups. Even some­one who was not a Lcwisian about causation might be tempted to depict the cause and .effect as circles with a causal arrow connecting them. ~uch n~uron (hagrams are presented with the tacit claim that they are IdeologIcally neutral. They purp0l1 to be simply a clear way of repre­sentmg what happens, or not, and what is causally related. One might conclude, therefore, that one could use such neuron diagrams whatever one's theory of causation. But this is not the case, it will be argued here. N~uron diagrams aTC conducive to a Humean ontology and, through a WIdespread and sometimes unquestioned use, they promote that ontol­ogy. If one were to be a realist about powers, however, one could opt for a better way of depicting a causal situation. Such a way will be offered­the vector moJ~l - and it wilt be argued that a realist about powers should prefer thIS way of representing causation. The vector model for causation will be introduced and it will be explained how this model is hetter ~uited to display many of the features of a dispositional theory of c~usa~lOn, such as multiple causal factors, countervailing powers, and dlffermg causal intensities_

2.2 Neuron diagrams

Causation is often assumed to be a contingent relation that holds betwecn two distinct events. A neuron diagram is well suited to repre­sent these clemcnts. Figures 2.1 and 2.2 provide some of the simplest examples. The basie idea is modelled on that of a neural system, such as a human brain. Some neurons fire, and when they do so, they stimulate other neurons to fire. In a neuron diagram for causal situations, circles represent the relata, such as events. If the event occurs, it is shaded. "This is analogous to a filing neuron. Causal connections are represented by anows, such as those that appear in figure 2.1. If one event a occurs and it is causally connected to another event b, then b must also o~cur.

0)---·0·)---'0 FIGURE 2.1: A neuron diagram

Neuron diagrams 21

01------·. 0

FIGURE 2.2: An inhibited neuron

In neural terms, a could be said to fire and then to stimulate the firing of b, which in tum could stimulate another, c.

Figure 2.2 shows a different kind of connection. Here, b is an inhibitor of c, which is indicated by the line from b ending in a large dot at c instead of an arrowhead. This means that when b occurs, c does not occur, even if a stimulator a of c occurs. In terms of neurons, we call think of this as a case where the firing of b will inhibit or prevent the firing of c. Where we are model1ing causal situations, however, c is nol a neuron that fails to fire; it is an event that doesn't happen, which is a strange idea :in itself. Because of the inhibitor, c does not occur at all, which is why the circle representing it is not shaded. Neuron diagrams allow, therefore, for the convention of representing non­existent things. The rationale for doing so, however, is perhaps that c is at least a possible event and it would have been actual - it would have occuned - had b, or any other inhibitor, not OCCUlTed.

Why, then, do we not make usc of this representative model? Many have employed it as a way of showing causal chains of events, preven­tions and pre-emptions. However, their standard inlClvretation is as depicting a contingent relation whose relata are events; and :"e will argue against this conception in chapter 5. Causation is also depIcted as all or nothing. When the cause occurs, and there is no inhibitor, the effect must occur. Stimulatory connections guarantee the effect. They do not, in their unmodified f011u, show cases where there is only a certain probability of an effect occurring, or a case whe~e an effect can occur to some degree, depending on the strength of the cause. On the other side of the coin, inhibitors guarantee that an effect does not occur, regardless of what else is going on. Again, there is no allowance for something that might inllibit an effect to some degree. or lower the probability of an effect occurring. And perhaps an inhibi­tor could be overpowered if there are enough other causes at work.

22 Modelling Causes as Vectors

~ dispositionalist about causation is likely to find neuron diagrams madequate or misleading in'most or all of these respects (Mumford and Anjum 20IIb). Nevertheless, neuron diagrams could be adapted, as Hitchcock allows. But it is not clear that they could show all these features without undergoing change beyond recognition. And we should not pretend that there is no alternative to neuron diagrams. Causal graphs augmented by stmctural equations are one such alterna­tive (developed by Pearl 20(0).

We 'Will argue that it is essential for understanding causation properly that we recognize its complexity. In chapter 3, we will argue that understanding the importance of countervailing causes is a vital step in seeing the dispositional nature of causation. To understand this, we need to accept that effects are typically produced by many powers working with each other or against each other. We need a model in which many competing factors can be represented. Neuron models show only a single cause for an effect and this is because Lewis's objective was to understand what it was to be a cause, rather than the cause, of an effect.

Causation, as we see it, is about properties and, more specificaUy, the powers or dispositions that make up these properties. We want a way of modelling causation that reflects this. The properties and any causal connections emerging from them arc not entirely distinct existences that could have been ananged in some other way. A cause should he seen as disposing towards an effect, in a more than purely contingent way (chapter 8). An important part of such an idea is that dispositions can have different intensities. Both the sunlight and the element in an electric kettle dispose towards the wanning of water, but the kettle disposes far more strongly in that direction. The sunlight can cause some wamling, but not very intensely, though the sunlight itself can of course be more or less powerful. Causation usually OCcurs when powers have accumulated so that there is enough to trigger a certain effect. There are frequently many powers involved, each disposing in the same direction, in varying degrees. It is also possible, indeed likely, that there are many countervailing powers at work, that dispose away from a certain effect, but that arc also relevant to that effect. W11ether and when the effect occurs will be just as much a function of those 'subtrac­tive' powers, that dispose away from the effect, as il is a function of all the powers that dispose towards it. We will now start to construct a model that represents these features.

The vector and the quality space 23

2.3 The vector and the quality space

Causation often, though it need not always, involves a change. When it does so, there is an event. Following Lombard's view of events, events are to be understood essentially as changes rather than as propelty exemplifications (Lombard 1986). A pm1icular exemplifying a property at a time, as in Kim's (1973) and Lewis's (I986b) theones of events, would be better understood as a state of affairs, like some raven's bemg black or Madonna being a superstar. Causation should not then be understood as a relation between two events, but. rather as what makes an event occur (for more on the rejection of the two-event model, see chapter 5). To begin with, therefore, we need a way of representing such a change.

Lombard provides the notion of a quality space, which stands as the background against which events can occur (Lombard. 1986). ,When one thing causes another to warm, for instance, it is causmg :or It a move­ment within the quality space of heal. To represent tIns, we need a spectrum or dimension within which there could be a ~ovement. Figu:e 2.3 illustrates this. We begin with the simplest posslble. case an~ WIJI

add the complications later. The simplcsl is a single honzontal ~m~en­sion that runs from P, at one ext.reme, to G at the other. ThIS IS a one-dimensional quality space. F could stand for hot and G. could stand for cold, so that we are able to represent changes ill the

F G

FIGURE 2.T A one-dimensional quality space

24 Modelling Causes as Vectors

temperature of something. Alternatively, F could be red and G could be green, when we want to represent the change in colour of something, such as when the sun ripens a tomato. The quality space has a straight vertical line in the middle and this represents our starting point. In the temperature example, this would be the starting temperature of the object in question. If we are trying to represent a causal situation with respect to, for instance, the temperature of someone's hand. then the vertical line represents the temperat.ure of the hand at the starting point such that it could become wanner, if the situation moved towards F, or colder if the situation moved towards G.

Upon this one-dimensional quality space, we are going to plot vectors that represent the dispositions or causal powers that are operating. A man sits by the fire and holds out his hands to wann them. Various powers of various things will be at work that will determine whether. and how much, his hands become warm. The fire will be a significant causal factor that can cause his hands to wann. But there will be other factors: how fast his healt is beating, whether there is also a draught in the room, whether there are any other sources of heat, and so on. In modelling tms situation, we seek to represent each causally relevant factor as a vector, showing how it either disposes towards warming of the hands or disposes towards their cooling. A vector is a representative device that appears in mathematics and in physics. In physics, vectors have been used as a way of representing forces (Cartwright 1999: 54). As vectors are used here, however, they are being used to represent the exercising dispositions or powers: those that are operating upon the quality space. How they come to operate is a subject we will address later (§2.6).

It is useful to employ vectors because they are understood as having two essential features. Vectors have a direction, indicated by the way the arrowhead is pointing. They also have an intensity, indicated by the length of the vector. This is helpful because a power will have a direction - that towards which it is disposed - such as fragility being a disposition towards breaking. And it has an intensity. A power can be more or less disposed towards an outcome, as the comparison between the electric kettle and sunlight, for the warming of water, shows. In the case of fragility, a wine glass will be more fragile than a car windscreen, which in turn is more fragile than plate glass. Different people are aggressive or shy in different degrees. Substances can be more or less

The vector and the quality space 25

explosive, ftarrunable, corrosive, volatile, soluble, poisonous, alkaline or acid. Some of these intensities are already quantified by a standard scale, such as using the pH scale for acid and alkaline. The understand­ing of their intensities is regimented in a robust scientific theory. Some may be less regimented. There may not be an exact science that measw'es degree of fragility. But clearly this is an empirical matter: there could be one. It would measure, for instance, the required impact for breakage. A wine glass would have a lower minimum impact for breakage than the car windscreen. The degree or intensity of a power is clearly a causally relevant matter and this is something we want to

represent. Figure 2-4 shows a single vector plotted on a one-dimensional quahty

spac~. This is a case where at a certain moment, at a certain starting point on the F-G quality space, there is a single disposition towar~s Fin operation, exercising its power. There arc already a number of thmgs to explain. First of all, in any real-world situation, there will be a great many relevant powers, which will dispose any particular object in all of many different directions. Some will dispose towards an object warm­ing, but some might dispose it to change colour, to tum, or to movc its position. A single thing could undergo a number of changes in this respect simultaneously. However, each vector diagram will represent and show only the coming together of operating powers for one-quality dimension. It is within a single-quality space that we are interested in change and causation. Why say this? The identity of an cvent is deter­mined by the respect within which change occurs as well as the subject

F G

FIGURE 2-4: A disposition towards r

Modelling Causes as Vectors

of change. The heating of a sphere and the rotating of the same sphere count as two different events and it thus makes sense to treat these as two separate cases of causation. The heating of the sphere and its turning are co-located, but clearly these events could be causally separated in that the causes of the sphere heating could be completely independent of the causes of its turning. We would thus aim to have one model for the heating of the sphere and a separate representation for the turning of the sphere. What interests us for the case of causation should thus be just movement within one-quality space. We could, if needed, have multi­dimensional quallty spaces, as we will show later on (§2.8). For now, we just say that within the F -G quality space, we plot only the vectors that are causally relevant 10 F and C. It is worth noticing that the vector model enables us to separate causally relevant from causally irrelevant powers, as the first would dispose with some intensity within the model's quality space while the latter would not dispose in either direction. So, in the example of the heat.ing uf the hands, the model includes only the dispositions towards F and the dispositions towards G that are spatiotemporally brought together to bear on the same situation.

The next thing to explain is the notion of a moment. The vectors depicted within a quality space ,ue meant to indicate how things dispose in that particular situation. The vectors represent only the operating dispositions but the model does not show, for instance, any actual change or movement within that quality space. It shows how the situa­tion would dispose towards a new state or property, but it doesn't show whether it succeeds in producing that propelty. But if it were to succeed in moving to a new position in the quality space, then we would represent that situation afresh in the next vector diagram, where the vertical central line was the new starting point, with perhaps a new set of powers disposing in a new direction. Each vector diagram represents the causal situation at one moment, therefore, showing what, at that moment, is disposed to be caused. But a moment does not automatically mean an instant or an unextended temporal time slice. A world of powers suggests a world of active, dynamic particulars (see Harre and Madden 1973) and there are some problems in squaring that with time­slice views of persistence and change (see Mumford 2oo9a). Some powers may involve such dynamism as cannot be captured at an instant. They might be always in a state of flux (as urged by Whitehead 192 9: 30 9). Thc notion of a moment thus allows some extension tlu-ough time and hence could accommodate this sort of power even if it made no sense to ascribe it at an instant. Powers often do need time to do their

Composition of causes and vector addition

work (see §S.6). A heater takes time to warn} a room, and some historical or ev01utionary pressures requhe an age to do their work. The moments we represent have, therefore, to be open as to their temporal extent.

The key points, therefore, arc that each vector diagram represents one causal situation, usually relating to powers that are causally relevant to one propmty dimension and one subject of such change. That subject of change would typically be a particular thing, though it may be under­stood in a broader way so as to include, for instance, some particular sample of stuff such as a pile of sand, or a whole room for which we are interested in its temperature, or evolutionary changes within a species, but also regular commonplace objects in the world around us.

2-4 Composition of causes and vector addition

Figure 2-4 represented a single vector within a quality space. It would, however, be an extremely unusual case if there were just a single disposition operating. IL wuuld be such a ran.: situation that we wuuld need to treat it as a special case and comment all its atypical nature (§2.6, below). In any causal situation that we arc likely to encuunter, many dispositions will be disposing towards or away from F. To take a biological case, suppose you ingest calcium, which disposes towards bodily health in a number of respects, such as good bones, teeth and muscles. Let us represent this as a vector towards P, where F stands for bodily health and G sk1nds for ill health. At the same time, however, you may be subject to a number of factors that dispose away from health. You could be tired, stressed, have drunk too much coffee, experienced passive smoking, and so on. All these factors dispose away from bodily health. But as well as ingesting calcium, there are other relevant factors that dispose towards health. You get just the right amount of sunlight, for instance. You eat a balanced diet that includes a variety of vitamins, and you also eat food that contains magnesium, which allows calcium to better do its job. Whether your body moves along the quality-space towards health or ill health, from its current status, will depend on a whole host of such factors: no doubt far too numerous to list here. The true sit.uation is Ukely to be extremely complex and any movement that is produced will thus be produced polygenic ally, to use Molnar's (2003: 194-8) term: one effect but many different powers that produce it. Mill also emphasized this feature and called it the composition of

Modelling Causes as Vectors

d

b

F G

f

FIGURE 2S Multiple powers

causes (1843: Ill.vi.3). The aim in this section is to explain the compo­sition of causes in terms of the vector model.

Given such complexity in standard causal cases, a more realistic vector model is one such as that depicted in figure 2.5, in which a number of different powers are operating. At this point, we aTe thus able to make use of another notion that comes from vectors as used in physics, namely, vector addition. Powers can combine with additive, and sometimes subtractive, effects (and in chapter 4 we will see that there are other ways they can combine too). When they do so, they may overall dispose in one direction or the other.

How does vector addition work? If our vectors can have a numeric value assigned to their intensity, then it will be a simple matter. Vector a may have an intensity of 3 units, vector b an intensity of 7 units, and c an intensity of 6 units. That adds up to 16 units disposing towards F. But disposing towards G we have d = 6 units, e :::: 3 units, and f:::: 3 units. That shows 12 units disposing towards G. The resultant vector is thus one in the direction of F with an intensity of 4 units.

Vector addition, in any case, can proceed in a rough-and-ready way without having to add and subtract the numbers. We can perfonn a simple analogical addition by placing the tail of one vector on the head of another. 1 First we add all those in the direction of F, onc on top of another, and then, from the point that we reach, we start subtracting all the vectors towards G in the same way, the tail of one connecting to the

j Suggested to U~ by Charlotte Matheson.

Composition of causes and vector addition

F G R

FIGURE 2.6: A simple vector addition for figure 2.5

head of another. When we have added and subtracted all the vectors, we get the resultant R, as shown in figure 2.6.

There is a speciaJ case of vector addition that is very important to distinguish. This is a case where the dispositions towards F and the dispositions towards G balance out perfectly, such that the resultant vector is neither directed towards F nor towards G. Where wc have perfectly counterbalancing dispositions in this way, we say that we have a zero resultant vector. This is shown in figure 2.7, which shows the zero resultant vector as a dot. An impOJtant thing that this illustrates, within the dispositional theory, is that there can be cases of causation where nothing IS outwardly happening. The neuron model would have difficulty in representing this kind of causation as one of the related

F G

R

FIGURE 2.T A zero resultant vector or equilibrium

... - ... -----~---------------------

30 Modelling Causes as Vectors

'events' would have to be nOll-exIstent. Yet there clearly are cases where the effect of various causal factors is that nothing happens, precisely because the dispositions involved balance each other out. Two books may lean against each other at an angle but in such a way that each supports the other and they stay put. Yet this is prima facie a clear case of causation. A fridge magnet sits on a flidge, motionless. Gravity disposes it towards falling, but this is counterbalanced by the magnetism which disposes it towards staying OIl the fridge and the net effect is that nothing happens. In another case, two teams of academics are involved in a tug-of-war contest - the theologians versus the philo­sophers - but the two teams are equally balanced and neither gains an advantage. The rope therefore falls to move from its starting position. Again, this seems a clear case of causation and the dispositional theory ean explain why. There is a world of difference bet ween this situation, which can be represented as in l1gure 2.7, and the situation shown in figure 2.3. In both cases, there is no overall disposition either towards F or G and, let liS assume, nothing happens. But, in the latter case, powers have made their contribution to the zero resultant vector and have produced what might best he called an equilibrium state. Causation happens when powers do theh work. In the case of figure 2.3, there are no powers at work so it is not a case of causation. That could be a case, for instance, where the two teams pick up the rope and merely hold it, in readiness for action, but without actually pulling it. In neither case does the rope move left or right, but in one case we have causation and in the other we do not.

Apart from the themetical importLUlce of permitting zero resultant vectors, we should also note that equilibrium states are generally impor­tant for the theory of causation. Many cases of causation will involve some such balancing out. The orbit of the Earth around the Sun is a case. There is movement, of course, as the Earth orbits and thus moves. But within this movement, there is also a stahility. The gravitational pull of the Sun on the Earth is counterbalanced by the centrifugal force that pushes the Earth away from the Sun. If an equilibrium were not maintained, for instance, the orbit might decay and the Earth crash into the Sun.

2.5 What thp vector model explains: standard cases

We are now in a position to explain some of the standard cases of causation. We start with such cases only because they are the simplest.

What the vector model explains: standard cases 31

Other, more complicated, instances of causation are to be acknowledged and will be explained in due course (especially in chapter 4), but it will help to begin with some paradigm examples and use them as a starting point.

Where a resultant R is not zero, we will say that it is a directed resultant vector. This will be a case where many powers come together to overall dispose in one direction. A match is struck, for instance, and lights. The striking of the match was a cause of its lighting, let us assume (we set aside deviant causal chains and so on). The model shows what it is to be a cause, namely, to be one of the operating powers, represented as a vector, that disposes towards that effect. But whether, how, and to what extent the effect occurs will be determined polygenically: by many factors working together. The model shows this complexity and poly­geny, unlike the neuron model. It is vital for these features to be illustrated in order to get a proper understanding of causal production and how it differs from causal necessitation (see §3.9).

Given such complexity, we can see how many different things have a right to be called a cause of the effect. The presence of oxygen was a cause, even though it is one rarely highlighted hecause it is such a ubiquitous factor. The match can only hurn in the presence of oxygen or other flammable gas. The rouglmess of the surface against which the match was struck is also a factor. ]f it were struck against a smooth surface, there would have been inadequate friction to ignite the flamma­ble tip. And the dryness of the wood is also important as matches can fail to light, even if struck, if they arc damp. There arc no doubt many other factors that could also be highlighted but, for practical reasons, we have to stop somewhere.

This gets us to what Mill called the total cause, to which we allied in §1.3. Thcre are two issues that need to be discussed. One is that it is controversial that all the factors count as causes of such an effect. Some draw a distinction betwcen causes and background conditions. The other complication is whether those powers that disposed away from an effect were nevertheless a cause of it because they did, in their own way, make some contIibution to the effect in that it. may have been different if not fOT the subtractive influence of their countervailing power.

First, let us consider the issue of causes and conditions. It might be argued that striking of the match was the only real cause of the match lighting because the oxygen, dryness of the match and friction of the surface were all just background conditions. Mill's notion of total cause is a challenge to such a distinction but the distinction has been

-----------------_____ . ·_~o ___ ,.

32 Modelling Causes as Vectors

reasserted, for instance, by Dueasse (1924: 19). The grounds for assert­ing the distinction, however, seem entirely pragmatic: usually to do with OUT explanatory practices and assumptions rather than to do with the efficacious powers in the world. The distinction is therefore primarily an epistemic one, rather than a matter for the ontology of causation.

The presence of oxygen, for instance, would usually be depicted as merely a background condition by those who defend the distinction between causes and conditions. Oxygen is there all the time, the story goes, while the striking of the match is something that gets added at the last second and is thus, in those circumstances, the thing that does the real causing. The tenn 'efficient cause' has been used to identify such a factor. Certainly, the vector model can explain what is going on in this case in a way that shows what is special about the striking of the match. All the other factors were there, but they were not yet enough on their own to cause the match to light. Although some powers disposed towards lighting, they were balanced out by other factors that disposed away from it. The oxygen is mixed with less flammable gases, the flammable tip of the match also contains chemicals that ensure adequate stability so as not to light spontaneously. Until the match is siwek., we have, therefore, an equilibrium situation. Striking the match is the occasion that takes the situation out of equiliblium. It is the extra power that gets added to what was previously a zero resultant.

At the moment all the requisite powers are assembled, thcy all make their contribution. The final one that gets added might not even be the most significant. The fable of the straw that broke the camel's back, for instanc-e, shows that it could be a very small power that takes a situation out of equilibrium. A whole weight of straw is already on the camel's back but it has enough strength in its body and legs to counterbalance it. The last straw that gets added only has a very small weight itself and without the other straw it would do practically nothing. Thinking of causation metaphysically, all powers do the work even if for pragmatic reasons we only focus on certain of them. As will be explained in chapter 6, it is often pragmatic reasons that base our notion of efficient cause. Metaphysically, wc should judge them on a par to the extent that they all contributc. A distinction between causes and background con­ditions cannot have any real ontological strength because the effect is not triggered until they are all presenl. which can in any case be a momentary matter. At that moment, it matters little from the point of view of the effect that one of the factors that contributed to it had been around for ten hours while another had been around only for one second.

What the vector model explains: standard cases 33

And a factor that had been around for a long time could, in any case, have played the role of being the last onc to have been assembled. Striking of the match is often that las! to be added, for instance, while the presence of oxygen is seen as a background condition. Scenarios are easy to imagine, however, in which the presence of oxygen is the last factor to be added to a causal situation. WeaTing a breathing apparatus, a man strikes a match repeatedly in a vacuum-filled room. It doesn't light. But, as he continues striking, oxygen is suddenly released into the room and the match lights. In this example, striking is a background condition and the presence of oxygen is an efficient cause, or stimulus condition. The example is similar to the Apollo I fire of 1967, in which the chief cause of the fire was said to be the presence of oxygen, which shouldn't have been there. But what the example is designed to show is that there is no real ontological difference between such factors. The distinction between causes and background conditions is not an ontologically bTfounded one, but rather a pragmatic or epistemological one. If all conuibute to an effr.;ct, then they are causes of it. (In ~7.6, however, we will draw another distinction between causes and conditions that we think can he supported: where conditions arc not causes at all but, rather, meTe sine quibus non.)

If we understand every causally relevant, operative power as a cause with respect to the effect E, then this leads us to the second issue. Some powers are disposing away from an effect, though that effect neverthe­less happens. Should those countervailing powers be considered a part of the cause of that effect? Celtajnly they can affect or influence how the effecl occurs. A philosopher in the tug-of-war against the theologians has made some contribution to the theologians' victory, but only in so far as they delayed it slightly. Countervailing powers can affect the timing, chance, or extent of an effect, and perhaps for that reason we should include them as a part of the cause.

This is not, however, how we think the cause should be understood. This may be nothing more than a dispute over whetheJ 1t is correct 10

apply the term 'cause' to countervailing. powers. They arc there and they can make a difference. That is accepted. But we still may think it perverse to call something a cause of E if it was disposing away from E. We might prefer to say that E occurred in spite of those counter­vailing powers, and that would allow us to retain a very attractive idea that a cause of E is something that disposes towards it.

We could say that those countervailing powers were not a cause of E without Tuling out the possibility that those same powers could be a

34 Modelling Causes as Vectors

cause of Ehappcning in a certain way. Consider an example of someone who has a bullet lodged in their heart. This certainly disposes towards their death. But the victim is also put on a life-support machine that is somehow able to keep them alive for a week, before they do eventually succumb. In this case, we wouldn't call the life-support machine a cause of their death. The machine was instead disposing away from their death and they died eventually in spite of it. The bullet (and no doubt some other factors) caused the death, by disposing towards it. But the lifc­support machine could nevertheless have been a cause of the victim dying a week after being shot in the heart (see also §7.6, on transitivity of causes). Loosely speaking, the machine disposed towards prolongation of life, in the circumstances, and it did indeed succeed in doing so.

Finally, it should be noted that the vector model can be used to represent either token causal claims or general causal claims, because exactly the same principles will apply. The type-token distinction applies to powers as much as properties (Mumford 2008). Hence the tokens of a power - its instances in particular things - will dispose in the same direction a'3 the type. As Armstrong's (1978) immanent realist theory of universals shows us, the Lype is an identity: a one that runs through the many. There would be no difference, therefore, whether the vector diagram showed us a general causal truth or a pmticular one. The powers, their directions and intensities. would be the same.

2.6 Mutual manifestation arui single powers

The basic idea of causes as powers has been presented and the vector model introduced. One justification for this new way of modelling causal situations is that it shows up some of the issues that arise from a dispositional theory of causation. While it raiscs such issues, however, it can also suggest a response, as the rest of this book aims to show.

Martin, for instance, has defended a notion of mutual manifestation for powers. The claim (Martin 2008: 48) is that a power manifests itself only when it meets its mutual manifestation partner. The manifestation can then be thought of as something produced by the two pmtncrs working together. Instead of thinking, for instance, of water having a power to dissolve salt. we should think of water and salt as mutual manifcstation partners whose manifestation is the production of saline solution. i\nd two objects manifest their gravitational mass - a disposi­tion to attract - only in tandem.

Mutual manifestation and single pOlvers 35

The vector model offers an explanation of mutual IDmlifcstation but it also displays a limitation. Fixst: the explanation. Effects are almost always produced by many powers acting together. The same power can produce different overall effects depending on which other powers combine with it. Powers can thus have different partners for the produc­tion of different mutual manifestations. Depending on its partnerings. heat can produce expansion, explosion, melting, boiling, steam, fever, burning, flre, pleasure, pain, growth, life, death, and so on. This can be shown in the vector model, which allows a power to be depicted working with other powers on different quality spaces. It shows that pmtnership need not be solely a dyadic relation. Powers can partner with two. threc. four. or any number of other powers to manifest an effect

together. There is, however, an apparent limitation or puzzle that is raised by

the notion of mutual manifestation when illustrated using the vector model. What would happen if we had just a single power in operation? This may be a fare case and perhaps only of theoretical interest, although Cartwright considers some carefully controlled laboratory experiments when we screen off a power from all other interferers so that we get to see a single power at work (Cartwright 1999: ch. 3)· So what could we say about a model with a single vector?

The vector model suggests that if there were just one powcr at wOlk as depicted in figure 2.8 (also figure 2.4), thcn it would have to move towards G on its own, unaided by any mutual manifestation partner. If there were just a single power operating, it would have the same effect as if it were a resultant vector of the samc direction and intensity, and would thus dispose towards a movement within its quality spacc. This creates a puzzle because it sounds as if this power is then able to do some work on its own, without any accom­panying mutual manifestation parUlers. Some might find this unaccept­able on the grounds that it amounts to a power that might be able to manifest itself unstimulated or spontaneously. If it is implausible that powers can behave this way, then it might he thought of as a restriction on the vector model or, worse, that the vector model indicatcs the wrong result in such a situation. If we just had the flammability of a match, for instance, with no further powers at work, then it could be objected that it would never light on its own. If there were something fragile. with no other powers working with it, then it wouldn't just

break on its own without being struck.

Modelling Causes as Vectors

F G

FIGURE 2.8: A 'lonely' power

The vector model indicates that such 'lonely' powers would work alone, hut this is on reflection a defensihle claim. Tn the first place, the notion of a power that manifests itself spontaneously already exists. Radioactive decay is an example of a power that is understood to manifest itself without any further stimulation. Particles are dis­posed to decay at a certain time, though their actual lifespan can vary. They do indeed tend to manifest this disposition but not because anything stimulated them to do so. Momentum is also characterized in Newton's First Law as a power that will operate without further stimulus, unless stopped from doing so. Spontaneous human combustion, so fcared in the 1980s though now believed to be spurious, shows that we can at least accept the idea of a spontane­ously manifested power.

Apparent counterexamples in which we think we have a single power, which fails to do its work through lack of a stimulus or trigger, might be cases where there are indeed other powers at work. The power in question may, thus, fail to manifest itself due to an unknown, hidden, or just taken-for-granted countervailing power. Dynamite, for instance, has an explosive disposition that seems to manifest only when it is ignited. Without stimulation, it might be thought, it does nothing. On further inspection, however, we find that dynamite's explosive power comes from it being made up in three parts of nitroglycerin, a substance that is so explosive that its disposition has

Mutual man~festation and single powers 37

F

G

FIGURE 2.9: Counterbalanced powers

to be counterbalanced by one part diatomaceous earth, which gives it a countervailing power of stability. The true situation should be repre­sented as in figure 2.9, therefore, which shows that nothing happens in respect of the dynamite's power of explosiveness only because it is counteracted by other hidden powers. When the fuse is lit on a stick of dynamite, this is actually the addition of a further power, which then takes the situation out of equilihrium. To take another example, fragility on its own seems to do nothing, but isn't this only because the fragile object also possesses some countervailing stability and elasticity, which holds that object together enough until some knock is sustained?

There is thus some credibility in the idea that if there were to arise the unlikely situation of just a single power in operation, then it would indeed dispose towards its manifestation. It might indeed manifest itself. The thought that a stimulus is always needed for a power may derive from a passivist view of the world (see Ellis 2001: 7), in which all the sources of animation must come from outside the objects. The vector model, in this respect, tempts us also to think of powers as released or unleashed rather than only stimulated. A stimulus may often be just a further power that gets added, taking the situation out of equilibrium, but it could just as well be a power that gets taken away and thus no longer stands as an obstacle in the way of the manifestation of some further power. Opening a tap lO release a now of water would be an example.

Modelling Causes as Vectors

Not all powers need mutual manifestation paltners, therefore, but many do. A book may be readable,2 for instance, but will not manifest that. disposition, in being read, unless it meets its partner: someone capable of reading it. This kind of power needs its partner in order to operat.e. It is not exercising otherwise. And this shows us that it would never be represented in a vector model as a single 'lonely' power because vectors represent only the powers that are exercising or operating. In such cases, the mutual manifestation partners can only work together, and thus they are plotted only in pairs or groups in a vector model. A lonely power will therefore only ever be represented where it is one of those that can operate without the need for any further partner.

2.7 Realism about component powers

This account of causation is founded on realism about powers. The individual powers make the causal truths. But there 1S a possible threat to such an account that comes from the comparison with vectors and subsequent use of the idea of veeLor addition.

When it comes to vector addition, there is an argument that only resultant vectors are real and the component vectors are not. In physics, vectors arc used to represent forces and the view is that only a single resultant force exists and the constituent forces cannot exist besides. If comparison is being made between powers and vectors, therefore, an analogous argument might be made to the effect that the individual component powers cannot be treated as real. Only the overall resultant power is real, some might say, and this would undermine realism about powers and detract from the strength of the vector model of causation. The model explains much about causation, however, precisely because it relies on the reality of the constituent powers. In the case shown in figure 2.10, therefore, the opponent's claim would be that only the resultant R is real and none of the component forces, represented by a·-1: are.

Why, then, would someone deny the reality of component forces? Cartwright voices the argument in the following way:

The vector addition story is. I admit, a nice one. But it is just. a met.aphor. We add forces (or thc numbers that represent forces) when we do calculations. Nature

~ This example was provided by Barbara Vetter.

Realism about component pOV1,lers 39

d

F G

f

FIGURE 2.10: Component powers and their resultant R

does not 'add' forces. For the 'component' forces are not there, in any but a metaphorical sense, to be added; and the laws that say they are there must also he given a metaphorical reading. (Cartwright 1983: 59)

Mill had argued, in his work on the composition of causes, that where two causes are combined, both have their full effect. Hence:

In this important class of cases of causation, one cause never, properly speaking, defeats or fnlstrates another; both have their full effect. If a body is propelled in two directions by two forces, one tending to drive it to the nOlth and the other to the east, it is caused to move in a given time exactly as far in both directions as the two forces would separately have carried it; and is left precisely where it would have arrived if it had been acted upon first by one of the two forces, and afterwards by the other. (Mi1l r843: Ill.vi.l: 37o-J)

Cartwright quotes the first pmt of tins passage and then dismisses it (Cartwright 1983: 6~ I), but she does not quote the last part of the last sentence, which explains what precedes it and makes it more plausible. Mill's example has some initial plausibility, but it could be argued that this arises because it is a special case. Where we have a force due north and a force due east, and there are no other forces acting, then the resultant will indeed be a force north-east that, if it js allowed to manifest itself, will produce a motlon exactly as far north and exactly as far east as if each force had acted fully (figure 2.J I). But thls occurs only because the two component forces arc at a goO angle to each other. Two-dimensjonal vector addition follows the parallelogram law. This means that if there are forces at an acute or obtuse angle, then the

40 Modelling Causes as Vectors

N

r R

FIGURE 2.JI: Mill's example of a resultant force

movement they generate will not have the feature Mill claims. With the forces in figure 2.12, for instance, which stand in an obtuse angle to one another, the resultant vector will take us to a place that is not as far west as the component vector b would have taken us had it acted alone. Contrary to what Mill claims, therefore, it looks as though the force represented by vector a does defeat the force represented by vector h.

This problem in pmt adds to the force of Cartwright's argument against Mill. In the first place, she says that in Mill's own example (figure 2.11) there is neither a movement n01th nor a movement east, but a single movement north-cast. Mill is therefore wrong, she claims, to say that both forces have their effect: neither do. In a second kind of case, Cartwright (1983= 61) asks us to consider the situation where there are two forces in exactly opposite drrections that balance out and thus there is no movement at' alL How could we then sustain Mill's claim that both forces have their full effect'? Doesn't it look as though neither force has any effect?

This is where it is important to consider, however, the explanation given by Mill in the last palt of the above l}uotation: 'and is left precisely where it would have aITived if it had been acted upon first by one of the two forces, and afterwards by the other'. If this is the explanation of

N

w

/ ............. m···7 ••. ~ ! a

'4

E

FIGURE 2.12: An example not considered by Mill

Realism about component powers 41

Mill's claim that both forces have their full effcct, then it sounds much more plausible. The case of two perfectly counterbalancing forces in opposite directions certainly need not involve any actual movement, but this is because, under Mill's account, it is as if there was first a move­ment east, for example, and then a movement of the same distance west. which gets us back to where we started, Another of Mill's examples illustrates what happens when we have this kind of equilibrium of balancing causes:

A stream running into a reservoir at one end lends to fill it higher and higher, while a drain at the alher extremity tends to empty it. Now, in such cases as these, even if lhe two causes which are in joint action exactly annu1 one another. still the laws of both are fulfilled; the effect is the same as if the drain had been open for half an hour first, and the stream had flowed in for as long afterwards. Each agent produced the same amount of effect as if it had actcd separately. though the contrary effect which was taking place during thc same time ob­literated it as fast as it was produced. (Mill r843: IILvi.r: 372)

The causes having their full effect need not be interpreted in the way Cartwright suggests, therefore. Mill is not claiming in the case repre­sented in figure 2.1 r that the body really does make a movement due north, only that it moves as far north as it would have done had that force been acting alone. This it indeed docs, even if it also moves at the same time cast as mlleh as it would have done had that force acted alone. And, in the case of the counterbalancing forces, the body remains where it Si.:'U"ted without making any actual movement as if it had first moved in one direction, and then an equal amount in the other. There might thus be some plausibility in Mill's clajm that, even in these cases, both causes 'have their full effect'. The vector model shows that had one of the causes not had its full effect, then a different resultant and outcome would have followed. There is, thus, at least some kind of counterfactual truth that indicates the presence of a component cause: had it not been there, things would have been different,

Cartwright also hao;; a won)' about the vector addition story because any addition is done by us, not by nature. Again, however, such addition may pelmit a worldly interpretation. Mill is talking about the composition of causes: how causes can add and subtract, not about any calculations we make in our heads or models of those causes. In the academic tug-of-war, each team member makes a contribution to a force in the SillDC direction. The forces are worldly phenomena, let us assume, and the way in which they compose to make a resultant force is a worldly phenomenon, so we

"""""------"----~----------

Modelling Causes as Vectors

shouldn't be sidetracked into thinking that addition is only a mental procedure. Certainly, we might calculate that three stones added to a pile of ten totals thirteen stones, and that addition 1S in our heads. But there is also a fact in the world about these two accumulations of stones being gathered together. TIrree of them added to ten makes a pile of thirteen irrespective of whether anyone perfonns mental arithmetic.

111cse, however, aTC not the only problems that await a defender of component powers. One more comes from the possibility of causal overdeterminat.ion (sec Wilson 2009). If we assume that the resultant power is real, and does causal work, then there would he a problem in positing also component powers that did the same work. If both the resultant and the components produced the same effect, then that effect would be overdetermined. Overdeterrnination is, in many ac­counts, regarded as a bad thing and thus a problem if a theory entails it. A response is thus demanded.

The first thing to note, however, is that the causal dispositionalist theory being developed herc can accommodate the possibility of over­determination. In §6.8, it will be argued that it is prima facie implausible lo delly the possibility of overdctermjnation. Ovcrdctcrmination is pri­marily a threat to cOlUlterfactual dependence theories of causation and thus much time and effort has been spent on trying to explain away apparent cases of it. The vector model of causation, in contrast, has no reason to reject the prima facie possibility that. an event can have two independent causes, each of which would have been enough on its own to produce the effecL However, while standing by the possibility of overdetennination, it nevertheless looks dubious that realism about component powers really does commit one to it. For it to do so, the resultant and component powers would have to be distinct. existences, but they do not appear to be. On the contrary, it is marc plausible to say that t.he resultant and the components are somehow the same things under different guises.

The problem is, as Wilson (2009) points out, specifying exactly what the intimate connection is between resultant and components that allows us to say they arc not distinct exist.ences. A prut-whole relat.ion would be one that springs to mind, though both C31twright and Wilson reject it Cartwright says that a motion due north cannot be a part of a motion north-cast. Wilson notes that forces are individuated by their direction and intensity. In that case, how could a component force west be a part of a resultant force east? Perhaps, then, part-whole is not quite what is needed.

Realism ahout component powers 43

A compositional model ought Lo be a more obvious candidate because they are, after all, called component forces, vectors or powers. The statue and the clay that makes it are not identical, in t.hat one could cease to exist while the other persists. But, while they both exist, they are not entirely distinct exist.ences ehher: one is composed of the otheL FUlthermore, any effect they produce, they produce together but without overdetermination. Both the statue and the clay may fall on someone and crush them to death. We would not say that the death is overdetermined because, although both the st.at.ue and the clay exist, they ru·e not entirely distinct. Tn such a case, it is usually taken as understood that composition cannot be analysed in other t.erms. It. is not as simple, for instance, as the clay being a part of the statue, so its composition cannot be reduced to the part-whole relation. And compo­sition is not identity because the clay ruld the statue differ in their modal properties: one could sUTvivc bcing remoulded into a different shape, while another could not. But composit.ion, even if it is sui generis, is something we can grasp through cases like the clay and the statue. The component powers could, therefore, make up t.he resultant powers in this kind of non-part-whole way. The resultant would have been different if one of the components had been absent, or a different component had been added. And the components make up the resultant rather than the other way round: there is an asymmetry in composition. Given a set of components, there is only one resultant that they make, while given a resultant alone, one cannot. infer the componcnt powers as a potential infinity of different components could make up the same resultant.

In a dispositionalist theory of causation, commitment t.o the compo­nent. powers is central. It is they that drive causal transactions. If the dispositionalist were forced to choose bctween component and resultant powers, if there really were a danger of overdetermination, it would makc morc sense to be an anti-realist about the resultants. Perhaps they have just instrument.al value, as summaries of all the distinct powers that are brought to bear on a situation. Wilson has an experiential argument to the effect that result.ant. forces are better known t.o us than component". In many cases, we could feel a resultru1t force whcn the components are unknown to us. But. this is also the kind of argument that a realist. about dispositions is likely to reject as carrying any real weight. Dispositions often are epistemically problematic or even verification transcendent, as allegedly finkish dispositions are (Martin 1994). They operate below t.he phenomenon, producing it. But there are nevertheless cases where we can acquire knowledge of them (see chapter 9), and we

on..... . ......

44 Modelling Causes as Vertors

also have the possibility of intervention and experiment in the world that detects component powers. The dispositionalist, therefore, need hold no special brief for resultants_ It would, however, be only a fallback position to adopt instrumentalism about them. If a compositional model can be used to explain the relation between the components and the resultants, along the lines of the statue and the clay? then we should be able to be sufficiently realist about all the powers involved, whether composed or simple.

2_8 Multi-dimensional cases

In §2.3, the simplest model was presented of vectors within a one­dimensional quality space. It could then be ventured that more complex cases of causation, in which there are changes within multiple quality spaces, might just be taken as conjunctions of changes within one­dimensional spaces.

That would be neat and simple, but it is worth noting that even if there were irreducibly complex causal processes, which cmmot be reduced to conjunctions of changes within one quality dimension, they could still be accommodated within a vector model. Suppose, for instance, that we adapted an example given by Geach (r961: 102), in which a room contains both a heater and a cooling air conditioner. We will make the case two-dimensional. The heater can, let us say, warm the room to 25°C within an hom with dry air. The air conditioner can cool the room temperature to rooe within an hour with slightly damp air. Suppose both the heater and the cooler arc left on and that the powers along the hot--cold and dry-damp dimensions are inseparable. We can still, nevertheless, undersl..'1nd such complex powers along the lines of vec­tors, and understand their combined effect along the lines of vector addition. We simply need a two-dimensional quality space, as iHustrated in figure 2.13 (both fIgure 2.ll and 2.12 are already two-dimensional).

It needn't end there. Vector addition can be perfonned in principle on any number of dimensions, though the formula for calculation becomes mOTe complicated. A three-dimensional-quality space, for instance, would have vectors emanating from a central point in one of six direc­tions (fIgure 2.14). When the dimensions increase, we permit more possible directions for our vectors within a space. Some of these issues of complexity, and inseparability of powers, will be taken up in chapter 4. For now, however, it should simply be noted that the number of quality

'All things are vectors'

............ Dry

R ••••••• -

...... .. ..... Hot .....

h Damp

-­ ... Cold

FiGURE 2.13: Vectors within a two-dimensional quality space

FIGURE 2. '4: Vectors within a multi-dimensional quality space

45

dimensions would not be a challenge to the vector model. The difference would only be degree of complexity. If that is correct, then for practical purposes in the rest of this book, it will make no difference if we stick to the one-dimensional cases, purely for ease of exposition.

2-9 ·AII things are vectors·

Whitehead's Process and Reality puts forward thc claim that "all thines are vectors' (1929: 309). What exactly Whitehead meant by this, ;e may never know. His work defies simple and unequivocal interpretation. But we have offered a model for c311salion in which Whjl~head's

statement would make some sense. All things have properties and all propelties are powers, for the pandispositionalist. If such powcrs arc understood as directed towards a manifestation, with a degree or

Modelling Causes as Vectors

intensity, then all things become vectors or at least they can be repre­sented as such.

A new vector model has been proposed, therefore, which is more amenable to a dispositionalist ontology. Understanding causation in this way allows us to depict a number of its well-known features but it might also allow us to discover some new, unexpected, consequences. In the next chapter, for instance, it will be argued that causal production does not occur via necessitation. The idea of the composition of causes as vector addition will suppott this view and show the value of the vector model as a heuristic tool.

We have introduced enough of the vector model to proceed. This is not to say that the model is complete, however, and we will be offering some further development as we continue, notably in connection with the OCCUlTence of threshold phenomena and probabilistic causation (chapter 3) plus the case of non-linear composition (chapter 4)·

3

Against Necessity

3.1 Explaining the familiar by the obscure

When you strike a match and it lights, you may be in no doubt that the stIiking caused the hghting. But whether the striking necessitated the lighting is a different matter. Where one thing necessitates a second, it is a sufficient condition for it. This means that if there is the first, there has to be the sccond. If you could have the first thing without the second, then the second was not necessitated by the first.

Pli.ma facie, causation does not look to be any kind of necessity at all. Anyone who uses matches knows that, in at least some cases, matches are stl'llck and fail to light. Something can alway.s go wrong. Even if you .strike the match exactly right, there may be some external factor, outside your control, that prevents the match from lighting. You still have no doubt that when the match does light, the striking was the cause, or at least a cause. Does that mean that the .striking necessitates the lighting in just some cases, namely, the successful ones, but fails to do so on other occasions? That seems like a misuse of the concept of necessity. If someone were to say that, in some cases, being water necessitated being H2 0, but in other cases it did not, prima facie it would seem as if they did not understand the meaning of necessity. In the causal case, it seems more plausible in such circumstances to say that particular a caused or produced particular b without necessitating it. That a caused b suggests Ihata made h happen (Woodward 2003), but why should that automatically mean that a necessit:'1ted b? Could there not be an account of causal production without necessitation? Is necessitation rather more than is needed for causation? Isn't causation between a and b alrcady a strong enough connection'! The philosophers who try to accollnt for causation in terms of necessity are, we argue, over-bidding in their theOli.es.

Different things could have been meant when Hume raised the idea of necessary cOImection. Mackie (1980: 12ft) distinguishes three possible roles for necessity that Hume could have had in mind. One was merely

Against Necessity

that which would distinguish causal from non-causal sequences. We would certainly agree that there is somcthing that so distinguishes causal from non-causal sequences but, as we will go on to argue, calling this thing necessity is a misnomer. A second role of necessity is to warrant a priori reasoning from cause to effect and from effect to cause. On our account, there won't be anything that would provide such a priori reasoning about the relation between cause and effect, but, 'if there were, it would have to be something very close to logical necessity. A third idea would be that necessity is what licenses causal inferences. But we have already seen grounds for caution in our causal inferences. From the mere fact that we know an event to have occurred, we cannot straightforwardly infer that its typical effect will have OCCUlTed. We may be able to infer some things, as we will see in due course, but with nothjng like the certainty we would have if effects were necessitated.

In this chapter, we arc going to advance arguments to the effect that necessity is not correctly a part of the notion of cause. To treat causation as a type of necessity, or even as involving necessity, is to take causation as something it is not. It is reducing the vital ingredient of causatioIl, which SUIIH.:l!UW cunnects one thing with another, to some­thing else that we may think is more familiar. We will go on to argue, however, that causation is as familiar to us as anything, and certainly better known by us than necessity itself. The attempt to treat causation as necessity is a case of explaining a familiar notion in terms of a more obscure one and thus any such analysis is pointless.

We will here concentrate just on the issue of necessity and offer an argument against it as being a legitimate part of causation. In chapter 8, we offer a more positive account in which the kind of connection that is needed for causation is a dispositional one, rather than necessity. But for the moment we have a more limited and negative aim: to show that Hume was knocking down the wrong theory in his attempt to establish a constant conjunction account.

3.2 'There is a necessary cannexion to he taken into consideration'

In his Treatise, Hume set out to consider the constituents in our idea of cause. The first he found were contiguity and succession. The cause must be proximate to its effect, spatially and temporally, and the effcct must succeed or come after the cause. But there was more to say:

'There is a necessary connexion to be taken into consideration' 49

Shall we then rest contented with these two relations of contiguity and succes­sion, as affording a compleat idea of causation? By no means. An object may be contiguous and prior to another, without being consider'd as its cause. There is a NECESSARY CONNEXION to be taken into consideration; and that relation is of much greater importance, than any of the other two above­mention'd. (1739: 77)

Hume's assertion in this passage needs some fmther examination as it introduces an alleged key pmt of our understanding of causation. We argue that he was wrong. As is well knmvn, Hume went on to add constant conjunction as his fourth constituent of our idea of cause but then argued that, of these four constituents, necessruy connection had no legitimate place. 111crc was no original sense impression m compound of other ideas that would warrant us having an idea of necessary cOImection between cause and effect. In our philosophical studies, therefore, we should acknowledge that constant conjunction, together with contiguity and succession, is all we can signify when we speak of cause and effect. Necessary connection signifies no experience and is thus ultimately just empty words.

Much uf the subsequent discussion of causation has focused on whether Hume was right that there was no necessary connection in causation ovcr and above constant conjunction. This has become a key battleground but, we claim, mistakenly so. Humeans have defended the adequacy of constant conjunction while anti-Hum cans have defended the need for necessary connection. But this is an error on the part of anti­Humeans. Hume has wrong-footed his opponents by lumbering them with an indefensible position and we take it that they have largely fallen into the trap.

Let us look at the problem afresh. Take as an example a common case of prima facie causation, for instance, when someone ingests alcohol followed by their drunken behaviour. In this example, we assume that there are two events: the ingestion of alcohol and drunken behaviour. We assume also that the first caused the second. Now let us consider, as does Hume: in our ordinary concept of cause, do we, as welJ as constant conjunction, contiguity and succession, feel a need to posit a necessary connection? Many people seem to think so. Like Hume, however, we say that they have no justifiable reason. The idea that causation involves a necessary connection is one that docs not survive scrutiny, though we have differcnt reasons for claiming this than Hume's.

Many of us see the need to posit something more than constant conjunction. But we should consider whether there really docs need to

50 Against Necessity

be something added and, if so, what it is. It is easy to imagine examples where some kind of thing A is constantly conjoined with a kind of thing B (11 and B), and where A and B arc contiguous and in a succession (A before B), but where we do not think that A is a cause of B (B because of A), Night following day, barometers falling being followed by rain and all manner of 'accidental' conjunctions are the sorts of cases we have in mind. But if 'something more' is needed for causation than merely every case of A being followed by a case of B, it does not follow immediately that this something more must be necessity. Argument would be needed to cstabJish that necessity was the missing ingredient. rather than something else.

h may be, thcTcfoTe~ that Hume '8 duly considered account of causa­tion, which has only the three constituents, was inadequate but that does not mean that his initial four-constituent account, which contains the addition of necessary connection, was right. Whether an extra ingredi­ent, if required, is necessary connection, is something for which we need an argument. Yet it was the only extra ingredient that ]-Jume offered us. This needs closer scrutiny.

3·3 The case for causa/necessitarianism

We arc not the first to have dellied that necessity is a pmi of the concept of cause. Anscombe (I97I) famously did so, though not because she was explicitly a dispositionalist. But are we just attacking a 'straw man', or is there a widely held view that causation involves necessity? Before advancing the argument against necessity, we will present at least some examples of philosophers who have defended necessity for causa­tion. We could call this view causal necessitarianism.

Philosophers who take causal necessitarianism as a basic truth about causation could be divided into two classes: those who merely speak of necessity in causation and those who positively defend it. The former case is less serious but still worthy of note as an illustration of how widespread and sometimes unquestioned the assumption is. Talk of causal necessity occurs for instance in Popper, when he says:

in the tight of a conjecture we can not only explain cause and eiIed much better than Hume ever did, but we can even say what the 'necessary causal link' consists of. ... Given somc conjectured regularity and some initial conditions which pennit us to deduce predictions from our conjecture, we can call the

The case for causal necessitarianism 51

conditions the (conjectmed) cause and the predicted event the (conjectured) effect. And the conjecture which links them by logical necc5sity is the long­searched-for (conjectural) necessary link between cause and effect. (Popper

1972: 91)

This is framed within Popper's notion of conjectures and refutations, but the idea is clearly present of a non-Humean necessary connection betwecn cause and effect. A similar idea is found elsewhere, for example, in IIamS and Madden's (1975) Causal Powers, subtitled A Theory or NaturalNecessity, and in Skyrms's (1980) Causal Necessity, Shalkowski, speaking of a number of different problems, says: 'Tn so.me way, t~e): involve the causal modality, some forn) of natural or phYSIcal neccs::aty (Shalkowski 1992: 55), All these philosopbers merely speak of causal necessity and offer no serious argument for it. Shalkowski, for instance, shows that the Humean position of constant conjunction is inadequate to account for causation, modality, disposition claims and counterfactual conditionals. That may be the case but it does not demonstrate that the only alternative is to move to somcthing as strong as necessity_ Causation could be a link that was more than pure contingency but less than necessity. Causal necessitarianism is widely held by non-Humeans, how­ever. In Baldwin's Dictionary, quoted in Russell's well-known paper 'On the Notion of Cause', causation is defined in tenns of necessity:

CAUSALITY. The necessaty conncction of events in the time-series ... (Russell

1913: 2).

Although Russell famously was dismissive of causation, according to Anscombe this is partly because he took necessity to be part of the notion of cause:

he cast doubt on the notion of necessity involved, unless it is explaincd in terms of universality, and he argued that upon examination the concepts of determination and of invariable succession of like objects upon like turn out to be empty ... Thus Russell too assumes that necessity or universality is what is in question, and it never occurs to him that there may be another concept of

causality. (Anscomhe 1971: 135)

Explicit commitments to causal necessitarianism are perhaps more important, however. .And there is a long history of commitment to tl~e view that for one thing to bring about another it must do so by neceSSI­tating it. Here is a diverse range of instances:

There is also a peculiarity of potentialities of the. _. non-rational kind, and it is this: whenever the potential active and potentially affected items are associated

I

II i'

li,' 'I· li,,,,1

52 Against Necessity

in conditions propitious to the potentiality, the former must of necessity act and the latter must of necessity be affected. (Aristotle Metaphysics e 5: 264)

From a given definite cause an effect necessarily follows; and, on the other hand, if no definite cause be granted, it is impossible that an effect can follow. (Spinoza I67T r, axiom .ill: 46)

[0 conformity with such a rule there must be in that which precedes an event the condition of a rule according to which this event invariably and necessarily follows. (Kant f78l: lLii.3, second analogy)

It is necessary to our using the word cause, that we should believe not only that the antecedent always has been followed by the consequent, but that as long as the present cons1itution of things endures, it always will be so. (Mill 1843: III.v.6)

Now, it is argued, this law [of causality] means that every phenomenon is dctcnnined by its conditions, or in other words, that the same causes produce the same effects (Bergson 18g9: T99) .... a certain phenomenon P, which ap­peared after the conditions a, b, c, d, and after these conditions only, will not fail to recur as soon as the same conditions are again prcscnt. ([bid. 202)

The same idea can be conveyed using different terms.

The fuller we make the description of the cause, the better our chances of demonstrating that it was sufficient (as described) to produce the effect. (Da­vidson 1967: 698)

Cause: A state of change X of an ohject is said to have been the cause of a state or change Y of another objcct, if the factuality of X ... was sujficient to thc factuality of Y. (Ducasse 1924: 55)

la cause] is an insuffiCient but non-redundant part of an unnecessary but sufficient condition [for the effect]: it will he convenicnt to call this (using the first letters of the italicized words) an inus condition. (Mackie 1980: 62)

The terminology may differ slightly but the commitment is the same. Mill speaks of the effect invariably following, while Davidson and Mackie speak of the cause being sufficient for the effect. We will lake this language to mean the same as the cause necessitating the effect. Saying that the cause is sufficient for its effects means jusL as much that if the cause occurs, the effect must occur.

Our target in what follows is indeed what has become known as sufficient conditions as applied to the case of causation. The target is not what is known as a necessary condition. A necessary condition is a sine qua non: some event or condition without which we would not have the effect. A necessary condition in that sense need not guarantee the effect. A suflicient condition would guarantee the effect, though it need not be a necessary condition. Different things could be sufficient

Interference and prevention 53

conditions while none are individually necessary. We now move on to the argument against there being such sufficient conditions in causation and thus against a cause ever necessitating its effect.

3-4 Interference and prevention

Anscombe ended her inaugural lecture 'Causality and Determination' with the words: 'The most neglected of the key topics in this subject are: interference and prevention' (Anscombe 197 I: ] 47). Any causal process can be prevented or interfered with in some way so as to affect the outcome and, according to Ellis, Hume thought so too: 'Hume was not. of course, making the obviolls point that causal processes can al ways be interrupted, diverted or swamped by other processes. Everyone ac­knowledges that' (Ellis 2002: II2). Geach states this view as 'Any uniformity is defeasible by interference or prevention' (Geach 196J: !O3). But what is the implication of this? We defend the bold thesis that the possibility of prevention leaves no room for any kind of necessity in causal production. We arc not just mling out logical necessity. Fev. people think that logical necessity is the kind of necessity at issue. Few of those quoted above are arguing for it, for instance. But neither is there any other kind of necessity involved in causation, whether you want to call it metaphysical, natural or simply causal necessity.

When a causal process is interfered with or prevented in the token case, concerning individual events, it may prevent causation from ever occurring. But, even if it did not, it could have done: a may have caused b but might not havc done so if it had been interfered with or prevented. In the type case, concerning general causal facts, we have to say something different. Although there could in theory be causal constant conjunctions, where events of type A always cause events of type B, the possibility of interference suggests that at least some of the instances of A might be interfered with and prevented from causing instances of B. We could even venture that this is the norm, as docs Mill (1843: lIT. X.S: 292). But if that docs happen, and there is less than constant conjunction, need it falsify the general causal claim that A causes B? Not necessarily. Such a general causal claim would be falsified only on the assumption that a general causal claim was, or at least entailed, a constant conjunction. Hume is often criticized on the grounds that constant conjunction is not sufficient for causation because something more needs to he added to rule out accidental conjunctions (for example,

54 Against Necessity

Amlstrong 1983: eh. 2). But perhaps the bigger mistake is to aSSume that constant conjunction is even a necessary condition [01' causation. If A causes B, intended as a general causal claim, means that A disposes towards B, for example, then this may remain true even if there are some individual a-tokens that are prevented from causing b-tokens.

In chapter 2, a model of causation was offered that already allows the possibility of prevention and interference. The vector model shows the complexity or polygeny of causation. That a certain event occurs is typically the result of many different factors working together. If one or more of these factors are counteracted, the effect might be interfered with or prcvenLcd. Wc can use the vector model to illustrate the difference between interference and prevention. When an effect is interfered with, it still occurs but differently: perhaps not as strongly as it could have occurred, or not quite in the same way, or perhaps it becomes delayed, as in the case of the death that still occurs but is delayed by the life-support machine (§z.S). Interference typically happens because of some extra factor being present that disposes away from the kind of event identified as the effect. We can represent the interfering factor I as a vector pointing in the opposite direction and the effect towards which the situation is disposed as a resultant veetor R.

When an effect is prevented, on the other hand, it docs not occur. Prevention happens either because of some factor not being present or

F G

1

R

FIGURE 3. I: Interference

Inlerference and prevention 55

because of some extra factor P disposing away from the effect. Exam­ples will illustrate the difference between the two types of prevention. Consider two cases where a match is struck. In the first case, it is stmck against the matchbox but does not light. The reason in the first case is because some factor was not present that usually is and would have contributed towards the match lighting. Perhaps it is that the flammable tip of the match had been knocked off or it was not struck fast enough or, in some exceptional case, there was no oxygen present. This is certainly a case of prevention but it. is not that kind of case that will be the focus here. The second kind of case is more important for our purposes. This is one where all the factors are present that would usually be enough for the match to light. The match is struck, its flammable tip is intact as well as oxygen being present and the wood being dry. In this second case, the match is struck but doesn't light because of some extra factor that is added. In terms of the vector model of the previous chapter, this is represented as an additional vector P that. disposes away from the match lighting, as illust.rated ill figure 3.2. Its direction is opposite to the other vectors that, in different circumstances, caused the match to light, and as a result we have a zero resultant vector.

It is this latter case ofprevent.ion that will particularly detain us in this chapter as it is a case where somet.hing is added to a situation and acts as a prcventer, ralher than a case where something is taken away. The additional factor P could be something as simple as a gust of wind that just happens to blow at an inopportune moment as far as the mat.ch lighting is concerned. Whether the match actually lights, therefore, is contingent upon many factors. There is the possibility of some factors being taken away and the possibiUty of some interferers being added.

F G

p

R

FIGURE 3.2: Prevention

Ii

II! I

I I I ,J

Against Necessity

This point is mundane and ought to be uncontroversial. Geach has already stated it and Hume himself used the possibility of prevention as a crucial step in his argument against necessary cOimection. We now proceed to do the same.

3,5 Antecedent strengthening

This section presents an argument against causal necessitmianism, based on the assumption that any causal process can he interfered with or prevented by the introduction of some additional factoL The idea is that if causation involves any kind of necessity, it should survive the test of antecedent strengthening.

Let us assume the Millian thesis that the causes of an event are complex. Suppose, for sake of argument. that there are four causes of an effect e, namely, c I' c2, ('3 and c4 . Let us suppose also that there is an instance where cl -c4 in fact produced e. The question of this chapter is whether C1-C4 in so doing necessitated e. According to the above quotations in §3.3, if they caused e, then they jointly necessitated it. But then we also saw in §3.4 a claim that has at least prima facie plausibility: that causation can be prevented or interfered with. That raises the thought that even if C1-C4 caused e, they did not necessitate e because there was at least the possihility that some additional factor, let us call it Cj, could have occurred and, had it occurred, even though c ,-c

4 occurred, e did not occur.

As Geach (196,: 103) said, any (causal) uniformity is defeasible, In the present case, this suggests that any causal process, which in many, most, or typical cases succeeds in producing E, could be prevented from doing so. Massive objects fall to the bJTound, but not if pulled away from it; struck matches fail to light in the wind; elastic bands may fail to stretch when pulled if they are very cold; water does not boil at lOOGe at high altitude; fruit docs not rot in a vacuum; smoking does not cause cancer in every person who smokes. It is thus empirically plausible that for any type of causal process, in which C J-C 4 are typically causes of the type of effect E, there is some possible Ci that when added to C,--C

4 typically results in E not being caused.

Now let us retunl to the distinction that was drawn between two types of prevention: the tirst where something was taken away from a causal situation and the second where something extra was added. The second kind of case was thc one that intercsted us and the reason for this is how

Antecedent strengtheninR 57

it can connect with the notion of necessity. Necessity would support monotonic reasoning. Hence, where A necessitates B, then whenever A is the case, B is the case. A is then a sufficient condition for B. In non­monotonic reasoning, the addition of extra premises can intcrlere. A may justify B, for instance, but that does not entail that A, plus C, for any C, would justify B, That you left home ten minutes later than usual might justify the expectation that you will be ten minutes late for work, for instance. But that you left ten minutes later than usual and left in a helicopter, which you do not usually do, might not justify the expectation that you will be late for work. Such non-monotonic reasoning should not be thought inferior to monotonic reasoning. It just shows that one is prepared to revise one's inference in the light of new infonnation. But in the case of genuine neccssity, where A necessi­tates B, no new information or extra premise can prevent B if A is the case. If A necessitates E, then even A and -,B necessitates B, according to standard logical theory. Such monotonicity presents us with a test of necessity. If A necessitates B, we should have a true conditional of the fonn if A and 4>, then B. for any value of ¢. Hence, we will be llsing this as our necessity test:

If A necessitates B, then: if A plus 4), for any rjJ, then B.

Some believe, following Kripke (1980), that water is necessarily H,O, Suppose he is right. Then there will be various true conditionals for different values of 4>: if this is water and Madonna is a man, then it is H2 0; if this is water and Barack Obama is President, then it is H2 0; if this is water and in a bottle, then it is H20, and so on. What we thus have is an antecedent strengthening lest of necessity. We put the claim into conditional form, if we can, and then strengthen the antecedent of that conditional to sec if it remains true under various conditions. If the conditional is robust under antecedent strengthening - that is, if it remains true for all strcngthenings of its antecedent _. then it passes the test and is necessary_If it fails for some strengthenings. we do not have a case of necessity.

Cutting to the chase, if we want to know whether causes necessitate their effecls, we should put them in conditional fOID) and apply the test. But we have alTeady seen enough to judge that they will fail any such test. We cannot say that if A, thcn necessarily B, even where A is typically a cause of B. We can take the conditional if C>-C1, then E, and then strengthen the antecedent with C i , and produce a conditional

!

i

I I

58 Against Necessity

that is false. C J-L'4 may be the striking of the match, the presence of oxygen, the dryness of the wood, the flammability of the tip, and they may, when combined, succeed in producing fire. But now we can add more to the antecedent - there was also a gust of wind - and we see that this additional factor could result in the match failing to light, even though C 1--C 4 remain in place. OUf case thus fails the antecedent strengthening test, and if one follows Geach's view that every natural process can be prevented, then we can generalize to say that causes never necessitate their effects (see §8.2, below). Causal necessitarianism is thus false.

3.6 Other anti-necessitarians

Celtainly, this is not the first denial of causal necessitarianism. An­scombe (197T) denied the necessity of causation, but that was not for the same reasons offered hcre. Rather, she was chiefly concerned with pointing out. the plausibility of indet.enninistic causation. Our notion of cause had to be consistent with the possibility of indetenninistic, irre­ducibly probabilistic, causation and it. would not be, she argued, if the very concept of cause committed one to necessitation. We will return to the conceptual analysis of cause and to probabilist.ic causation in §3.12 and §3.13.

It should also be noted that. others have advanced similar arguments but without drawing the inference that causes do not necessit:te their effects. Johnston's (J992) masking and Bird's (1998) antidotes could both be used in support of antccedent strengthening arguments. An antidote, for instance, is something that. get.s added to a disposition and its stimulus that is able nevcltheless to prevent the disposition's mani­fest.ation. As an example we can take the disposition of arsenic to kill. If its antidote is taken quickly enough, t.he arsenic can be prevented from producing its fatal effect. The existence of the antidote shows us that arsenic does not necessitate death, even in the cases where it indeed causes death. The antidote could have been ingested, even if it wasn't, and that is adequate to defeat necessitarianism. Ellis (2002: lJ2) is another who accepts the possibility of prevention, but he still says elsewhere that a causc necessitates its effect (2001: 7).

Some have seen the attraction of the argument. offered in §3.5 and have drawn the same inference. Schrenk (2010) and Eagle (2009) offer similar arguments. Before that, Hume, Russell and Mill all proposed

Other anti-necessitarians 59

tests akin to antecedent strengthening and the first two of them saw that causation would fail the test. Russell said: 'In order to be sure of the expected effect, we must know that there is nothing in the environment that can interfere with it. But this means that the supposed cause is not by itself adequate to ensure the effect' (1913: 7). Mill before him had seen that this would be an argument against necessity. It is implicit in the following, which offers an antecedent strcngthening test of necessity:

This is what wliters mean when they say that the notion of cause involves the idea of necessity. If there be any meaning which confessedly belongs to the tenn necessity, it is unconditionalness. That which is necessary, that which must be, means that which will be whatever supposition we make with regard to other things. (Mill 1843: I1I.v.6)

Hume himself gave a simlIar argument to the one that has been offered. Having initially noted necessary connection as a part of the idea of causation, he then went on to dismiss it on a number of grounds. One was that t.here were no impressions gained in our experience of causa­tion 1'h<11 cOllld deliver ns legitimately any such idea. The necessary connection could not. be experienced: a view we challenge in chapter 9, below. But Hume offered anot.her argument against the idea of causation involving necessity. For necessary connect.ion, 'We must distinctly and particularly conceive the connexion betwixt the canse and cffect. and be able to pronouncc, from a simple view of the one, that it must be follow'd or preceded by the other' (1739: 161; emphasis added). That is to say, in our tenns and among other things, that causal necessitarian­ism would support monotonic reasoning. But that is implausible: 'Such a connexion WOll' d amount to a demonstration, and wou' d imply the absolute impossibility for the one object not to follow, or to be conceiv'd not to follow upon the other' (1739: 161-2). But there is no such impossibility. One can always at least conceive of the cause happening but the effect failing to happen, and given that Hume holds a conceiv­ability test of possibility, this amount.s for him to it being a real possi­bility that C and, E. If it is possible that C and, 10', then it cannot be that C necessitates E.

Unlike Burne, one may not accept a conceivability test of real possi­bility (see Mumford 2004: 53-4). But in any easc it is plausibly a real possibility that an effect can fail to occur because of intelference and prevention. The reason given here is not merely that. we can conceive of the effect not occurring but that there arc enough actual cases where it

I .... ! .11 11

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III!I,'I'

'.'.11·'

.. 11" , .

i· '. 11,:;1

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, 'I

1:111

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60 Against Necessit)'

fails to occur because of prevention and interference. Where those preventers are additions to a situation, rather than subtractions from it. then the antecedent strengthening argument comes into play.

3·7 Is addition just subtraction in disguise?

The basic argument set out, it is now time to anticipate some of the likely objections, of which there are a number.

First, the argument against necessity might be doubted on the follow­ing grounds. It is presented as an antecedent strengthening argument. This works only if something, Ci, is added to the situation that prevents the effect of c1-c" occuning, where C1-C4 are all the factors that other­wise would cause e. But is the interferer Ci really something that gets added to C 1-C4'1 Might it be that Ci is really just the removal of one of those other factors, C 1-C4' that are needed for e to be caused? If it is, then we do not have an antecedent strengthening argument; indeed we have no argument against necessity at all.] The necessity view is that when­ever we have the cause C, we must have the effect l!.'. But if a part of Cis being removed. it would in no way be a threat to causal necessitarian­ism. All it would show would be that C is complex and its parts are non­redundant.

Why might this response be attractive? The reason is that there could be some cases where the putative interferer is plausibly just the removal of one of the causal factors. The causal factors C [--c4 were the striking of the match, the presence of oxygen, the dryness of the wood and the flammability of the tip. Suppose that when the match is struck, the atmosphere is damp and this makes the match fail to light. The damp atmosphere is certainly a preventer, let us suppose, but while it is presented as an addition to the causal situation, on further reflection might ltju~t actually be a subtraction? One of the factors in cc-c

4 is that

the match IS dry. If the atmosphere is damp, it can make the match damp as well. But ifit does so, it ceases to be dry. 111at means that rather than adding an extra factor, for purposes of an antecedent strengthening test of necessity, we have just taken away a factor - the dryness of the match - so we are no longer testing the necessity of the causal connection,

1 'Ibis objection was put to us by Malia Jm;e Garcia Encinas.

Is addition just subtraction in disguise? 61

The response to this kind of objection is that although there may be some cases where a putative addition to a causal situation is really just a subtraction in disguise, this does not demonstrate that every putative addition is a subtraction in disguise, and thus the thesis of causal necessitarianism remains under threat. All we need to counter causal nccessitm'ianism in general is onc case of causation where the anteced­ent strengthening test is failed. And all we need to show that each particular kind of causal connection is not necessary is one case of antecedent strengthening test failure for that specific causal connection. There are many general causal claims we make: striking matches lights them; thrown rocks smash windows; increasing the money supply causes inflation. To show that these do not involve necessity, we would need just one possible antecedent strengthening preventer and it seems plausible that there are some for each of these instances.

Some other cases might be arguable. Suppose the match is struck and a gust of wind comes, just at the wrong time. This is presented as an addition but perhaps one of the factors that causes the match to light is stability of the air around the match. The gust of wind removes this, so perhaps it is a subtractive preventer rather than an additive one. But this interpretation is questionable. When we say that the air must be stable, or the match dry for that matter, are we not just specifying a negative condition: something that mustn't be there? Aren't we really trying already to exclude interference from moisture and rapid air movement? When there is moisture or wind, they certainly seem like things that are added rather than things that are taken away. We might, therefore, be prepared to argue about -"nch alleged exceptions to the argument.

Notwithstanding the outcomes of any such discussions, the possibility and existence of actual additive preventers seems implausible to deny as a general claim even if some specific inst.ances may on reflection be dubious. A match might be struck just as a hlack hole appears and sucks the match, and everything around it, into space. Isn't the black hole the addition of something - a hugely massive something - to a situation that should otherwise have lit the match? And Bird's antidote cases are plausible, which are cases where the typical cause is not taken away but an antidote is added, British anti-Lewisite, for example, is the antidote that prevents the fatal effects of arsenic even when the arsenic is present. It is not like a so-called fink, which works by removing the disposition towards some effect. TIle antidote is added to something that remains there and otherwise could have produced the effect.

II '"'"""--l""'----_________________ . ___ ... ___________ ~~~~

j I I I I

I'

Against Necessity

F G

.......... ~

I

FtGURE 3.3: Subtractive interference

In chapter 2, the vector model of causation was presented in which the distinction between subtractive and additive intelferers is easy to repre­senLln figure 3-3, I is a subtractive interferer, namely, one that removes a cause, while in figure 34 there is an additive interferer: one that adds to the cause. In figure 3.3, the dotted-hne-vector I represents a power that was present in a prior situation, which then gets removed. WhlIe it is there, the situation overall disposed towards G. With its removal, how­ever, the overall situation no longer disposes towards G but, let us assume, will be in equilibrium.

In figure 34, in contrast, the interferer I is added to a situation that was, until its addition, disposing towards G. That I is added, is indicated by a broken-line-vector. Again, the situation depicted is one where the interferer results in an equilib11urn situation arising. Figures 3.3 and 3-4 thus both represent situations where there would have been a resultant disposition directed towards G though it is inteIfcred with and, in these cases, wholly prevented: in one case through subtraction and in the other case through addition.

F

+----1

FIGURE 3-4: Additive interference

G

What if there is no interferer?

Given that we have at least some plausible examples of additive interferers, the onus of proof seems to be on those who would deny that there are any genuine cases. Otherwise, if there are at least some real additive interferers, then the argument from antecedent strengthen­ing seems to go through and causal necessitarianism is defeated_

3.8 What if there is no interferer?

There is, however, a further possible objection along these lines. Doesn't it appear to he, at least in some sense, a contingent fact whether or not there is an interferer for some particular causal process? There arc, of course, some who sec little room for any kind of contingency in the workings of nature (see Ellis 2001 and Bird 2007). Perhaps, then, the workings of nature arc necessary rather than contingent and any such appearance of contingency is merely doxastic. But might there be some causal processes where either there just happens to be no interferer in the world that could prevent the effect or, for nccessitarians, there is some process that of necessity (;allllOL be prevented? Thu~, allhough it might be accepted that there are some genuine cases of additive interferers, and that may be enough to falsify causal necessitarianism as a general thesis, there might nevertheless be some specific causal processes [or which there is no interferer, and which thus remain necessary. In such cases, once all the rclevant causal factors are asscmbled, the effect simply must follow.

A lot hinges on the scope of possibility here. Suppose, as some think, there is an element of contingency in the causal processes of our world. In that case, an antecedent strengthening test could still defeat causal necessitarianism. Alll'hat is required is that it is possible that the effect be prevented by an additi ve interferer. Perhaps there is none as a matter of fact, but if that is a contingent fact, then still there could be one, in some metaphysical sense of could. Then, arguably, the cause necessi­tates the effect only if there could not be an interferer, which is a strong claim. Even ifit is 'merely' possible [or there to be C and -lE, then C does not necessitate E.

But suppose the so-called laws of nature arc necessary. Does that mean that causal necessitarianism is true? It does not mean so automati­cally because the connection between the necessity of laws and causal necessitarianism may be loose only. In §3.14, indeed, it will be argued that the new necessitarianism based on essentialism should not be

Against Necessity

understood as a thesis about the necessity of causation at all, and it would be a mistake to infer that from essentialism. We would need, therefore, to get clear about what is and is not claimed to be necessary. The sort of case imagined, however, is one where there is some causal process leading from C to E where, given C, there is then no possible interferer that could prevent E. Furthermore, the laws are assumed such that it is a matter of nomological necessity that there is no such interferer and a matter of nomological necessity that, whenever C, E.

In that case, the appropriate response is not to deny that this scenario is possible, in the sense that ours might be a world of this kind. But even if the situation were exactly as described, it would still not he a proof of causal necessitarianism. The thesis of causal necessitarianism, as it is defined here, is a claim about what it is for one thing to eause another: C causes Eby necessitating it. As will be argued in §3.12, when the issue of detenninism is considered, causation is consistent with there being necessitation in the world. But the claim is that causation does not itself provide that necessitation. E might be necessary, given C, but that does not follow just from a truth that C causes E. It is some furthcr claim that adds the necessity, over and above the causal tmths.

This last point will be revisited shortly, but we should first summarize this reply. There could in principle be causal processes for which there is no interferer or preventer such that whenever a token of C occurs, a token of E occurs. This could be a matter of contingency or necessity, according to one's general view of the metaphysics of our world. If it is a contingent matter, then although as a matter of fact there is no intelferer, there remains the possibility of one and this is enongh to defeat causal necessitmianism. If it is a matter of necessity that there is no interferer, then this still does not save causal necessitarianism. To do that, we would have to show that it was the causation itself that provided the necessity of E, given C. In §3.12 we will present an account in which causation is consistent with worldly necessity but does not entail it. In that case, somethjng else other than causation is providing that necessity.

3.9 Shouldn't we just include more'

Another objection that might occur is that the argument against neces­sity rests on under-specifying the true causes at work. As initially stated, there are just four causal factors, c[-c4 ' such that when some further

Shouldn't we just include more?

factor Ci occurs, the effect e is prevented. But isn't this a grOSi> oversim­plification? The vector model of chapter 2 represented complexit.y in the causal factors behind an effect, but perhaps it doesn't represent enough complexity. And, in that case, perhaps if we specified the factors that produce an effect in enough detail, including everything that was rele­vant and contributory, then we would see that this large set necessitated the effect. Instead of there being just four causes of the match lighting, wouldn't there be a great many, C[-Cn, including everything that is needed? Pcrhaps there are even very remote factors that we wouldn't ordinarily think of as relevant, such as the presence of gravitational attraction, but whieh would have interfered with the effect if they had not been present. If that is the case, even in the very slightest degree, then such things should have been included in the causal factors.

Extending the idea even further, perhaps we would have to include in a cause some negative causal powers as welL So among the powers that cause the match to light is that there is no sudden gust of wind just at the wrong time, that no black hole appears in the vicinity, and so on. Given that all these factors could prevent or interfere with the effect, then their exclusion mighl have to be considered f1mong the full causes of the effect Let us call this full set of circumstances, including the negative ones, ~. The true cause of e would be J~ and, it is alleged, :E really does necessitate the effect e. This proposal was sUPPOlted, in different words, by Mill:

TIle cause, then, philosophically speaking, is the sum total of the conditions positive and negative taken together; the whole of the contingencies of every description, which being realized, the consequent invariably follows. (Mill

1843: II1.V·3: 332)

Before him, Hobbes had the same idea:

an entire cause, is the [lggregate of all the accidents both of the ageots ... and of the patients. put together: which when they are supposed to be present, it cannot be understood but that the effect is produced at the same instant; and if any of them he wanting, it cannot he understood but that the effect is not produced. (Hobbes, 1655 ch. IX)

But there are a number of problems with the proposal. The first concerns the legitimacy of the strategy. Although the causes of an event may be numerous and complex, is it legitimate to include negative factors among them? Causes me usually regarded as lhings that exist. In an attempt to gain necessity, Mill has including negative features: that x, y,

66 Against Necessity

or z are not present. But can a fact that something is not the case be suitable to participate in causal transactions? According to the argument of this book, the causal factors are powers: the dispositions of particular things, events or facts. That something is not the case is not a thing, and thus has no power. It is no kind of existent at all, so how can it affect another thing? Considered purely metaphysically, as we win see III

chapter 6, absences cannot be causes. Even if we set aside such concerns, however, and pennit that z=

contains such negative factors, causal necessitarianism is still a long way from proved. Russell had some major concerns ahout the strategy of including more and more in the cause:

The principle 'same cause, same effect', which philosophers imagine to be vital to science, is therefore utterly otiose. As soon as the antecedents have been given sufficienily fully to enable the consequent to be calculated with some exactitude. the antecedents have become so complicated that it is very unlikely they will ever recur. (Russell 1913: 8··9)

The more we include in the cause, the less the probability of recurrence. Suppose we include everything that could possibly be of relevance -what is sometimes called the backwards light cone of our effect e - then the possibility of recurrence is practically niL In what way, then, would the :E-strategy have established causal necessitarianism? It would not even have established that there was a constant conjunction, except in a trivial single-case sense. In no useful sense would we have proved that if there was the same cause, there would be the same effect. That is merely a statement of causal necessitarianism, not an argument for it. Russell's point, then, shows that the :E-strategy, of including more, actually makes it less credible that causes necessitate their effects, rather than more credible. The cause can become so narrowed down that it becomes a singular, lltuepeatable instance, which is followed by an effect. That is of no use to someone who wants to show that the effect was necessitated by the cause.

There remains, however, even a further problem for the causal neces­sitarian. No matter how big :E becomes, it still cannot exclude the possibility of prevent.ion. There remains some possible Ci that could prevent e even if all that is included within ~ occurs. The Millian strategy thus misses the point because the size of the cause is not relevant to the effectiveness of the antecedent strengthening argument against necessitarianism. All that is needed is some possihle interferer, and no finite list - even if it includes negative factors - can exclude

Can we exclude all interj"erers?

every possible interferer. No matter how big an antecedent is, it can always be strengthened. The :E-strategy is thus of no usc in the aid of causal necessitarianism. But maybe the necessitarian just needs one extra claim to win t.heir case.

3.10 Can we exclude all interferers?

Having gone as far as :E - a huge set of circumstances, c [-en, that. produce e - perhaps we need just one additional premise to gain causal necessitarianism. The extra premise envisaged is one that automatically excludes all possible intelferers. Once in place, we would have some cause to which nothing possibly could be added. Wc will call this the )~*-strategy, where the star adds this extra catch-all qualification?

It lllay be helpful to note a parallel in argument.ation het ween the case for causal necessitarianism and the issue of truthmakers for nega­tive tmths. Some truthmaker theorists arc t.mthmaker neccssitarians (sec Armst.rong 200T 5-6), believing that. the way facts in the world make certain propositions true is by necessitating them. The table that sits in my room, for instance, necessitates the truth of the proposition <there is a table in my ro0111>. But what of negative truths like <there is not a hippopotamus in the room> (see Russell 19 [R: TR9)? What in the world necessitates that? One answer is parallel to our Millian I:-stratcgy. All the individual things in the room - the t.able, the chairs, the books, and so on - necessitate that there is no hippopotamus in the room. But they camlot do so. There could be all these things plus a hippopotamus. If A, E, C and D are consistent. with the presence of a hippopotamus, then they cannot necessitate that there is none (see Mumford 2007)·

Annstrong's solution to this problem, which saves truthmaker neces­sitarianism, is to admit totality facts into his ontology. Ifwe haveA, B, C and D, none of which are facts about the presence of hippos, and we add the totality fact that these are all the facts about the room, then we get the truth (necessitated) that there is not a hippo in the room. Russell (t918: 207) had already seen the need for such higher-order facts to account for universal generalizations. We could not get the truth of <everyone in the room is a philosopher> just from the individual facts that a is a philosopher. b is a philosopher and c is a philosopher. \Vc would also

2 This general type of strategy was pointed out to us by Matthew Tugby.

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68 Against Necessity

need the higher-order fact that a, band c are all the people in the room, and G, band c cannot on their own provide that. It has to be some further fact that a, hand c form a totality.

The parallel with the case of causation is that all the causal factors Cr-Cn cannot entail that they are all the factors. They cannot on their own entail that they are a totality_ For that reason, they carmat necessitate that there is no more, and thus they cannot exclude a possihle interferer Cj.

cI-en cannot, therefore, necessitate e, just as A-D could not necessitate that there is no hippopotamus in the room. But given that Annstrong has a strategy jn the case of truthrnakcr theory, to include a higher-order totality fact, could one adopt a parallel strategy to salvage causal necessitmianism? Doing so is the L:*-strategy.

There arc a number of different responses to the argument against necessity that could be classed as E*-strategies. Mill simply introduced a phrase that straightfOlwardly said that nothing could be added to the cause:

The negative conditions, however, of any phenomenon, a special enumeration of which would generally be very prolix, may be summed up under one head, namely, the absence of preventing or counteractive causes. (Mi11 r843: IIl.Y·3: 332)

But how does this do its job? It looks like a mere stipulation just to avoid the possibility of antecedent strengthening. Two more modern proposals are Lewis's closest possible worlds and the aforementioned totality facts.

We will largely defer discussion of Lewis's counterfactual depen­dence theory of causation until chapter 6, but it would be appropriate here to consider it as a variety of the L:*-strategy. Although we do not attribute this directly to the official Lewis position, it does prompt a line of thought that counts against the whole idea of antecedent strengthen­ing as a test of causal necessitarianism. The thought is that in consider­ing whether the same effect must always follow from the same cause, we are entitled only to consider the closest possible worlds to those in which our original causc succeeded. The idea would then be that in all the closest worlds to the one in which the match was struck and lit, if a match was struck there it would also light. Why? Being the doscst worlds to ours means that they have no gratuitous differences from ours. Hence there can be no sudden gusts of wjnd when the match is struck, if there was no such gust in the actual case where we succeeded in lighting it. There can be no miraculous appearance of a nearby black

Can we exclude all interferers? 69

hole, and so on. So if in all the closest worlds in which the match is struck, it lights, then that is, according to the Lewisian position, what it is to be necessary that the match lights when it is struck.

The totality strategy has already been introduced. In the case of causation, the idea would be that the full cause of e, the E*, is the full collection of causal factors together with the totality fact that there are no more additional causal factors than these. E* = (eI-·em plus the totality fact T), which then necessitates e, allegedly.

It is not claimed that the closest possible worlds view and the totality fact view exhaust all the E* positions. Others could be offered. Indeed, the most common E*-strategy is perhaps found in scientific experiments and theoretical models, where only certain causal factors are taken into consideration while others are shielded off or abstracted away from the model. Newton's mechanics is a system of theoretical abstractions, where any possible interferer to the situation is excluded from the model in order to isolate the contribution of a single factor. But this doesn't entail that some further factor could not be introduced to the model and interfere. On the contrary, the aim of the theoretical abstrac­tion is to be able to shield off all the causal factors that would nonnally be operating and interfering with the causal process that one wants to investigate in isolation.

The '-mechanism of the E*-strategy may vary, of exactly how the causes are limited and nothing may be added, but our response applies to any view that deploys such a limitation.

The first thing to say is that any defence of causal necessitarianism to be found in the L:*-strategy is assumed rather than demonstrated. Why should we concede that the effect occurs in all the closest possible worlds to ours in which the match is struck? Why should we agree that C I-en together with the totality fact necessitates e? And why agree with Mill that the consequent invariably follows? All these claims merely assume what we deny, namely, that a cause necessitates its effect. The match lights in all the closest worlds in which it is struck only if it is necessitated. What we need is some reason to think the match will light in all the closest worlds in which it is struck, in other words some reason to believe that the cause necessitates the effect.

We have offered a test of necessity in terms of antecedent strengthen­ing. There may be other tests of necessity. Lewis offers one in tenns of truth in all worlds but in chapter 6 we will explain why we do not use this test. We prefer the test of antecedent strengthening because it is a this-worldly correlate of the mono tonicity that necessity is supposed to

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support. We nevertheless accept the possibility of some better test of necessity being proposed. But until that point, we note that the )~*-strategy cannot pass the antecedent strengthening test. The very strategy is a refusal to take the test. The strategy is to exclude automati-cally anything else being added to 2:;. TIle strategy is thus onc that precludes an antecedent strengthening test and is thus the ve1Y reason for our scepticism about any claims of necessity resuHing from :B*.

But we can push this further, inspired by the thought that the refusal of an athlete to take a drugs test 1S tantamount to an admission of guilt. Why does this strategy avoid the possibility of antecedent strengthening? Might it be because the embattled causal necessitarian realizes that if something is added to 2:; it could indeed prevent e'? But then resort to the )~*-strategy looks like an admission of defeat. It is an acceptance that if more could be added, it could prevent the effect. But then what more is needed for an admission that the cause does not necessitate the effect?

There is thus an inherent tension in the whole approach. The same tension can be found in Mackie, for instance, when he says that the cause is 'sufficient in the circumstances' for the effect (1980: 38). 'Sufficient' says one thing that 'in the circumstances' takes away. The phrase is oxymoronic because if the cause were sufficient for the effect then whenever the cause occurred, the effect would occur, in any circumstances. If, on the other hand, the effect only followed in certain circumstances, then the cause was not sufficient. The 2:;*-strategy is then an attempt to immunize the cause from any such interfering circum­stances. Whatever this does, it cannot preserve the thesis of causal necessitarianism. Any genuine necessity has nothing to fear from such contingent circumstances, as the antecedent strengthening test shows.

3·II How can there he causal production without necessitation?

Some of the direct objections to the antecedent strengthening argument against necessity have been anticipated and answered. But there could be some wider concerns, not about the specific argument against neces­sity that has been offered but against the general position it establishes. It may be objected that such an anti-necessitarian position cmmot be correct because it does not sit with what we otherwise already know about causation.

How can there he causal production without necessitation? 71

The first such concern would be whether the removal of necessity from the account would leave a viable theory of causation. One thought might be that a cause could produce its effect only by necessitating it. The opponent might deny the distinction that has been drawn here between causal production and causal necessitation on the grounds that necessitation is the only way in which there could be causal production.

Such an objection should be challenged. In the first place, it may be possible to offer an account of causal production that docs not involve necessity, and this is what win be done below. But before that it is also worth noticing the conceptual poiIlt that the notion of causing B does not entail the necessitation of B. Russell noted, for instance, that 'A may be a cause of B even if there actually are cases where B does not follow A. Striking a match will be the cause of igniting, in spite of the fact that some matches are damp and rail to ignite' (Russell 1913: 13). Russell suggested instead that the cause merely made the dIed more probable. This is intended as a conceptual claim: what cause means is making nU)re probable, which is now known as the probability-raiser theory. Anscombe has a similar point, while arguing also for singularism:

If A comes from B, this does not imply that every A-like thing comes from some B-Iike thing or set-up or that every B-like thing or sct-up has an A-like thing coming from it; or that given B, A had to come from it, or that given A, there had to be B for it to come from. Any of these may be true, but if any is, that will be an additional fact, not comprised in A 's coming from B. (Anscombe 1971: 136)

The next sectioIl retums to the issue of how, if at all, causing is consistent with necessitating but for the moment we simply endorse the claim that A causing B does not entail A necessitating B. Russell's example seems to establish this whether we are talking of type causal claims or singular causal claims. In the type cases, it is cIear that we use cause in such a way that we can assert a general claim, for instance:

(I) Smoking causes canccr,

without endorsing the claim that:

(2) Smoking necessitates cancer.

On the contrary, most people will believe (I) and not believe (2). Not everyone who smokes gets cancer. The rejeclioll of (2) is consistent with the truth of (1). The same example shows that not only does causation not entail necessitation, it does not entail even a constant conjunction.

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Matters are a little more complicated with singular causal claims. Where a and b are particulars and it is true that a caused b, a test of whether a necessitated b cannot be whether all cases like a cause cases like b, for that is to return to a type causal claim. And it is also controversial for singularists about causation that any other events than a and b, even if they resemble a and b, are relevant to a's causing of b. What matters, then, is whether this particular event a necessitated this other particular event b, given that a caused h. Here, then, we have to consider whether b had to happen, given that a happened, and there are good reasons to think not if we re-apply the antecedent strengthening test. Given that a did indeed cause b, the antecedent strengthening test can only be deployed through consideration of a conditional whose antecedent is contrary to fact. If there had been something more as well as a, must b have followed? For reasons already developed, the claim is that it need not. The match could have been struck, and lit, but had there been a gust of wind just as it was struck, it might not have lit. On such conceptual grounds, therefore, we should pronounce that even in a singular causal case, where the causation succeeded, it did not require necessitation for its success. lIenee, we can endorse:

(3) The striking of this match caused it to light,

without endorsing the claim that:

(4) The striking of this match necessitated its lighting:.

The case for causal necessitation then looks prima facie dubious but there still needs to be consideration of whether necessity is the only account of causal production available. For now, thereforc, the question is set aside of how plausible causal necessitarianism would be as an account of causal production, and instead an alternative is offered: the threshold aCCOllnt.

The basics of the thrcshold account can already be inferred from the vector model of causation offered in chapter 2. The idea is that an effect occurs when there is enough for it. Given the complexity of causation -its polygenous nature - an effect is typically produced by many different factors working at once, some of them disposing towards the effect in question, and some of them disposing away. When CC-en do succeed in producing e, it is like the causes reaching a finishing line or a threshold for e to occur. We can illustrate this situation within the vectors modcl (figure 3.5), where the tlu·eshold for e is represented by a vertical dashed line marked 'T':

How can there be causal production wit/lOut necessitation? 7~

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The threshold is not some extra existent. It simply marks a point, the reaching of which we might identify as an effect. Some thresholds wiU be causally interesting places because they might mark a point at which some dramatic change occurs. When water is heated to lOOoe, for instance, it undergoes a transfOlmation and turns to steam. Other thresh­olds may be less dramatic: for instance, if we are interested simply in having the room temperature raised to 21 ""c. A threshold is thus some point along the F-G quality space that we call an effect when it is reached.

The notion of a threshold does not reintroduce causal sufficiency: the same arguments against causal necessitarianism still apply. A collection of powers may reach a threshold without it being a matter of necessity that they do. There is, thus, never a set of conditions, C1-Cm that necessitates e. CI-Cn may on some occasions he enough to produce e but on other occasions Lhey might not be: where Ci is also operating, for instance, as in figure 3.6.

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74 Against Necessity

A mistake ofthe necessitarirul is to consider only the positive circuIIl­stances in play - the ones that dispose towards e -- and to ignore the negative circumstances that dispose away from e, but. the threshold account. shows why they are just as important in the reaching of a threshold.

Necessitation is t.herefore an oversimphfication: an attempt to explain causation in terms of something it is not. The threshold model is rather crude. but nevertheless a closer model to the trut.h of causation. It is based on the vector addition analogy, which of course includes vector subtraction. We need to add up all the positive causal factors - those that dispose towards e - but not. forget to take away all the causal factors t.hat dispose way from e.

It might be wondered, at this stage, whether the vector model fails to depict causation at all or only shows the powers. Aftcr all, on OUr account, even if we have a resultant vector that meets a ce11ain thresh­old, given the lack of necessitation, we cannot guarantee that the threshold will actually be met.. R depicts only a resultant power, which still no more than disposes towards its effect. So the model does not show the effects at all, it might be t.hought: it shows only the causes. We have more to say on this later in the book but we can already explain why this is no serious objection. On our account, causation occurs whenever powers operate: even in the equilibrium case, we said, where no change occurs. Even jf we have a case where the resultant power disposes towards thc passing of the threshold, but ncvertheless fails to do so, some causation has still occurred: be it a change that is short of the threshold or no change at all. Still, the vector model does not show what actually happened: wherc on the quality space the powers actually took us. But it is just an appllcation of our thesis that causes never necessitate their effects. Where powers have run their course, however, and an actual effect has been produced, we can celtainly represent it. How we do so, howevcr, is as the starting point - a vertical Jjne - on a new vector model. Each effect win he the realization or instantiation of a new propelty, available for more causal interactions.

3.12 What if determinism is true?

A further objection to any account. that rejects causal necessitarianism is that it might seem to rule out determinism a priori, the truth of which is

What if determinism is true? 75

perhaps an a posteriori matter. 3 The philosopher would surely not want to judge from thell.' armchair on a matter that might be refuted empirically.

This line of crjticism can be answered, however. In it, detcrminism is taken automatically to mean causal determinism, which then looks to he the very same as causal necessitarianism. But need determinism be equat.ed with causal necessitarianism? Isn't the reason for equating these two theses simply an assumption that causes necessitate and are thus the means hy which detelminism does its work?

In response, therefore, it will be argued that, first, there are many possible ways in which determinism could be spelled out without the involvement of causation at all; second, that the dispositional account could be true when such fonns of detenninism are true (or when they are false) and, therefore, third, causal dispositionalism docs not judge a priori on the truth or falsehood of such determinism. This is how it should be because the point is granted that the question of whether or not det.erminism is true ;s at least in part an a posteriori matter. It is worth noting, therefore, that a philosophical theory should not commit to the truth of causal determinism a priori either. Indeed, following Anscombe, it is very tcmpting to say on the contrary that t.he mere concept of caUSe makes no such commitment.

Detenninism docs not mean automatically, then, causal determinism. The idea of causal detemlinism would be that causation is the vehicle by which detenninism docs its business. Once all the causes are in place, an effect is completely necessitated. But that is already an implausible way of capturing the general idea of detenninism. Causal determinism could dictate or necessitate only those events that are caused. It has nothing to say about, and cannot exclude the possibility of, uncaused events. And we have no other principle by which they are detennined. It is all very well for the caused events to be detennined, or necessitated by their causes, but we do not have a deterministic universe if there are also some events outside the grip of causation.

The core idea in determinism is fixity of the futurc by the past. This can be expressed in a number of ways, none of which involves the claim that causes necessitate their effects. There may be some necessi­tation involved, but causation docs not have to be its modus operandi.

3 Thanks to Steve Barker for raising this issue.

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One' causally neutral' statement of determinism would be that the total state of the world Plat time t T dictates that only one state tP.2 is possible at t2 • On the ~ame theme, we might also say that if two deterministic worlds coincide in their histories until time t, then they will coincide in their histories after t. The past can thus necessitate, fix, limit, dictate, or make the future without a commitment to causal necessitarianism. To add one more example in favour of such an interpretation, detenninism is consistent with a broadly Humean metaphysics in which there is no real causation at all, other than contingent constant conjunctions. A 'Humean determinist', if anyone wanted to hold such a metaphysic, need commit only to the claim that two Hume-worlds, that coincide in every detail at a time, must continue to coincide in every detail after that time (Montague 1962 outlines detenninism in this kind of way). Such descIiptions of detenninism capture its basic commitment far better than causal detenninism, and do so without any mention of causation.

The disposiLionalist view of causation can accommodate these ideas. It is compatible mth the idea that worlds with duplicate histories until time t will continue to cojncide after t. Most importantly, the argument against causal necessitarianism docs not rest, as Anscombe's argument does, on indeterministic causation being the case. Hence, it is consistent with the antecedent strengthening argument against necessity that if two tokens of the same dispositions were placed in identical contexts -identical in eyery causally relevant respect for that disposition - they would produce identical manifestations. The argument against necessity required only that if something had been different, the manifestation need not have occurred. Most determinists would accept that. But nor should we commit a priori to the truth of detenninism. Again, it is consistent with causal dispositionalism that two tokens of the same disposition could produce different manifestations in identical contexts, if there were irreducibly indetelministic dispositions for instance. One such token might manifest, and the othcr not. The example of an irreducibly indetenninistic disposition that is taken most seriously is radioactive decay, and the idea would be that, in exactly the same contexts, one particle might manifest its disposition to decay after an interval of time while another does not. Again, therefore, the account. is compatible with either determinism or indeterminism. The issue of detenninism and indetenninism is thus orthogonal to the position of causal dispositionalism.

Probabilistic causation and multi-directional powers 77

3.13 Probabilistic causation and multi-directional powers

Having broached the issue of indct.enninistic disposit.ions, this seems an appropriate point at which to consider probabilistic causation. It should again be reiterated that the argument against necessity does not rest on there being probabilistic causation. Ours is an ant.ecedent strengthening argument against necessity. But we also want a position that is consis­tent with irreducibly probabilist.ic causation, in case there is such a thing in the world.

Probabilistic causation is not. quite the same thing as indet.erministic causation, though there are somc similar issues involved, but it is a constrained sub-category of it. The pure indeterministic case would be akin to randomness, where either of the available effects can be caused but nothing det.ennines which. Probabilistic causation, however, has some additional probabilistic constraints, there being a fact of a particu­lar chance, greater than zero but less than one, of an effect occurring. It is arguable that many cases of causation involve a less than one chance of the effect occurring, so some take causation to he an essentially probabilistic notion (see, for jnstance, Suppes 1970 and Mellor T995). Rather than necessitating its effect, a cause is taken as a probability­raiser for it. Mackie (1980) argues that this move is mistaken:

Saying that A is likely to cause B docs not pul likelihood into thc causing itself ... Thus it may often happcn that the only fully explicit causal generaliza­tion that a speaker is prcpared to make is a probabilistic one, and yet he may still be taking it that the causal relation in any particular casc that fulfils it is one of necessity, and perhaps also sufficiency,. in the circumstances. To go straight fronl this evidence to a probabilistic theory is a mistakc, and one that results from holding on to the Humean doctrine that. causation is essentially general while admitting that causal claims need not involve universal generaliz.ations. (Mackie ly80: 50)

We agree with Mackie that t.he c[[ect having a less than one chance of occurring given its cause is not in itself a reason to assume t.hat all causation is probabilistic. Rather, we lake all causation to be subject to interference and prevention, which means that causal product.ion is never guaranteed. Still, we want to accommodate the idea of prob­abilistic causation, even though we are not convinced it is the case for all causes. Causal dispositionalism not only can do this, but the probabilist.ic case gives a tine corroboration of anti-necessitarianism.

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A probabilistic disposition is one that tends towards a certain distribu­tion of events only; it never necessitates that distribution.

Two of the simplest probabilistic cases known are the toss of a coin and the roll of a dice. Some people think these are not genuine cases of probabilistic causation because the probability is merely epistemic. If we know all the initial conditions, it is argued, then at the moment the dice leaves the hand, it is determined how it will land. This view sits particu­larly well with causal necessitarianism, as the cause would necessitate a particular effect even if we arc not in an epistemic position to predict the outcome. Even if the probability is merely epistemic rather than ontolog­ical, however, it still provides a probabilistic model. With a com, we have two possible outcomes: heads and tails. In this respect, the coin resembles the case of radioactive decay, which some consider to be a case of a genuine, irreducibly probabilistic disposition and not merely epistcmic. Let us assume, for ease of presentation, thcrefore, that we have a genu­inely probabilit>tic coin. There is an equal chance of landing heads or tails.

We can represent the coin's probabilistic power in the vector model. To begin with, we consider a single coin before it is tossed. What does its probabilistk power consist in and how should that be understood within the model? With the fair coin, there is a disposition towards heads and tails in equal measure. There is a reason, however, to think of these not as two distinct powers. Given that there are two possible outcomes, wcre it to be tossed, then the chance of one outcome limits the chance of the other. If the chance of heads is 50 pcr cent. then the chance of tails has to be 50 per ccnt. The two chances are incxtricably tied with each other and a plausible way of understanding why that should be so is to see that what we really have is a single disposition: a disjunctive­probabilistic one. This is a disposition towards one or other outcome, there being a certain probability of each, with those total probabilities adding up to one. In the vector model, therefore, this is represented as a single, double-headed vector, showing that there is an cqual disposing towards each direction (figure 3.7). Given that the combined chances of each outcome must be one, then a loaded coin would he shown by a vector of the same length, hut moved more towards heads, for instance, so that we can depict a 70 per cent chance of heads and only 30 per cent chance of tails. We can, therefore, model probabilistic cases where there are two possible outcomes but they are not equally likely.

It is also possible to model probabilistic cases vectorially where there are more than two possible outcomes. As an example, let us consider the disposition of a fair dice to land with equal chance with one of six sides

Probabilistic causation and multi-directional puwers 79

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face up. For this, we move to a multi-dimensional quality space. The outlines of the cube in figure 3.8 represent the thresholds for each of the six faces landing on top, and each vector has one sixth of a chance of reaching its threshold.

Again, there can be cases where the chances of each outcome are not equal, such <'IS if the dice is loaded. If that were the case, one head of this six-headed vector would have to be extended. There are again reasons to think of this as a single power towards six different outcomes, the probabilities of which again must add up to one, so if one vector-head is extended, others will have to retract.

Although this is a very clear way of understanding probabilistic dispositions, it does raise an apparent problem for the vector model. In

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§2.6, the theoretical case was considered of a single 'lonely' power and the question was raised of whether it would do its work, unaided by any stimulus. It was answered that, in this largely theoretical case, a power could indeed manifest, depending on the power. The opposite may only seem to be the case because in real-world situations, the power is often being held back by countervailing powers. In figures 3.7 and 3.8, similar single dispositions have been plotted, even though they are multi-directional. Again, it suggests that if nothing else was acting, these dispositions would issue in events - movements within their quality spaces - unaided, and this might seem counterintuitive. In the case of the fair coin and fair dice, it looks like the equal disposing in each direction would cancel out, leaving an equilibrium situation in which nothing happens. But what about the loaded dice and coin? Why don't they flip on to their favoured side on their own?

The answer to this puzzle is similar to that given in §2.6. In all the real~world situations we encounter, this probabilistic disposition never occurs alone. Gravity, for instance, holds the dice down on a flat surface so even a loaded dice does not move without some further push. But. if there were some solitary probabilistic power loaded in one direction, with no other powers at work, then again the response would be to say that it could manifest itself. It. is doubtful this could ever occur, however. Both the dice and coin need gravitational powers in order to land. A coin toss in zero gravity would be point.less and result~less.

Prevention and interference remain issues in the probabilistic case. Causal dispositional ism allows that any process such as a coin toss or dice roll could be interfered with. Someone might catch the tossed coin, for instance, and it neither lands heads nor lands tails. TI1e combined chances of this probabilistic disposition add up to one, but it is still nothing more than a disposition towards one of the two outcomes and, like all dispositions, it typically only contributes to an outcome.

The primary factor in understanding irreducibly probabilistic causes is that there cannot be anything more than a tendency towards a certain distribution of events. This tendency will be consistent with any out~ come over a finite series of trials but some outcomes will be vastly more probable than others. The dispositional accounts sits nicely with this, first because it permits a propensity account of single case trials, and second because it makes some distributions more likely but all of them possible. Hence, the disposltional account allows that in a singlc~casc triaL a coin heavily loaded, 90 per cent towards heads, could neverthe~ less land tails. Although there was only a TO per cent propensity towards

The new necessitarianism 81

tails, tails might just happen to win out. This single coin given a single toss disposes towards some outcomes more than others but it never more than djsposes. The idea of a genuine probabilistic case is that the outcome is never necessitated (quite apart from any antecedent strength­ening considerations). And if we continue to toss that coin, say over 100

trials, the most likely outcome is 90 heads and 10 tails, but it is only marginally more likely than 89 heads and I I tails. Even 100 tails cannot be ruled out., but it is very unlikely. There is no significant disposition towards that distribution.

Moving, then, from considering the powers of an individual coin to probabilistic distributions over whole sequences of trials, such as 100

coin tosses, we may prefer to offer different vector representations. Even a fair coin has some disposition towards 100 consecutive heads when tossed, but the vector representing it would be miniscule. To show it, we would need a threshold that stood for 100 consecutive heads and a vector directed towards it, but it would be almost too small to see, given that the chance would be a half to the power 100. The chance of 2 I consecutive heads is already as low as 1 in 2,097,152.

In all such cascs, thc manifestation of an irreducible probabilistic disposition over a series of trials should be understood as a distribution of events between the relevant options, be it heads or tails, faces of a die, radioactive decay or not. The calculus of probability tells us that this distribution tends to show itself as the number of trials tends towards infinity. Even in the case of a single trial, it tends to show itself in so far as the outcome with greater probability is more likely to manifest itself in the first tlial, even where it is only marginally more likely. Disposi~ tionalism has a great attraction in this case. Even those who are neces­sitaTians about 'regular' causation can see a problem in applying it to probabilistic scenarios. That certain outcomes are no more than dis~ posed towards seems the common~sense view. Few would want to say that a particular distribution was necessitated, for that would seem not to be a genuine case of probabilistic causation at all, but rather a case of (pre- )determination.

3.14 The new necessitarianism

Necessitarianism generally has undergone a recent revival. This has primarily derived from a notion of essence as outlined by Kripke (1980) and. some say, Putnam (1975). But there is a brand of essentialism for

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which causation has come into view as a possible candidate for necessity. As has already been suggested, Burne's opposition to necessary connec­tions in nature has attracted many of his opponents towards a defence of such necessity. Essentialism is now a leading fann of opposition to Hume. The new essentialists, by which is meant, among others, Harre and Madden (1975), Shoemaker (1980), Ellis (2001, 2002), and Bird (2007), aim to explain ahostofmetaphysicaI problems such as properties, laws of nature, causation and the problem of induction. If there really were necessity to be found in causation, for instance. then the problem of induction would seem to be dissolved. The future would indeed proceed like the past if it were for all time necessitated what caused what.

While there is plenty to admire in the new essentialism, however. an argument for causal necessitarianism is not one of its pay-offs. There is no ground for a thesis that causal production is causal necessitation even though the new essentialists, in their more relaxed moments, have spoken as if there was. What this seems to be, however, is some sort of elision from properties having a causal essence to causes necessitat­ing their effects.

Shoemaker (1980), for instance, has a thesis about properties having a causal essence. Properties, for him, are bundles of powers. In that sense, the essences of propelties ale what they are causally for. This makes the causal role of a property necessary to it and is an attractive view (see Mumford 2008), Saying that the causal features of properties are neces­sary to them, because they are identical with them, is one thing. But it would be wrong to go from this to causation as itself necessitating, so that, for instance, a disposition D necessarily manifests M under stimu­lus S, Shoemaker misleadingly appears to make precisely this jump. He starts with: 'insofar as causal laws can be construed as describing the causal features of properties, they are necessary truths' (Shoemaker 1998: 61) and proceeds to the view that 'causal laws arc metaphysically necessary, and that causal necessity is metaphysical necessity' (ibid.: 66). But 'causal necessity' is not demonstrated here. Saying that the causal role of a property is necessary to it is not at all to say that causes necessitate their effects. Not all fragile things break when struck and not all soluble things dissolve in water. This should be especially evident to one who holds to a dispositional ontology. The causal role is itself dispositional - it is provided by the property's causal powers - so it is one involving the disposing towards a manifestation, not the necessita­tion of one.

The new necessitarianism

Such an elision is a tendency of the essentialist. In the case of Ellis, and Harre and Madden, a key idea is that to be a member of a cCltain natural kind K is to have a certain set of causal powers D I-D no This makes a set of causal powers necessary for kind membership, so that if an x is a member of the kind K, then x has the dispositions D I-Dn. Being hydrogen or oxygen, for instance, of necessity involves having a celtam valency, which effectively is a combining power (Harre and Madden 1975: 125). But Harre and Madden move from that to saying 'it is clearly necessary that a substance having this constitution behave in this way' (ibid.: 126), This appears to say that x - being a member of kind K and thus having disposition D - necessarily will display it under stimulus S. But this does not follow. What is necessary is that something with this constitution is disposed to behave a certain way, but how it actually behaves is a different matter. And causation is what occurs when things actually behave; it is not about the dispositions necessary for membership of a certain kind, as will be further argued in chapter 7· Commitment to some kind of causal necessity is clearly what Harre and Madden want, however, as the following shows:

Considered as causes amI effects they are not indepcndent for they are relatcd through the generative mechanisms upon which they operatc and through which they are produced.

The rela1ionship betwecn co-existing propelties or successive events and states is naturally necessary when they are understood by scientists to be related in fact by generative mechanisms, whose structure and components constitute the essential natures of the pennanent things and materials in the world. (r975: 130)

But thcre is no argument for causal necessity here. The generative mechanisms are the combined causal powers of the natural kinds, which they have of necessity in virtue of being members of those kinds. But that does not entail that those generative mechanisms neces­sitate their effects, even if they bring to the world something more than Humean constant conjunctions. Bane and Madden offer no argument for it being specifically causal necessity that is involved, other than saying that such mechanisms are 'reducing the field of the possible' (1975: 130). Causal powers would indeed involve some such restriction of the merely possible, as will be argued in chapter 8, but there is still much more argument to be had that specifically there is necessity irNolved.

In Ellis's brand of essentialism, we similarly find a tentative sugges­tion that causal processes themselves involve necessity, while the

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essentialist position is primarily a thesis concerning only property or kind membership, like whales being mammals or humans being mortaL For instance, we find:

Causa] relations are relations between events and causal processes. If an event of a natural kind that would activate a given causal power in a certain way ocems, an event of a natural kind which would then be an appropriate display of that power must occur (even though the effect may sometimes be masked by other effects). (Ellis 2001: 7)

But note how we find a parenthetical qualification thal acknowledges the possibility of masking. Saying that a certain effect must occur, but that in some circumstances it might not, takes away with one hand immedi­ately what it has just offered with the other. Necessity is ventured, and then immediately retracted. Calling such a thing necessity, that in some circumstances need not occur, is necessity in name only. But perhaps this tendency shows just how orthodox and engrained is the commitment to causal necessitarianism. Anti-Humeans especially find it attractive as a way of rejecting the adequacy of constant conjunction accounts. But there are better ways of rehlting Hume.

3.15 Causal necessitarianism jettisoned

This long chapter has laid the ground for some of the morc positive arguments to follow. The key claim is that there is an unchallenged orthodoxy in many accounts of causation that does not withstand criti­cism. The idea that a cauSe makes its effect happen is a perfectly valid one. But if this is taken further, to the idea that when there is a cause, its effect must happen, then a mistake has already set in. Such an idea is all the morc tempting for those who aim to reject Hume.

Any necessit.y worthy of the name should be robust under antecedent strengthening. This means that if A causally necessitates B, it would have to produce B under any circumstances. This is implausible for the case of causation. Some circumstances are always possible that could prevent, or interfere with, the effect. A number of objections to this view were anticipated and answered. One important point to emerge was the idea of the 2:*-strategy. The lingering temptation in the idea of causal necessitation plausibly comes from something like a E*-strategy: the thought that if only all interfering factors could be isolated and shielded off, then we would have exposed causal necessity. As argued above,

Causal necessitarianism jettisoned

however, this cannot possibly do the job hoped of it. Such shielding off only evades the test of necessity, and thus this strategy can never more than assume that a cause necessitates its effect. But such an assumption then starts to look highly implausible. Wby docs this approach seck to avoid the very tcs11hat could convince us of the necessity of causation? It seems there is only one conclusion we should draw.

In chapter 8, we return to the issue of the causal modality and argue that dispositionality brings with it a sui generis modality that is less than necessity but more than pure contingency. This will be the key modality for the dispositionalist.

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4.I The composition of causes

Various different causal powers can come together to produce some­thing jointly that they could not have produced alone. But how do they do so? The model proposed in chapter 2 showed how we distinguish between component and resultant powers, with the latter being some­how the product of the fonner. But how does that work? The suggestion there was that we make use of the notion of vector addition: the different powers would simply add up, or subtract, such that the resultant power would be merely the sum of all the component powers. But that will not quite do - at least not for all cases or causation - as we will be arguing in this chapter. We will not only be developing a problem for the vector model, however. We will also be offering a solution in which it still makes sense to model powers in a vector-like way. What we need, however, is a better account of how powers compose. Specifically, it will be argued, we need to accept compositional pluralism: that there is a plurality of ways in which powers compose to produce an effccL

Why is there a need for compositional pluralism? It seems that there will be many cases of causation in which the component powers, when they do their work, do not simply add but come together in a more comphcated way and in some cases seem to interact and even affect each other's contribution. Here are some simp1e cases that we will need to explain. A chocolate bar disposes towards pleasure when ingested. This could be represented as a component power in our vector model. But wouldn't that suggest that if you eat ten chocolate bars, you should have ten times the pleasure? Experience tells us that this isn't right if you eat them all one after another. The second chocolate bar doesn't give you quite as much pleasure as the first, and the third even less. The fourth might produce no pleasure at all and the fifth displeases you when you feel nauseous. There can be cases, therefore, where something disposes towards pleasure but ten times that thing does not have ten times that effect; rather it disposes in the opposite direction. There will

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be many examples of this. Water disposes towards plant life, for instance, bUl only in the right quantity. Plants can be overwatcrcd and die. Wealth can cause some happiness. But sociologists and psycholo­gists know that it does so only up to acquisition of a certain level of comfort. Extra money beyond that has relatively little effect and there is even evidence that excessive wealth disposes away from happiness.

Some other types of case will be offered later but, just from these few examples, we can see that there is prima facie reason to doubt that the mode of composition of causes is exclusively additive (and subtractive). The cases call into question what we may name the principle oj additive composition. Such a principle would state that:

Where

DT is the power to MI D2 is the power to M2

Then

D I and D2 working together are (nothing more nor less than) the power to

Mr + M2.

In calling such a principle into question we are not, of course, casting doubt on the composition of causes in general. We do not doubt the thesis of polygeny, for instance, which simply states that effects are typically the result of many causes working together. The only aspect questioned by the case is how that result is achieved and how powers work together. Addition looks too rcstrictive to account for some cases of composition and for that reason we will be making a move towards plural ism. The mode of composition can vary for different combinations of powers. We will have to allow that, for some cases, causes compose according to non-linear functions; contrasting with addit.ion, which is a simple linear fUllction.

Some broader issues come from this seemingly small and technical detail. It could look simply as if a minor amendment is being made to the vector model to account for recalcitrant cases of causation that don't fit the standard model. But the amendment reveals some rather major issues. If powers can combine in surprising, non-linear, non-additive ways, then it suggests that some causal interactions will have to be understood holistically. We will not. be able to take such combined powers as merely mereological sums of their componcnt powers, which means t.hat they cannot be reduced to the isolated workings of the individual powers involved. The powers involved often interact and

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alter in their nature as a result of those interactions. It is not the case that they are always able to do what they would have done had they been acting alone or in a different context. This suggests some variety of emergentism because two powers could produce a novel phenomenon that can be both surptising (weak emergence) but also genuinely pro­ductive of something new in the world (strong emergence). Emergent­ism has a controversial place in the history of philosophy, and there is still a struggle to understand how it could be a real feature of the world, but here there looks to be a case where an appeal to emergence might be non-trivial and useful. To see that, we need to go back to the standard vector model and look at the types of case that create its problems.

4.2 Alleged problem cases for the vector model

The additive model would be the simplest way in which causes com­pose. The causes could just be piled one on top of another, to speak figuratively, accumulating until there was enough for a celtain kind of effect Of until a significant threshold had been met. C01llpositiol1 could reduce to simple mereology. Accumulating the requisite powers for an effect would then be like piling stones together untillhe pile had reached a desired height. Nothing more than the addition of discrete elements would be needed and those elements would remain unaltered by the fact that they hact been added together with others. Whether some effect occurred would simply be a matter of whether there was enough to add up to it, minus any factors that were disposing away. If we are to reject the generality of this simple principle of additive composition, we had better have some pretty good reasons and so far we have offered only a couplc of examples. But there are more and they are not always of the same kind.

The examples mentioned so far are what can be called overdose cases. Something can dispose towards F but only if it is in the right qwmtity or proportion. If the appropriate quantity is exceeded, there may no longer be a disposition towards F and there might be a disposi­tion away from it. We cannot always, therefore, just add more of the same to an existing power to get more of the effect. That would be the same kind of fallacy under which children are operating when they fatally overfeed their goldfish or new plant owners who overwateT. When people receive money and it makes them happy, it is quite easy for them to think that receiving that same amount again would produce

Alleged problem cases for the vector nwdel

the same additional amount of happiness, but we know that this is not the case. It looks, therefore, that there is some more explaining to do for the vector model. The model seems to be committed to the view that if we have twice the total quantity of component powers (or, in the model, vectors of twice the length) we should have twice the resultant power (or a resultant vector of twice the length). The overdose cases alone are enough to show that this need not al ways be the case.

There are also different ways in which something can be an overdose. One is simply that we get more things with the same power, as in the case of eating too many chocolate bars. Another is that we keep the quantity the same but prolong the exposure, in other words, let the power do its work for longer. Ice, for example, is an anti-inflammatory, which is why it is applied to sports injuries as soon as possible after an injury has been sustained. But it should only he applied for a period of five minutes. During that time, the blood vessels in the tissue contract so that any swelling in minimized. But if the icc is left on for longer than that, it can increase the swelling. The body reacts to the cold through a homeo­static process whereby blood is directed towards the cold area. Hunter's reaction is when the blood vessels dilate, as a result of this, leading to inflammation. lee thus has both an anti-inflammatory power, when applied for five minutes, and an inHammatory power, when applied for ten minutes, and this can also be considered a type of overdose case. J

It should be clear from overdose cases that simple addition is not the mode of composition because the resultant power fails to be doubled when we double the extent of the component powers. Hence, these cases count as non-linear composition. A linear system is one in which the extent of the output is directly proportional to the extent of the input. such that if we plotted the function on a graph, it would give us a straight line. With addition as the mode of composition, we would get a straight line because the output would always increase proportionally to the input. If we look at wealth as a cause of happiness, however, it is plausible that the relationship is non-linear. Very little money seems to cause no happiness at all. But, at a certain level, there does seem to be some causal connection (in our consumer society) where the more money you have, the happier you can be. But then this tops out and can eventually decline or become negative. A function that could descrihe this relation, which we are not denying is a causal connection,

1 Thanks to Roger Kerry for this e.xilIHple.

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90 Reductionism, Holism and Emergence

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FIGURE 4. T: A non-linear function relating wealth and happiness

is a non-linear one as depicted in figure 4.1. The extent of the output (the resultant) is not propoliional to the extent of the inputs (the components) .

A second kind of problem for the principle of additive composition is what we might call the escalatory case. With an overdose case, succes­sive increased quantities have a diminishing and eventually no effect. An escalatory effect is one where a very small power can have greater effects further along a causal process. A very small cause, such as the flapping of a butterfly's wings, can have a major effect elsewhere, such as altering the path of a tornado, via a chain of other effects on the atmosphere. Such a case, to be genuinely escalatory, would be one where the resultant power was greater than the sum of the component powers. The butterfly flapping its wings produces a very small immedi­ate effect, but through a series of intermediate effects and other input.s and their interactions, it eventually is responsible for something quite large. Would it be possible to offer a linear account of this apparent non­linear response? We will offer one such linear solution but do not pretend it is a definitive answer. The so-called butterfly effect is usually given as an example of chaotic behaviour, and chaotic phenomena, about which we will say more later, are notoriously non-linear. Chaos does not mean the same as randomness, however, as there can be deterministic but chaotic phenomena. But it does mean that t.he output of a chaotic system is not directly proportional to its inputs.

A third kind of problem for additive composition is what can be called the antipathetic case (figure 4.2). There are some well-understood

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Alleged prohlem cases for the vector model 91

F G

R

FIGURE 4.2: An antipathetic case

examples of this nature that arc to be found in medicine. The general structure of an antipathetic case would be where there are two individual powers that disposed towards F but which, when combined together, jointly dispose away from F. Two medicines may individually dispose towards health but not if taken in combination. In most cases, medicines that dispose towards the same effect will do so - they will work in sympathy - when taken together. But there arc some cases where the opposite happens, which is why a doctor should always check what other medicines their patient is taking before prescribing new drugs. Clonidine and beta-blockers both individually lower blood pressure, so can be prescribed as antihypertensives. But taken in combination, there is strong evidence that they raise blood pressure: for example, in six out of ten subjects in one study (Saarimaa et. a1. I976) where the beta­blocker was sotaloL Another study of the beta-blocker propranolol found that it also could raise blood pressure in combination with cJoni­dine (Warren et aL 1979)2

Hypertension is not the only such example in medicine. Buprenor­phine and morphine are both effective pain-relievers but, when taken together, they might have no effect. If Buprenorphine is given to an opium addict, it will not work but, rather, cause a withdrawal reaction by hlocking the opioid receptor. And if given in combination with mor­phine, which in this situation could otherwise have worked, it still fails because the buprenorphine displaces the morphine from the receptor. These sorts of effects are relatively rare as in most cases there would be synergy effects between t.wo drugs that dispose in the same direction. There does nevertheless seem to be sigllitlcant empirical evidence that

2 These examples were suggested to us by Michael Randall.

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there are at least some cases in which two component powers can dispose in one direction while the resultant they produce disposes in the opposite direction.

The overdose, escalatory and antipathetic cases all pose problems for the standard vector model presented in chapter 2. At the VCIY least, they challenge the principle of additive composition that was used in the presentation of the model. A response is needed, or perhaps several responses.

4.3 Some possible replies

We do not think that a single response can be given to every apparent violation of the additive principle. Indeed, some putative cases might not violate the principle at all and might, despite appearances, bc explicable within the standard vector model as already described. Other cases raise more serious concerns, however, and we wiJl not try to hide from them. They will requiTe us to make an amendment to the theory. This amendment will be relatively minor in terms of the theoret­ical cost, we will argue, though it will open the way for some version of emergence. lndeed, emergence is an issue that will come to the fore and all the responses we give can be classified as either strongly or weakly emergentisL The distinction we make between weak and strong emer­gence can be the one employed by Chalmers:

We can say that a high-level phenomenon is weakly emergent with respect to a low-level domain when the high-level phenomenon arises from the low-level domain, but truths concerning that phenomenon are unexpected given the prin­ciples governing the low-level domain. (Chalmers 2006: 244)

On the other hand:

a high-level phenomenon is strongly emergent with respect to a low-level domain when the high-level phenomenon arises (in some sense) from the 10w­level domain, but truths concerning the phenomenon arc not deducible even in principle from the truths of the low-level domain. (Ibid.)

Chalmers does, however, couch the latter in unnecessarily epistemic terms. The distinction that really counts is between higher-level phenomena that arise merely or only surprisingly and those that involve gcnuinely novel phenomena. Par that reason, we will set the discussion of emergence latcr against the background provided by Kim's (2006)

Some possible replies 93

search for real emergence. The responses provided to the problem cases, however, may be thought of as cases of merely surprising phenomena (weak emergence) or as genuinely (strongly) emergent.

a. In and out of equilibria

A first possible reply is to explain the problem cases within the standard vector model. At least some overdose cases could be explained in this way without any amendment to the model. To see how, we need to apply the notion of an equilibrium, which was invoked when we comidcrcd cases of causation in which nothing was conspicuously happening. These were cases of causation because powers were at work but they were counterbalancing So that the situation was taken towards neither F nor G. Our overdose cases were those where some degree of a certain power seemed useful, in that it disposed towards a healthy outcome, but where a greater degree - more of the same power - disposed away from that healthy outcome. In the case of overwatered plants, however, we can instead think of the 'correct' quantity of water disposing towards plant health but only in the sense that it helps to maintain equilibrium. It contributes towards the maintenance of a healthy balance between death by dehydration and death by drowning. The surrounding atmosphere sucks moisture from the plant, its root and soil and this has to be replenished because the plant needs water so as not to dehydrate. But the roots also need air and if they stand in watcr the plant drowns. What we have, therefore, is a balance between the right quantities of water and air in the soil that surrounds the roots. This maintains the plant's life by upholding the equilibrium (figure 4,3), If we add too much water, that

Death by drowning

Death by dehydration

FTGURE 4.3: Plant moisture equilibrium

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equilibrium is lost. There will be too much that disposes towards death by drowning, which indeed can then be caused.

Similar explanations can be given for the other overdose examples. Chocolate contains sugar and flavour that most people like. But to experience such pleasure, the body must be in a position to receive it. OUf sense receptors must have a balance between various different nutrients. Too much chocolate too quickly can throw us out of that cquiliblium. A sudden rise in blood-sugar level nauseates us (as does a sudden fall). Hannone insulin in our bodies breaks down the sugar but only at a certain ralc. If we consume sugary food at a faster rate than our body breaks it down, which is not dilTlcult to do, then we get the rise in blood sLigar. Too much sligar over a sustained period can also have serious health risks as the body increases insulin production, which can then cause a number of complications. Outlined in such tenns, the chocolate-bar case looks perfectly well suited for an explanation in tem1S of addition and subtraction. The equilibrium is maintained where the total addition of sugar inputs is roughly matched over the medium tenn by sugar subtractions through the work of insulin. If either of those factors changes, the body faces problems.

The first kind of answer 1S clearly no more than a weakly emergentist one, therefore. What looks to be a SUIIJIising phenomenon can be given an explanation that invokes no more than the powers that are present and their sum. Given a detailed understanding of the processes involved, we might be able to explain a number of cases in this way. Hunter's reaction, for cxan1ple, might be about the preservation of certain biological homeostatic processes. Ice may restore equilibrium but its continued application could remove it.

b. Ihreshold el(errs and tipping cases

The second kind of answer is also no more than weakly emergentist. This would be to explain the apparent violations of additive composition simply by pointing out that the prob1cm cases in question are more complex than typically presented. A standard vector model, or even a number of such models, that represented the full richness of the situation would indeed explain resultant powers through addition alone. For this, we need to apply the notion of a threshold effect from §3.1 1.

An escalatory case is one in which the output seems to be more than the input. The flapping of a butterfly's wings seelllS to be a very small cause, but the tornado it produces or affects seems to be a very big

Some possible replies 95

effect. How might we get this through pure addition of powers? It is possible to uphold additive composition if we explain the case in a certain way, namely, that the butterfly's power is just one of many other powers that are also operating and the big effect is produced by all of them jointly such that the effect is after all no bigger than the total of the causes. The butterfly's contribution is then added to an overall pool of powers but it could be the contribution that, although small, tips the balance in favour of the tornado behaving in a certain way. The butterfly flapping its wings might be enough for some localized atmospheric disturbance to occur: a small breeze perhaps. The breeze adds a relatively small power but the situation may be so close to a threshold that this small addition becomes a tipping poim (see Moore 2009: 469) and a wind is produced. And the same story can be told about how this wind contributes to the production of a gale. This situation was also close to the threshold for a gale to occur and the addition of the wind tips the situation over the threshold. In turn, the gale is enough for the production of a stann, and so on, until we reach the point for a tornado. The case can be likened to one in which a number of rocks each sit precariously on the side of a mountain. A tiny stone may stmt to roll down, hitting and passing on its momentum to two slightly bigger stones. If each of these stones hit two even bigger stones, and this pattern continues, the situation could escalate into a rock avalanchc.

The appearance of escalation could thus occur because we have a series of tipping points lined up and a tiny cause could be the factor that tips the first of them, which tips the second, and so on. It is analogous to the way that adding 0.000001 tips 0.999999 over to l. Each decimal place is already as big as it can be and thus adding a very small number at the start tips them all over their thresholds in turn. The notion of a tipping point Of threshold might explain apparent escalation because all the other powers are at work at every stage and they are contributing to the final effect in a far higher degree than the extra small power that gets added. The final effect depended on the first tiny cause but, if we induded every causal factof, there need not have been any ontologically serious escalation that occurred.

If we return to the simple example of eating too many chocolate bars, the situation in which someone tircd and hungry with low blood-sugar level cats a chocolate bar is very different from one in which someone who is already bloated with fat and sugar eats one. Doesn't that show that wc should model these cases as two entirely different causal

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situations? We could have on,e model fOT consumption of the first chocolate bar by a hungry person, where the chocolate's various ingre­dients restore some deficiencies and fill the person up. But when they start on the second chocolate bar, they are in a different position from when they ate the first. And by the time they get to the fifth, they start feeling nauseous and are experiencing a surge in blood sugar. Each chocolate bar will have the same causal powers as the last, but they are being introduced into different overall causal situations and will have different impact on the body. When the final bar is consumed, the threshold for sickness is within reach so that the final bar could be the one that pushes the case over that threshold. The non-lineru-ity of increased pleasure to increased chocolate consumption 1S therefore ex­plained within the standard additive model, simply by noting the com­plexity and changing nature of the case.

The previous example shows us something about how we should understand vector models. These models are designed only to represent a single causal situation, with all the powers at work in that situation. If there is a rapidly changing process under way, then the model may only represent the powers at work at an instant (though see Lite discussiull uf moments in §2.3). In other cases, the powers at work may not change and may result in no changc, thus the causal situation could be one that endures over times, as an equilibrium situation might. Where we need to consider a new situation is when some power begins or ceases to operate or we have a new starting point. In the overdose case, each chocolate bar (indeed, each mouthful) changes the sit.uation, so we ought then to model the whole process with a succession of vector diagrams. What then looks to be a surprising, non-linear system, may tUTIl out to be perfectly explicable in the standard model and any such overdose case would thus count only as weakly emergent.

c. Compositional pluralism

There are, nevertheless, some more strongly emergent causal interac­tions that have to be granted. Despite the deflationary attempts to explain some cases away as only weakly emergent, it is hard to deny the reality of at lcast some genuinely non-linear systems. To take the simplest of cases, mass and distance produce a gravitational force in a non-linear way: not by mere addition but by the inverse square relation­ship described in the law of gravitational attraction. This means that just a small addition of mass, or two objects being brought just a little bit

Some possible replies 97

closer together, can have a disproportionally large effect on the gravita­tional attraction. Non-linearity simply involves the output of the system not being proportional to the input. More accurately, a non-linear system does not obey the principle of additivity, which is that:

!(x + y) ~ !(x) + !(Y)

The weather is a real-world system that is acknowledged to be non­linear. A small change in one of the variables affecting the weather can make a large difference to the end result and it cannot bc taken for hTfanted that this could be truly described as a mere tipping case.

Because non-linear systems arc so sensitive to small changes, and may involve many different factors that feature such sensitivity, they are notoriously difficult to predict. A system that is hypersensitive to minute changes in its initial conditions is called chaotic. This makes such systems unpredictable in principle even if they m'e also determin­istic. The effects may well be determined by all the different powers at work and their exact magnitUdes, but the tiniest of difference in anyone of them could produce a vast and conspicuous difference at the end. Any prediction we make will be based on a specification of the magnitudes involved but those specifications can only be to a finite number of relevant variables. So, even if we could identify all the causally relevant variables involved, it would always be possible to state them more specifically. Mathematically, this point can be stated in the following way. Add one further decimal place to the specification of a variable and the calculated result could be vastly different than the previous calcula­tion. This means that a causally relevant difference could be found at a further decimal place than prcviously considered, which then had a major affect on the calculated outcome. Hence, two deterministic but chaotic systems that are identical when specified up to a certain decimal place may subsequently diverge in their behaviour because there arc further decimal places at which the causally relevant magnitudes differ.

The existence of such systems shows that the principle of additive composition is inadequate for the complex way in which some effects are produced. How. then, can we account for them? Compositional pluralism IS the simplest answer, and requires only a relatively small amendment to the standard vector model. This is the idea that there arc a variety of ways in which powers can compose. Addit.ion (and subtrac­tion) is the simplest mode of composition but it is only one among many.

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Additive composition would almost always occur when the powers involved have no interaction such that being involved in a causal situa­tion does not alter the degree or extent of the component powers. The resultant could well then be regarded as the mereological sum of all the component powers. The addition of forces could be an example of this kind of addition. When Martin gives a model of causation as nothing more than the coming together of powers, it is inadequate to the extent that it could only work for linear composition. Martin says:

You should not think of disposition p31tners jointly causing the manifestation. Instead, the coming together of the disposition partners is the mutual manifes­tation; the partnering and their manifest.ation are identical. This partnering­manifestation identity is seen 1110st clearly with cases such as the following. You have two triangle-shaped slips of paper that when placed together appro­priately, form a square. It is not that the partnering of the triangles causes the manifestation of the square, but rather that the partnering is the manifestation. (Martin 200X: 51)

Non-linear cases show that this cannot quite be right, however, at least not generally. It is, rather, in non-linear cases as if the two triangles come together to fonn a square that is bigger in area than the sum of the areas of the individual triangles before being joined (figure 4-4)- This would give us an analogy for what is happening in non-linear cases.

In a non-linear case, it would be as if Martin's two triangles, in being joined, interact and do something together that they could not have done when separate. Many natural phenomena involve interaction of the components where they produce something together that is not the mere addition of the components. This involves a genuine joint effort of two or more powers where the resultant is composed by some nOll-linear

-------. CAUSES EFFECT

FIGURE 4.4: Non-linear composition for area

Some possible replies 99

function. Any such [unction could be involved: multiplicative, inverse square, or far more complex.3

But what in the world are these functions? How do they work and how are they physically realized? How do they relate to composition? Tradi­tionally, such functions would have been thought of as laws of naturc. They would have told us that when one propelty F and another property G interacted they would produce property H, where the magnitude of H was a non-linear function of the magnitudes of F and G. Such an answer will satisfy many people though there is something that is also unsatisfactory about it. We might want to know whether these laws govern and determine the non-linearity of the functional relation between F. G and H. If they do. then what are these laws and how do they do the work that they do? Calling the function a law of nature has merely displaced the problem of accounting for it and it is questionable whether a satisfactory account of naturalistic goveming laws has ever been provided. Alternatively, some people think that laws of nature are just descriptions of what actually happens in the world: they report the regularities rather than determine them. But, in that case, it doesn't answer our question at all uf what these non-linear functions are. The

law just states that there is such a function and that it correctly describes the relation between F, G and H. There are, then, reasons to be sceptical that calling something a law tells us much of any use (for a more detailed argument to this effect, sec Mumford 20(4).

In the metaphysics of powers, there is an alternative to nomological conceptions of nature. What we take to be laws arc just descriptions of how the powers behave and affect each other. Powers do all the work and there is no need to posit laws as additional entities besides. While this may be a metaphysically more satisfying and economical picture, in respect of explanation the powers view does little bettcr than the laws view. Stating that some property, F, has a power to compose with G to fonn H according to non-linear function f is only slightly better than saying it is a law that it does so. The powers view attributes the responsibility for H, and its magnitude, to F and G and their magnitudes. It makes it a feature of F and, according to dispositional essentialism. an essential feature of what it is to he F, where each property is identified with a cluster of powers. So there is some explanatory role in the attribution of powers, but only a limited one. The attribution of a

3 Thanks to Dagfiml D0hl Dybvig for making this point.

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IOO Reductionism, Holism and Emergence

power does not tell us how F and G compose H in this way, only that they do as part of their nature. There might be some explanation available, if the powers of F and G are not fundamental. F and G might be grounded in other, lower-level powers. But we may come to powers that are ungrounded (Mumford 2006) if there IS a fundamental level (which is an open question; sec Schaffer 2003). With such funda­mental powers, no further explanation can be given. All we can say is that the power is the power to compose H, with G, with magnitudes determined in a non-linear way. And the reason for accepting this view is that it is a p311 of the metaphysics of powers: a view that we have been only assuming in this book, though we do think it has much to recom­mend it.

Composition is, then, a coming together of powers to do work jointly. The effect that is produced, H in our casc, is not just the conjunction of F and G. Indeed, there might be nothing that is recognizably F or Gonce they have jointly produced their effect. Causation often involves change or transformation so there is no reason why the cause should survive in thc effect. What makes powers work together? Unfortunately, it is not easy to spell this out. Some approximate geographical proximity is required but it does not have to be precise. The rough idea is that the powers are working on the same subject of change. Two heaters may produce an effect jointly, raising the temperature in the room-space between, even though they are some distance apart. The relevant causa­tion all takes place within a spatial region. The powers do not need to interact, as we may grant that the action of one heater has no effect on the action of the other. What counts is that there is a localized effect to which each of them makes a contribution. In most cases, this would mean that the effect would have been different without them, and we certainly get this with non-linear cases, especially the hypersensitive ones.

It should be apparent now that non-linear composition of causes introduces a kind of emergentism. The quantity of H is not just the addition of the sums of F and G but some new quantity. It is a function of the quantities of F and G but not their sum. The coming together of F and G has therefore resulted in some transformation and, in the case of ungrounded powers, there is no deeper explanation for the non-linear function involved. The non-linear case shows that Martin's account of causation as powers adding together leaves something out. In the non­linear case, a magnitude of F and a magnitude of G form a magnitude of H that is not simply the addition of the components. TIlis would be akin

Some possible replies IOI

to the two triangles forming a square thaL was either larger or smaller than the sum of the areas of the two triangles. Both the shape and, more importantly, its magnitude are emcrgent in the sense that they are not to be found in the parts.

d. Fmergence

The most radical answer to our problem cases, in which the principle of additive composition looked to be violated, is to allow for full-scale emergence. Emergence is a controversial notion in philosophy, partly because it was associated with celtain solutions to the mind-body problem. Thesc solutions were largely rejected, though they have been revived by Chalmers (2006) and others, who think that conscious­ness is an emergent phenomenon. Emergentism faces problems, how­ever. One is just how a notion of real, strong emergence can be spelled out, as opposed to mcrely epistemic weak emergence (see Kim 2006). Another is that it opens the way for top---down causation if, for instance, our consciousness is causally productive of physical events. The mental then emerges from the physical yet is also able to affect it causally. On the other hand, the alternativc to emergentism is reductionism, which is also undesirahle. There is as yet no good argument, cither empilical or purely rational, for why we should accept reductionism. Perhaps a few higher-level phcnomena have been explained in telIDS of lower-level phenomena but reductionism is a global thesis: a claim that every high­level phenomenon is reducible to low-level phenomena. Tn almost every case, the reductionist will claim that it is physics - fundamental physics - to which everything is ultimately reducible. The rcductionist will have to concede, however, that it is not yet possible to reduce all other theories to physical theories. Physics is not yet complete as a theory, so reductionism will have to be modified to the claim that it is the ideal, completed physics to which all other legitimate theories will be reduced. But this seems an act of faith in the power of sllch an ideal physics. For all we know, we may yet have no idea of what it will look like.

Some foon of emergentism looks undeniable. The parts of alann clocks are not alann clocks. The parts of persons are not persons and the parts of lead atoms arc not themselves lead. These arc holistic phenomena, which need lo be considered as wholes, at a certaiIl level of reality and not below. Both colour and solidity are properties that arc only to be found at a certain level of nature. Once one goes too

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102 Reductionism, Holism and Emergence

microscopic, they disappear. One need not deny that these are real features of the world; only that they appear at a certain relatively macro-level of reality. Kim (2006: 191) calls such instances Modest Kind Emergence. They do not pose any really great difficulty for a reductionist view because reductionism allows that there will be phe­nomena found only at certain levels. Thc key idea is that these phenom­ena are all pelfectly explicable by the arrangements of their parts and introduce no real ontological novelty.

But there could be more serious fOrulS of emergence in the world. Certain social phenomena might only be explicable at the level of society rather than at the level of the component individuals. There might be new powers that emerge only when individual people interact: those concerning language use. for instance. According to the private-language argument (WittgenstelD J 953= §243), it does not even make sense to ascribe language use to a solitary individual. There are, of course, at­tempts to explain sociology in t.erms of the particular appetites and aversions of individuals. Sociobiology is in a tradition that stretches back to Hobbes (1651). But it is arguable on the contrary that Hobbes's reductionism misses all the social postulates (MacpheTson T962). [f there were facts about the behaviour of people that emerged only whcn they interacted, and involved more than just the separate individual powers added by each person. then reduct.ionism is threatened. The explanation would be irreducibly higher level and no Enear function would be able to define it.

Although we are far from having established strong emergence, it is nevertheless wm1h emphasizing that such emergence is not ruled out by causal dispositional ism. Powers are not necessarily physically reduc­ible, to forces, for inst.ance. The theory is a transfer theory, as in Dowc (2000). But what is passed around is powers, not necessarily conserved quantities. If some foml of emergentism is lIue, then the powers that are passed could be relatively macroscopic. Many causal attributions are relatively higher-level and seem to be causally powerful only qua high level. To usc an example in Collins, Hall and Paul (2004: 14), a kiss to the cheek can have the power to make t.he recipient blush. Energy may be transfeITed when the cheek is kissed. The kiss depresses the cheek. But. it is not the energy transfer - the cheek depression .-, that causes the blush. You can depress your own cheek with your finger and it never makes you blush. It is lhat il is a kiss that causes the blush: a high-level, complex matter involving psychological, biological and sociological factors. Perhaps not all of those factors are reducible to physics. But.,

lVhat type of emergence do we have when powers collide? 103

if they are not, causal dispositionalism can just ascribe the power directly to the kiss and have some powers that arc only ascribable to macro~level phenomena. It seems to be an asset of the dispositional theory, therefore, that it leaves the question of emergentism versus reductionism open. Most transfer theories do not and side with the hope that physical reductionism will succeed.

4-4 What type or emergence do we have when powers collide?

The emergence that. is to be found among powers does not seem as controversial as some of the other cases, such as consciousness. That new powers can be found when others combine is a regular palt of common sense, even if some may have a faith that it can al1 be reductively explained in the end. Something fragile may come into contact with something hard. Together, they produce something broken, whose parts have the power to cut. A new power is the product of two other powers mutually manifesting. But this kind of emergence is nothing more than the causal int.eraction of two properties resulting in a change and the manifestation of a new property. For the pandispositionalist, this will be a matter of two or more clusters of powers producing a new cluster of powers.

We also accept that the resultant powers may bear little or no resem­blance to the component powers of its parts. A dramatic example of this is salt:

Sodium is a soft, bright, silvery metal. It can float on water and, when doing so, decomposes with the production of hydrogen and the fonnation of hydroxide. Sodium may ignite spontaneously on water, depending on the amount of oxide and metal exposed to the water. It nonnally does nol ignite in air at temperatures below lI5"C.

Chlorine is a greenish-yellowish gas that is a respiratory irritant. As little as 3.5 p.p.m. (parts per million) can be detected as an odour, and 1000 p.p.m is likely to be fatal after only a few deep breaths. Chlorine is so toxic it was used in gas warfare in 1915.

From this infonnalion it is impossible to predict that sodium chloride should be the benign compound that makes the oceans salty and is an essential compound ror life, not to mention potato chips and margaritas. It is possible that a k.Ilowledgeahle chemist could make this prediction - not today, but perhaps sometime in the future - but at this point 'salt' appears as an emergent property of sodium and chloride. (Rothschild 2006: 153)

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104 Reductionism, Holism and Emergence

Like other cases of emergence, however, such phenomena can still be linked to lower-level phenomena. We still would want to allow, for any dctenninistic case, a supervenience thesis. In the case of powers, this means that even if the resultant is composed non-linearly, or is a case of plain emergence, 1t is stili the case that it supervenes on the component powers. If we have exactly the same component powers, then we get exactly the same resultant powers. This may be a case of hypersensitive chaos where the resultant is unpredictable but supervenience would hold in spite of that. If we had two metaphysically, as opposed to only epistemically, indistinguishable sets of powers, then they would com­pose the same resultant. This is not, of course, to say that they would always produce the same outcome, they would only dispose towards it, and one or more of those powers might be irreducibly probabilistic. Nor does it say that, even in the non-probabilistic case, the resultant then necessitates an outcome it produces.

The emergence involved is thus a relatively mundane affair. Causa­tion typically involves change, and this means a change of properties. For dispositionalists, that is also a change of powers. When we described causation as a passing around of powers, we allowed that it was sometimes a different set of powers that is passed on. New powers come from old ones, therefore, and this is how we have a changing, dynamic world. The regular nature of such changes is often called nomological, though we think the powers alone can do all the work, Certainly calling such regularity in behaviour lawlike adds nothing of explanatory value that powers do not have already.

4.5 Emergent powers

We began this chapter with a simple problem. There looked to be some exceptions to the standard vector model for causation that was presented in chapter 2. Overdose cases and the like seemed to suggest that component powers didn't always add in a simple linear fashion. What was under threat was the principle of additive composition for causes.

In reply, we have offered various strategies. Some of those did not involve overturning the basic additive compositional model. Those cases might be explicable within the standard model just if we take into account more of the complexity that will be involved, either in tenus of more of the component powers at work, the new causal situa­tions that might be gone through, or thc moving into and out of

Emergent powers 105

equilibrium. Overdose cases might fhen be ultimately explicable and only weakly emergent in Ule sense that tile powers involved in such cases may be a surprise to us.

But then we conceded that wcak emergence might not answer every case. There could be some genuinely non-linear composition of causes in reality, such as we are told occurs in chaotic systems. Here we can make a relatively simple amendment to the theory: we allow composi­tional pluralism, which means that the mode of composition can be open. Addition is just one function - the simplest to grasp - among many other functions that may describe the compositions of powers that have magnitude. The non-additive modes of composition will be by non-linear functions. Finally we argued that, even if straightforward strong emergentism were tme, causal dispositionalism could accommo­date it. There could be powers that simply emerged at a certain level of reality or where two or more component powers interacted. In overdose cases, perhaps some novel power does emerge at a certain level. But causal dispositionalism contains no intrinsic commitment as a theOlY of causation to reductionism. Emergent powers could be accepted.

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Simultaneity

5.1 The causal relation

A theOlY of causation has been developed in hasic outline in which multiple powers come together and produce an effect jointly. The effect is their joint manifestation. This raises a question of how powers relate to their effects. Causes are often said to precede their effects and Hume took temporal priority to be one of the key components of our notion of a cause. If causation essentially concerned constant conjunctions, then temporal priority would be one of the few ways of distinguishing causc from effect. Tt might seem relatively easy for a powers-based theOIY of causation to accommodate temporal priority. The power and its stimulus might be said to temporally precede their manifestation. The sugar is dropped in the water first, for instance, and only some moments later is dissolved.

But we will see that temporal priority of cause over effect is not, after all, something that sits comfortably with the powers view. If we leave a temporal gap between cause and effect, we need to provide some story about what happens in that gap and, specifically, about what extra is needed to gct the effect to occur once all its causes are in place. How long is the gap and why is it of exactly that length? What is it that puts an end to the gap by producing the effect? A broader concern is the picture of causation that in the first place tempts us towards a temporal priority view. Two events are depicted as standing in some relation, which stretches across the gap and ties them together. But this immediately raises questions of what this extra element - this causal relation - is and how we can know about it. It is, after all, assumed that the two events in question, or two just like them, might also exist without the causal relation connecting them, and this invites causal scepticism. Instead, the upholder of powers is invited to reject the two-event. model, which has become the standard account. The powers view has depicted causa­tion as a coming together of many powers, having an effect as a jojnt, combined manifestation according to some function of composition.

Temporal priority 107

Something will still be identifiable as cause, and something else as effect, but these will not be two events that must stand in some relation, as the standard accounts tells us. Rather, the cause will be depicted as merging into and becoming the effect through a natural process. Hence, the sugar and water become the sweet solution. It may take time for the BugaT to be completely dissolved, but this doesn't mean that the cause and effect are temporally separated. Causation occurs as soon as the sugar and water are united and continues, unless the process is inter­rupted, until total dissolution has been achieved and then ends at that point.

5.2 Temporal priority

Burne commits to the temporal priority of causes over effects as follows:

The second relation I shall observe [after contiguity] as cssential to causes and effects, is not so universally acknowledg'd but is liable to some controversy. 'Tis that of PRIORITY of time in the cause before the effect. Some pretend that 'tis not absolutely necessary a cause shou'd precede its effect; but tbat any object or action, in the very first moment of its existence, may exert its productive quality, and give rise to another object or action, perfectly co-temporary with itself. But besides that experience in most instances seems to contradict this opinion, we may establish the relation of priority by a kind of inference or reasoning. (Hume

1739: I.iii.2: 75-6)

Temporal priority has at least some intuitive appeaL Smoking causes cancer, for instance, but if it does so, the disease sets in some time after exposure to smoking, even if such smoking persists through the disease. Alcohol causes hangovers, as is well known, but the alcohol was drunk in the evening while the hangover is the morning after. And in Hume's billiard ball case, his perfect instance, first we have the ro1ling of ball a, then the collision, and then the rolling of ball b. Ball a rolled before its effect in ball b rolling. There are countless many other examples that could be produced. After all, given that the cause produces the effect, or so we think, then clearly the cause must exist before the effect can exist.

Hume's own theory of causation puts constant conjunction at the centre. The two events or 'objects' must be constantly conjoined such that one al ways occurs with thc othcr. But they must also be contiguous or close together and, of course, the cause must precede the effect.. It is this latter clause that is our real subject of study and we should therefore

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108 Simultaneity

acknowledge that other theories of causation can contain this same thesis. It does not matter too much to us now whether the two events arc constantly joined or whether the second counterfactually depends on the first; nor indeed whether the first necessitates the second. These can all be consistent with a commitment to temporal priority.

5.3 Problems with temporal priority

We will raise a number of problems for the standard account. OUf focus at first will be on the temporal priorit.y condition but we will move on to question generally the two-event model that leads to temporal priority as a way of distinguishing cause from effect.

OlIT concern init.ially relates to the examples used in motivating temporal priority and we will contend that they do no such thing, even in the case of Hume's own example, the 'perfect inst.ance' of causation (Hume 1740: T37). Let us consider balls a and b that roll along the billiard table. Ball a rolls a metre in length, let us assume. It then impacts with ball b, which then also rolls a metre in length. Did the cause precede the effect in Hume's pert'cct instance? What. was the cause? Was it the roll of a? But the problem is that while ever a is rolling along the metre of green baize, it has not yet met. with ball b. How, then, can any causation, with respect to ball b, have yet occurred? Doesn't the causation occur at that place and time that balls a and h meet and not before? Wc could have stopped hall a at any point along the one-metre roll it took before impact and the causation would not have OCCUlTed.

What happens in the path and direction taken by ball a whilc it rolls is just the story of how it got to the point of impact. It is the impact that is causally efficacious, not how ball a got to the point of impact. It would be absurd to say that the causing, or any part of it, was OCCUlTing prior to this impact. Let us take it, therefore, that no causation, with respect to ball b moving away occurs until ball a meets it. No part of the cause can be before the time of impact.

Now let us look at the same incident from the other side, conceming the movement of b. Does the effect follow after the cause? Ball b does indeed roll away after the impact but isn't this the story of what happened after the causation occurrcd? Doesn't this case of causation complete itself with the impact? The impact is complete, let liS say, and at that point so is the causation. A momentum was passed on [rom a to b, and this dccd is already done once ball b moves along its path. We could

Problems with temporal priority 109

stop ball b at any place along its path but the causal act that involved a would have been completed just the same. We cannot at this point stop the fact that fhe causation between a and b has already occurred. What ball b does with the momentum, that it acquired causally from a, is another story (conceming its manifestation of the acquired momentum) but it is not the story of the causation between a and h. No causation with respect to ban a occurs after ball b has left it. And no pmt of the cause, therefore, can be said to be after the time of impact.

Let us quickly set aside a caveat. It may be objected that the causation in this case looks instantaneous but actually takes time. Very slightly, when the balls collide, both a and b deform. They are not perfectly rigid. They squash ever so slightly against each other and then a pushes b away. While this looks to the naked eye to take no time, it rather just takes a small amount of time. What we actually have is a process rather than a momentary collision. Ball b docs, therefore, start to move a bit even during the collision and, thus, while the causation is still occurring. But this need not detain us. The claim to be made will be that causation is a matter of simultaneity and simultaneous does not entail instanta­neous. Ball a first meets b at time t a , let us say, and they go their separate ways, after some interval, at time two For as long as they are together, squashing into each other and then springing apart, causation is going on, according to our account. There is a process, which takes time, hut this causal process has not begun until t':J. and has not ended until two Cause and effect were together, at this point. The cause was ball a, with its momentum. The effect was the acquisition of momentum by ball b. This passing on of powers takes time. It is passed on gradually but quickly. And when it is passed on, or enough of it for h to go separately along its own path, then causation is over and done with.

An alternative way to reprcscnt the causation that goes on in the billiard table example is to take ball a's rolling as a manifestation of the ball's momentum comhined with lts shape, the flat surface of the table, and so on. Thus, the rolling of a is itself an effect of a number of powers working togethcr, and one that is simultaneous with the cause. Once the momentum is lost Of obstructed, the ball stops rolling. The effect stops with its cause. If the rolling of ball a is taken as only a cause, as in Hume' s presentation, this docs not (ell thc full causal story. As mentioned in §2.5, what we call cause, stimulus ,mo effect w11l usually be a matter of pragmatics. We might be intcrested in a certain causal factor and a certain threshold. So we may call ball a's rolling the cause

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110 Simultaneity

and b's rolling the effect, but.that doesn't mean that causation is not happening continuously throughout.

What we would need to establish the temporal priority condition, therefore, is a good example of causation where there is a clear tempo­ral gap between cause and effect. The billiard table, despite being Hume's perfect instance, does not back up his temporal priority thesis. But are there bettcr examples? Alcohol causing a hangover might be hetter? Upon ingestion, there is first a temporal gap before any notice­able effect and, when it comes, that effecL is first of all drunkenness. Only a number of hours later does the hangover occur and there is little doubt that the alcohol consumption is almost always the cause of the headache and nausea. Isn't this, then, a better example of a temporal gap between cause and effect? There is a problem here as well, how­ever, which possibly applies to many similar putative examples. These are cases where a succession of causal situations is involved. We have a causal chain or cone that leads from the drinking to the hangover via a number of much smaller steps. Alcohol produces inebriation, which then produces the hangover. But we know that this is still oversimplil1-cation. A whole host of different causes and effects in the stomach and bloodstream will be intermediate between the consumption and the hangover.

Where we have such a chain, each small hnk in that chain might then be like the billiard ball case with simultaneous causes and effects. Such an explanation i:::; not ruled out, even though we might think it leaves other matters to be explained (which will be addressed in §S.6 below). But even if each link in the chain involves simultaneous causation, it can hardly be denied that causation still can go along the chain and an initial cause clearly can be temporally separated from the eventual effect. We will not deny that causation can t.ravel down a chain (though see §7.7 on transitivity). But this point does not really address the concern about the temporal priority condition. Such a condition states that causes must always occur before their effects - as part of what it is to be cause and effect·- and is thus more than a claim ahout temporally extended and transitive causal chains. Hence, even the smallest case of causation involves a temporal distinctness between cause and effect if the standard view is correct. What we need to Hnd is a plausible example of this kind.

It is not easy to find such examples, we maintain, and there may be good reasons why it is not easy. There are also theoretical problems with adopting a temporal priority account. One point comes from Russell

Problems with temporal priority III

(1913: 197), which is that jf there is a gap between the cause and effect, then there is always the possibility that something else could occur that nevertheless, in spite of the completion of the cause, could prevent the effect. This problem does not especially alarm us, however, for we have already argued in chapter 3 that the possibUity of prevention is applica­ble in every case of causation. The possibility is not therefore something we can hold against the temporal priority view. But Russell's question does bring out. some of the metaphysical sensitivities of the account. If there is a temporal gap between cause and effect, how long is it? What, if anything, can happen within that gap? Most of all, why does Lhe effecL suddenly happen after an interval of time? What more is needed than the cause for lhe effect to occur immediately?

If something else is needed, then clearly a regress looms. Suppose we have some assemblage of causes: then either their effect begins as soon as the causes are assembled, which the position we will defend, or it doesn't. Suppose it doesn't and there is some gap between cause and effect. Tben what, after such a gap, produces the effect? One might say that nothing makes the effect occur, after the gap, conceding that one caIlnoL an:::;wer the question. Alternately. one might say that something more does occur that explains why the effect did eventually happen after a time intervaL But then shouldn't this further factor be considered one of the causes of the effect, among the olhers, and shouldn't we then say that once it: is in place, along with everything else, then the effect occurs immediately? If we deny this, and allow a gap between this assemblage of causes and its effect, we are left with exactly the same question again. What else was needed for the effect to occur?

Setting up the problem this way presents us with the stark alternatives. Either causation is simultaneous and effects occur immediately once the causes are assembled, or there is a time gap between causes and effects. If the latter, then the effect occurs some time after the causes are assembled. There are then two fUJther possibilities. The first is that the effect just takes some time to occur - even though nothing further changes - after all the causes are in place. The second possibility is that the effect occurs, after the time gap, because some further factor occurs. But then the effect occurs as soon as this extra factor occurs or there is a time gap between it and the effect. and we are back to the problem with which we statted.

One thing that. remains here is to clarify the relationship between the notions of simultaneous and instantaneous. For an effect to happen instantaneously, there must be no temporal gap between it and the

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causc. For causes and effects to be simultaneous, on the other hand, they must entirely coincide temporally. Effects being instantaneous does not require that they are simultaneous with their causes. There could be a cause, with a certain duration, which ends but is followed by, in the next instant and with no gap in time, an effect that also has a certain duration. The cause and effect could be spatially adjacent without overlapping but with no temporal gap between them, presumably because they occupy adjacent spacetime points, which is possible if spacetime is discrete rather than dense. For causes and effects to be simultaneous, however, requires that they be instantaneous in the sense that the effect would commence as soon as the cause commences, or is in place. There are already two scnses of instantaneous in play here: a strong and a weak sense. Both qualify as notions of inst.ant.aneous because neither involves a temporal gap between cause and effect. The stronger sense of instantancous means that the effect must occur at the same time as the cause. In the weaker sense, the effect can occur at a different but adjacent time: the next moment such that there is no temporal gap. Thus, we could still havc total temporal priority of causes if their effects are weakly inst.antaneous in that there would be no temporal overlap between causes and effects and thus not even any part of them would be simultancous.

We see that some versions of the temporal priority condition, though not all, face a difficulty of accounting for a temporal gap and what, if anything, takes the situation out of the gap by producing the effect in question. But another version of the temporal priority view need not require that thcre ~ any such temporal gaps. An upholder of the standard view might, therefore, feel that they can still resist simultane­ity. Returning to om billiard ball case, they might urgc that t.he move­ment of ball a ends at a certain point in time and the caused movement of ball b begins at the very next point in time.

We move on, however, to consider the two-event model of causation in general, setting aside the temporal priority thesis. In the Humean view of causation, it is vitally important that causes and effects arc dis6nct existences that bear some kind of relation (or relations) to cach other. Hume was keen to emphasize this so as to distinguish causal relations from logical or conceptual ones, which were just relations betwecn ineas. That all bachelors arc men is a different kind of truth than that all hread nourishes. The former is what we would call analytic: just that the concept of man is already contained within the concept of bachelor and thus bachelor and men are not entirely distinct existences. Bread and

Simultaneity of cause and effect 113

nourishment are ent.irely distinct existences whose relation is somet.hing to do with the facts of how the world is and not just a relation of ideas or concepts.

The current problem of causation, according to our diagnosis, is in part a creation of how Hume originally framed it. The two events in question simply occur, 'just one little thing and then another', as Lewis said (1986: ix), and are distinct in the sense that one could have existed apart from the other, The philosophical problem of causation then becomes the question of the way in which two such distinct events Can be cOimected causally and how we can know of such a connection. We are able to perceive only the two distinct events in question and never the causation as an extra element. As Hume said, the causal connection between the events seemed imperceptible and led him to his 'sceptical solution', that causation was nothing more than a regular succession between types of events. The third element - the tie connecting cause and effect - seemed invisible.

But need causation involve this third clement? Might there be just two clements but two that fit together so closely that they have to come as a package deal? Or maybe causation involves just one thing: a single event or process in which one thing gradually turns into another, often in a perfectly transparent, perceptible way. Indecd, it. is this latter way of understanding causation that we will recommend. The Humean under­standing of causation has made it problematic by breaking the world down into distinct events that have to stand in some relation. But what that relation is, and what count as its relata, is something we find hard to pin down.

SA Simultaneity of cause and effect

We began with examples of causation that suggest the temporal priority of causes over effects, including Hurne's own billiard table example. It. was argued, however, that Hume's example did not clearly illustrate the thesis that the cause must occur before the effect, and some of the other examples may have shown only that there are extended causal chains and not conclusively that the individual causal links within that chain involved temporal priority. We will be returning to this question again soon.

First, however, let us look at some examples that can be used to motivate the opposite view: that suggest that causes are simultaneous

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with their effects. Just as the temporal priority view has an advocate among the Great Philosophers, so does the simultaneity view. Kant provides two famous examples of simultaneous causation in one passage:

For instance. a room is warm while the outer air is cool. I look around for the cause, and find a heated stove. Now the stove, as cause, is simultaneous with its effect, the heat of the room. They are simultaneous and yet the [causalJ law is valid .... [And] If I view as a cause a ball which impresses a hollow as it lies on a stuffed cushion, the cause is simultaneous with the eHeeL (Kant 178r: A203)

Once we see how such examples can work, it is not hard to find others. Two books may lean against each other at an angle, each propping up the other. A kitchen magnet sits on the front of the fridge. A locomotive pulls a truck, both moving at the same time (Taylor 1966: :lS). An iron bar glows at a high temperature, say 1,000 degrees (Gasking 1955: 479). The pressure of a gas varies with its temperature (Brody 1972: 21). Some of the examples are less commonplace, yet they might be 1110re scientifically sedous. In Newton's Second Law, a body's acceleration at a time is proportional to the force exerted on it at that time and inversely proportional to the body's mass and in the Lorentz equation in electro­magnetism bodies always expedence the effect of the electromagnetic field at their spatiotemporallocation (both examples from Hucmcr and Kovitz 2003: 558--<)).

Apart from the more scientifically inclined examples, however, the idea of causation being simultaneous has a clear common-sense appeal. You lift up a book, for instance, and the book being lifted (the effect) is simultaneous with you doing the lifting (the cause). As soon as you take it from the table, the effect is in existence as well: the book is elevated. And as soon as you stop holding the book, and set it down, the effeci ceases too. That there are at least some such cases, clear-cut and commonsensical, seems impossible to deny. But that still leaves a question of whether all, or only some, causation is simultaneous. Per­haps there are two types, simultaneous and successive, as Kant seemed to be allowing even if the 'great majority', in his view, were simulta­neous (Kant I78J: A203). Before we try to answer that question, however, simultaneous causation still needs some defence. Just as we can question the putative examples of successive causation, involving the temporal pliority of cause over effect, some have questioned the prima facie appearance that the examples cited really do involve simultaneity.

Objections to simultaneous causation lIS

5.5 Objections to simultaneous causation

There arc a number of reasons why a case of simultaneous causation might be questioned and these will be discussed in tU111. First, it might be wondered how causation can be temporally extended if it is simulta­neous, which is an especially pressing matter in the case of extended causal chains. Second, it might be wondered how a cause Gill be distinguished from its effect if they are simultaneous. If, as Hume says, causation relates simply events, then we can distinguish cause and effect only by some asymmetric relation in which they stand. That the cause precedes the effect thus would provide a way of telling them apart. So how cotlld we tell them apart if it were not for temporal priority? Third, there are a numher of a posteriori objections to the simultaneity of cause and effect, which amount to the asseltion that it would violate the laws of physics if it was a claim that there could he immediate action at a distance.

Objection 1'- How can causation be temporally extended?

Hume had argued that there was a problem with extended causal chains if causation was simultaneous. We have already said that simultaneous does not mean instantaneous, but the problem Humc raises is not just that causation could not take time but that it could not pass down a chain that was extended in time. Thus, we could have a case where each link in a causal chain involved simultaneity of causation. But how could cau­sation ever pass from one link at time t I to the next link at time t2 if causation had always to be simultaneous? If there were to be chains of causation, then it seems that all the links would have to be simultaneous with each other (Frankel 1985: 367). The problem is that it seems evident that there are at least some cases where causation occurs across times, where the cause is at an earlier time than the effect, because, if there were no such cases, then how could we have a chain of events passing through different times that were nevelthe1ess causally related? This is how Hume makes the argument:

'Tis an establish'd maxim both in natural and moral philosophy, that an object, whieh exists for any time in its full perfection without producing another, is not its sale cause; but is assisted by some other principle, which pushes it from some state of inactivity, and makes it exert that energy, of which it was secretly

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possest. Now if any cause may be perfectly co-temporary with its effect, 'tis certain, according to this maxim, that they must all of them be so; since anyone of them, which retards its operation for a single moment, exerts not itself at that very individual time, in which it might have operated; and therefore is no proper cause. The consequence of this wou'd be no less than the destruction of that succession of causes, which we observe in the world; and indeed, the utter annihilation of time. For if one cause were co-temporary with its effect, and this effect with its effect. and so on, 'tis plain there wou'd be no such thing as succession. and all objects must be co-existent. (Hume l739 I.iii.2: 76)

This is, however, another case where we allege that the two-event model does damage to our way of thinking about causation. The events are depicted as occupying different times and then requiring a causal rela­tion to unite them but one that can stretch across distinct times, hence the temporal priority condition. We have already stated that we wish to throw off the two-event model, but by setting up causal chains in this way it seems that it has very quickly come back into the picture. A causal chain is being depicted as a succession of two-event causal cases stretched out in a temporally extended line.

Our response to this bears some similarities to that of Huerner and Kovitz (2003). The problem comes if we understand causation as leap­frogging from one event to the next where each is located at a different temporal atom or particle. In this 'particulate' structure, causal relations form a sequence when they join essentially changeless, non-causal events that occur at different times (Huemer and Kovitz 2003: 559). But it has been argued elsewhere (Mumford 2009) that this is not an ontology that appeals to the upholder of powers. It suggests a perdur­antist view in which change is explained by the holding of celtain relations across essentially changeless temporal parts, such as 'static' events. Instead, an ontology in which particulars and events endure through processes is more suitable to d'ispositionalism. Processes are seen as dynamic in the sense that change is undergone throughout the process, which means it is to be found in any part of it, and it thus cannot be broken down into a string of changeless parts. With perdurantism tends to go the view that it is essentially contingent what follows what. Thc reason for this is that it is no part of the essence of the temporal parts that they be arranged in any pmiicular order. They could preserve their identity through rearrangements such that, as Humeans intend, there is no reason in principle why they could not occur in a different order to the one in which they actually occur. The dispositionalist, on the other hand, sees causal processes as more than a purely contingent matter.

Objections to simultaneous causation I!7

They are the manifestations of certain natural processes that bear a more-than-Humean connection to the powers that produce them. Such a process, as well as being dynamic, has a unity to it that comes from being the expression of a collection of causal powers.

Instead, therefore, of seeing a causal chain as a sequence of distinct events falling into contingent causal relations, explicated in terms of constant conjunctions, counterfactual dependence or whatever, we explain change over time in terms of the developing and unfolding of various natural process, some of which may overlap. The way in which they do so, and how this can produce a succession of causal processes, will be described in SS.6.

Objection 2: How to distinguish cause/rom effect?

The question of how we can distinguish cause from effect is one that may be answered with relative ease. Even in Burne's view, Lhere is a way of distinguishing causes from effects other than by temporal prior­ity. Every case of the cause A, is accompanied by an effect B, but not necessarily vice versa, so there could be a B that is not accompanied by an A. The objection is not, therefore, a serious one. Indeed, there will be many simultaneous relations that are also asymmetric. Being taller than is a relation that would hold simultaneously between A and B, but it, of course, also has a direction: an asymmetry. And. with more ontological seriousness, both supervenience and reduction have a direction although they will hold simultaneously. Thus, we may have two families of properties, M and P, mental and physical properties, for example, that are instantiated in some particular a simultaneously, but where M is reducible to P and not vice versa. There is, thus, no reason why A and B cannot be simultaneous while A is the cause and B the effect. The comparison with reduction and supervenience may be a dose one. While M and P exist simultaneously, it is P that is productive of M (noll-causally, we might assume) and M that depends on P (if depen­dence is thought a legitimate way of explaining reducibility). In the case that concerns us, then, we need to explain how, given that. A and Bare simultaneous, A causes B rather than vice versa. According to the causal dispositionalist view, it is that powers arc passed from A to B rather than fromB loA.

n ought to be acknowledged, however, that there can be some recip­rocal cases in which a causes hand h causes a, so causation in general has to be classed as non-symmetric rather than asymmetric. If a causes

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b, b mayor may not cause a. In the case of the two books, book a causes book b to stand at a 45° angle and book b causes book a to stand at the same angle. The example originates in Pollock:

Tt seems to me that there arc 'feedback examples' in which each of two propositions causes the other. I-or example, consider two boards arranged in an inverted 'y' ~o that their tops are leaning against onc another. Each board is holding the other onc up. What this comes to is that either board's not starting to fall at time t prevents the other board from beginning to fall at time t, and hence we have a case of symmetric causation. (Pollock 1976: 173)

We will set aside Pollock's statement of the case in terms of 'proposi­tions' causing each other, and also causation articulated in terms of prevention. In our case, we just have book a and book b causing each other to stand at an angle. Frankel (1986) has disputed that this kind of case is genuinely symmetricaL Instead, he argues that book a standing at 'f causes book b to stand only at later time ':2-, and h standing at f2 causes a to stand at later timc f3 , and so on. Similarly, b standing at '1 causes a to stand at t2 , which causes b to stand at t3 , and so on (Frankel 1986: 365-6). But, as Molnar argues, this is implausible. Frankel's interpreta­tion gives us two distinct causal chains rurming concurrently. There could be such cascs, but the example of the two books is not best understood as one. If we let a I be that book a is standing at an angle at fI' a:2- that it is similarly standing at '2' and the same for book b, then we would have:

Causal chain I: a j --I h2 '-I aj ---+ b4 .... --+ an j ----)- hn Causal chain 2: hI -> a 2 ---+ b j ---+ a4 .... .. ,,)- b"'J ---+ an

Apart from the general concern that this misrepresents the case, Fran­kel's account fails to give any causal explanation for a I and b J, contrary to the thought that they have a very obvious causal explanation: namely that they are the cause of each other (Molnar 2003: 193).

On the temporal priority view, it almost. goes without saying, sym­metrical causation becomes an impossibility, as usually understood. For a to cause b, it must be prior to b. In that case, b cannot also be the cause of a. Exceptions to this have been found in the case of backwards causation or causal loops. Modulo this special case (Dowe 2000:

ch. 8), symmetrical causation has not been considered viable primarily because of the temporal priority condition. If temporal priurity is set aside, symmetrical cases can be possible. SymmetI}' cases may also he thought to create difficulties on other grounds. If a causes band b causes

Objecfions 10 simultaneous causation 119

a, for instance, one might worry that some kind of bootstrapping or self­creation is involved. BuL there need be nothing like this. How books a and b got into their arrangement, each leaning against the other, is another story and one that can be told, no doubt. But once they are placed in that alTangement, there seems no obstacle to saying that a causes hand b causes a.

We have spoken here of a causing b and it might look as if we ,are returning to a relational view of causation, although we purport to reject it. Of course, we want to allow that something is identifiably the cause and something the effecL But what we don't want to allow is that the causation is some extra element additional to a and b that could in some way connect them (or might not). Rather, we see the causation as an unl:olding process whereby a tUnlS "into b (as In Marlin 2008: ch. 5). The combined powers of the cause, such as the solute and the solvent, become the effect - a substance held in liquid suspension - as part of what it is to be those powers.

Objection 3: Hmv to square causal simultaneity with physics?

The third argument against simultaneity is that it is inconsistent with what we know about physics. Among other things, physics denies that there can be instantaneous action at a distance, which makes some putative cases of simultaneous causation look suspect. Consider the example of the locomotive pulling the truck, for instance (Taylor 1966: 35). The locomotive is some distance from the truck, perhaps WIth other carriages between. When the locomotive starts to move, the truck at the end of the train cannot move at exactly the same time, [or that would be to assume the whole length of the train formed a perfectly rigid body, which nothing is (Taylor 1966: 35-6 and Brand 1980: 138). And nothing can travel over a distance faster than the speed of light (Tooley 1987' 208): neither forces nor whatcver else is the physical vehicle of causation. Causation is the passing around of powers, on our account, and surely they cannot be passed faster than light speed. There is ev~n a further scep6cal challenge from physics. Einstein, it might be smd, h.as cast doubt on the very notion of simultaneity. That two events are SImulta­neous can be only [rom a certain perspect.ive on them, so, it might be objected, thcre cannot be simultaneity of causation in any real sense.

Interpretations of physics vary, however, and it is far. fr~m ~lear that the authority of physics stands behind the temporal pnont.y VIew. Huemer and Kovitz (2003), for example, argue that physics itself

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delivers some of the best examples of simultaneous causation. A reason for this is that physical laws ~re most typically understood as equations in which a change in a quantity on one side must be accompanied simultaneously by a change in a quantity on the other side. In Newton' s Second Law, for instance, a body's acceleration at a time is proportional to the force acting on it and inversely proportional to its mass at that time. These factors must vary simultaneously because, if one factor varied before the others, there would be a period of time during which the two sides of the equation did not equate, and Newton's Second Law would be false at that time. Similarly, the Lorentz equation can be cited (Huemer and Kovitz 2003: 559), which relates charge, velocity and force, and a central strand of Russell's (1913) famous sceptical attack on the notion of causation was that science had replaced the asymmetric notion of cause with equations that were symmetric. This argument works against causation, of course, only on an assumption that it must involve a temporal asymmetry, which we now say it does not.

Huemer and Kovitz defend simultaneity by rejecting the discrete, 'particulate' view of time with which Burne was working (Burne 1739: 1.ii.2). TIl is meant that he had to see causation as involving a jump from an event at one spatiotemporal point to an event at another. Instead, they recommend a dense view of time in which between any two spatiotemporal points, there will always be a third. Events are then seen as already temporally extended:

On this understanding of time and change, temporally extended events are not 'built up' from some smallest units. Rather, every event is already a temporally extended whole, which can be divided into indefinitely many parts, each of which is itself a temporally extended event. (Huemer and Kovitz 2003: 560)

This is one way to go and it may not be alatming to someone who already favours a dense rather than discrete view of time. There is a thought, however, that it would be a shame if the whole case for the simultaneity of cause and effect depended on a prior question of whether spacetime was dense or discrete. A dense view of time has a number of counterin­tuitive consequences, for one thing, and it is not clear that one really has to buy all of them in order to reject the temporal priority condition.

What we recommend is the rejection of the two-event model of causation and instead that we understand it as involving a single tem­porally extended change in which cause and effect occur together, almost as though the one tums into the other: a cold room turning into a warm room, for instance, through the diffusion of heat, or a lukewarm

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drink with a solid ice cube in it turning into a cold drink with no ice cube left. Causation comes in temporally extended wholes rather than as constructions from changeless discreta.

It is then suggested that, once we have such a view ~ of causation involving change and temporality ~ it does not matter ultimately whether time comes in discrete particles or not. The extended and changing cause must occupy an expanse of time and, it is argued, the effect occupies exactly the same expanse. With the melting of the ice cube (which is also the cooling of a drink), for instance, as SO(lll as the ice is in the drink, the cooling begins, and it continues until all the ice is melted, assuming the process is allowed to mn its course. Causation is not seen as something that passes along the distinct temporal particles. therefore, because they are, to put it bluntly, too small and insignificant to be causal relata.

Ttris could raise some of the other alleged issues from physics. Causation still canIlol involve immediate action at a distance and simul­taneity remains problematic. But we can also see that neither of these need be major concerns on our modeL Our cause and effect are co­located. The melting of the ice cube is a process occurring in the glass, the stove is in the same room it heats, and the colliding billiard balls touch. Just as the causes do not have to traverse time to meet their effects, nor do they have to traverse space. We have immediate action, therefore, but not at a distance. And as there is no distance, the Einstei­nian consideration also vanishes for it cannot be used to challenge simultaneity at the same location. This is not to say. however, that we rule out the possibility of non-local immediate causation (sec Bigaj 2008: 237~8, for instance), only that our account does not depend on it.

A numher of concerns about the simultaneity view of causation have been raised in this section but none of them, we argue, are significant enough that we should rule out simultaneity. Simultaneity of cause and effect is an attractive and intuitive view and we need some good argu­ments if they are to count against it. We still have work to do to explain causation through a process, however, and we must also return to the difficult issue of extended causal chains.

5.6 A sweet solution

We can now draw together a number of themes that have emerged as we oilered powers as a basis for simultaneolls causation.

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First of all, we draw on Kant ,again when he says:

The great majority of efficient natural causes are simultaneous with their effects, and the sequence in time of the latter is due only to the fact that the cause cannot achieve its complete effect in one moment. But in the very moment in which the effect first comes to be, it is invariably simultaneous with the causality of its

cause. (Kant 178T: A203)

We aTe beginning, lhen, with the case of a single natural process, such as the stove heating the room, as in Kant's own example. Clearly, the stove cannot have its full effect instantly. It takes tjme for that to develop. The dicct is a change in the room temperature, but it can manifest this only gradually, passing through all the intennediate temperatures between the starting point at which the stove was first lit and the point it reaches eventually. This is a case of causation involving change, which we account for as a change in properties, moving through a quality space, as the operating powers manifest themselves. We thus have a move [rom one quality to another produced by all lhe powers working on that quality space.

We will come back to the stove shortly, but first we will develop another example that also illustrates the sense in which causation is simultaneous, yet extended through time, with one quality being cxchanged for another. The example concerns the manifestation of solubility when sugar is placed in a liquid. Figure 5. I illustrates this. A traditional and Humean way of understanding the case would be that sugar being placed in liquid at time t I causes it to dissolve at a later time 12 , such that causation is a relation reaching across those two events at different times. We offer a different interpretation. For a start, the event of the sugar being placed in the liquid should not be considered the cause in such a case. That tells us the story of how the sugar got into the liquid, but it is not of any intrinsic relevance to the case of causation that is our subject. l The cause in this case is the sugar being in the liquid, or rather the coming together oftheir powers, and the effect is its dissolving. How the sugar gol there, who placed it in, or whether it fell in accidentally without human agency, is not a matter that need detain us. For the effect of it dissolving, all that matters from a causal point of view - as an accurate and informative causal explanation of its dissolving - is that it is in the liquid and appropriately empowered. The effect is depicted above as being the dissolving of the sugar at t-.! but this also is inaccurate

j Our thanks [0 John I1eil for this point.

A sweet solution 123

and misleading. At 12 , the sugar is entirely dissolved but it start') dissol­ving before that point. Our hypothesis is that at 1 Io the moment the sugar is in the liquid, it begins to dissolve but, as Kant said, it takes time for the full effect of this process to be realized. Causation is going on right from the first moment at fl. The sugar starts to dissolve as soon as the liquid makes contact with it but it takes time for that process to mn its course. The liquid breaks down the existing bonds aud makes new ones but takes time to pervade the whole cube. In its centre, there are some molecules that are protected from the watcr, bUl as the cube remains in there and more of the surrounding molecules are dissolved, eventually the liquid gels to all the molecules. In /lgure 5. T, therefore, we take it that our cause at lex is the soluble sugar cube plus the water that is for il a solvent. We have a coming togethcr of mutual manifestation partners aud they begin their work the moment they are together. But what we then have between fa and fw is the development and unfolding of the process that takes the sugar from solid to solute. The solid cube becomes less and less solid as more and more of it goes into solution until, at t(M

we have the full effect: a sweet solution. It would be counterintuitive to say that we have the cause only when

the sugar cube first comes in contact with ilie water (ta) and thc cffect only once the whole sugar cube has dissolved (tw). At somc point between fa and tw , thc causal process could have becn halted in mid­track, for instance, and the sugar cube would only have been partially dissolved (suppose the cube is placed in the liquid which is then rapidly boiled off). Some causation will have occurred, as some change will have happened, even if the process was stopped short of what it could have been. The Humean framing or the case misrepresents this, suggest­ing that we go immediately from having no effect at all, prior to t w , and

EFFECT

CAUSE

L--:-____ . ________ ""-

Sugar cube Sweet solution I water

FIGURE 5.J: A simultaneous but temporally extended causal process

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124 Simultaneity

then suddenly the wholc effect at two Rather, in this case and the stove case, causation is process-like in that one property (being solid, being cold) is replaced gradually by another (being dissolved, being warm) in a continuous alteration through intcnnediate properties (being partially dissolved, being mild). The cause takes time to do its work, but the effect coincides with that time entirely. We thus have our basic model for a single causal process that takes time but nevertheless involves simultaneity of cause and effect.

Because causal processes typically take time to run their course, we have another reason why Martin's model of mutual manifestation is not satisfactory. It will be recalled (from §4.3c) that Martin likens mutual manifestation to two triangles being placed together to make a square (Martin 2008: sT). But not all powers that arc brought togethcr have their full effect immediately. The more usual case would be like the sweet solution, taking time for the process to unfold. Martin's analogy would, to account for this, have to allow that the two triangles take time to form a square, even when they have been put together. But this just shows the limitations of Martin's analogy. It is not quite what we want for causation.

There is still a problem that faces us, however, of how a causal chain can take time rather than all of its links being simultaneous with each other. This was a problem we left hanging. Even if we allow that eaeh link in a causal chain involves simultaneous causes and effects, under­stood as the development of an extended continuous process, isn't there a problem that one causal process can lead on to another that is later in time? And if we say that an earlier process causes a later one, then it looks like we have granted at least some instances where causes are temporally prior to effects. In that case, it seems that we have to concede that some causation involves simultaneity and some does not.

Examples will illustrate the issue. TIle sugar dissolves in some tea, let us assume, and the process runs its course. But then other processes follow on. Someone chinks thc tea and it tastes nice and sweet as it stimulates their tongue. Again this can be a case of simultaneous causation, as the tea tastes nicc to the person while it is passing through and lingers in their mouth. Then, when it reaches their stomach, another causal process begins. The tea warnlS them and its sugar content is gradually turned into energy and again this process can be understood in the same simultaneous way. It might then be argued that there are three distinct processes involved here - of sugar dissolving, then stimu­lating the tongue, then being turned into energy - but there are causal

A sweet solution 125

connections betwecn them even though the processes occur at different times: the sugar first dissolves, then is consumed a brief period later, and is converted to energy last of all. It seems clear that at least these causal processes are temporally separated. The sugar is consumed ten minutes after it has been fully dissolved, for instance, and is not processed in the body until after it has passed through the mouth. Yet it looks as though there are causal connections between these three, prima facie temporally distinct, causal processes. It might then be concluded that at least some cases of causation must be non-simultaneous.

We are nevertheless going to resist this conclusion. We do so by distinguishing causal episodes that arc a part of a single process from causal processes that are enabled by powers instantiated in earlier causal processes. VariOllS different processes may occur and be at different times, as the example of the sweet tea showed. Sugar was dissolved in the tea as part of a single causal process. It then sat for ten minutes before it was consumed (during which time it was cooling). It was then drunk and stimulated the tongue in a separate process, though one that overlapped temporally with the one in which the body converted it to energy. The laS1 process was underway, we can assume, as soon as 1he first tea hit the stomach and while the rest of the tea was still being consumed. The analogy of a causal 'chain' is clearly limited, howcvcr. The sugar being dissolved did not cause the sweet tea to be dnmk. It may have enabled the drinking of sweet tea, in being an indispensable part of an explanation of how the sweet tea camc to be dmnk, but it didn't. cause it. An enabler does not produce a certai n effect e on its own, but it could be part of such a production if it met appropriate manifestation partners. for e. A single causal process may unfold in a ceJtain way and naturally dispose towards a certain out.come. A collection of causal powers might be able to do this work without any further assistance. But there are properties along the way, during this process and at its end, which may then provide huther powers for fUlther causal processes if they meet other mutual manifestation partners.

Propelties, according to the pandispositionalist view, are taken to be clusters of causal powers. The manifestation of a power or set of composed powers will typically be in a movement within a quality space. This means a change in properties and thus, by pandispositional­ism, a change in causal powers. During a single simultaneous causal process, therefore, a number of other causal powers will be instantiated, though some only fleetingly. A new and distinct causal process could be triggered, therefore, if one such power meets its mutual manifestation

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126 Simultaneity

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FIGURE 5.2: Overlapping causal processes

partner(s). What we will have, therefore, is a serie::; of temporally over­lapping causal processes, each of which starts when an arising power -one that is instantiated in some other process - meets a new partner. Each of these processes will be operating on separate quality spaces QJ to <2n (di::;tingulshed vertically). Thl::; is illustrated in figure 5.2.

A key point to note in this model is that one causal process is not seen as the cause of another but only as an enabler; thu::;, we do not need to invoke causltion between temporally distinct events. Is this a mere ad hoc dodge to avoid temporal priority in causation? No. According to the causal dispositionalist theory, the cause of each process is the various mutual manifestation powers that, having come together, do their joint work and go through a t.ransformation: a change of properties. How these powers came to be assembled is another stOlY, which we have told in terms of new powers arising during the running of other causal processes. As causation typically involves changes, it thereby makes new powers available for composition and thus instigation of new causal processes. But it would be wrong to think of this as one process causing another in a sequential temporally separated chain. All it does is con­tribute a power or powers to a further process that might occur if the other partners for that process also become available.

We can also think of this in terms of polygeny in which causes form a backwards cone (see Moore 2009: 276), as in figure 5.T the further hack in time one goes from an effect, the more causal ancestors it has. Our first causal process will not be the total cause of a second one because that will involve many other powers besides. All our process does is provide one or some of the powers for a further process, and that is not the same as causing that process on its own. Just as dropping the sugar in

A sweet solution 127

• •

FIGURE 5.3: The backwards causal cone

the tea is not the cause of its dissolving, but only the story of how it came to be in a place where it would dissolve, so the providing of a power that contlihutes towards a process is not the same as the causation that goes on once that process is underway. What., though, if one process con­tributes all the powers that lead on to another process? We see no reason in principle why this situation couldn't arise, but we also see no rea::;on why we should not give the same response. One reaction is that this further process should just be bett.er understood as a part of t.he original process, rather than a new one in its own right. But there may be a point in a process, at some point after it is already underway, where a group of powers happen to come together and initiate a whole new causal pro­cess. Again, simultaneity of causation can be preserved if we tell the same kind of story. One process merely provides the powers for another, rather than causes it. One can put the sugar in the tea but never drink it. But once the tea is drunk, the processes start in the stomach to break down the sugar and tum it into energy (provided that one's body is capable of breaking down the sugar and so on). The difference between the single process st01Y and the two separate processes story may come down to whether the second process arises as an integral patt of the first process or follows because of a contingent compresence of mutual manifestation pm1ners.

The account given of causal processes understood in telms of simul­taneity thus counts strongly against the causal chain idea in which there is a succession of events in time, each causally connected by a relation that involves temporal priority. Instead, we can have any number of overlapping processes, some of which enable each other and contribute 10 each other but not in a way that should be understood by the

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T28 Simultaneity

dispositionalist as causal. W~ thus move away from the causal chain metaphor to the causal cone. Having allowed for simultaneous but temporally extended causal processes, we can now note a pay-off. There may be a worry about the cone that, as each new power requires a number of powers for its origin, the world could run out of powers. A large number of powers at one stage would causally produce a smaller number of powers at the next stage, and so on, until all the powers are reduced to onc. Similarly, we all have two ancestors, both of which have two ancestors, and so Oll. Thus, a great many ancestors are needed to produce one single person. But we can now sec why there is no real danger of the world running out of powers. Each person has the ability to produce more than one other person. When powers come together they produce an effect, which is either partially or fully realized according to whether the process has run its course or is only partially complete. But at each stage, in the case of change, there are new properties instan­tiated. Each of these properties is, for pandispositionalism, a cluster of causal powers. For complex properties, these will be clusters of many powers (Mumford 2004: 171) and these can contribute to many other causal processes. Just as we have one cone in which powers funnel into ever fewer and fewer powers by coming together polygcnically to produce effects, so we have a cone that works in the opposite direction where powers proliferate through their interaction (figure 5.4). This is the pleiotropy of powers: one power can be involved in the product.ion of many different effects. A property can consist of many powers and,

FIGURE 5-4: The forwards causal cone

A sweet solution 129

when they produce more properties through their own causal actions, they can proliferate further. There is no danger, then, that the world will run out of powers.

This concludes OUT discussion of temporal priority versus simultane­ity in causation. We will be returning to it, however, when we consider the perception of causation. In chapter 9, it will be argued that causation is perceptible in a way that Hume denied. Depicting it as a process, rather than as an invisible tie between two distinct events, is one step in the argument for the perceptual accessibility of causes as powers. There are a number of other issues to be explored first, however, and some of them will show why the issue of the perception of causes is such an

important one.

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6

Explanation, Absences and Counterfactuals

6.1 Epistemology and metaphysics

Causation is often invoked in explanation and prediction, though not always so. There can be non-causal explanations and predictions, but they are not our topic here. Thus far, the concerns of this theory of causation have been primarily metaphysical, but the ambition is not solely a metaphysical one. It is unlikely that we would have so much interest in causation if it were not for the central role it plays in explanation and prediction: a point which rather puts an onus on us to show how the metaphysical theory that has been developed accords with more familiar epistemic concems.

True and relevant causal explanations tend to be satisfactory explana­tions. When some event in the natural world stands in need of explana­tion, causal explanation fits the bill. A house has bumt down, for mstance, and we want an explanation for an insurance claim. That there was an electrical fault that created a spark, which ignited some papers, if true, could be a good explanation. There are other constraints, however, that can make something a good or bad explanation. Was there, at the same time, an even more obvious and more contributory cause of the house fire? Did the burning papers only set light to the house via some deviant causal chain? If either of these two factors is the case, then something may be a true causal explanation without being a good one.

Predictions can also be causally based.. Given our accumulated. causal knowledge, we can predict that jf there is a pile of burning papers in a house, the whole house could easily catch light. Such predictions are very often important in actions, as we frequently act based on a predic­tion of the likely consequences - often causal consequences - of what we do. In planning a shot in snooker, for instance, you predict on the basis of your causal knowledge where the object ball will move once you hit the cue ball into it. Apatt from the case of action, however, it seems a commonplace that we have expectations about, and predict on

Explanation

the basis of, causal knowledge. You expect the sugar to dissolve in your tea. An eXpcIt predicts more global warming based on their knowledge of increased levels of carbon dioxide and an understanding of what that does to the enviIornnent.

As well as dealing directly with the issues of explanation and prediction, this chapter also addresses related issues. The first is causation by absence, which might he the basis of an alleged counterexample 10 the central theory. It hac') been argued that causation occurs when powers are exer­cised. A possible objection, however, is that there are some cases of causation bv absence in which there arc no powers at work, [or instance, lack of ins~lin causing diabetes or lack of oxygen causing suffocation. A response must be provided to this objection. The reason such a response appears here is that causation by absence should be understood in telIDS of our explanatory practices rather than as a case of genuine causation. There arc indeed no powers at work, if we really do have an absence. An absence is powerless. But there are nevertheless good reasons why absences are invoked in explanation of some phenomena. To understand why, we need to turn to epistemology rather than metaphysics. Certainly, there is a temptation 10 treat causatiuIl Ly absence as metaphysically real but, it will be argued later, it is better if we understand it as an cpistemic issue.

An interesting consequence follows from the treatment of causation by absence, which concerns the analysis of causation in terms of COU11-

terfactual dependence. Pollowing the influential work of Lewis, this theory has a great deal of popularity and sets the agenda for many of the current debates. 'What is said of causation by absence can, however, be transfened to the issue of counterfactual dependence. The chapter will end by consideling the truthmakers of any such counterfactuals but also the prior issue to that of whether it really is the case that whenever a is a cause of h, there is a true counterfactual that, had a not been the case, b would not have been the case.

The problems in this chapter are united, therefore, in all having an epistemic or pragmatic focus. Such problems may appear insoluble if we seek a merely metaphysical answer and we should avoid doing so.

6.2 Explanation

First we begin with explanation and will then move on to prediction, though a disposilionalist will have the same point to make in relation to both, namely, an anti-dcductivist one.

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132 Explanation, Absences and Counter/actuals

To give a causal explanation is to explain some phenomenon (the explanandum) in terms of one or morc of its causes (see Lewis 1986c). In the contcxt of the current theory, this means that the explanation works by naming one or more of the powers that produced the expJa­nandum. Power(s) will thus be the explanans. The flourishing of a plant, for instance, can be explained by it receiving a good balance of air, water and sunlight, where all these factors dispose towards plant health. Anything that would be truly represented as a vector disposing towards this particular plant's health could thus be a legitimate causal explana­tion of this particular cxplanandum.

This shows why there can be many different but true causal explana­tions of the same phenomenon. Consider all the possible causes of a bush fire. There were prolonged high temperatures, there was a dry forest, there were high winds, and there were arsonists and people who were carelessly disposing of cigarette butts. Assuming that all these factors polygenically contributed in some way to the bush fire, then all of them m'e legitimate causal explanations of it. They each pick out a causal factor which contributed to the bush fire taking hold or occurring in the specific way it did. This is what it is [or something to be a causal explanation (see §2.5, above).

We nevertheless might at times speak of the causal explanation, as if there is only one. There arc two things that could be meant by this. One is Mill's total cause, which inc1udes all the causal powers that con­tributed positively towards the elfect (sec Mill 1843' 1II.v.3: 217; and also Lewis I986c: 2 I4). 1lle other thing that might be meant IS one of the causal powers being picked out as being of special importance or privileged in some way. It is implausible, however, that any such privileging has a special metaphysical status. Instead, that status should be understood in epistemic or pragmatic terms. That something is the cause of an effect, in this privileging sense, need not mean that it is the biggest contributing power. The point of the straw that broke the camel's hack is that the addition of a very small power can be the one that allows a situation to reach a threshold. The straw is the final power that is added. But, again, it need not always be the final power that is privileged. The cause of the bush fire may be singled out as the hot d,y weather, even though the final factor that was added was the dropping of a cigarette butt. What we are likely to single out as the most important causal factor is almost certainly an interest relative matter. The meteorologist blames the weather but the criminologist blmnes the arsonist.

Explanation 133

There is an objection to this approach based on the accusation that powers or dispositions would be ill suited to playa rok in causal explana­tion. Dispositions, it is sometimes argued, are vacuous causal explainers: no better than the virtutes dormitivae in explanation of something causing sleep. This view docs not, however, acknowledge the rich variety of ways in which dispositional explanation can be used. There are some contexts in which dispositional explanation is trivial but still many contexts in which it is not. If one asked for the cause of sleep and was simply told that something had a donnitive viltue, then this may be urunfOlTI1ativc. The reason for this, however, is that dispositions aTe picked out entirely by their causal or functional role. If dormitive just means something that can cause sleep, if ingested, then it is not an informative explanation of the cause of such sleep. If disposition ascriptions pick out a propeliy in the manner of 'the cause of G', then they offer only trivial causal explanations of the cause of G (Mumford 1998: 139-41).

There are, nevertheless, many cases in which dispositional explana­tion is non-trivial and, further, it is arguable that such explanation is in any case indispensable. If we seek an explanation of why someone fell asleep unexpectedly, for instance, in the middle of the afternoon, then identifying something that has a power to induce sleep will very often be infonnative. The person could just have been very tired after missing a night's sleep, they could be ill, they could have narcolepsy, or they could havc been hypnotized into sleep. Finding that they slept because they had too much wine with their lunch, which has a known dormitive virtue, is explanatory because it offers new infonnation. This explana­tion could be true, while none of the others are. And the explanation could also be falsified, thus cannot be merely trivial. There is nothing in principle that rules out a discovery that wine is not, after all, donuitive. There might be nothing in it that disposes towards sleep. The meal might be what induces sleep and wine is merely an accompaniment to the meal, which then gets incorrectly blamed for sleep.

As has been detailed elsewhere, there have been attempts to offer explanations that are disposit.ion-free or law-free. McMullin (1978) offered hypothetico-structural explanations, such as the molecular struc­ture of glass explaining its fragility. Such explanations leave an explan­atory gap, however, if they fail to connect such structures with causal roles. Knowing the structure that something has does not in itself causally explain that thing's behaviour unless we also know what S011S

of behaviour a thing of that structure can cause. An extra premise will have to supply such a causal Iok and McMullin's cxamples look

:1 I 134 Rxplanat;on, Absences and Counterfactuals

plausible only because they make a tacit appeal to such causal roles (see Mumford 1998: 131). Disposition ascriptions are a way of picking out the causal rolc. That cansal role can in many cases be given further explanation because powers arc often nested within each other. The disposition of a car to move along the road, for instance, is a higher-level disposition relative to its many component powers. It is produced by the causal powers of the engine and vehicle superstructure. The powers of the engine are produced by the powers of the component parls, such as the carburettor, spark plugs and combustion chamber. The morc we know about these constituent powers, the deeper can become our causal understanding of a situation.

Dispositions can. thus, play an explanatory role. This may indeed be an indispensable explanatory role. But explanation is also important for dispositions in another way. A distinction 1s frequently drawn in causal processes between the stimulus, the disposition and the manifestation. It might be tempting to judge from this distinction that we have three kinds of entity, where there is a move from one to another during the process. Here is a case, however, where it would be an error to take what is an epistemological distinction for a metaphysical division. According to pandispositionalism, all of stimulus, disposition and manifestation are powers. Stimnlus and disposition are jusl two ways of picking out distinct powers, each of which contributes, to an effect. The manifesta­tion is at the end of the process but it too 1S just a power for a further effect. The basis on which we distinguish these things is not, therefore, metaphysical. They are all on an ontological par. It is, rather, their places within a particular causal sequcncc, or type of causal sequence, that interests us, and that dictates whether they arc identified as stimulus, disposition or manifestation. A stimulus, which can also be thought of as a triggering condition, would just be the tinal power that gets added, which pushes an accumulation of powers over a threshold. Thus, a pan of milk may be warming gently without reaching its boiling point. Turning up the heat on the cooker might, however, be the extra power that takes the situation over the threshold for boiling. TIns disposition of the milk to boil, in contrast, is a power that is there throughout, both before and after the heat is turned up. The manifestation is the bubbling and rising on the milk, sometimes spilling over. In boiling, the milk clearly has new powers that it did not have before that threshold was passed: for instance, to scald human skin. All are powers, therefore, and it is their explanatory places within the causal process of interest to us that is the basis for any distinction that is drawn.

Prediction 135

6,3 Prediction

As 1n the case of explanation, predictions could be made on another basis than causal, but the concenl here is with only causally based prediction. This will be prediction based on OUf causal knowledge of a situation and the powers that are at work. Knowing what powers are present, how they work (ogether, and whether (here will be any emer­gent phenomena, allows us to make predictions about outcomes. The more we know about the situation, the better our prediction will be.

What makes a good, a better or worse prediction, need not be deter­mined entirely by whether it would be a correct or true outcome that was borne out by the eventual facts. That would trivialize the notion of a good or better prediction. When one calls 'heads' at the toss of a coin, there is a 50 per cent chance of calling right, but if one does so, one has not made a good prediction. It is reasonable to assume that one had no better knowledge or understanding dictating that heads would be the outcome than one had for tails being the outcome. Instead, a good prediction would be one based on the evidence and where the more relevant evidence is included, the better the prediction is, even if it turns out to be false. Meteorologists, for example, consider a wide range of atmospheric phenomena when making their five-day forecast. They might consider all the availabJe good evidence, as understood by the latest thinking and tcchniques. What determines the weather, however, are the many competing powers, some of which are still outside Olir understanding. Suppose someone else makes a five-day forecast at the same time but based on the use of dowsing rods. On the fifth day, the dowsing rod forecast may tum out to be doser to the truth than the meteorologically based forecast. It would entirely trivialize the matter, however, to say that the rod forecast was the better one simply because its prediction was closer to the truth. This is not to deny, however, that if the rod forecast was consistently closer to the truth than the meteorolog­ical one, thcn the meteorologists should reflect critically on their prac­tices. A good forecast should tend to be right even though sometimes it can fall.

The basic suggestion, then, is that to know about the powers of various things is to have a basis for predicting their behaviour. Knowing that the match has a flammable tip is a basis for predicting that if it is struck along a rough surface in a certain way, it will light. Knowing that a coin has a certain shape and weight distribution is a basis on which to

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l!.xplanation. Absences and Counterfactuals

predict that if it were tossed, ~hlch it might never be, it would have just as much chance of landing on the head as landing on the tail. Given the complexity or polygeny that is at work in almost all the cases of causation of which we have experience, the bettcr predictions will be those that accommodate more of the operative powers. If the match is struck in windy conditions, for instance, then one might wish to revise a prediction that it will light.

The key point is that a relatively good causal prediction is nevcIihe­less a fallible one. Predictions should be thought of as defeasible in that one should be willing to revise them in the light of new, relevant evidence. This seems the right thing to say in relation to prediction irrespective of one's theOl)' of causation. But it can be noted how well the point sits with causal dispositionalism. The anti -necessitarian view gives liS an explanation of why predictions fail: extra powers can intervene. An assembled set of powers does not necessitate an outcome, even if there are many situations in which it indeed succeeds in produc­ing such an outcome. The addition of extra powers could always result in prevention or interference. Similarly, we can see that there will be no guarantee that a causal explanation is correct, even if it is one that is well grounded in the evidence. Powers may be invoked by way of explana­tion, and they may well have been present, yet they might not have been the powers that produced the explanandum. Some unknown and unex­pected thing might instead have been the true explanans, such as where a deviant process was at work. This suggests that we require a general account of explanation that docs not depend on the explanation necessi­tating the explanandum or the prediction necessitating that which is predicted. There is such an account.

6-4 Models

Both explanation and prediction work by reference to a model, which is understood as constituted by a set of parameters and assumptions. The number of assumptions made is finite, which it has to be for an explana­tion or prediction to be calculated. Parameters have to he assumed. In any quantities that are included in the model, a decision has to be made, for instance, as to how many decimal places should be specified. In the case in hand, the model will consist in a set of assumptions about the powers that are relevant for the effect in question, whether that is an effect to be explained or one to be predicted. The vector diagrams that havc been

Anti-deductivism 137

presented in chapter 2 are thus a way of representing such a modeL They depict a finite number of powers contributing towards a certain effect. .Prom such a model, a prediction can be made as to the effect produced. In explanation, such a model is constructed from a known effect.

It is possible that predictions be made with deductive certainty, but the clUcial point is that such certainty exists only within the model. As soon as the model is applied to the world itself, there is always a chance that the prediction fails. The reason, of course, is that certain powers may be inlluential in the actual outcome that were not included within the original model. It is the limitations of the model that result in its predictive failure. In the case of quantitative phenomena, for instance, there are the kinds of 'chaotic' cases discussed in §4.3c, where some slight variation from the model leads to a noticeably different effect. In theory, it is possible that this slight difference is simply uuspecificd because the model was based on only a certain number of decimal places. The significant factor may have been found if only a fmiher decimal place had been specified and yet this makes all the difference concerning whether a certain threshold is passed or noL The most obvious inade­quacy of a model is, however, simply that some further power may be at

work in the world that was not included in the finite modeL Predictions are thus defeasible in the case of there being some such further factor.

Explanations, on the other hand, do not fail but arc either true or false, accurate or inaccurate, useful or useless. The model is reconstructed fTom what is known of the powers present and knowledge of how they would combine to produce the explaoandum. Explanation and predic­tion are linked by the notion of the model in that the same model that is reconstructed for purposes of explanation can then be used for purposes of prediction. But the same issues arise with respect to the model. It could fail to mirror the facts. It is based 00 a finite number of factors being present and may miss somethlng that wa.. .... actually present and influential. An explanation of a disease, for instance, may be inaccurate because it fails to include some vital bacterium. If that explanatory model is then used as a basis on which to make predictions, then those predictions may fail to be borne out.

6.5 Anti-deductivism

What form of explanation is being utilized in such cases, then? Is there a kind of explanation that fits causal dispositionalism well and any kind of

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explanation that would fit it badly? The key claim here is that lhe dispositional framework leans towards an anti-deductivlst account of explanation for natural phenomena. This, however, seems to be an advantage of the account because there are already prima facie reasons for favouring an anti-deductivist framework for explanation.

The dispositionalist theory of causation has it that a cause never necessitates its effect but only disposes towards ii. There might be a worry about this, however, that it means we can never know our explanations to be true with certainty and we could never know for sure that our predictIons arc light. The necessitarian view, in contrast, at least in principle offers us: the hope that if we knew all the causes, an effect could be predicted with certainty. Necessity in tile world would give us a grounding for such certainty.

There is a further theoretical motivation for a deductivist account of explanation. The deductivist will exploit the thought that some phenom­enon R is explained by ;1 only if B is deducible from A, where A perhaps entails B. Deductive-nomological explanation exploits the appeal of this thought. From the premises that:

(1) A rat r has just eaten ten pellets of poison,

and

(2) If any rat eats at least three pellets of poison it will die within one hour,

we can predict that

(3) Rat r will die within one hour.

This is because (I) and (2) entail (3). Similarly, we can explain (3) in terms of (I), if we all"eady know (2) (or in tefms of (2) if we already know (I)), or we can explain (3) by (1) and (2) together.

It is tempting to think that entailment is the only adequate kind of explanation because of the idea that if A does not entail B, it must have fallen shOlt of (fully) explaining it. There might still seem to be some­thing of an explanatory gap. Perhaps there is a missing premise or missing informat.ion that, were it added to A, would indeed entail B and only this, bolstered-A, is the true explanation of B.

Dispositionalism is not well placed to provide such an entailment. According to this view, no causal process necessitates its effect. There is, therefore, no ontological grounding that would underwrite the entail­ment of one thing by another. Deductive-nomological explanation could not, therefore, accurately minor the world. In the above example,

Anti-deductivism 139

premise (2) slates lhat any rat that eats the poison will die. The disposi­tional view carmot accept this as a true premise, however. In theory, a rat could eat three poison pellets but also eat the antidote. Or a rat could have developed an immunity to the poison. For a disposilionalist, therefore, premise (2) would have to be replaced with something like:

(2*) If any rat eats at least three pellets of poison it is disposed to die within one hour.

Being disposed to die within an hour does not entail dying within an hour because of the possibility of intelference and prevention, that is, some antecedent .strengthening consideration. Altering the premise in this way, however, means of course that (3) will no longer follow. All we can make, instead, is the defeasible conclusion that rat r is disposed to die within one hour, which itself is not even a prediction: it is merely a statement that r has a disposition. This is not to deny that we can predict the acquisition of a disposition, to die, for instance, if a rat has eaten poison.

As has already been stated, however, that prediction is of this nature seems more plausible than the prediction of the deductive-nomological theory. It ought to be acknowledged, inespectivc of any dispositionalist considerations, that predictions can fail. Now why do they faj1? Accord­ing to the deductive-nomological model, if a prediction fails it must be because one or more of the premises was false. If this is the case, however, a revised premise would still have the samc basic form as the one it replaced. But according to thc dispositionalist, the basic fonn of one of t.he premises is always mistaken and inappropriate in any case. The premise that is a conditional states that if the antecedent circum­stances obtain, the consequent cUTumstances do also. But we have already seen reasons to believe that nothing in causal processes behaves this way. If we alter that premise to one with the correct fonn - of a conditional whose consequent is a disposition ascription - then it does not even leave us with a prediction. All it then would entail is the presence of that disposition, which asserts nothing about what will happen, only about what is disposed to happen.

Predictions are thus defeasible and that we should always counte­nance revising them in the light of new information. The rat has eaten the poison, for instance, but it also ate the antidote. Upon hearing this second fact, we ought to be prepared to alter an initial prediction that it will die. The raL might of course still die, even if it gets thc antidote. The antidote is also no more than disposing towards counteracting the poison, and the poison might manage t.o do enough of its causal work

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before the antidote kicks in. Explanations are also defeasible in the sense that they will always be open for revision in the light of new infonna­tiOil. A model may be offered of what explains some palticular effect, and that effect may be entailed by the model, within the model, but an alternative model that includes some extra factor may be the true onc.

Dispositionalism fits these data welL It allows that we can never know an explanation to be truc, or a prediction accurate, with absolute cer­tainty. It nevertheless allows that prediction and explanation can be rational even though they are defeasible. It accepts that one natural phenomenon could be deduced from another distinct natural phenome­non only if one necessitated the other, which in the case of causation it never does. Dispositionalism underwrites, therefore, only a non-deduc­tive explanation. Deductivism is thus judged to be over-ambitious. Again, this is not to deny that certain deductions about dispositions can bc made (for example: If A , then B is disposed to happen. A happens. Therefore, B is disposed to happen).

What, though, of the alleged explanatory gap that would be left if deductivism were rejected? The dispositionalist will almost always be ahle to fill such a gap. W11ere a prediction fails, for instance, they might be able to identify the reason: some additional power that was not included in the original model. In some cases, the gap cannot be filled, however. If there were to be irreducibly probabilistic causation, (hen some effect that is 'only' probable might nevertheless be caused, even though there was nothing that necessitated it. Again, the dispositionalist can accommodate this.

Summing up thus far, the dispositionalist should favour a non-deduc­tive account of explanation. The powers invoked in explanation and prediction will not entail any particular outcome. Rather, they only dispose towards those outcomes. A could be a rational basis for explain­ing or predicting B even where A does not necessitate B. It may tend or dispose towards B only. This is to say that something else could be added to A such that B docs not then occur, which seems to be something we ought to accept. The more we know about the powers at work. the better our explanation::; and predictions will be.

6,6 Inductive inference

Given the dispositionalist framework, there is also something that can be said about the infamous 'problem of induction'. Inductive inferences

Inductive inference 141

sometimes concern natural processes, though not all need do. That all ravens are black, for instance, has been thought of as a possible conclu­sion of an inductive inference but it is almost certainly not a causal one (see chapter 7). Unless one argued that being a raven is a cause of being black, which is dubious, this inference is about the accompanying of a natural kind (ravens) with some superficial quality (blackncss). Even if this particular inductive inference does not concern a causal process, however, many others surely do. If one thinks that the falling to the ground of an apple is a causal process, with gravitational attraction doing the causing, thcn one might think that there is an inductive inference to be made that produces a general causal truth: that all unsupported apples fall to the ground. Similarly. one might aim to conclude inductively that all helium-filled balloons rise, that all bread nourishes, that all struck billiard balls move, all fiuit exposed to air decays, all beheaded people die, all ignited wood bums, and so on.

The justification of induction is a task that historically has distracted philosophers of science, many of them seeing such a justification as a primary task of their subject. In the abstract, the problem was how, from all the particular pieces of knowledge we acquire, such as that a is F and G, b is F and G, C is F and G, and so on, we might come to some general knowledge that anything that is F is also O. In the case of causal knowledge, the required inference would be from many single truths that something's being F causes it to be G to the general claim that anything that is F is caused to be G. Bacon (1620) had the ambition of producing a foolproof method that would, almost mechanically, issue in an inductive generalization that was absolutely secure. His Novum Organum supposedly did this. It is easy to undcrmine such security, however, as Popper (1959) in modern times and Hume (1739: !.iii.6) before that showed. Inductive inferences are deductively invalid so can never be a matter of certainty. The conclusion that all things that are F are G could be false, even though the premise that all observed things that are Fare G is true.

According to the dispositionalist theory, however, there is no 'prob­lem' of induction as such: it is a pseudo-problem. For x being F to be a cause of x being 0 does not. require that the first necessitates the second, nor even that there be a constant conjunction bet ween Fx and Gx. There should never he a valid path to a ,e:eneral causal truth of t.he form '\Ix (py

-----\0 Gx) from any number of particular causal truths. We allow that there are some general causal truths, such as that smoking causes cancer, but these have t.o be understood dispositionally rather than as absolute

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regularities. Particular a being F may indeed cause it also to be G, and b being F may cause it to be G, and so on for further particulars c, d, c. But such particular causal 'successes' for F, where it manifests its power to produce G, should never be understood as meaning that everything that is F will produce G. On the dispositionaiist view, there is always the possibility that the next thing that is F be prevented from causing G, Although the inference from particular instances of F causing G to every F causing G is an insecure one, therefore, it is dghtly so. It is entirely appropriate that we cannot infer a general uniformity from partic­ular causal truths insofar as the lack of any secure infercnce mirrors logico­linguistically the metaphysical lack of necessity in causation itself.

Hume had considered, and dismissed, an attempted solution to the problem of induction based on the adoption of a unifOlmity of nature principle (Hume 1739: 89), His ground for rejecting this proposal was that it couldn't jut>tify induction because it was itself the conclusion of an inductive argument. The 'justification' of induction would then be circular. But there is another reason to reject this approach. The unifor­mity of nature principle, if it means absolute regularity, is simply false. Not everyone who smokes gets cancer, not all bread nourishes, and so OIl. Nature is not strictly uniform, even if some things tend to be the case. This point applies also to the non-causal inductive inferences. Not every raven is black. Some may be albinos, have lost their plumage, or have some other abnonnality.

If we do find absolute unifonnity, it is more likely from some other source (this is taken up in chapter 7). All electrons are indeed negatively charged, for instance. But the reason for this is that it is an essential property of being an electron that something be negatively charged. It would not be an electron otherwise. But our knowledge that all electrons are negatively charged is not then gained by induction. This illustrates Strawson's point that if we have deductive certainty for a general truth, for that VCIY reason it would have ceased to he an inductive argument (see Slrawson 1952: ch, 9), Nevertheless, Ellis (2002: 134-7) does indeed suggest a solution to the problem of induction derived from essentialism. Applied to causation, essentialism tells us that being a cause of G is essential to something being F. But we can see that, contrary to Ellis's suggestion, this does not entail that \:Ix (Fx .....-+ Gx). The essential truths in question are nothing more than that being F (causally) disposes it towards G, as an essential part of what it is to he F. What is necessitated, therefore, is only that each F is disposed towards G. This could indeed be the case, and even necessarily so. But

Causation by ahsence 143

it does not tell us that eveIYthing that is F is actually also a G because it causes it to be so. It is this conclusion that the Oliginal inductive inferences sought. The quest was for occurrent ~U1d general causal facts: about what actually happens in general, not about what is disposed to happen,

A 'solution' to the 'problem' of induction was, then, misconceived by the lights of the dispositional theory. There are no, or at least need be no, occurrent general causal truths. But there can, nevertheless, bc somc dispositional general causal claims. Being F can dispose towards being G, and this does not and need not entail the regularity that \Ix (Fx ~ Gx), Nature may well contain few, if any, causal truths of this general occurrent fonn, in which case the search for a method that produces such statements as the conclusion of a sound argument is also not a goal worth seeking.

Do we have something like induction, however? We believe there aTe many dispositional general causal truths, for instancc, such as that smoking causes cancer. Is this known by some kind of inductive argu­ment: perhaps a non-necessitating one that avoids conclusions about ausolute uniformities? There may he some such considera6ons. It de­pends on what we decide is the best scientific methodology. Certainly a less-than-uniform tendency is something that can be discovered empiri­cally, through statistics for instance. Hence we might note that smokers tend to get ill more than non-smokers, when we screen off other factors. But we also should allow that onc well-conducted experiment, or a good mechanistic knowledge of the powers involved, might do an equally good job of teaching us this.

6,7 Causation by absence

A theory of causation has been developed, the basic tenet of which is that a cause is something that disposes towards its effect. All causation, on this view, is powers at work. An effect is caused when a disposition or dispositions exercise.

There is, however, an alleged case of causation that would be a counterexample to this view. Some people think that absences can be causes, as in the cases where we think that absence of water causes a plant to die, lack of insulin causes diabetes or vitamin C deficiency causes scurvy (see for instance Schaffer 2004). Assuming such absences really are nothing at all, then they pose a flu'cat for the theory because it

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144 Explanation, Absences and Counterfactuals

seems that there are no powers present that are doing the causing. The claim seems to be that it is a complete lack of something - a nothingness - that is doing the causa] work. Someone suffocates, for in-.tance, from lack of oxygen. There is no oxygen present in their lungs and it is alleged that this very absence of something is the cause of a human death.

There may, of course, be cases where something sounds Eke an absence, though it is not really so. These are not the cases that would present a problem for the theory. A rod might lack rigidity, for instance, but where a lack of rigidity is the same thing as the presence of flexibil­ity, which we assume is a real property. The cases that would really trouble the theory are those where nothing at all is supposed to be nevertheless doing causal work. Such an absence, lack or nothingness, is not merely something else in disguise.

The problem is, then, that there is an apparcnt nothingness that is involved in causation. In this case, the absence is the cause, though as J)owe (2001) notes, there are also reasons to puzzle over cases where the absence is the effect. We find this second case less problematic and have treated it in §2-4 as a case wherc the effect is an equilibrium (see figure 2.7). Causation by absence is the bigger problem fOT us. Tl11.TC are, however, various possible responses that could be made by way of explaining it, or explaining it away:

A. Reify absences (reification) B. Allow that absences can have powers (empowerment) C. Deny that. claims of causation by absences are tme (denial)

Reijication is an attempt to make a nothing into a something and, in that respect, is somewhat self-destructive of the notion of causation by absencc. The reason causation by absence is problematic is precisely because nothing is supposed to be doing the causing. If that nothing is then given some kind of being, then the causing is, after all, being done by something and the problem dissolves. Perhaps the suggestion wou Id be that ahsences and lacks exist in some sense but not t.he same sense as all the other things that exist ordinarily. This might be one way of kecping absences distinct from other things but it comes at the price of dividing existence. As originally set out, realism has as its central claim that there are no degrees of being: no bifurcation of reality. Existence is univocal (see Mumford 2007b: ch. 1 for an account of Armstrong and John Anderson on realism, and Molnar 2003: 21). It would thus not he attractive to a realist to accept absences as 'real' in some attenuated sense.

Causation by absence 145

Since the rise of realism in metaphysics, reification of absences has not tcnded to be a position someone would explicitly support. It could very easily, however, be an implication of someone's position if they supported fully /ledged causation by absence, as Schaffer docs. If one thought absences could be as causally powerful as presences, and one also committed to a f01m of Eleatic principle that took causal power as the mark ofreality (Plato, Sophist 247d-e), then it seems that absences would pass that test as much as anything else. Causation by absence plus the EJeatic principle then seems to entail rcification. If one's abhorrence of absences were strong, therefore, one might be more tempted to regard such an entailment as a reason to reject the premises: siding with the modus tollens of that entailment against a modus ponens.

Empowerment might offer a way out of this bind, though. The idea would be to avoid reification, while accepting causation by absence, by allowing that nothingness can nevertheless be a possessor of causal powers. Lewis (2004) seems to allow something like this when he suggests that the deadly void could pull your body apart, were you cast into it. This could, of course, slide into the first strategy, of reifica­tion. but there also seems the possibility of a view in which the causal power is real, as per the Eleatic test, but the subject in which il would inhere is not. The void itself remains completely nothing: the idea is that it is an absence of anything. But the deadly power itself is real.

There would be at least two difficulties with the strategy of empow­ering nothingness. The first is whether we would want a metaphysics in which powers arc free-floating, not inhering in anything reaL Powers are usually understood to be property-like in the sense that they inhere in, or are instantiated by, some particular: the match is flammable, the glass is fragile, the sugar is soluble, and so on. In Lewis's example, it is the void that is deadly. Yet we are also to believe, upon further consideration, that the void is really nothing at all. The void is just a name for an absence and, at this point, we are avoiding reifying that absence in any way. The power is supposed to be real, therefore, but its subject. is not. But this is rather like an object disappearing but not its shadow. If a thing ceases to exist, so too do its propel1ies and liS powers; hence Carroll's joke about the Cheshire cat vanishing while leaving behind its grin (Carroll 186s: 90). There seems to be a tempting principle of metaphysics that if a 'thing' does not exist, nor do its property instantiations.

Suppose we could overcome this first difficulty, however. That still would leave a second. Although the void, to persist with that example,

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Explanation. Absences and Counter/actuals

remains an absence, the powers it 'has' do not. The void's deadliness, within the strategy of empowcnnent, is as real as any other causal power. Is this really, then, a genuine case of causation by absence? As a way of accommodating such a kind of causation, has it really just avoided the problem by detaching the existence conditions of powers from the existence conditions of their possessors? The possessors arc absences, on the empowerment strategy, but the powers arc presences. But then the causal work is being done by something whose existence is not a threat to the dispositional theory of causation that has been offered. Real powers are doing the causal work: it is just that they belong to nothing. It is, then, not the kind of causation by absence that concems us. It is, instead, entirely consistent with the dispositionalist theory of causation because the response is one that has real, existent powers doing the causal work.

Despite the difficulties of these last two strategies, which both attempt to accommodate causation by absence, denial would perhaps be the boldest stance to take of the three. It does seem true that absence of water kills plants and lack of insulin causes diabetes. It seems entirely reasonable to assert such things. Some causation by absence claims seem downright conect, while others would be incorrect. It is not the case that absence of good reading kills plants or that lack of plutonium causes diabetes. Nevertheless, we side with the denial. Causation by absence claims are false. The challenge is, therefore, to explain why some of them nevertheless seem reasonable while others don't.

Dowe (2001) argues along the right lines when he invokes counter­factuals in place of absences as causes. The idea would then be that where we make some statement of the fonn 'absence of A caused B', what we have in mind is the counterfactual conditional that 'if A had not been the case, B would not have been the case'. Where the unwatered plant has died, therefore, it is not that the absent water had the power to kill it. Rather, we have in mind that had the plant received water, it would not have died.

The question then is in virtue of what is the eounterfactual true. There are other accounts, the most famous of which is addressed in the next section, but what is here offered as the tlUthmaker of sneh a conditional is a causal power or powers. In the case of the above cxample, the truthmakcr of the counterfactual is the power that water has to maintain plant health, together with the reciprocal power the plant has to take sustenance from water. It is nevertheless the powers that are actually present that arc causing the plant death, not the absent water. That kind

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Causation by absence '47

of answer should then be generalized so that in all cases of putative causation by absence, some other powers of things that are present are doing the causal work.

The vector model allows us to see the plausibility of this claim. In figure 6.1, we have a complex causal situation ill which there are, to begin with, two powers disposing towards F and two powers disposing towards G. They are represented by four vectors: a and h towards F and c and d towards G. Vector b is represented by a dotted line to indicate that this is a power that at some point ceases to act. ¥/hen it does so, what was once an equilibrium situation now overall disposes instead towards G: a situation indicated by the broken resultant vector R. This condenses what could be shown in two different vector models, before and after, whieh we could provide if required. What the model shows, which is the really important point, is that it is the remaining powers c and d that would cause the situation to move towards G, not the power b, which is now absent from this causal situation. In such a case, we IIlay well say that the removal of b caused x to G, but this would only be a way of gesturing towards the metaphysically more accurate claim that c and d caused x Lo Gonce b had been removed. It also gestures towards some richer contextual infOlmation. The removal of b was the occasion for c and d causing x to G, though this is not to say that the removal of h was itself also a cause of x to G. In saying that b's removal was the occasjon for the causation, we are saying in this case that nothing was happening until that point, pat1ly because of b' s contri~u~ion to the equilibrium, but that when b ceased to contribute, the remammg puwers took the situation out of equilibrium. To state all this routinely would be too much, though it is nevertheless understood tacitly, we maintain, and it is thus quite reasonable to allude to all this simply by saying that the

a

d F b

G .... .. R

FIGURE 6.1: 'Causation by absence'

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148 Explanation, Absences and Counterfactuals

absence of b caused x to G .. Thus we deny that causation by absence claims arc literally true while also offer an account of why some such claims are reasonable. Understood as elliptical for the kind of explana­tory story outlined, where removal of a power allows remaining powers to do their work, we can understand perfectly well why It is so natural to make causation by absence claims while nevertheless, metaphysical1y, absences are never real causes.

Let us return to the example of lack of water causing the plant to die. The response to this would be to say that the plant's living was a kind of equilibrium state: maintaining health through a number of changes and a number of factors. Some factors always disposed towards the plant's demise. Moisture evaporatcd from the soil and from the leaves all the time, for instancc. But other powers were disposing towards plant health. The plant had waler, which had a power to feed the plant, and it had sunlight, which allowed it to photosynthesize. Receiving water was allowing the plant to counteract the dehydrating tendencies that were working on it and thus maintain its equilibrium. Ceasing to water the plant, however, allows those dehydrating tendencies to triumph. The plant receives no water for a week, lel us suppose, and wc return from holiday to find it dcad. Was it the absence of water that caused the plant's death? Literally: no. The other remaining powers did all the causal work. But in the context, reference to the absence of water may still play an illuminating explanatory role.

The theory seems to work for all the alleged cases of causation by absence of which we know: a fire alarm not working for absence of a battery, a watch stopping for absence of a cog, a horseshoe coming lose for want of a nail, and so on. We willlcavc the topic Lhere, then, and next consider an insight that follows on from it.

6.8 Causal cotlnter!{!C'tua!s

Given this answer to the problem of causation by absence, a stance on the issue of counterfactuals also suggests itself. Where we think of an absence of a causing an effect e, it was suggested that we actually have in mind a eounterfactual that if a had occurred, e would not have OCCUlTed. Powers, of a, were then ventured as the trulhmakers of such a counterfactllal. This offers the prospect of powers always being the truthmakers of any counterlactuals that hold in causal contexts. It will be seen, however, that the relationship between causation and

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Causal counter/ar.-tuals 149

cOllllterfactuals is not a simple one and that the causal dispositionalist has reason to take a position on the issue.

PiTst, however: some context. A countcrfactual analysis of causation is suggested by Hume when he says:

we may define a cause to be an object followed by another, and where all the objects, similar to the first, are followed by objects similar to the second. Or, in other words, where, if the.first object had not been. the second fitTer had

existed. (Humc 1748: §VIIl: 56)

Humc offers two different theories of causation in this short passage. The first half descrihes a constant conjunction theory; the second half describes a cOllnterfactual dependence theory. In relatively recent times, it is the second theory that has received most attention because of the advances in the philosophy of counterfactuals, due mainly to Stalnaker (1968) and Lewis (1973). The basic intuition that motivates ~hc counter­factual dependence theory of causation is, as stated by LeWIS, that:

We think of a cause as something that makes a difference, and the difference it makes must be a difference from what would have happened without it. Had it been absent, its effects - some of them, at least, find usually all wonld have heen absent as well. (Lewis 1973: 161)

It is this counterfadual intuition that Lewis develops in his theory of causation. Essentially, causation is analysed in terms of counterfactual dependence between events and an account is offered of the trutlmlake~s of those counterfactuals. Notoriously, those counterlactuals are true Ll1

virtuc of facts about possible worlds. This -is outlined in the following:

Given any two propositions A and C, we have their counterfactual A ~--:> c: t~e proposition that if A were tmc, then C would also be true. The Opc~tlO~ 0 . ; IS

defined by a rule of truth, as follows. A 0-) C is true (at a world w) Iff eIther (1)

there are no possible ;\-worlds (in which case A U---+ C is vacuous), or (2) some A-world where C holds is closer (to w) than is any A-world where C does not hold. In other words, a counleri'actual is non-vacuously true iff it takes less of a departure frum actuality to make the consequent true along with the antec.edent than it does to make the antecedent true without the consequent. ... We dId not assume that there must always be one or more closest A-worlds. But if there are, we can simplify: A 0 :> C is nonvacuously true iff C holds at all the closest A-worlds. (Lewis 1973: 164)

The notion of greater or lesser deparlUIe~ from reality is crucial to the analysis. In considering a counterfactual, A 0----+ C, Lewis urges tl~lat we keep as much else as possible fixed, consistent with the cOlUlterlactual

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assumption that A. We arc considering what would be the case if A -which is not the case - were the casco In doing so, our intention is to consider the situation where everything else is the same, consistent with the truth of A. We should not, therefore, make any gratuitous assump­tions about other things being different. We want to consider, for instance, what would have happened had we struck this match, assuming everything else to be as far as possible the same as the actual situation. Causation is thus analysed in terms of such counterfactuals and, when it comes to the truth of those counterfacluals, Lewis offers his possible worlds account. In those terms, therefore, we are interested in the closest possible worlds to ours in which A is thc case (and ours could be the closest world if A is indeed the case in our world). These tend to be worlds with the same laws of nature as ours, for instance, and containing as many of the same facts as our world, consjstent with A being the case. But neither of these are sacred. Closeness of worlds has to be an overall judgement and sometimes a world with different laws might be closer to our world than one with the same laws but many different matters of fact.

The simplest thing for the dispositionalist to say about Lewis's theory would be to accept the counterfactual analysis but disagree over the truthmakers of those counterfactuals. It is tempting to grant the cQunterfactual intuition but offer powers as the truthmakers of the countenactuals instead of a plurality of other concrete worlds. Assum­ing that the match was not struck, a few moments ago, then the reason it would have lit if struck is because it had a power to do so, rather than because of what happens at other, spatioternporally isolated worlds. The debate between the dispositionalist and the Lewisial1 would then come down to the matter of whether powers or possible worlds are the best trutlnnakers. A dispositionalist may feel confident of victory. We have at least some epistemic access to powers (see chapter 9) and thus some independent grounds for believing that they exist. But Lewis's other possible worlds are not even spatiotemporally continuous with ours so we can have no experience at all of them. The only reason Lewis can offer us as grounds for believing in them is thc explanatory utility they have within his theory. But that might tempt us to think that if we can find some other explanation, in tenns of something better epistemically grounded, then we should prefer that. In short, powers arc this~worldly and one-worldly truthmakers for counlerfactuaIs and we can thus know them, use them, and interact with them. The plurality of worlds has none of these features. They are, literally, out of this world.

Causal counterfactuals

This, however, would only be the simple answer - to accept the counterfactuals and fight over their truthmakers - and it would be a tempting fight to enter. But it is not, on rellcetion, how the causal dispositionalist should go. For the dispositionalist, the eountcrfaetual analysis itself is questionable.

In the first place, supposing there was a one~to-one correlation to be found between the causal truths and counterfactuaIs, that still would not mean that the fonner were to be analysed in terms of the latter. There is an obvious Euthyphro question to be asked where we have the biconditional:

Bi: (c caused e) jf and only if (e counterfactually depended on c).

Is it tme that c caused e beeause e counteriactually depended on c; or did e counterfactually depend on c preciscly because c caused e? The causal dispositionalist takes powers or dispositions to be basic and the truth of counterfactuals 10 be secondary and parasitic. In contrast, Lewis makes use of the counterfactual analysis as part. of his project of Humean supervenience in which all the other truths, including the causal truths, are mcrcly supervenient upon the patchwork of unconnected events that makes up a world. For him, causation is analysed in terms of counter­factual dependence between events. The view here would, in contrast, not be an analysis of causation.

There is a bigger problem than that, however, which is that the counterfactual analysis is in any case, according to causal disposition­alism, false. We do not, therefore, have even the hiconditional, let alone an analysis. There are clear prima facie cases where we do not want to affinn the counterfactual intuition. Causes can - perhaps they usually do - make a difference but not always. In cases where they don't, the corresponding counterfactual will be false. The cases in mind are those of overdetennination or late pre-emption. In the case of a two-man firing squad, two gunmen, Bill and Ben, may shoot simultaneously through the heart of the prisoner and cause his death. Bill's shot would have caused the death even if Ben had not shot, and vice versa. But hecause both in fact shot, there is no true counterfactual that had Bill not shot, the prisoner would have Jived, nor a true counterfactual that had Ben not shot, the prisoner would have lived. By the counterfactual analysis, that means that neither of them caused the death. If we tried, as a way of avoiding such a counterintuitive result, saying that the death counter­factually depends OIl both Bill and Ben having shot, that would also deliver a wrong result that only together did they cause the death,

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contrary to our original, and plausihle, assumption, that either shot alone would have been enough.

Lewis tries to answer this kind of difficulty under the heading of pre­emption (I986c: §E), in the case where C T pre-empts c / s causing of e by causing e first. Had c[ failed to cause e, (.'2 would have. His answer to this problem is that there is no causal chain leading from C2 to e, whereas there is a causal chain from c) to e. But this answer suffices only when there is a chain between eland e, Suppose that c 1 is the last event in a chain before the causing of e. There is nothing between them, by way of a chain, and nor would there have been between C2 and e. 11Mt would leave us back with the problem of e counterfactually depending on neither c] alone nor C;2 alone.

There is a vast literature on the problem of overdetermination within a Lewisian, countelfactual dependence framework (for a summary of the problems see Moore 2009: ch. I7). Refined analyses are offered, new counterexamples suggested. and yet more refined analyses that over­come the new counterexamples. But this looks like a degenerating research programme because the new analyses have no independent motivation. Their only rationale is to overcome the new counterexam­ples to the theory and they look, therefore, ad hoc. Fmthennore, the only reason to reject the prima facie possibility of overdetennined effects seems to be to save the counterfactual analysis.

Overdetermination is not an issue for many other theorics of causa­tion, including the dispositional theory. There is no reason not to allow a case where two separate powers arc in operation each of which, in the circumstances, would have been enough on their own to have taken a situation beyond the threshold for a particular effect (see figure 6.2). This is what happens, for instance, in the firillg squad example or perhaps where a person is exposed to two carcinogens for the same cancer at the same time or the case where a neuron fires because of two distinct inputs, each of which would be enough to push the neuron beyond its threshold for firing.

The possibility of overdeterrnination shows us that there can be causation without counterfactual dependence. But we would abo argue that there can be counterfactual dependence between events without causation, namely, cases of double prevention. Double preven­tion is the case where one event prevents what would have prevented a second event. Lewis (2004a: 84) gives an example of where one colli­sion of billiard balls prevents what would have prevented a second collision. Did the first collision cause the second? Ned HaWs example

F

Causal counterfactuals

h

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FIGURE 6.2: Overdeterrnination

153

G

is of a fighter plane (2004: 24 I) that escorts a bomber. \¥hen the enemy sends an interceptor to prevent the bomber dropping its load, the fighter shoots it down and the bomber completes its mission. Did the fighter's shooting down of the interceptor cause the bombing, through preventing what would have prevented it? Elsewhere (Mumford and Anjum 2009) we say not. Prevention works by absence - making the absence of what would have prevented an effect - and so cannot count as causation by our lights, even if there is a eountcrfactual dependence between these events.

What then should be said about counterfactuals and conditionals? The two cases will have to be treated separately. In the case of counter­factuals, we can say only that their truth is a symptom of causation having occurred but not a totally reliable one. There can be at least some cases of causation that do not make accompanying counterfactuals tme. Where there is a true counterfactual dependence between events, how­ever, this is a good indicator of causation having occurred but it cannot be more than that. Specifically, it cannot be constitutive of such causa­tion, given that there may be some cases of causation without counter­factual dependence.

Causal claims are often closely associated with conditionals and this seems a good place at which to discuss them. In addition to the countcr­factual intuition, there is also a conditional intuition that where we have a causal relationship between C and H, there should be a tme conditional that if C, then E. Someone who holds to Hume's first theory of causa­tion, based on constant conjunction, would be tempted by the condi­tional intuition. Por the causal dispositionalist, in contrast. a constant

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T54 !!"xplanation, Absences and Counterfactuals

conjunction between C and E is not. a necessary condition fur there being a causal relationship between C and 8. Instead, it suffices just that C disposes towards E. This has implications for any accompanying condi­tional intuition. Any conditional made true by such a dispositionally causal relationship cannot be the conditional as it is usually understood by logicians. In standard logic, if it is true that C -} E, then whenever C occurs, E occurs. C would be understood as a sufficient condition for E, thus permitting the inference of modus ponens. The dispositionalist would not assert that this follows for causation, however.

What, then, docs the dispositionalist say about conditionals? On this theory of causation, any such conditional relationship can have disposi­tional force only. It is only that C disposes towards E and thus we can only say that if C, then E is disposed to happen. Sometimes, this is acknowledged when we add a ceteris paribus clause to the conditional: C -----+ E, cp. ll1cre has been much discussion of what exactly is meant hy a ceteris paribus clause but Lipton's (r999) view is persuasive that the best non-trivially true account we can give of their meaning is that they indicate that the conditional has dispositional force only (see Mumford, 2011). Every causal conditional claim will thus have this force. In practice, however, the cp clause will be only tacitly attached to the conditional claim. It nevertheless seems to be there because we also are prepared to accept that such causal conditionals are defeasible. Hence, 'if C, then E' is asserted even though it is accepted that there are some conditions, /, in which C could obtain without E obtaining. This is explained if we accept the conditional as having dispositional force only and thus having a tacit cp clause. These are the caveats attaching to counterfactuals and conditionals that were promised under causation by absence.

This chaptcr has offered an account of dispositional causal explana­tion and prediction and inductive inference. In addition to that, an account of causation by absence has been developed, showing that there is no such counterexample to the claim that a causc is something that disposes towards an effect. The account was an epistemic solut.ion to a supposedly metaphysical problem. The account employed the notion of a counterfactual, which it has been suggested could be used to analyse causation in generaL The counterfactual analysis is rejected, however, on the grounds that overdetennination is a possibility. And even where there are true countelfactuals associated with the causal truths, they will have to be given a distinctly dispositional reading.

Causal counterfactuals ISS

There is a plentiful supply of fmther discussion on these topics but we have not engaged with it in any detaiL To do so would have diverted us from our primary goaL We are not offering a detailed, critical analysis of a counterfactual theory of causation. Our aim is to develop a positive accowlt that is an alternative to it.

7

The Logic of Causation

7. I Relating cause to effect

The logic of causation is a matter of interest in its own right. We want to know, for instance, whether causation involves transitivity or not, sym­metl)' or not, and reflexivity or not. Thi~ will tell us something about how causation behaves, what causal claims imply and what they do not. It will allow us to say something more about the characteristics of causation. As Molnar (2003: 191-2) shows, these characteristics are contested. ,Ale will not discuss them all but some arc of importance to our aims in this chapter, which is to show what is distinctive about the logic of causation.

The view of causation we have presented clouds some of these traditional battles. Causation, we claimed in chapter 5, is not best thought of as a relation between distinct, discrete relata. Causation i~ a continuous process with a beginning, an end and change between. The truth that A causes B depends on whether there is a power or partnered powers, A, that manifest in some process of which B is a part. A will often be the start of the process and B the end but not always. B might also be some point before the end of the process or A some point after the stalt of the process. As illustrated by the sweet solution (§5.6), however, we need not even be picking oul earlier and later stages of the process but merely the productive and produced parts, which are simultaneous. This allows causal claims to have a relational structure: there is a productive cause and a produced effect. But from this we should not try to read a metaphysics of distinct and discrete relata, contingently related, as an account of how causation works in the world.

We may, therefore, legitimately ask whether causal claims involve features such as transitivity. We already allowed that, because of the simultaneity of causation, there can be symmetrical instances, where A causes Band B causes A. But not all causation need involve symmetry so we categOlize it as non-symmetJic. We will not go into symmetry further in this chapter nor do we have anything to say here

Distinguishing causal claims 157

about reflexivity. Instead, we deal with some other matters that are key to marking out causation as distinctive. We aim to cover logic and philosophy of language as they relate to causation, and it will be clear that our findings are informed by the way in which we have understood causation metaphysically.

7.2 Distinguishing causal clainls

Although the logic of causation is a subject matter of sufficient interest in its own right, we also have a further motive. It has been doubted that causation itself has any essence. Is it one single thing at all? And are we therefore making the same kind of claim on every occasion that we make a causal statement? Causal pluralism is the view that there are many different types of causation, and there can thus be, correspond­ingly, different things being claimed in causal statements. According to Cartwright, Psillos and others, there is nothing that unifies all cases of causation, which means that all univocal theories of causation would fail. If lhis is the case, it looks bad for our theory as it is one that aims to be univocal. Cartwright motivates pluralism as follows:

there are untold numbers of causal laws, all most directly represented using thick causal concepts, each with its own truth makers; and there is no single interesting truth maker that they all share by virtue of which they arc labelled 'causal' laws. (Cartwright 2007: 22)

On Cartwright's account, then, causation is not just one thing. Rather, she says, there might be as many ways for one thing to cause another as there are causal verbs: 'the pistons compress the air in the carburettor chamber, the sun attracts the planets, the loss of skill among long­term unemployed workers discourages firms from opening new jobs' (Cartwright 2007: 19-20). She calls such causal verbs 'thick causal concepts', and argues that they lue both more precise and more con­tent-rich than the explicit, though less commonly used, causal vocabu­lary. Is it not, after all, mainly philosophers who use general terms such as 'cause' and 'prevent'?

We agree with Cartwright that there are a number of ways in which one thing can cause another, so the use of thick causal concepts is entirely legitimate. There are lots of different powers - to cut, to smash, to dissolve, to heat, to grind, and so on - and powers can compose in all sorts of ways. But this does not mean that causation

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The Logic of Causation

itself is to be pluralistically cOlll-:eived. It might be claimed, though, that there is no single essence of causation in common to and underlying all the individual thiek causal concepts (Psillos 2010). After all, the pro­posed analyses have all admitted counterexamples so might that show that there is nothing in common to every causal case'? The failure of analysis would not count against causal primitivism, however. The primitivist can agree that nothing is definitive of causation in the sense of providing a reductive analysis. But all cases of causation, on Ollr

account, concern the passing around of powers. We did not offer this as an '-Ulalysis of causation because we conceded that the concepts of cause and power were too closely related. But as causation occurs when, and only when, powers are doing their work, we can offer at least some unity to the notion of cause. Unity is desirable because pluralism leaves us with a problem. Why are the thick causal concepts all specifically and recognizably causal concepts? Something needs to be provided for this diverse group of concepls that explains why they are all causal. Calling them a Wittgensteinian family of concepts (Psillos 2010: J 44) does not do tbe required work. We still want to know why they all belong to the same family_ And nor has it been ruled out that the notion of cause is merely an abstraction from all its diverse instances. Cause could be the detenninable of which thick causal notions are the dctcnninates.

This is where we get to the possible pay-off of considering the logic of causation. The features we find revealed will collectively mark causa­tion out as something distinctive. Many of these features have already been explained but others that we introduce are new. To show how they pick out causal claims, we will be contrasting them with some close types of claim: claims with a similar superficial fonn. Nevertheless, we will urge that causal claims can be marked as distinctive according to how they relate to such matters as exceptions, the problem of induction and transitivity. Despite the similarities of logical fonn, therefore, causation can be contrasted with non-causal claims on the basis of exhibiting a distinctive character set. While we will outline some of the main components of this character set, we again do not, however. offer it as a reductive analysis of causation. We are merely picking out some of the features of causation without claiming that these features are constitutive of causation. It will also be far from clear that the fealures we desClibe will be exhaustive of our notion of causation.

Preliminaries stated, we now move on to the more serious business of this chapter. We will be tracing out the key logical characteristics of causation. In doing so, we will use non-causal claims as a foil. Causal

Some causal and non-causal claims 159

claims, and causation itself, should by the end be justiJied as a distinc­tive and unified kind.

7-3 Some causal and non-causal claims

Cartwright is correct that the claim that C causes E can be expressed in various more specific ways. Wc use causal verbs: we print a papeJ,/eed a child, increase the volume, and press a button. But there are other, more generic ways to express causal claims and as abstractions from the more specific causal verbs. We think these to also be legitimate. One could for instance use the conditional 'if ... then', the explanatory 'hecause', or even law statements such as 'All Fs are Gs'. Examples of such tacit causal claims are not hard to find:

a. If you get hit by a train, you'll die. h. All heated iron bars expand. c. Because you stopped to get the newspaper, we missed our bus. d. If ice is heated. it melts. e. All water boils at 100 degrees. f. The cat died because he fell from the balcony.

These expressions can be translated into explicit causal claims: 'Getting hit by a train would cause you to die'; 'Stopping to get the newspaper prevented us from getting our bus'; 'Heating iron bars causes them to expand' _ As causal claims, however, none of the statements above should be understood as implying that the cause guarantees the effect, since any causal process can be counteracted. This was argued at length in chapter 3 and now we will say that it is one of the definitive features of causation. If (a) to (0 are causal claims, they must be taken as claims about what is disposed to happen only. This feature might seem obscured in the claim. The conditional 'If you get hit by a train, you'll die' seems to imply that you must die if you are actually hit by a train. 'All heated iron bars expand' explicitly states that all heated iron bars in fact expand. We will see that there are further caveats to be made, however.

As we argued above in §6.S, such claims should be given a disposi­tional reading: (all) icc has a disposition to melt if heated; (all) cats have a disposition to die if they fall from a tall height; and (all) trains bave a powcr to kilt if they hit someone. For (c), the most infonnative way to express the causal claim is with the use of the verb 'prevent' rathcr than

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160 The Logic of Causation

'cause'. The truthmaker of this cl~im is a power disposing away from­not towards - the effect: stopping on the way to the bus disposes away from getting there in time.

Conditionals, law statements and causal explanations are only some of the ways in which causal claims can be expressed without explicit causal vocabulary. But not all statements that use these formulations are causal claims and we need to find a way to distinguish these from the causal uses.

A. Non-causal uses oJ 'if'

Some examples of call sal conditionals are already given above. A causal conditional is onc where the antecedent describes a cause and the consequent describes an effect of that cause. But there arc also some non-causal conditionals, where the antecedent and the consequent can­not plausibly be said to stand in a cause--effect relation. For instance, in none of the conditionals (g) to (k) can the antecedent be understood as a cause disposing towards some effect described in the consequent.

g. If you're hunglY, there's dinner in the kitchen. h. If that is Madonna, I'm Bart Simpson. I. If 1 win the lottery, I cannot afford that car. j. If this is water, it is H2 0. k. If Socrates is a human, he is mortal.

You being hungry cannot, in any standard way, cause the dinner to be in the kitchen. That must be caused by something else: the person who made dinner and put it in the kitchen. And it would seem absurd to think that some person turning out to be Madonna could cause someone else to become Bart Simpson. Furthermore, winning the lottery cannot be the cause of not being able to afford that cm. None of these conditionals state a causal relation between the antecedent and consequent We should therefore expect these non-causal conditionals to have different logical properties from causal conditionals.

While causal conditionals never state the consequent unconditionally, since the effect is always conditional upon the cause, some non-causal conditionals do. We can see this in (g) where the consequent could easily be stated alone: 'There's dinner in the kitchen'. The antecedent is only added to make the consequent contextually relevant: 'If you are hungry, you might want to know that there's dinner in the kitchen'. Also in (i) it would be possible to assert only the consequent: 'I cannot afford

Some causal and non-causal claims 161

that car.' But this conditional differs from (g). Here the antecedent plays Lhe role of strengthening the assertion of the consequent by adding an antecedent that would normally alter its truth: 'Even ifI win the lottery, I cannot afford lhat ear'. Winning the lottery is commonly regarded as something that disposes towards affording expensive things, but in this claim that causal relation is denied rather than asserted: it is not the case that winning the lottery would enable me to buy that ear.

But what about claims like (j) and (k)? Is it possible to say that water disposes towards being HzO and humans dispose towards being mortal? It seems not. Being water cannot be the cause of being HzO. Arguably, it is one and the same thing (though we are admittedly neglecting issues of reflexive causation). And even though being a human involves having several dispositions and being mortal is one of them, the claim that humans are mortal is not a claim about some cause disposing towards an effect. Being a human is not itself the cause of being mortal. We will ruscuss such claims in more detail in the following sections.

B. Non-causal uses of 'because'

Just as there are non-causal conditionals, there me some non-causal uses of 'because'. Clearly, 'because' is often in a causally laden context, commonly associated with causal explanations. 'The dog died because we didn't feed him' and 'He is crying because his wife left him' arc examples of causal explanations. But some such explanations are not causal in the traditional sense: where the because-clause describes an explanation (explanans) for some phenomenon to be explained (expla­nandum). Rather than pointing to the cause of the explanandum itself, the explanans can instead be some epistemic reason for concluding the

explanandum:

1. The room is occupied, because the red light is on. m. Jill's here, because her shoes are in the hallway. n. I'm pregnant, because my period is 8 weeks late.

In (1) it would clearly be wrong to say that it is the red hghl being on that causes the room to be occupied, or in (m), that her shoes being in the hallway causes J1lI to be here. Instead, we could say that the bccause··c1ause in (1) offers a reason for concluding that the room is occupied. The red light is only an indication of the room being occupied and in (Ill) the shoes in the hallway are only an indication of Jill being here. The same holds for (n) where being late with one's

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The Logic of Causation

period does not cause the pTcgnancy, hut might instead give us some indication of it.

Similarly, what is described in the because-clause can offer a reason for stating something, or give one's utterance a context:

o. Becausc you'll find out anyway, your wife is having an affair. p. Because I want you to hear it from me, I'm getling married this

summer.

In (0) the wife is not having an alTair because her husband will find out anyway, and, in (p), I'm not getting married this summer because I want you to hear it from me. Still, they are both some kind of explanation. What 1S explained is why the speaker is providing this infonnation. There are of course other naIl-causal uses of 'because' than these, but these examples should suffice to show that not all uses of 'because' arc causaL

C. Non-causal general s'tatements

There is a long tradition of fonnulating general causal claims as lawlike statements having the [OIDI 'All Fs are Gs'. We have already seen some examples above: 'All heated iron bars expand' and 'All water boils at TOO dCblJees Celsius'. But not all general statements are causal.

q, All apples are fruit. L All angels are immortal. s. All swans are white.

None of these statement') can plausibly be understood as causal laws. To be an apple is also to be a fruit. But being an apple is not the cause of being a fruit. Similarly, being an angel might involve being immortal but cannot cause it. Being an angel is not a power towards immortality. A better way to interpret these statements is as classificatory claims, subordinating one kind to another. Apples are a sub-class of fruit, angels are a sub-class of immortals, and swans were allegedly a sub-class of white things. Sometimes, however, the two classes are interdependent coextensive or even identical, rather than subordinated.

t. All triangles have three angles. u. All bachelors arc unmarried men. v. All even numbers are divisible by 2.

If by 'triangle' we just mean 'something that has three angles'. for instance, then these two expressions refer to the same class. The same

IIypothetical versus categorical

seems to be the case for bachelurs and unmarried men. and for even numbers and numhers being divisible by 2. Being an even number is not the cause of its divisihility by 2, and being a bachelor is not the cause of being UDlllaLTied. No causation is therefore involved in such claims.

So far we have seen that causal claims can be more or less explicit and can come in a variety of syntactical fonus, such as the conditional 'if', the explanatory 'because'. or as law statements' All Fs are Gs'. But we have also seen that these fOTITIS are not reserved solely for causal claims. V{hat we need, then, is an account of some characteristic features of causation that are used to separate tacit causal claims from non-causal ones without relying on sUlface syntax. We do indeed seem to have awareness of sl1ch characteristics as 1t is rare that anyone would be unable to distinguish the causal from the non-causal dau11s in our lists. And it looks promising for the theory of causation we have offered that it is able to identify and explain some of the characteristics of causal claims.

7 A Hypothetical versus categorical

In order to distinguish the logical nature of genuine causal claims from others, we reintroduce Kant's distinction bet weell categorical and hypo­thetical statements from his table ofjudgmcnts (Kant 1781: A70). This distinction has tended to be ignored, at least since FIege (1879: 4), who didn't acknowledge it as logically relevant. FIcge interpreted all general categorical claims, "All Fs are Gs', as logically equivalent to - or even synonymous with - general hypothetical claims: 'for all x, if x is F, then x is G' . All general statements could then be given a conditional reading. Even setting aside the well-known problem that Frege interpreted this as a quantified material impl1cation, \/x (Fx :) Gx), making the condi­tional true whenever no xs are F', there arc reasons to be cautious about the alleged logical equivalence between categorical and hypothetical claims.

One problem with the conditional interpretation of categoricals is that it blurs our distinction between causal and non-causal claims. Without a logical distinction between categoricals and hypotheticals, we have to treat fhe pairs uf statements under I as logically equivalent with the pairs of statements under 2 just because they have a similar surface syntax.

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The Logic of Causation

1. (a) All iron bars expand if heated. (b) If an iron bar is heated, it will expand.

2. (a) All humans aTe mortal. (b) If something is human, then it is mortal.

But this would be a mistakc. Both statcments under I arc for Kant genuinely hypothetical claims, corresponding to the category of cause and effect (r78T: A8o). On our account this would mean that these claims are about the operation of powers. Kant further takes both statements under 2 as genuinely categorical, corresponding to the cate­gory of inherence and subsistence, or what he calls 'substantia et accidens' (ibid.).) Such categorical claims are generally about some substance and its properties. For instance, 'All humans are mortal' states that being mortal is a propelty shared by all humans, and this is not a causal claim. In categorical claims, for some kinds F and G, F is a sub­class of G: for instance, humans are a sub-dass of mortals, angels are a sub-class of winged things, and swans are a sub-class of white things. Alternatively, other categorical claims state an identity or coextension between two classes, such as 'All even numbers are divisible by :2',

. Bachelors are unmarried men', or 'Triangles have three angles'. For our purposes, we can leave it open whether the truth of such statements is merely classificatory or involves a more metaphysically involved notion of essence. Following Ellis (2001), for instance, one might argue that it is essential to being human that something be mortal. In contrast, one might argue that it is a mere classificatory convention that even numbers are divisible by 2. Whether - and which of - our categorical statements are genuine truths of essence, rather than only classificatory, is a deep question we need not answer here.

Statement (I b) is an instance of what we call a causal condiLionaL Such conditionals can also be particularized in statements such as 'if this iron bar is heated, it wiII expand'. A particularized causal conditional, a generalized one as in lb, and a universal statement such as fa are all made tme, where they are true, by the existence of powers. Because of that, they all have to be understood with the caveats of §6.R, as having dispositional force only. All iron bars have the disposition to expand if heated but whether one actually expands when heated will depend on other matters. This is the consideration that allows us to find the real

1 Our thanks to 10han Amt Myrstad for bringing to our attention the importance of the hypothetical/categorical distinction in Kant.

Prevention. induction and ceteris paribus clauses 165

differences between the hypothetical and categorical statements. While categorical claims are about the logical relationship between kinds, propelties or classes, causal claims are about powers disposing or tend­ing towards an effect. This shows itself in how the two different types of statement, despite their superficially identical fonn, relate differently to matters such as prevention, falsification, induction, modality and transi­tivity, to which we now tum.

7.5 Prevention, induction and ceteris paribus clauses

"That therc is a logically relevant distinction between causal and cate­gorical claims can be further established by considering how they relate differently to cases of prevention and exceptions. Prevention is when something is counteracted or intcrfered with, so that it. fails to manifest properly. It is itself a causal notion. What prevents an effect must also therefore be a causal power: one that disposes against a particular effect. Two powers P J and P2 that dispose in opposite directions with equal magnitude can be each other's preventers, if we gel an equilibrium state, for instance.

When we speak of an exception, on the other hand, we understand this as meaning a departme from a rule or generality. There might of course be some causal explanation for this but exception is not explicitly a causally laden tenll. The relation to exceptions allows us to make a distinction between hypothetical and categoricals. In the case of cate­gorical statements, an exception would amount to a falsification. If we find a hlack swan, for instance, or an immortal man, we have falsified the corresponding categorical a.;; a universal truth. A consequence of the fact that causal relations are subject to prevention and interference. however, is that where C disposes towards 1:;, it is possible that we have an occurrence of a C without ll. General or type causal claims thus tolerate exceptions. It is truc that smoking causes cancer as a type­causal claim cven though not everyone who smokes actually develops cancer. Because they have dispositional force only, general causal claims are not falsified by having some exceptions. Hence a situation where c occurs without e is not a falsification of the claim that C causes E, contrary to what was been implied by Hume, Popper (r959) and many others. Smoking indeed disposes towards cancer, and has its way in many instances. TIle existence of some smokers without cancer, how­ever, docs nothing to falsify this dispositional claim.

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166 The Logic of Causation

The way a generality relates to cases of exceptions call thus help us draw a distinction between the causes invoked in hypothcticals and the classifications, essences or identities invoked in categoricals. If excep­tions are pennitted without falsification, then classifIcation and essence claims are ruled out. Categorical claims are not subject to prevention or interference. We would not consider seriously whether there are condi­tions under which a tl"iangle does not have three angles or whether some power could counteract an apple from being a fruit.

Since any causal process call be counteracted by other powers, all causal connections are defeasible. Although sugar causes tooth decay and pressing a doorbell causes the bell to ring, there are always condi­tions under which the effect does not follow the cause. Causal claims arc therefore essentially subject to the 'problem' of induction that was discussed in the previous chapter. Even if instances of C have been followed by instances of F, and even if it is a type-causal truth that C causes E, the inductive problem remains that we will never know for certain that the next c will cause an e. Some have tried to show that an advantage of a dispositional ontology is that it might yet solve the problem of induction (Ellis 200 I: 283-6, for instance). We have offered arguments to the effect that it cannot do so and this attempt is a mistake. But, more than iliat, such a mistake overlooks one of the vital points to emerge from causal dispositionalism. Being subject to the problem of induct jon is one of the things that is definitive of natural causal pro­cesses. With our categorical claims, it does not even make sense to raise the inductive question. I do not worry, for instance, whether the next human I meet will also be mortal. Yet T can meaningfully wonder whether the next match I strike will light. Although these two questions may have the same synlactic form, how they relate to the problem of induction is one thing that separates them as being of completely different kinds. The possibility of a problem of induction is thus a further indication that causal processes can always be prevented or interfered with. Rather than dismiss it, or 'solve' the problem, we accept it as what marks off our inferences about the causal processes of nature from other inferences, such as those of deductive logic. This explains why Strawson's (1952: ch. 9, ii) response to the problem is thus an appropriate one: we should not expect induct.ive inference to behave like deduction.

This same point is evident when we consider lhe addition to causal claims of ceteris parihus, or all else being equal clauses. Geach (196 J:

102) notices that such ceteris paribus clauses are informative when they

Transitivity

point to the fact that a causal relation can be prevented. We say this shows the dispositional character of causes. EvelY causal process must, in principle at least., have some conditions under which it is prevented or intetfered with by counteracting powers. But we need to be able to indicate that, despite all the possible interference, there is a definite disposition from one thing to another. This is what we take to validate the use of a ceteris paribus clause (sec Lipton 1999 and Mumford forthcoming), and it is not something we need to explain away or solve in order to make causal claims more contextually robust. Saying that salt dissolves in water, ceteris paribus, indicates that thc attribution is dispositional: salt disposes towards dissolving in those circumst.ances but it is not necessary that it. does so. Ceteris paribus clauses would not even be relevant for claims of identity, essence or classification. No change in context or introduction of new powers could prevent an apple from being a fruil, a bachelor from being unmarried, or a triangle from having three angles. Accordingly, as long as the categorical claim' All Fs are Os' is true as a classificatory essence or identity claim, something being F will gum:antee that it also is G. This indicates that categorical claims involve some kind of necessity that causal claims do not.

7.6 Transitivity

One other way in which we can distinguish causal from non-causal claims is by how they relate to transitivity. If we take classificatory claims, for instance, we can argue that they would all admit transitivity. All bachelors are men and all men are mortal, and by transitivity we can know that all bachelors are mortal. This follows from the relation of suhordinatioll. To accept the transitive case, we need only see that suhordination can apply in the case of three terms, such as being a hachelor, a man and a mortal (figure 7.1). That should be uncontrover­sial. There is a thought, however, that causation similarly admits transi­tivily and there should be, therefore, no way of distinguishing causal fn 1m non-causal claims on this basis. Conventional wisdom tells us that t':Il1sation can transfer down a chain. Dominoes can be stood in a line, for IIlslance, such that when one knocks the first over, it knocks the second ovcr, which knocks a third, and so on. In such a case, we can accept II ,llIsitivity when we admit the claim that pushing over the first domino was a cause of the falling of the final domino.

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FIGURE 7.1: Transitivity of classification

We accept that some cases of causation have this nature. There are some routine causal claims to which we would all assent but which would be true only if causation passes down the chain. Arsenic can be a caw.;e of death, for instance. But it is so only through intennediate stages. Arsenic has the power to disrupt production of ATP (Adenosine 5' -triphosphate). Disrupted ATP productions leads to various organ failures and organ failures cause death. In this case, transitivity goes through. Disrupted ATP production is the immediate effect of ingested arsenic but death can certainly be considered its mediate effect. The powers account can explain this. Arsenic should be thought of as having the power to kill humans, even if that power works in an intenneJiate way. Arsenic, in this case, can be thought of as having multiple powers: of disrupting A TP production, of causing organ failure, of killing. A reason why we can attribute all these powers to arsenic is that it is able to initiate a biological process, going through various stages. As well as having the power to cause death, therefore, which is at the end of that process, arsenic should also be thought of as having the power to cause any part of the whole process that ends in death (figure 7.2). Which power we attribute to arsenic depends on the level of detail in our description.

That there are some instances of causation passing down a chain does not, however, show that causation in general is transitive. A transitive relation, R, is one where if aRb and bRc, then aRc, and this may not be true generally for every causal chain. The transitivity of causation is threatened by alleged cases in which aRb and bRc but where it is not the case that aRc. If there are some cases like this, and yet' other cases where

Transitivity

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causation docs transfer down a causal chain, then causal claims would come out as non-transitive. This would be a basis for distinguishing causal and non-causal claims.

The alleged counterexamples to the transitivity of causation are controversial but here is one. Let us assume that two villains, Anders and Bengt, are looking to assassinate Cato. They conspire and both follow Cato with guns, looking for an opportunity to shoot him when there are no witnesses. They see an opportunity. Anders fires but misses. Seeing this, Bengt fires and hits, killing Cato. We can understand this incident in the following way. Anders missing caused Bengt to fire. Bengt would not have bothered had he seen that Anders had already successfully completed the assassination. And Bcngt firing (accurately), certainly caused Cato's death. The bullet lodged in hjs brain and there were no other causal factors at work that were threatelung him. We have a chain: Anders missing caused Bengt to fire and Bengt firing caused Cato's death. Is it transitive? Hit were, it would mean that Anders's shot that missed Cato nevertheless killed him, which seems counterintuitive. Excluding any deviant causal chain, such as Anders's missed shot ricocheting and hitting Cato in the back, it seems we could defend the view that Anders's miss did not kill Cato. I-Tcnce, it seems we have a case of a causal chain in which transitivity fails.

Moore, however, argues that such cases of transitivity-failure for causation are spurious (Moore 2009: 360). In all the alleged cases he knows, says Moore, at least one uf LhL: putative links in the chain is some kind of absence or omission. Like us, Moore does not accept that "causation by absence' is genuine causation. If one of the links in the

qo The Logic of Causation

chain is not a genuine case of causation, then we do not have a real, unbroken causal chain and the transitivity-failure is apparent only. If we did have real causal links, then the transitivity would go through, says Moore (with a qualification, to which we return shortly).

How plausible this response is will depend on whether we can always claim that one of the putative links in the chain is an absence or omission. Anders's shot, for instance, seems to be something real enough but Moore could claim that it is specifically because it is a miss - an absence of a successful kill - that Bengt shoots. It doesn't cause Bcngt to shoot, says Moore, because absences cannot be causes. Bengt's shot could connterfactually depend on Anders having missed but, and we agree, there can be counterfactual dependence without causation (see §6.8). There is room for further discussion on this exam­ple because it is not obvious that a causal story could not be told that. invoked only positive things. Anders's shot may lodge in the wall and it is Bengt seeing the bullet hole that causes him to shoot. It could be answered, however, that Bengt shoots not because of a bullet-hole in the wall but only because the hole indicates that Anders's shot missed, and was thus the absence of a kill. But we will not pursue this example further because we believe there are better ones.

First, however, we can raise a different issue that might persuade us that not all causation should be taken as transitive. Moore himself not.es that if all causal chains are transitive, then we have to cite every contributor, no matter how distant, as a cause of an effect. A cause of you scratching your nose at midday in Aachen, for instance, is that your great grandparents conceived your grandfather seventy years ago. There will be a chain of causes that gets from the conception of a grandparent to the scratching of your nose but do we want to say that the conception caused the scratching? If transitivity is universal, we would ultimately have to concede that the Big Bang was also a cause of you scratching your nose. There does seem to be something counterintuitive about this. Our response is that causation is not always transitive, and we will explain why shortly. Moore's own response (the above mentioned qualification) is that causation 'peters out' through its links (Moore 2009: 397-9), and he thus supports the view that the transitivity of causation is 'limited'. Time is a reasonable indicator of how many causal links havc been involved, in which case we can say that causation peters out the further back we go in time. This would mean that neither the Big Bang, nor your gTandparent's conception, is a cause of you scratching your nose.

Transitivity 171

While we are in agreement with the result of this response, we are not convinced that Moorc has the right reason for it What could be a non­arbitrary threshold at which a cause peters out: after a year, ten years or a millennium? And Moore's response would entail that all equally distant causes from a certain effect must have all petered out together or not, whereas we think some might still count as causes while others don't. Instead, therefore, we argue for another reason why transitivity fails. This will allow that it fails for some distant causes hut not for all. And indeed it could allow transitivity failures over relative few causal links. We should consider some cxamples_

Conducive weather in the Caribbean leads to a bumper banana crop. The fine crop leads to reduced prices and this influences you to buy bananas. Having bought the bananas, you eat them more often and on one such instance you discard the skin. Later, you slip on the skin, fracturing your elbow. Did the good Caribbean weather cause you to fracture your elbow? There was a causal chain, as we have just described, thal starts in the Caribbean and ends with an ann in plaster. But should we accept that the first link in the chain caused the final one? We have some temptation to say that it docs not but why?

Bennett has a similar example:

There was heavy rain in April and electrical storms in the following two months; and in June the lightning look hold and started a forest fire. If it hadn't been for the heavy rain in April, the/orest would have cau?;ht.fire in May. (Bennett

1981' 373)

But clearly there is something wrong with the idea that heavy rain in April caused the forest fire in June. We add a third example that is even simpler. A fire takes hold in a building. The building has a water sprinkler system and the fire causes it to switch Oll. The sprinkler system extinguishes the fire. Here we have the shortest chain possible for which we can ask the question of transitivity; and it does not obviously seem to be a case subject to Moore's charge that at least one of the putative causal hnks is actually an omission. The fire started the sprinkler system and the sprinkler system put the fire out.. Would we want to say that, by transitivity, the fire caused the fire to be extin­guished? It seems to be another case where we would want to resist transitivity.

Why, then, does it seem like some causal chains are non-transitive? The disposit.ional theory of causation has an answer. We can have cases wherc a caused hand b caused c but it is 110t the case that a caused

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C. The reason for thls is that while a disposed towards b, and b in tum disposed towards c, there wa-; nevertheless no disposition from a towards c. The fire and sprinkler case illustrates this. Fires can spread. The heat of a fire, a, disposes it towards more fire, F (see figure 7.3). When a reaches a certain threshold T, the sprinkler system, b, begins to operate, disposing away from the fire and it succeeds in extinguishing it. The reason we would want to deny transitivity in this case, therefore, is that something that disposes towards F causes something else that has a counteracting effect, disposing in the opposite direction. The fire has no power towards its own extinction. It does so only because we have a context in which a smoke-sensitive sprinkler system is able to respond in such away.

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Transitivity

This kind of response can be generalized. Bennett's case seems to be a good counterexample because rain does not seem to dispose towards forest fires. Again, however, it is in a context of other meteorological factors, such as heat, in which it causally contributes towards an electri­cal stonn which does have a power to start a fire. The causal chain is genuine but there is no transitivity. Similarly, missing with a shot does not dispose towards the target's death. And we can say that the warm weather in the Caribbean has no disposition at all to break people's elbows even if there can be a causal chain, in a certain context, leading from one to the other.

This latter point would allow us to make some distinction betwecn causes and conditions. In chapter 2, we said that everything that dis­posed towards an effect should be considered among its causes. This was a rejectiun of the distinction some draw between causes and back­ground conditions. Hence the presence of oxygen was a cause of the flame as much as was the striking of the match. But we can now make a different distinction that is similar in intent but better grounded. It also shows a weakness of the counterfactual dependence theory of causation. The conception of your grandfather, we argue, is not a cause of you scratching your nose at midday hecause it docs not dispose towards it (and nor away from it either). Neveltheless, that concept.ion would be part of a causal chain that leads to the scratching of your nose. We say that the causal chain is non-transitive. But where two things are linked by a non-transitive causal chain, we can say that the first is a condition of the latter, without necessarily being a cause of it. Your grandfather's conception is certainly a necessary condition for you scratching your nose, in the sine qua non Sense. You wouldn't have scratched your nose without it. But it is not a cause because it didn't dispose towards it. This distinction is one that the counterfactual dependence theory of causation cannot make because it takes necessary condit.ions to be causes. That delivers the absurd results that your death was caused by your birth, the building of the Empire State Building was caused by the Big Bang, and the presence of oxygen is the cause of you telling a lie. On our theory, these can all count as sine qua non conditions of those events occmring but not their causes.

The thought that causation admits some t.ransit.ivity failures can therefore be supported. In general, therefore, we should say that causa­tion is non-transitive. In SOme cases where aRb and bRc, indeed aRc, but in other cases it is not t.he case that aRc. This gives us, therefore, one further way in which causal claims can be distinguished.

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7.7 Context-sensitivity

There is a final way in which causal claims differ from the kind of nOll­causal claims that have been discussed in this chapter. We began by noting the superficial similarities between statements of the fonn 'All Fs are Gs' and 'if A, then B'. But we have then distinguished statements of these kinds that are causal from those that are not causal on the basis that they relate differently to issues such as prevention, necessity, induction, ceteris paribus clauses and transitivity. The final way in which they differ could also be used to explain all of the above. Causal claims are context -sensitive in a way that categorical statements are not. If it is a tme categorical claim that all men arc mortal, then this remains true in any context. But for any causal claim, there will always be some context in which it is potentially false. This idea should now be familiar. Indeed, it is the reason why causal reasoning, we said in §3.5. is non-monotonic. Where it was true that a caused b, it might not have been true that a plus cpo for some cp, would have caused b. The truth of any causal claim will in thi~ way be a context-sensitive matter. Similarly, my prediction that if 1 drop this glass, it will break, will be accurate for some contexts but disappointed in others.

As we saw in §4.2. there are some systems that are hypersensitive to changes in any of their causes. These are cases of extreme context sensitivity. But they are only towards the end of a scale. Whether or not any power is able to manifest itself is a matter always dependent on context. We will return to this issue when we look at the case of hiology in chapler 10.

8

Primitive Modality

8. I Something in between

Dispositions compose to fonn 'bigger' dispositions. As a result of all the components, the overall ~ituation disposes in one direction or another. But this still does not tell us how we get from the disposing in a particular direction to what actually happens. Can we simply infer, for instance. that if the overall situation disposes towards F, then F will indeed eventually occur? If the flame. sunlight, and heater overall dispose towards the room getting wamIer, then must the room indeed become warmer?

In this chapter, it is explained why we shuuld Ill:ver say more than that a causal situation overall disposes towards a certain outcome. Even the resultant vectors can represent nothing more than a tendency towards an effect. II may well produce that effect, and indeed one would be justified in expecting it to do so. The connection between a causal set up and its effect is, however, an irreducibly dispositional one. Such disposition­abty cannot be cashed out in other terms without sacrificing truth. Dispositionality is a worldly connection that can link one propelty, situation or type of event Mth another property, situation or type of event. The connection has modal strength in that it provides the world with more than pure contingency. But this link is one of tending or disposing only. It is not something as strong as a tie that binds things together inseparably. An effect does not always follow its typical cause: even a total cause cannot be relied upon always to be accompanied by its effect. The notion of cause is not something that automatically and immediately involves necessity. It is, rather, that of something that disposes towards its effect, where the modality of dispositionality is sui generis, of its own kind, and certainly not reducible to pure necessity or pure contingency. It is something in between.

Some philosophers may profess that they have no idea of what this sui generis dispositional modality is. If it cmmot be cashed out in terms of necessity, nor of pure possibility, which are the more familiar modal

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values - at least familiar to philosophers - then it cannot be a well­defined, meaningful concept. Su~h protests are artifice, however. We all know what the dispositional modality amounts to. The dispositional modality is the modality that we all know through our experience, as causal agents and patients. In this respect, it is the modal value best known to us. Therc is work to be done to establish (he plausibility of (his claim and in the next chaptcr we will concentrate on the argument that causation, and therefore dispositionality, can be experienced directly.

This chapter proceeds first by contrasting dispositionality with neces­sity and then with possibility. This establishes what disposilionality is not. What then is it? The difficulty in giving a positive account is that the very claim being made is that dispositionality is something that resists reductive analysis. The account is thus a primitivist one: dispositionality is a primitive modal value. But some positive things can nevertheless be said. The notion of a selection function will be introduced and illustrated with the familiar notions of nOTInativity and intentionality. These also employ selection functions, but it will be ventured that they do so 1ll so far as they themselves involve the dispositional modality. Because of that, attempts to explain dispositionality in tenns of iulenliunaliLy or in terms of normativity, both of which have been seriously developed, are judged to have the direction of explauation the wrong way round. They are explained by dispositionality, rather than vice versa. The sui generL~ nature of dispositionality also tells us that no conditional analysis of disposition ascriptions can work. If there is no dispositionality in the analysis, then we cannot get dispositionaiity out of it. If there is some such dispositionality, then the analysis will be circular. The conditional analysis fails primarily because the modality of dispositionality cannot be captured in other, non-dispositional, temlS.

8.2 Dispositions and necessity

In chapter 3 we saw that to be disposed towards an effect or manifesta­tion does not imply that such an effect or manifestation is necessitated. The main argument against the causal necessitarian view was that a disposition can always be prevented or interfered with by other disposi­tions. This indicates a contrast between dispositionality and necessity. We can illuminate this contrast by making the following four claims about how dispositionality relates to necessity:

Dispositions and necessity 177

A. Not (if DFa, then oFa): dispositions do not always mauifest. B. If DFa, then -I oFa: the manifestation of a disposition could always

be prevented. C. Not (if lJFa, then DFa): not every necessity is dispositionality. D. If oFa, then --, DFa: cases of necessity are never cases of

dispositionality.

Claim A says that it is not the case that if something is disposed to be F then necessarily it is F, and this is simply the case if there are some unmanifested dispositions. This has already been m:gued for and sup­ported at length in chapter 3, which showed that to be disposed towards an effect or manifestation does not imply that such an effect or mamfes­tation is necessitated. Objects can be fragile without breaking. They dispose towards breaking only but such breaking is not necessitated even if, as argued there, a stimulus occurs that can, in other circum­stances, lead to that effect.

For the same reasons, claim B can also be supported. Claim B states that if something is disposed to be F, then it is not the case that necessarily it is F~ in other words, something can be disposed. to b.e F without being actually F. In chapter 3, it was argued that dlSPOSI­tionality fails the antecedent strengthening test. This is because it is distinctive of' causal processes in general, and dispositions in particular, that they can always be prevented, masked or finked. If that is the case, to know that something disposes towards F is to know that it does not necessitate F.

Claim C says that not every case of necessity is a case of disposition­ality. Suppose some particular necessarily is F. Does that entail that it is disposed to be F? That does not seem to be the way we have to treat such cases. If Socrates is necessarily human, it does not seem quite right to say that he ;s therefore disposed to be human, as we saw in the previous chapter. If something is necessarily the case, would it even make sense that it is also disposed to be the case? Such dispositionality could add nothing more that could playa role in bringing that thing about. Dis­positionality would be, at the least, redundant. But worse than th~t, a disposition should always be, at least in principle, capable of prevcntlOn, which cases of necessity are not. If something is F necessarily, therefore, this does not entail that it is F dispositionally.

Claim D might be the most controversial because it says that cases of necessity are never cases of dispositionality, so a disposition never necessitates its manifestation. Some might think this goes too far,

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presumably because they think tha,t some but not all dispositions are capable of prevention and that it ought to be at least allowed that a disposition could necessitate its manifestation. But D is just the contra­positive of B, so we should be able to defend it if B is defensible. Suppose that, whether known or unknown, there is just nothing that can prevent a certain disposition from manifesting. The logic of disposi­tions nevertheless allows that if there were, counterfactually, some such process of prevention, then this disposition need not manifest itself. A necessarily manifest property looks to be, if anything is, a categorical property (Mumford 2006: 481), and this mles out the case of a disposi­tion involving necessitation.

8.3 What if everything is necessary?

There is a possible objection to our claims abOUl the relationship between dispositions and necessity: that it might be the ease that evcry­thing is necessary. Something that is necessary would then also be dispositional, something that seems to at least rule out claim Band D. There arc two rcsponses to this, dependenl on how the claim that everything is necessary is understood.

If some form of detenninism is true, there is a sense in which everything that happens does so necessarily. There was, however, in §3.12 a discussion of Anscombc's view in respect of determinism. She was quoted there as saying that a causal claim is consistent with neces­sitation but causation was not itself necessitation. The source of ne­cessitation must be elsewhere: it is not carried in the cOllcept of causation itself. In the light of that, the claims above have to be understood a ccrtain way, in particular claim Band D. They should not, then, be read as the contradiction of the Anscombe thesis. Disposi­tionality should be understood as consistent with that kind of necessity.

But claims Band D can also be understood as saying something important and true about the relationship between dispositionality and necessity, even under this particular detenninistic assumption. In claim B, [or instance, it is never qua disposition manifestation that Fa is necessalY because there is always the possibility of prevention or mask­ing of that manifestation. Dispositionality is t"hus never a source of the necessity of something in the world, even if it exists alongside it. Tn the deterministic case, for instance, where it is necessary that Fa, that is not because there was a disposition towards it. What delivers the necessity

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Dispositions and possihility 179

in claim B is that, somehow, everything got llxed. That will include the fixedness of all the background conditions - including which disposi­tions do, and which do not, act to produce the necessitated outcome - but it was not those powers that necessitated that outcome.

Since claim D is the contrapositive of claim B, it has to be accepted if B is accepted. Given what has been said about B, therefore, claim D should not be read as saying that necessity and dispositionality are incompatible absolutely. Rather, it needs to be read as disposing towards F is never the necessitating of F, even if F is for some other reason, necessitated. Saying that if Fa is necessary, does not make disposition­

ality its source. As a way of making this clear, we should say that the if·· . then of

these claims is not to be read as a truth functional material conditional but as a natural conditional. If of a, thcn any material conditional which has that as a consequent will be true, but that would not show any interesting coonection between the antecedent and consequent. It is wOlih saying, thereforc, that the claims A to D are explicitly not material conditionals. Claims Band D thus tell us that dispositionality is never the origin of necessity, and vice versa.

RA Dispositions and possibility

Let us now consider thc relationship between dispositionality and pos­sibility. Dispositionality is not the same as pure contingency. There are many things that will count as mere possibilities that arc not disposed to bc. This is true whatever our account of pure possibility: whether we just mean by it logical possibility, as involving no fonnal contradiction, or recombinations of all the existing elements (Armstrong 1989), or truth in other concrete worlds (Lewis 1986). Many things are possible in this wide sense without there being dispositions for them to happen. \Vhilc it is the case that something being disposed towards F means that F is possible for it, the opposhe entailment does not hold. We can therefore show the relationship between pure possibility and dispositionahty, but also mark their difference, in the following two claims:

E. If DFa, then OFa (and 0 ~Fa): if something is disposed to be F, then it is possible that it be F (and that it not be F).

F. Not (if OFa, then DFa): it is not the case that if it is possible that something is F, then it is disposed towards F.

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It ought to be uncontroversial that something disposing towards F entails that it is possible that it be F. If someone is fertile, then it is possible that they bear offspring even if they choose not to do so. If something is fragile then it. is possible that it be broken (and, of course, it follows from claim B that it is possible that it is not broken). Disposi­tions thus open a horizon of possibility. They make, what Goodman (I955: 40) caned threats and promises of their manifestations.

There is, nevertheless, one objection to this claim that someone might. care to make. The objection comes from the idea of a finkish disposition of the kind discussed by Martin (1994) and Lewis (1997). A tjnkish disposition is one that is removed at the very point it is stimulated. That might tempt one to think that there are dispositions that can be had even though it is not possible for them to manifest themselves. Something might, then, be disposed towards F even though it is not possible for it to be F, contrary to claim E. However, a consideration of the argument against causal necessitarianism allcviates us of this concern. Such an argument would work only if the finkish mechanism, which removes our original disposition at the moment it is tested, can itself be guaranteed to succeed. But that would be to assume a necessitarian view of causation for the fink. It would be to assume that 1ts manifestation was necessitated when it was stimulated and arguments have already been produced against such causal necessitarianism. The finkish mechanism could itself be prevented, interfered with and indeed linked.

There is a historical case of a link that failed. Mellor (1974) made use of the example of a nuclear reactor being disposed to explode or go ctiticaL But he said, when it was about to doso. sensors triggered various safety mechanisms that shut the reactor down. These safety mechanisms were effectively finks whose job it was to remove the explosive disposi­tion of the reactor when it seemed it would manifest itself. Such safety mechanisms could nevertheless fail to do their finkish work, which is what happened at Chernobyl in 1986, allowing the reactor there to go critical. It is, thus, far too strong a claim to say that our original disposition could be held even though there are no possible circumstances under which it can manifest itself. Its manifestation is impossible only if the fink's manifestation is necessary, contrary to causal dispositionalism. Instead, like all causal claims. we should say only that the fink is disposed to remove our original disposition and thus the oliginal manifestation remains always a possibility. Claim E is. therefore. upheld.

What, though, of the opposite case? If it is possible that something be p, should that mean that it has a disposition to be F? We say noL In the

Dispositionality as natural possibility 181

sense of pure, logical possibility, we can say things such as that it is possible that the struck match turns into a chicken, that lead could turn into gold, or that pigs could fly. But there are no corresponding dispositions to do so. Similarly, it is possible that when a fair coin is tossed 100 times, it might land heads 99 of those times, but, again, it is not disposed to do so, at least not with any significant probability.

We want to allow cases of dispositions with an extremely low proba­bility of manifestation, and indeed according to some interpretations of quantum physics there is a disposition of the match to turn into a chicken but it is just a disposition with a very low probability. Let us for now just assume, if the world is as such a view ofpbysics states, that we ascribe a disposition to something only where it is a disposition with a non­negligible probability. If we mean something like this, in standard cases of disposition ascliption, then we will say that there are many things that are merely possible without them being non-negligibly

disposed to happen. On the other hand, the probabilistic case raises some interesting

questions about what it means to say that something is disposed towards something else. A fair coin giving hundred consecutive heads is more than a mere logical possibility. In some sense the coin has a disposition to land heads 100 out of 100 tosses: it is just that this disposition is an extremely weak one. It is only just more than a logical possibility because the fair coin's di&position towards 100 consecutive heads is so small it would be barely perceptible if plotted as a vector on a gigantic quality space. If the world really does contain probabilistic dispositions. then we would need to revise some of the common ways we think about what is possible. Some things that we thought impossible might turn out to he possible after all, even if they are extremely unlikely.

But we would still not want to collapse the notions of pure possibility and dispositionality. 111ere would be a need for an intennediate modal value because we would still want to pick out those dispositions that were reliable, tended to manifest, or what is disposed to happen with a non­negligible probability. We thus uphold claim F, that it can be possible that something is the case without it being disposed to be the case.

8.5 Dispositionality as natural possibility

A notion of natural possibility is often employed and distinguished from logical possibility. There are those such as Ellis (2001: II) who arc

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sceptical about there being different kinds of necessit.y, mainly because he thinks of the modalities as univocal. But he docs allow that there are different groundings of those modalities. The reality of dispositions seems to provide precisely such a grounding of natural possibility, where what is naturally possible is what is disposed to happen.

In thc sense of natural possibility, therefore, it would actDally be the case that if F is possible then there 1S a disposition towards F. No contrast is being offered, therefore, between dispositionality and natural possibility. On the contrary, the former may ground entirely what the latter consists in. What better candidate could there be for supplying the world with natural possibility than the dispositions that particular things have?

We think dispositionality is the core modality from which the other two standard modal operators draw their sense as being limiting cases on a spectrum. We have an idea of a vase being fragile while steel is not fragile. A vase is disposed to break if struck, while steel is not so disposed. But if we add some further conditions to the situation, steel might be disposed to break, for instance if frozen down to a low enough tempcra­ture. Under such conditions anything would be fragile and thus disposed towards breaking. In this way we can get an idea of ever more distant possibilities, of which time-travelling and a vase growing a beard might be at the far end of the spectrum. Roughly, the more context onc has to bring to bear, to specify more and more unusual circumstances that are required to produce a particular outcome, then the more one is moving away from a notion of dispositionality and towards possibility. Eventu­ally we reach the idea of a pure contingency as an ideal, limiting case.

Likewise, we can gain an idea of what dependably happens with hardly any exceptions from which the idea of necessity occurs, though again as an extrapolation from our core modal notion of what is disposed to happen. 111e less context that is needed, the more one moves from dispositionality towards necessity, which is the opposite limiting case to pure possibility. The extrapolation to what is impossible would be similar. We are disposed to breathe, for instance, and find it extremely hard to resist this disposition. It seems one that we manifest of necessity in that it is virtually impossible that we stop. But there arc, of course, circumstances in which we can bc made to stop breathing. This is a very this-worldly account of possibility and necessity and is ellcctively a restricted combinatorialism (sec Mumford 2004: ch. 10; see also Armstrong 1989) by extrapolation. This is not to say that the pure, alethic necessity occurs in nature. We have argued in this book that it

Disposirionality and normativity

does not. But dispositionality could be what gives us the idea of there being modality in the first place: that what is, might not he, and what is not, could be. But we are not claiming that the alethic modalities are logically derivable from dispositionality (in agreement with Eagle 2009). Our claim concerns only natural de re modality, which is free of necessity.

It may be thought that the idea of a dispositional modality is still not complete. We have said only what it is not~ not what it is. Disposition­ality is not necessity and it is not pure possibility but something in between. Some might profess to still know nothing positive about it. In due course it will be argued that this is disingenuous on the part of philosophers because dispositionahty is actually the modality with which we arc most f::illliliar in our experiencc. Setting the full argument for that aside until chapter 9, however, we can still nevertheless illumi­nate the notion of a dispositional modality by analogy with other notions that philosophers do claim to understand. We will start with normativity.

R.6 Dispositionality and normativity

When we say that something ought to be the case, it must. be possible that it is the casc. If a doctor ought to save a patient's life, then it must be possible for the doctor to save that patient's life. BUl if something ought to be, we are not saying something as strong as that it is necessmy. That something ought to be the case does not entail that it is the case and much less that it is necessarily the case. Thus, suppose it ought. to be the case that we are kind to animals. Animal cruclty nevertheless exists so the mere fact that we ought to be kind to animals (GA) does not entail that we are (A). We can say t.hat OA does not ent.ail or necessitate A.

But saying that we ought to be kind to animals says more than that kindness to animals is a mere possibility. Many things are possible where it is not the case that they ought to be. It is possible that we dress animals in clothes or that we place vegetables in our beds at night but arguably neither of these things ought to happen. A certain subset from all possibilities is picked out as special or preferred on the basis of them being the possibilities that ought to be the case. Exactly how this subset of possibilities is picked out is a job for the moral philosopher to explain. A subjectivist or an intersubjectivist would say that the subset is picked out by us and our preferences while a moral objectivist would say that there is some real, mind-independent basis upon which a subset is

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selected. A utilitarian has a halfw~y position where what ought to be is an objective matter but one that essentially involves the maximization of human happiness. However it is done, the basic idea is one of a selected subset of the possible, prefclTed on the basis of what ought to be but not necessarily is.

Analogously, dispositionality picks out a subset of preferred possibi­lities: the ones that arc disposed towards and would be the manifestations of the dispositions in question. Not everything is naturally possible; only certain possibilities are disposed towards by the things that exist in nature. And just as with nonnativity, some manifestation being disposed t.owards does not entail or necessitate that it occurs. If we are familiar with and able to use normative concepts, therefore, we should have no real difficulty in understanding the dispositional modality.

Lowe has suggested a nonnative account of dispositionality that has Aristotelian ancestry (1989: ch.8, for instance; and, for a detailed dis­cussion, see Mumford 2000). The nonnative account of nature is usually associated with Aristotelian metaphysics where it is often now dis­missed as offering an outmoded view of the world for science. Objects are seen as having a proper place where they ought to be and thus having a telos or final cause. Physical objects want to be on the Earth, for instance, and that is why they fall towards it. Teleological explanation has shown something of a revival in more recent times (e.g., Wright 1973 and Sober 1985), though it is still controversial.

Lowe, however, attempts to develop a normative account that is compatible with a modem empirical view of the world. Law statements for Lowe arc in a sense about what ought to be the case. The 'ought' i<; not an explicitly moral or anthropomorphic one but instead tells us what is the natural behaviour of kind members. An acorn ought to grow into an oak tree in the sense that it is natural for it to do so if it falls in the right sort of conditions and has all the right circumstances in its favour. It ought to grow into an oak tree and it ought not to grow into a plulll tree. A 'good' acorn is one that can do this, whereas a 'bad' one might not be able to do so.

Exploiting this naturalistic account of good, bad, and ought, might enable us to understand how nature works. We could, for instance, understand how a set of circumstances might dispose towards an out­comc, without necessitating it, in nonnative terms. A match ought to light when struck even if it might not do so. A good match is one that is disposed to do so. A bad match is one that is not disposed to do so, perhaps because it has had its flammable tip knocked off. If wc have

Dispositionality and intentionality 18S

nOlmative notions, therefore, we can understand the modality that is invoked when we make disposition ascriptions to things in naturc.

8.7 Dispositionality and intentionality

Intcntionality is another notion that produces an illuminating analogy for dispositionality. Identified by Brentano (1874) as the mark of the mental, intentionality is sometimes characterized as a directedness or aboutness. Beliefs, desires, emotions, intentions and perceptions all have intentional objects. A helief is about a day of the week, for instance, such as the belief that Thursday is a busy day. A desire can be for a new pair of shoes. 1\n emotion such as fear can he of the stTanger who has entered the room. You can intend to wash your car and you can perceive the sunset. These cases arc all about or directed towards their intentional objects.

But what is also accepted of intentionality is that those intentional objects need not be reaL The stranger who entered the room may have been a mere psychotic fantasy rather than a physical human being. Your fear is nevertheless real even if its intentional objcct is not. Having a belief, dcsire or emotion about X does not entail that X exists. Similarly, having an intention to do Y does not entail that Y gets done. Despite your good intention, your house could remain untidy. We sec, therefore, that intentionality involves this kind of halfway modality that we have been developing. Something is selected or preferred from all the available possibilities. There is thus a limit on possibility to some suhset and we are thus not dealing with 'pure' contingency or possibility.

But we are not dealing in necessity either. That things are selected for this subset does not mean that they are the case. Having a fear of the burglar downstairs does not necessitate that the burglar exists. Intending to send a letter does not necessitate that. it is sent. Other things could get in the way or one might just lack the resolve to see through one's intention. There is thus another close analogy between intentionality and dispositionality. Both place a limit on the possible. TI1CY select or prefer a certain subset of the possible yet they don't necessitate that subset being actuaL

Molnar (2003: eh. 3) argues that it is intentionality that is the mark of the dispositional. Conlrary to the Brentano thesis, there can be, Molnar argues, physical intentionality. If we want to understand how a disposi­tion can be directed towards a manifestation that never gets actualized

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then we should, he insists, lo~k to the phenomenon of intentional inexistence. It is like an intention that never gets realized. Just like intentionality, dispositions are for some subset of possible outcomes but which might not be actual. There are a number of other marks or characterizing features of intentionality and Molnar argues that they all apply equally to dispositionality.

8.8 Intentionality and normativity are dispositional no/ions

The problem with drawing analogies between dispositionality and other phenomena 1S that it might seem to undermine the claim that the modality of dispositionality is sui generis. One might now think that this kind of plimitive intermediate value is to be found all over the place, and dispositionality, intentionality and n01mativity name just three in­stances of it. It would be too soon to make such an accusation, however. That would be to assume that the modal features of these three cases do not. have a common explanation. There might, after all, be just a single modality involved that explains the similar features of each.

Alternatively, two of these three phenomena might be reducible to the other. One might be able to reduce nOIDlat.ivity, for inst:1Ilce, to inten­tionality. There have already been attempts to reduce dispositionality to both norrnativity (Lowe) and to intentionality (Molnar). However, we do not need to decide which of the nonnative or the intentionality account is the correct theory of dispositions because both of them, we argue, get the analysis the wrong way round. Certainly if we want a philosophy that is naturalistically grounded then wc should bc looking instead to explain nonnativity and intentionality in dispositional terms, rather than vice versa.

First, let us consider nonnativity. Conceptual analysis reveals that dispositional notions must be employed to explain it, and a specifically dispositional modality seems to be involved. If I ought to do something, 1 must have an ability to do it and to have an ability is to have a disposition. Ought assumes can; hence it makes no sense to say that. a ought to q" even though a is unable to q,. Being unable to q, means that q, is (naturally) impossible for a, whereas q, must be possible for a, jf a ought to 1>. An apparent exception to this claim is not, after all, serious. Suppose you are in a situation where you ought to perform first aid on an accident victim but you cannot do so because you have had no training. This example conftates two different ideas that are individually

Intentionality and nOr1nativity are dispositionaL notions

consistent with the claim, What. this might mean is thal you ought to have taken first aid training so that you were in a position to pcrfonn it when called upon. That could be correct. But also, given that you have not acquired the training, one is also justified to instead insist that you ought not to attempt any such first aid as it could make the situation worse. Such an example is one, therefore, where we admit that someone does not have an ability but that they ought to have the ability. You have a capacity, after all, to leanl first aid and you might then be considered irresponsible if you did nor and it was subsequently needed. What we have in such a case is a second-order ability: an abihty to acquire an ability. One may well have this in mind if one says that a ought to (p even though they cannot. They ought to be able to q, because they ought to have acquired the ability to q,.

This second-order case notwithstanding, ought implies can but it also implies something more. Just as saying that we ought to do some­thing implies that we arc able to do so, it also implies that the thing in question is less than necessary. We do not say that we ought to do something impossible and likewise we do not say that we ought to do something that is necessary. We wouldn't normally say that we ought to obey the law of gravitational attraction, since it is not in our power to choose whether to obey it or not. Similarly, it seems strange to say that we ought to breathe as doing so is a purely subconSCIous process in our bodies that we cannot resist. The explanation is again disposi­tional. If something is necessary, I can have no ability to resist it.

Normativity can be explained in dispositional terms, therefore, but earlier we explained the dispositional modality by analogy with nonna­tivity. How do we know which way, if any, the direction of explanation should go? Naturalism favours the priority of dispositionality. Disposi­tions are things that exist in the world, if the dispositional ontology is correct. They are the property-like powers of things: abilities and capa­cities, without which normative notions could not get started. That. something ought to be the case presupposes that there are dispositions that. can be both exercised and prevented. On the other hand, it is far from clear that dispositionality presupposes nonnativity. The reason t.he Aristotelian view of nature has been overturned is largely because it seemed implausible to apply normative concepts to nature literally, or at least this could be done only via a notion of dispositionality.l The idea

1 That a notion of nonnativity could be developed from clispositionality was suggested to us hy Svein Anders Noer Lie.

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that something ought to behave in such and such a way seemed to amount to nothing more than that it is disposed to do so. A good acorn would then merely bc one that had the typical dispositions for that natural 'kind and that is an idea that is rid of any irreducibly nonnative commitments. Dispositionality seems, therefore, to be the way in which normativity is naturalized.

A claim is not being made that normativity is explained entirely in tenus of dispositions. That would be too simplistic. An agent has many dispositions and only some of them ought to be exercised. Almost all human beings, for instance, are able, in a purely physical sense, to murder but again almost all would not do so because of their moral conscience or disgust. While OUf view of ought involves dispositions, therefore, it involves more besides, and this is what moral theory adds. The important claim in the context of this chapter, however, is that nonnativity involves the dispositional modality. It involves the modality that is more than pure possibility: where one ought to do rp it must be more than a pure possibility that one does rp: one must have an ability to rp. But the modality is less than necessary: it must be possible to resist it. rp Is something that can be prevented or can just fail to occur. Otherwise, the ought would be redundant.

Similar things can be said of intentionality. Molnar effectively ana­lyses dispositionality in tenns of intentionality but there still remains a question of what intentionality amounts to. A dualist might just appeal to this as some primitive ability of souls. Searle (1980), on the other hand, appeals to it as a special ability of brains, just as lactation is also a high-grade biological function. This is a dispositional account, in so far as an ability is dispositionaL But an explanation of such intentionality might be possible within causal and naturalistic terms. Annstrong (1968: ch. II), for instance, offers a causal theory of mind in which intentionality would, if the account is correct, be demystified. To have a belief about the cat on your lap, for example, is to be disposed to behave towards it, and causally interact with it, in a certain way. The account would have to be far more sophisticated than that, however, because of the intercOImectedness of mental phenomena. Which dispositions you act upon will also be determined by your desires towards the cat, and which beliefs you acquire about the cat will be detennined by your perceptual dispositions. The details of the account may be contested, as it will involve an analysis of almost all mental phenomena. TIle key commitment, however, is lhat intentionality can ultimately be given a causal dispositionalist account. Perhaps that account has not yet been

Dispositionality as a selection function

given in full but the basic idea is one with some plausibility and it is appealing because it holds the prospect of bringing intentionality down to earth and no longer being some mysterious or magical feature of nrinds. Such a view would then compel us to view dispositionality as basic, again, and a phenomenon that explains intentionality rather than the other way round.

Both the normative and intentionality account of dispositions look, from this brief survey, to have the order of explanation back to front. Both accounts identify similarities between dispositionality and other phenomena and they are indeed correct that there are analogies to be found. More plausibly, however, these analogies work because norma­tivity and intentionality involve the dispositional modality. That they do so is explained by so-called naturalistic accounts of them. These natu­ralistic accounts are dispositional, showing that both normativity and intentionality essentially involve dispositions at work. The analogies with dispositionality might, therefore, have aided us somewhat in under­standing its special modal character, but they still cannot tell the whole story if they ultimately themselves involve the dispositional modality.

8.9 Dispositionality as a selection jimetion

From the analogy with nonnativity and intentionality, something more can now be said in the abslract about the mechanism that permits an intermediate modality. Dispositionality, it will be suggested, can be understood as a sort of selection function - a natural one in this case -that picks out a limited number of outcomes from all those that are merely possible. These 'prefened' outcomes are the ones that the disposition is for. In Molnar's terms, they are the possible manifesta­Lions towards which the disposition is directed. The idea of a selection function is simply one Ihat identifies a subset from a realm of possibi­lities. It favours some of those possibilities over others. In nonnativity, for instance, certain possibilitles are selected on the basis of being the ones that ought to be. With an intentional notion such as purpose, possibilities are selected on the basis of being those intended. Disposi­tionality picks out those possibilities towards which there is a natural disposition or tendency. A particular disposition picks out a manifesta­tion type among all the possible manifestation types, and a certain cause picks out a certain effect among all possible effects.

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We cannot, however, use this to analysc in what dispositionality consists. It only shows the feature of being more than pure possibility but less than necessity. What cannot be reduced away is the relationship of a disposition to this subset. The subset represents the manifestation but the disposition only tends towards such an outcome. There is an irreducibly dispositional connection between the powers in the world and the outcomes they can bring about. Solubility, for instance, selects dissolving as its manifestation and will sometimes succeed in bdnging it about. But it irreducibly only disposes towards that manifestation: and similarly for each individual disposition and its manifestation. If we take together all the dispositions that are real - that exist in the world - then we select all the manifestations that are naturally possible.

Dispositions clearly have some connection with conditionals, as evinced in our tendency to articulate disposition claims in conditional fmID. Understanding this connection is no casy matter, however, as will be shown in the next section. According to the view of this chapter, the reason for this is that it is misconceived to attempt an analysis of dispositionality in tenus of something else. But that raises the prospect that the way to understand such a conditional is precisely as a selection function. The antecedent selects the consequent but irreducibly only tends towards it.

8,10 The conditional analysis

There 1m:::> been a long history of attempted conditional analyses of disposition ascriptions. We are now in a position to make a general diagnosis. No conditional analysis for dispositions can possibly succeed and we can now give a reason. There are two main ways in which a putative analysis fails. One is by being false and the other is by being trivial. The position has been advanced that dispositionality involves a sui generis primitive modality. It would follow that any putative condi­tional analysis would either be false, and susceptible to counterexam­ples, because it attempted to reduce this ,yui generis modality to something that it is not. Or, on the other hand, it would fail because it did contain this sui generis modality and was then trivial.

TIle simplest conditional analysis i.s to be fOlInG in Ryle (T949), which is that an ascription of disposition D is tme if and only if a non-material conditional is true whose antecedent names the stimulus for that disposi­tion and whose consequent names the manifestation. Something is soluble,

The conditional analysis

for instance, if and only if were it to be placed in water, it would dissolve. The general schema of the simple conditional an<Jlysis is given by SeA:

SCA: 'Ix (Dx ~ (Sx .~ Mx» There arc various inadequacies of this analysis, but the most obvious one in the current context is that it fails to accommodate the possibility of prevention. The generality of SeA is impossible to maintain given that there will be many cases in which something has the disposition D, receives stimulus S but fails to display manifestation M. A simple masker is enough to do that (sec Johnslon 1992), though a finkish one would also be a case in point (Martin 1994), Masks are effectively antecedent strengtheners, putting it in the tCIIDS of §3.5, above, and SeA does not survive the antecedent strengthening test.

In an attempt to save the conditional analysis, Lewis (1997) proposed a revised conditional analysis, which contained words to the effect that the problem of finkishness could be circumvented. The analysis should contain reference to a causal basis B of the disposition and, because finks work by the removal of this basis, it is specified that this causal basis is to remain from the time that the disposition is stimulated through to the time that it manifests itself Simplifying, and taking this last clause as read, the revised conditional analysis says (Lewis 1997: 149):

RCA, 'Ix (Dx' , ((Ex & Sx) --, Mx)))

Setting aside the obvious point that the analysis lIses the notion of a cause - in what it is to be a causal basis - and dispositions thus conceived could not therefore be used as the basis of a dispositional theory of causation, RCA is still inadequate as an analysis. A fink is what was called in §3.7, above, a subtractive interferer but there can, instead, be antecedent strengtheners that are additive interferers and RCA has no protection against them, Bird's (1998) antidotes work against Lewis's revised conditional analysis precisely because they are additive interfcrers. They take nothing away from the disposition, so the causal basis can remain, but they add a masker that prevents the mani­testation from occurring.

Bird (2001' 60) himself, however, is nevertheless prepared to support a kind of conditional analysis: one that tries to limit its scope of application to cases where finks and antidotes are not in operation. Such a conditional is simply ceteris parihus qualified:

CACP: 'Ix (cp (Dx H (Sx ~ Mx)))

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But what could a cp clause mean? There has long been an acknowl­edged suspicion that the meauing of cp is trapped between two fatal options. The first is falsehood: if the ceteris paribus clause is standing in place of a finite list of factors that are assumed to he the case, or even assumed to be not the case, then there could still be some further prcventer whose addition would render even this conditional false. The second is triviality: if ceteris paribus stands for a general clause that automatically excludes all interference, then it could become meaningless and circular. 'If S then M cp' could mean that every S is an M, unless it's not. For this reason, cp clauses have either been regarded as useless or a further interpretation of them has been offered. As discussed in the previous chapter (§7.S), we therefore offer a dispo­sitional interpretation of the clause. 'S --;. M, cp', under this interpreta­tion, means that the conditional'S -----7 M' has to be understood as having dispositional force, stating that the connection between Sand M is a dispositional one. This is thus akin to Mumford's (1998: 88) conditional conditional which is also irreducibly dispositional. If the meaning of a cp clause is dispositional, it is thus clear that CACP does not provide a conditional analysis of dispusitiollality. Any such putative analysis would be itself invoking dispositionality and would thus fail on the grounds of circularity.

Bird's discussion of the conditional analysis has another element which is best considered separately from the addition of a cp clause. He considers, as causal realists will be tempted to do, a modally strengthened analysis of dispositions (Bird 2001' 36):

MSCA: ulix (Dx H (Sx -, oMx))

For reasons that have already been offered, however, it would be unwise to stipulate that a disposition must make its manifestation necessary. That just does not seem to be the job that dispositions do. And it is dubious, to say the least, that there arc any dispositions which have such necessity, let alone them all. Additive interferers such as Eird's own antidotes are enough to show that. One might, then, be tempted towards an account that combines CACP and MSCA to give us a modally strengthened but cp account: nVx (cp Dx .,."-> (Sx -} oMd). The cp­clause, while present in an attempt to circumvent antidote cases, may be doing so only at the cost of circularity, as explained above. But. even if there is a non-trivial non-dispositional sense of ceteris paribus, the combined MSCA+CACP only gives with one hand what it takes away with the other. The conditional is necessary, yet only cpo

Dispositionality is the most basic modality 193

There have been many other attempted conditional analyses (see Choi 2008, for instance), which have employed increasingly sophisticated stratagems for avoiding the problem of additive interference. But if dispositionality really does involve a sui generis, primitive modality, any such analysis, no matter how sophisticated, will be subject eventu­ally to counterexample because it is attempting to treat this dispositional connection as something else. And were snch a conditional analysis to be resistant to counterexample, the most obvious reason would be that the dispositional modality had been smuggled back in under cover of disguise, which seems to be the case with the cp-strategy. If we accept the sui generis nature of the dispositional modality, therefore, we can draw a close to the Sisyphean task of endlessly producing new candidate analyses, only to see them fail and then starting all over again. Enough ink has been spilled on this doomed project already.

8. I I Dispositionality is the most basic modality

Dispositionality is a primitive, unanalysable modali1y that is intermedi­ate between pure possibility and necessity. It has been argued that because of its special modal nature, no analysis that fails to invoke it can succeed. It will be subject to counterexamples because it will attempt to reduce dispositionality to something else, such as necessity, which thereby misses the subtlety and flexibility of dispositionality. In particular, it would miss the key element that dispositions can be subject to prevention and interference. This modal feature is essential to dis­positionality: it is what makes it distinct from everything else. Unless it is inc1uded, therefore, a candidate analysis is bound to fail. If, on the other hand, it is included, the analysis will be circular and thus also fail.

By way of justification, the differences have been outlined between dispositionality and possibility and between dispositionality and neces­sity. These two more familiar modal values - more familiar to modal logicians at least are not fit to represent the worldly modality that we expclience in the causal transactions around us. But because causality is a part of our experience, which pure logical possibility and necessity are arguably not, there is an argument for saying that disposilionality is the most familiar modal value. It has also been suggested that the disposi­tional modality is the most hasic modality, from which an idea is derived of some stronger and weaker de re modalities. Our experience of dis­positions and their work shows us that there is such a thing as modality:

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that some things that are not, nevertheless can be, and that some things that are, might not have been. We have also suggested how such modality may fall on a spectrum, of there being stronger and weaker dispositions towards an outcome, which gives us an idea of there being remote possibilities and highly likely possibilities. While we do not claim that this delivers something as strong as logical contingency and logical necessity, because it is modality in the natural world only. it could nevertheless give us the idea that such logical notions might be of interest in other areas of thought.

The case for the perception of dispositionality in particulaT, and causation in general, will be made in the next chapter. This adds one strand by which we can come to understand the dispositional modality and acquire disposition concepts. Even if the notion resists analysis, it can still be known to us through experience. Added to that, we can note that there are some purely fomMI ways of understanding dispositional­ity, in terms of how it relates to the other modalities, even if these formal distinctions fall short of an analysis. A further way of understanding dispositionality is by analogy with other familiar notions of an interme­diate modality, namely from our grasp of nonnativity and intentionality.

These phenomena are finally to be explained in terms of dispositionality so there is no prospect of analysing dispositions in these telms either but at the very least the analogy shows that we are able to handle concepts that employ a dispositional modality. The suggestion was then made that the intermediate modality works via a selection function: identifying a subset of all the possibilities as favoured or preferred.

We have, therefore, a primitive dispositional modality in our notion of causation. This is evidently employed by us in our causal concepts . We understand enough of its formal features and, as we will now go on to argue, it can be acquired through experience. That it is resistant to analysis should nol, therefore, be taken as a cause for alann.

9

Perceiving Causes

9.1 Primitive but empirically grounded

We have claimed that causation involves a primitive sui generis modality, which we call the dispositional modality. 1t is primitive in that it is not constructed from the two other modalities of necessity and possibility, nor any other as felI as we can sec. The analogy between dispositionality and nonnativity and intentionality allows us to convey what we mean by dispositionality but, again, we do not think that dispositionality can be analysed in those tenus. We do not see that there is anything more basic.

This might be thought to leave our account with a problem. In seeking clariLy and precision, philosophers like an analysis of a concept as they think it shows exactly what the concept means. There could, then, be some scepticism that there really is this dispositional modality or there could be an allegation that it is an empty idea, not well dell ned. Such a charge could, however, be answered. Even in a standard empiricist epistemology, such as Locke's, not all concepts can be analysed. I~ ~s allowed that some are primitive. What gives the pdmitive ones legitI­macy is that they are known directly from experience (Locke 1690 :

ll.i.2). The dispositional modality could be acceptable by empiricist standards, therefore, if it can be known through experience. \Ve will argue that this is the case.

By engaging with such an issue, we should not be interpreted as siding with empiricist philosophy in generaL about which we have many reservations. TraditionalJy, however, empiricism has been a philosophy that has particular difficulty with dispositions (see Wrigbt 1991). The thought is, therefore, that if, even by relatively strict empidcist stan­dards, the dispositional modality can hold its own, then it would make no less sense and possibly more to those who go beyond empiJicism.

In this chapter, we argue that causes can be perceived, and further­more that such perception reveals their dispositional character. The perception of causation provides us, therefore, with knowledge of the dispositional modality. We will concentrate on the sense of touch for it

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is here that we think causation can ~e experienced directly. The standard division ofihe senses into five, however, is inadequate for us to describe our experience of causation, which is one major reason why the myth of the fivefold division needs to be ovcrtmned. The senses of balance and of proprioception are morc important. These senses can come under the heading of bodily sensations, where that is meant to exclude sight, sound, taste and smell, even though those four are of course types of sensation provided through our bodies. It is with our bodies that we are causal agents and patients and this is what, by touch, balance and proprioception. gives us the expclience of causation and reveals its dispositional nature. Once a causal, dispositional concept has been acquired from experience in this way, we can then also, by extension and analogy, permit perceptions of causes through sight, sound, taste and smell, though only analogously. At the very least, perception of causes by these means will be theory-dependent but it is, we argue, an experientially well-grounded theory-dependence.

9.2 Causal judgements and perceptions

It should be made clear that. the claim being made in this chapter is a relatively strong one, or so it might. be presented. But it is also a conservative one in t.hat if we are right. t.hen everyone is intimately familiar with the perception of causes. It has to be acknowledged Ihat since Hume, however, the perception of causation has been a matter of philosophical difficulty in which the stance that causes can be pcrceived is considered a bold one to take. This is, we will be arguing, because causat.ion was depicted in a way t.hat would make it impossible to perceive. Once we free causation of its Humean characterization we are able to allow. what we think everyone already understands,' that causes are perceived.

Our project should be distinguished from that of studying the nature of causal judgements. Michotte's (r946) famous work on the perception of causation was primarily about the judgement.s we make: finding the conditions under which we do and don't judge causation t.o have occurred. Work of this nature continues (Butterfill 2009) but it is not what matters for our project A judgement that causation has occurred can be made even when there is no causation at all: for instance. where a moving disc on a screen meets another, which then moves off. While the movements of these discs are caused, it is by the projector. The first disc

Causal judgements and perceptions 197

does not cause the movement of the second, though that is what the causal judgement in question is about. 1 Under certain conditions, we do indeed make the judgement that it looks like causation between the discs. Causal judgements can easily be deceived, we do not deny.

Our subject here is whether causation can be perceived and, given so, what it is that is perceived in such a case. Perceive being a success term, we are thus concerned exclusively with veridical causal percep­tions, that is, those in which causation has actually occurred. We will be arguing that there are such veridical causal perceptions and, in a tradi­tion going back to Locke (1690: ILxxi.4) and Reid (1788, Essay 4· ch. 2), plimarily these are bodily perceptions. That causes can be perceived has been argued more recently_ Ducasse, for instance, points to the evidence that the language we use is heavily causally laden. We use causal verbs all the time, which might be taken to indicate that we acquire causal concepts easily and use and apply them routinely: Lo cut, bend, corrode, push, scratch, kill, crush, motivate, irritate, and so on (Ducasse, T965: I76). From this, Ducasse moves straight to the claim that causation is routinely perceived, rather than just inferred, through all the senses including visioll. I see a bird land on a branch, for instance, and as it does so the branch bends (Ducasse 1965: 177). Cartwright offers support to this view. I may see a cat lapping milk or a person washing dishes. To do so is to see causation, not because causation is some extra connecting 'glue' that is perceived to hold one event to

anothcr, but because such individual causings arc instances of causation in the abstract (Cartwright 1993: 426). Seeing the cat lapping up tbe milk is seeing a token causing which thus also shows us the type. It is a mistake to look any further for causation as a 'secret cOlmection' hiding: somewhere within the cat's lapping.

At least this argument is direct but it is not one that we think would convince an opponent: a _Humean, for instance. It is too quick and the standard Humean analysis of causation would answer it. All we see is the biTd landing and the branch hending and our thought that this amounts to causation just consists in the fact that branches with weights on them always have been followed by those branches bending, in our experience. A constant conjunction account could still be given. We need a more circuitous route and detailed argument if we are to convince a Humean sceptic.

1 Our thanks to Markus Schrenk for demonstrating this to llS.

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There is another kind of sceptic, however, who also must be answered. Beebee (2003) suggests that even if we can sec causation, it doesn't prove much. In particular, the fact that we have 'thick' causal experiences - seeing that the bird bent the branch, the white ball moved the black ball, the fire gutted the building, and so on - doesn't prove that a regularity theory of causation is incorrect. Hurne might have been wrong about the experience and psychology and maybe we do sec some kind of causal connection between events. But that might just be an accident of our psychology and wouldn't demonstrate that there is anything more than constant conjunction in the world itself: it would just explain why we have an irresistible habit of making causal judge­ments. We can grant this possibility: that we see 'real' causes, though there are none. Refuting it is not our aim. But for a Humean to accept this is a major concession on the burden of proof. Hume' s argument was to the effect that we have no good reason to posit causal connections over and above regularities; indeed, because such causes are not even a part of our experience then the very notion is empty. If one concedes that Hume was wrong on this point then a major source of scepticism about causation goes. Instead of asking why anyone would need to posit rcal causal connections in the world, the tables would be turned and one should ask why anyone would then want to say that causation was only regularity, given that we experience it as something else. And the empiricist argument that we have no legitimate idea of real causation, over and above constant conjunction, will have entirely vanished from consideration. We will not, therefore, worry any further about the possibility that 'real' causation is perceived non-veridically, which would be an en-or theory about our causal experience.

We will now leave these preliminaries aside and move on to the substantial business of tlus chapt.er, which is the nature of our bodily causal perceptions. To make a staIt on this, we will first consider Hume's reasons for saying that causation cannot be perceived. This will be infonnativc for what follows as Hume makes what we under­stand to be a major wrong-turn in the way he considers causation.

9.3 Where can we find the causal COl1l1ect;OI1'

If you believe the philosophers, causation is far from easy to perceive. We can observe one event, and we can then observe a second that follows it. But. what. is it to see that the first caused the second? For

vVhere can we find the causal connection? 199

Hume. we cannot sec that the first. produced the second, or had a power t.o produce it. or compelled it, forced it or necessitated it. The common belief may be that we do see such tlungs and this is how we gain OUf

causal knowledge. But Hume poses a problem thus: all we can see is one cvent followed by another and never any connection between t.hem that. would correspond to what many people would call real causes. Any belief that. we do have in the first causing the second arnOlmts to nothing more than that the events are contiguous, that the first temporally preceded the second, and that events of the first kind are always fol­lowed at a later time by events of the second kind. Any notion of causation beyond that has no origin in our experience and thus no legitimate place in our thinking.

We observe a pattern of events, for Hume, but some would insist that there is more. There is some kind of real causal connection betwecn some of those events. Hume's challenge. however, is for t.hose who believe in such real connections to show from what experience the idea comes. And we cmmot, he says. When we examine the cases, no matter how closely we observe, we will never see more than the succession of events. The connection itself, which is said to tie together these events. is something that. cannot be observed. Contiguit.y, temporal pliority and constant conjunction are all observable, and for Burne provide all the notion of cause we can have. As he says:

We have no other notion of cause and effect, but that of certain objects, which have been always conjoin'd together, and which in all past instances have been found inseparable. We cannot penetrate into the reason of the conjunction. We only observe the thing itself, and always find that from the constant con­junction the objects acquire an union in the imagination. When the impression of one becomes present to us, we immediately form an idea of its usual attendant ... (Rume 1739: 93)

Those who believe in a connect.ion that is more seem to be invoking somet.hing for which we have no evidence and, given empiricist stric­tures on concept acquisition, thus something for which we cannot even assign meaning.

Causation seems evidently some relation that holds between two temporally distincl events. How could one possibly deny Hume's claim that the 'connection' relation cannot be observed, only its relata? And then why wouldn't one opt for some account of causation in which that relation is const.ituted by something that is empirically grounded, such as facts about constant conjunction? There are many sl1.ges of

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argument required to get us that t~r but the focLls of this chapter is that initial stage in which Hume argues that no connection or tic can be seen between the events but only the events themselves.

The position looks pretty hopeless at this point and, we would argue, is. If we accept that causation ought to be some kind of relation holding between temporally distinct events then the game already may be lost. It is hard to see how this kind of cause can be perceived. There is. however, another way to overcome Hume. Instead of seeldng to answer the problem as he poses it, we could instead reject the question or argue that it is misconceived. Is the thing he is asking us to find really what we should think of as causation? Certainly, it is hard to see how a causal tie between distinct events could be perceived, but is causation really a tic between distinct events? Is that the thing we are looking for?

In chapter 5, we offered an alternative conception of causation that was not about two temporally distinct events, with a relation between. In particular. we argued against Hume's temporal priority condition in which the cause occurs before the effect. Causation, we insisted, involved simultaneity. The effect occurs at the same time as its cause; where simultaneous does not imply instantaneous. Nor did we see any problem of distinguishing causes from effects as there are ways other than through temporal priority that this could be done. For the dispositionalist, the cause is something that disposes towards the effect and, in asymmetrical cases of causation, the effect does not dispose towards the cause.

Armed with this understanding of cause, we can sec that we have no good reason to follow Hume up this garden path, looking for a putative connection between temporally distinct events. Certainly we cannot observe that; but it is not anyway causation as we understand it. If causation is instead understood as a simultaneous process, in which the cause changes into the effect, moving continuously through the intemlediate stages, would causation become more easily perceivable?

Free of the two-event-plus-relation model, a barrier to the perception of causes is removed. Causation is about the unfolding of a process, and such an unfolding is something that can be observed; for instance, when water is heated in a pan over a flame and turns to steam. There is something far more promising here than the search for an invisible relation between distinct events. The model does not deny that there are events, and that some of these may be related to causation. But such events would be stages of the unfolding process, such as its starting point and its end point. We do not, as a na'ive Humean account may seem to suggest, go straight from one to the other. A continuous process can

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Bodily perception 201

be found in between, through observation. The sight afKan!'s ball m the cushion and Ducasse's bird bending a branch are cases where causation could be seen. But OUT argument will not be quite so swift as that either. Any sucb causal knowledge, an opponent might claim, could be infer­ential in nature. And even if we sct aside Hume's temporal priority condition on causation, we might still be inferring causes on the basis of our past experience of regularity. What we need is some kind of direct experiential knowledge of causes, obtainable in a single instance, rather than having them inferred [rom regular patterns of events. Fortunately. we think there is such a case of direct experiential knowledge of causes. from which our idea of cause comes. Furthennore, we think that it reveals also the dispositional nature of causation. The case we are talking about concerns hodily sensation.

9-4 Bodily perception

There is an idea that caLlsation ean be experienced within our own bodies. Locke suggested this, as did Reid. Bodily sensations arc a promising place to look. We ourselves are causal patients and agents: causes act upon us and we act causally. All this we do with our bodies. Everything we cause, or have caused to us, we do tluough being physically embodied. But what is fUlthermorc vital is that typically it feels like something when we move our bodies or have them moved. When we lift something, push it or pull it, it feels like something. And in doing these things, we are exercising our causal powers, so it feels like tlomething to us when we exercise our causal powers. 111is gives us a very special insight into causation. Hume's examples usually concern inanimate causes that we view from the outside. We may look at hilliard balls crashing around on the table, for instance. And of course it is possible to see only a sequence of events there. But we might instead focus on bodily sensations instead of visual perceptions and we might focus on those causal connections within which we are involved instead of those [or which we are an outside passive observer. Instead of looking at the billiard balls [rom above. Hume should have instead put himself in the billiard ball, causing others to move and being caused to move by others? Bodily sensations might be what gives us direct experience of causation in action.

2 OUf thanks again to Markus Schrenk for impressing this point upon U~

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Armstrong has pushed this line of argument in many places. In his book Bodily Sensations he considers the case of pressure being exerted on one's skin and the sensation of causation that it can give you:

The concept of pressure involves the concept of causation, of one thing making another happen. But can we have an immediate perception of a causal relation­ship? If wc cannot, pressure cannot be immediately perceived. The question is a difficult one, and deserves a mOre cxtended discLLssion than 1 am able to give it. But I am inclincd to say that thcre is no objection to the immediate perception of causal connection. (And, at the srune timc, I do not think that this necessarily contradicts a Humcan or serni-Humean analysis of the nature of causation.) It is simply one of the peculiar features of tactual perception that it gives us an immediate awareness of objects making things happen to our body, and our body making things happen to objects. (Armstrong Jg62: 23)

Note that Armstrong concedes, in the bracketed sentence, that the perception of causation docs not disprove Humeanism. Becbee's (2003) charge should not, therefore, apply to him at this place. The idea is that when something prcsses against your skin and into your flesh you are feeling causation at work, with you as the causal patient. This sensation is a perception of causation. You are experiencing causation inside of you, directly, and not having to infer 1t from other observable factors standing in a constant conjunction or other relation. Despite stating that this claim needed more discussion, Armstrong did not himself provide it, though he did go on to repeat the same claim a number of times (e.g., 1978: t64). Is it enough alone to show us that causation is indeed so perceived? Was it really that easy to refute the Humean claim that causation is imperceptible?

Perhaps this kind of consideration is enough to persuade someone who already believes in causation, over and above constant conjunction, as something that has real power in the world. If perception is to an extent theory-dependent, for instance, then if one believes in such causation one may well be able to pcrceive it when it acts upon your body in this way. But what about the sceptic? Hurne had set us a challenge to find something more in causation than the notion of con­stant conjunction. Has this chaUenge really been met" Might the Hu­mean be able to retort that some object can be observed pressing agajnst our body and this is always accompanied by a certain sensation in our minds? Can this case really give the Humean any cOJ11relline reason to abandon their constant conjunction account? Can it really be offered as a convincing case of powerful causation being perceived?

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Constant conjunction between willing and acting? 203

9.5 Constant conjunction between willing and acting?

When some object presses against our bodies, we are most likely patients. We are passive: something is being done to us. But Armstrong also mentioned agency. This thought is more promising, as a number of people have thought, going back to Locke. Why? One idea is that, within our own bodies, and transparently set out before us in every detail, we experience both the wi1hng and the doing. You dedde to raise your ann, for instance, and it does rise. You are witness 10 both the decision and the act and can' see' that the decision was the cause of the act. Unlike the case of the object prcssing against your skin, both the cause and effect are within your own body and, one must assume, so is the causal connection between them.

A Humean may deny this, however, and indeed Hume did. Even in the case of agency, he reasserts, all that we ever witness is one event f(.)Uowed by another, and our belief that the willing or volition caused the movement can never amount to more than an observed constant conjunction between willings and movements:

Some have asserted, that we feel an energy, or power, in OUT own mind; and that having in this manner acquir'd the idca of power, we transfer that quality to matter, where we are not able immediatcly to discover it. The motions of our body, and thc thoughts and sentiments of our mind (say thcy) obey the wi1J; nor do we seek any farther to acquire a just notion of force or power. Bllt to convince us how fallacious this reasoning is, we need only consider, that the will being hcre consider'd as a cause, has no more discoverable connexion betwixt an act or volition, and a motion of the body; 'tis allow'd that no effect is more inexplicable from the powcrs and essence of thought and matter. Nor is the empire of the will over our mind more intelligible. The effect is there distinguishable and separable from thc cause, and cou'd not he foreseen without the experience of their constant conjunction. We have command over our mind to a certain degree, but beyond that lose all empire over it: And 'tis cvidently impossible to fix any precise bounds to thc authority, where we consult not experience. In short, the actions of the mInd are, in this respect, the same with those of matter. Wc perceive only their constant conjunction; nor can we ever reason beyond it. No internal impression has an apparent energy, more than external objects have. Since therefore matter is eonfcss'd by philosophers to operate by an unknown force, we shou'd in vain hope to attain an idea of force by consulting our own minds. (Hume 1739: Appendix 632-3, to be inserted 1.161.12)

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The perception of causation wit~in ourselves, therefore, is for Hurne exactly the same as the perception of any other case. To see that a voHtion causes a movement is to see that the volition precedes the movement and there is a constant conjunction of volitions being fol­lowed always by movements. Exactly the same sceptical argument can then be brought to bear. Our experience is only ever of the causal relata, in this case within our own minds and bodies, but we never observe the causal relation itself as anything more than a constant conjunction. The line of argument from volitions to the real causal connection is, there­fore. in Hume's mind closed off. Nevertheless, we think the issue is worth another look.

9.6 A reunifi·cationist account of agencv

Hurne dismissed the perceptibility of causation through agency but that he was able to do so, we contend, rested crucially on his account of agency, which we think is an implausible account. If agency were as Hurne describes it, it would indeed offer a poor prospect for the percep­tion of causation. Agent causation would, like the standard case in Hurne's description, be a relation between two temporally distinct events: one a willing and the other a bodily movement. This volitionist account does not bear scrutiny, however.

In the first place, it is incredible that our movements are controlled by such volitions. Many of Oill' bodily movements are not accompanied by distinct volitions but nevertheless are rightly considered to be inten~ tional. In driving a car, for inst.ance, there are numerous intentional activities t.hat are perfonncd and all of them deliberate. But they are not all accompanied by volitions. Indeed, there are so many different small movements required in driving a car that to will each act - or just to think about it - would be a massively demanding exercise in itself. 1\s for driving a car, so arguably for virtually every other deliberate bodily movement. Consider the cases of playing football, riding a bicycle or even walking down the street. These are all motions that, for the most part, are intentional but it is incredible to suppose that they are all accompanied by a mental running~commcntary that gives instructions to all the various body-paTts involved. The number of individual bodily movements in kicking a football, for instance, would be hugc. It is implausible that the mind could copc with such complexity.

A reunificationist account of agency 205

A volition does not seem necessary for an act to be intentional, therefore, but it also docs not. seem sufficient. There could, of course, be cases where someone does concentrate very hard on a particular action, for instance, when threading a small needle. Perhaps this is what a Humean may consider to be a case of wilL But it seems that more is required than just willing to thread a needle. Someone may be resolute that they do it successfully and pay very close attention to what they are doing. Concentration may help them to succeed but what would . willing' that they thread the needle add? Wanting that something happens does not alone add anything if it is not accompanied by the right bodily movements. There is a criticism in Baldwin (I998: 114) that suggests a willing, as described by Humc, does nothing at all. It seems you can think that you want to raise your arm as much as you want but, alone, it does not produce any bodily movement.

The seeming disconnection between volitions and bodily movements is, we would argue, an instance of Hume's generally disconnected account of causation. In understanding causation as being about two disconnected but constantly conjoined events, Hume has left us with an unsolvable problem: of reculluecting what he has disconnected. The cause cannot make the effect happen, just as the willing canIlot make the bodily movement happen. All that we could ever then observe would be the constant conjunction. But, as we outlined in chapter 5, the model of two disconnected events is misleading. 'There, we argued for causa­tion as involving a single, unified and continuous, unfolding process in which dispositional parLnerships came together and, usually over an interval of time, becamc the effect. Our proposal now is that this same integrated account of causation be applicd to the case of intentional action to give us a reconnected account of agency.

Fortunately, much of the work is done for us already. There is a line of argument, developed through Locke (1690: Il.xxi-4), Heidegger (1925: §24), O'Shaughnessy (1980: VO!'2, chs II-iS), and Baldwin (998), in which agency is a unified process. A key feature for us is that any willing, such as it is, would have to be simultaneous with the act. The willing or volition need not be, as Hurne described, a distinct and observable mental episode. That would be psychologically implau­sible, for the reasons given above. But there is a need to give some account of intentional action for there is a clear distinction between the movements that are delibcrate or intended and those that aTe accidental, such as muscle spasms or being blown about in a gale. Only the fonner are actions. Instead of accompanying mental episodes, we would givc a

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dispositional account of intending, in a tradition going back to Ryle (1949: ch, 3) and Arrnstrong (1968: ch, Il), though with a more realist account of what it is to have a disposition.

The dispositional theory of causation, as developed generally, can then be applied to the case of mental causation. And, we would main­tain, there is a gain in psychological plausibility. In the case of 'will­ings', such as they aTe, simultaneity of cause and effect is more plausible than Hume's temporal sllccession account. It is not as if you will to raise your arm and then, sometime later, your ann rises. The temporal priority condition for causation loses all credibility here. Of course you may decide in the morning that you will deliberately raise your arm in the afternoon and, in that sense, your decision is temporally prior to your action. But it is not this decision that is the key explanation of why raising your ann was intentionaL You may, in the intervening time, change your mind about the raising of your ann or you may just forget the decision. For the raising of your afm to be an act, any willing must occur with the raising, at the same time. Any decision prior to the raising cannot be the cause of the raising because of the possibility of a change of mind or forgetfulness. And, even if it were not for these possibilities, the temporally prior decision could not be the cause, or at least not the whole of the cause, of the raising because we would always want to know why the ann was raised at precisely this time, some time later than the decision. Something new must be happening at precisely the time the ann rises that explains why it rises then. Again, you may decidc in the momulg that you will raise your ann at precisely 3 p.m. but unless something additional is added at 3 p.m., the ann will not lise. Typically, it would be the realization that it was time to raise the arm and then a deliberate raising.

If we are to say that some acts are deliocrate or intentional, therefore, it seems we need to consider what is happening at the time the act is being carried out, rather than considering some decision that is tempo­rally prior. We argued in chapter 5, however, that cause and effect were entirely simultaneous, which means that the cause must continue to have some existence as long as does the effect. Would this claim also hold in the case of agency? We say it does. Your deliberate raising of your arm must continue aU the way through the process of your aml rising, right the way until the alID is as fully raised as you want. The willing, such as it is - for us a dispositional cause of the aIm rising - is a power that must be exercising until thc action is complete. If the willing ceases, so will the act. Suppose you begin purposefully raising your arm but, at a point

The sense of proprioception 207

where it is only halfway extended, you give up £U1d change your mind. The raising of the ann will cease. This might happen in a seminar, for instance, when you think you have a question. Your arm begins rising but then you rcalize your question is misconceived. You change your mind and your ann immediately stops rising and comes back down before it was fully extended. If, instead, we applied a Humcan model of causation to this, and the willing was temporally prior to the act. then the cause will have been fully exercised in the act of will, which was already completed, and would have hs constantly conjoined effect after the willing had occurred. But, again, we know that this is psychologi­cally implausible. We typically can 'bailout' of our actions, changing our mind and giving up. This would be like any other causal process that can be halted by a preventer or simply if the power ceases to exercise. The radiator can heat the room to 25 degrees, for instance, but may be turned off when it has got only halfway there,

It is more than just that the willing and the movement are simulta­neous, however. They are integrated closely. We have sought to reunify them, following their disconnection by Hume. To see why they should be reunified, we return to the case of bodily sensation, as discussed by Armstrong, but this time concentrating on our sense of proprioception.

9· 7 The sense of proprioception

The division of the senses into five - seeing, hearing, touching, smelling and tasting - has in this case been a damaging oversimplification. In particular, the sense of touch is expected to do far too much. What of sensations sllch as balance and nausea? It seems that they arc supposed to come under the sense of touch but again this is misleading. They are not sensations that are located on the surface of the skin, so they are not about touch in that sense, which is too narrow a tenn. Annstrong worked with a broader sense of touch, which is why he spoke of bodily sensa­tion, but the problem with this term is that it is too broad because all the senses are bodily: vision, hearing, taste and smell included. Popular classification has not helped us in the search for a perception of causa­tion because the sense in which it is most clearly revealed, we contend, is the sense of proprioception.

Proprioception is thc sense, felt mainly in one's muscles, of required effort. You need to lift a glass, for instance. This must be more than just a volition to raise your ann. You must have the scnse of required effort

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208 Perceiving Causes

because if you exercise too little power, you will not succeed, and if you exercise too much effort, you will throw the glass over your shoulder. You should not, for instance, exercise the same degree of power in your muscles that you would if you were lifting a heavy chair instead of a glass. Sometimes this sense can surprise us. We may see a small object, for instance, and assume from visual cues and background knowledge that it is light but then be surprised when we try to lift it and it is heavy, Similarly, you may go to lift a suitcase, assuming it to be full, and then feel a sense of surprise when it is in fact empty. It is the sense of strain in our muscles that tells us this and allows us to readjust our actions accordingly, either increasing or decreasing our effort. The sense is a distinct one, and not merely based on information gathered by the other senses. If one were holding a bucket, for instance, wearing headphones and with closed eyes, and the bucket were being filled with water, becoming heavier and heavier, it would be the sense of strain in one's muscles that gave the cue to increase one's eHart in compensation so as not to drop the bucket. This is to perceive proprioceptively. The sense also assists with balance, in the case of walking in a gale, for instance. where one has to lean into the wind in all appropriate degree. It also facilitates bodily coordination and is why, for instance, one doesn't have to visually monitor the movements of one's limbs while riding a bicycle.

The sense of proprioception is the key to the reunification of agency because it shows why one cannot have entirely distinct and separate volitions and bodily movements. Not only must they be simultaneous, they must also be interactive in the sense that there will in the standard ea..<;e be what we would call a feedback mechanism. The lifting of the empty suitcase illustrates this and shows also why the volition and act must be simultaneous. You decide to lift the case, for instance. This is a future-directed intention or planned act only and does not become an intentional act until the moment it begins. You can bailout of the action at any time and until you begin lifting it is nothing more than a planned action. Once you start to lift, the causal process has begun, though again you can always abandon it at any time and before the process has been seen through to completion (perhaps your aim was to 11ft the casc on to a bed, for instance). You begin with visual cues and background knowl­edge but when you start actually to lift the suitcase you start to sense proprioceptively just how much effort is appropriate. Too little effort and it does not rise~ too much effort and you t1uow it in the air. With the initial lift, your muscles infonn you whether your effort is appropriate, too little. or too much. With that infonnation, we make corrections,

Perception and the dispositional modality 209

adjusting the effort accordingly. The willing and the movements thus must be an entirely integrated process. It could not be, for instance, that the volition has already been and gone, One could not successfully act it out, if it had, because it is only once one has the proprioceptive infor­mation available that one knows exactly what must be done in order to achieve one's aim. Without the feedback mechanism, most actions would have unexpected consequences.

Suitably refined, we can thus uphold a version of Armstrong's thesis. Causation can be perceived within one's own body. The key idea, however, in order to maintain this claim, is that agency must be under­stood as integrated and unified rather than as a constant conjunction between entirely discrete volition and movement. This has been obscured by the traditional fivefold division of the senses as it omits proprioception, which we claim is the key sense for the perception of causation. The reason it is key is that it allows us to get the sense of power acting upon OUT bodies that we are able to overcome and also power exercised by our bodies that meets with resistance. To understand this belLer. and why it counts as causation, we need to see that the perception of causation is a perception of powers at work.

9.8 Perception and the dispositional modality

We have provided a theory of causation in which it consists in the passing around of powers. Causation occurs when powers manifest themselves. and they do so in realizing other powers. How do we perceive this: specifically, how do we perceive that powers are mani­festing themselves? In order to meet Hume's challenge, we are keen to show how the concept of causation is acquired through the most direct awareness of causation in the case of our own bodies, exercising their powers and having other powers exercised upon them. The exercise of human bodily powers is of course just one case of causation at work but it is the case that provides our most inlimate experience of causation at work and, we contend, it reveals the specifically dispositional nature of causation. How does it do this?

Already we have explained what this dispositional modality is. We said in chapter 8 that it was something less than necessity but more than pure contingency, and this was based on the claim of chapter 3 that causes could always be prevented. In agency, we gain experience of these features. In short, we feel resistance to our actions when we are

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210 Perceiving Causes

agents, and we can offer resistanc_c to causes that act upon us when we arc patients. To perceive causation is thus to perceive something dispo­sitional. Two elements were required for a modal force to be disposi­tional. One was that there was a certain limited class of outcomes, out of all those that are merely possible, that would be the manifestation of the power if exercised. Molnar speaks of the powers being directed towards those outcomes. But, second, even if exercised, the power can be resisted and thus those outcomes are not guaranteed.

Clearly, our experience of agency provides these two elements: that of directcdncss (with a certain intensity) and the possibility of preven­tion. Baldwin argues in favour of the perceivability of causation but then asserts without argument that our experience is of causal necessity (Baldwin 1998: 110). Consideration shows that this is not the case. You walk in a gale, for instance. and you can feci what the power of the wind would do to you. Proprioceptively, you feci that you have to strain against the wind and lean into it, otherwise it may blow you over. But in one and the same experience, you feel that you can resist it by adjusting your body weight and tension in certain muscles. There is a definite disposition in the action of the wind, towards a certain outcome, but that outcome ;s not necessitated because it can be resisted by you. You arc the patient in this case - suffering change - but you can also be active and resist it, maintaining an equilibrium between forces.

In other cases you are more agent than patient. You go to lift a heavy weight for example, exercising the power that is in your muscles. Proprioceptivcly, you feel them at work and the effort that is required to succeed in the task. But you also fecl that your actions are resisted by the weight, and possibly by a variety of other surrounding factors (lifting the weight in a gale, for instance). There is a definite disposition towards some outcome, and your action is an attempt to achieve that outcome, but clearly it can be thwarted and this shows that the modality in these cases of agent causation is a dispositional one. The two exam­ples, of the gale and of lifting, show that the agent-patient distinction is not so clear-cut. Most causal interactions in which we arc involved will fall on a scale of more or less active or passive. Both examples involve a mixture.

It is distinctive of dispositions that they can be prevented from manifesting but, of course, they are not always. In some instances, the gale will succeed in blowing someone over. In many cases we succeed in lifting weights. This merely shows that there can be dispositional causal production without necessitation. Sometimes our muscles contain

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Perception and the dispositional modality 211

enough power to achieve a certain goal but, even where they succeed, they do not through necessiLating that goal. They could have exercised exactly the same degree of power and not succeeded because of the presence of an additive interferer.

The reunified account of agency still must be brought 10 bear. These two elements arc essential to the dispositional modality but they can also be experienced in an integrated whole. It is not, for instance, that we experience a mere constant conjunction of power being exercised and power being resisted. The two clements of the dispositional modality are, rather, experienced in one and the same unified process. When we lift a heavy weight, for instance, it is not as if we have one experience of the power we exercise and another experience of the resistance to it. We cannot separate the two in this way. There is just one proprioceptive sensation in each of the relevant body parts. In a bicep, for instance, we feel that the required effort is large because the countervailing force is. The muscle hurts because we have to push it towards its limit and we could only do this if it has met with a finn resistance. We cannot, for example, get the same sensation of muscle strain in a high degree by merely liftiug a paper cup. The resistance and interference is thus vital to the proprioceptive experience and cannot be disentangled form the exercising power itself. The experience comes only when the powers go up against each other.

What of powers that cannot be resisted? How would we experience the dispositional nature of causation in those cases? We cannot normally push over a building, for instance, or resist the power of an oncoming train. Would these cases give us experience of causation by necessita­tion? We argue not. Even in these cases, there is a sense that with more power, they could be overcome. What our experience shows us is that we do not have enough power to overcome some obstacle. Such an experience does not illustrate causal necessitation. To experience that, we would need to experience that no amount of power we had could be enough to overcome the obstacle and we do not experience that. Indeed, there are enough clues in our experience for us to draw the opposite conclusion. The trainee weightlifier, for instance, will feel when they are at their limit. But they can also extrapolate from that experience. If they hact more power, they might be able to lift the weight, and so fUlther training is required. By extension, it is a rational conclusion that any weight can be lifted with enough power and any force resisted. Our myths and legends are full of superpowcred beings capable of such

deeds.

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212 Perceiving Causes

9.9 Dispositional modality is the best known

OUf experience vindicates the idea of there being a dispositional modal­ity. As we argued in chapter 8, the dispositional modality is not derived from the supposedly bettcr known modalities of necessity and possibil­ity, and this explains why dispositionality is not reducible to them. This might have been thought to pose a problem. If we cannot Llnderstand dispositionality in terms of these other two modalities, how can we know of it? The answer, we now see, is that we know it directly from experience. Even empiricists allowthat not every legitimate idea can be defined in terms of others. Some come directly from experience and we argue that this is the case with dispositionalit.y.

It thus turns out that, far from being little understood or understood only via some complex inference, the dispositional modality is actually the modality with which we are most familiar. It is known by all of us intimately through our causal interactions with the world as agents and patients. We can try to bring something about, and may often succeed, b~t our success can be prevented or interfered with. Our actions only dIspose or tend towards their outcomes, never guaranteeing them, and everyone knows what this means.

This is also the reason why we would contend that the dispositional modality is the central modality and the one that explains the modality involved in normativity and intentionality, rather than vice versa (sec §8·9)· Dispositionality can be known directly, in our experience of causation, and then brought to bear on nonnative and intentional con­cept">. We can also speculate that dispositionality is central in compari­son to the pure alethic modalities of necessity and pure possibility, for it is the only modality that can be directly experienced. This is not to assert that pure necessity and possibility could be derived from dispositionality in a fonn that is needed for the purposes of logic. But the notion of dispositionality that is gained from our cansal involvement in the world gives us our first modal ideas: that what is might not have been, and what i~ not might have been. Our causal involvement, because of its disposi­~lOnal character, tells us that there is such a lhing as modality: that there IS a modal value of facts as well as a truth value.

Remaining in a speculative vein, we would also allow that our causal experience. once it has heen grounded in our proprioception, can then be extended, by analogy and extrapolation, to our experiences gained from other senses. In that case, we can accept Ducasse's position that our

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sight gives us causal knowledge too. Our argument was much less direcl than Ducassc's and this was necessary because we wanted to meet Hume's challenge. We wanted to show how we could have an idea of causal connection that is more than constant conjunction. The idea is grounded in proprioceptive bodily sensations. But, once acquired, all of our experience becomes causally loaded. We know that we live in a causal world and we can look for visual as well as bodily clies of it helped, no doubt, by some extent of coordination between our different sense faculties. In other words, OUf experience becomes theory-laden ami the theory in question is that we afe causally engaged with the world. This is what we sometimes call the 'thick' causal content of our

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10 .. 1 A reflective equilihrium

The philosophical theory of causation has now been presented. But how suited is it for the real world? Is it a theory that accords with the common understanding of causation and does it also fit the understanding of causation in science? The connection between metaphysics and empiri­cal science is a difficult one to define and itself a matter of philosophical controversy_ Should science dict.:'1te to metaphysics? Is it in a position to authoritatively solve metaphysical problems empirically? Or is meta­physics the First Philosophy, as Aristotle said? According to that view, metaphysical questions should be solved prior to any empirical knowledge and thus metaphysical questions arc answerable only to metaphysics itself.

These two views are the extremes of the spectrum, however, where either science or metaphysics is alleged to be in a position to overrule the other. There is room for views in between. One such view is that metaphysics and science do nol intrude on each other's territory. Although they both concern the nature and workings of the world, one does so in a very abstract way and the other in a concrete way. As such, a direct conflict might not be necessary because they do not address the same kinds of questions. Nevertheless, there might be some looser connection between science and metaphysics. What the philosophical theory claims in the abstract, might fit what can be found in the concrete, and vice versa. This is what we hope to establish in this final chapter. We have claimed that causes dispose towards their effects and sometimes succeed in producing them. This claim is made in the abstract. and eonce111S the philosophical theory of what it is for one thing to cause another. It is then a separate, elllpirical question, or what in reality causes what: or even whether anything causes anything. But then it would be regrettable if we had a philosophical account of a notion that

Why not physics? 2 15

had no instance in reality, or if nothing in the world disposed luwards anything else. Some fit between the world .and the.OlY ",,:ould ~e prefera­ble.. It will have made the effOlt of the phIlosophIcal d,SCUSSIon worth­while as we would then have an abstract account of something we had

encountered concretely. The ideal, we maintain, would be a reflective equilibrium. VI/hile

neither the empilical nor the metaphysical dictates to its opposite, our understanding of one can be enhanced by an understanding .of.the other. Our philosophical theory should thus both infoml and be mform~d b.Y our concrete understanding of causation. Our knowledge of causation IS

best developed by understanding both in tandem, but where neither comes first. Instead, we understand a phenomenon best when we con­sider the abstI'act and concrete in parallel, and switch our t.hinking back

and forth between them. We hope the present chapter illustrates this. The theOlY w~ have

developed so far, we will claim, can enhance our ~nderst~dmg uf how causation works in the world. And at the same hme, seemg some empirical cases of causation will offer us new ideas for our philosophi­cal theory. The latter has already been happening during t.his book. Some of the examples that will be raised in this chapter. have alre~dy been in mind while the theOlY was being developed. We wIll be ShOWlllg this by illustrating each of the key features of the theory with some of the empirical examples. The theory allows us to understand the examples

better.

f 0 .. 2 Why not physics?

The examples used in this chapter represent a departure from the norm in philosophical theories. Going back to the very s~art of the modem. debate with Hume's hilliard table, physics has proVIded almos! all the illustralions of causation in the world. Why should we not follow this trend? We think there arc reasons not to do so.

FiTst, physics is an accounf of only one aspec! of the world .. Why, then should all our examples come from there? What about causatIon in e~onomics, in society, psychology, meteorology, immunology, crim­inology or chemistry? Many of the cases of causation that sUIT~und us involve such factors. Cart.wright, for example, asks us to conSider the cxample of dropping a dollar bill in the street (Cartwright 1999: 27: the example is originally from Otto Neurath). Any useful explanatIOn of It.S

216 A Biologically Disposed TheOlY of Causation

motion will involve far more than physics. Certainly, there will be a gravitational attraction between the dollar and the Earth, but. that alone would tell us only that the dollal faUs straight down to the ground. What may actually happen is that wind resistance gives it a sidc-to-side trajectory as well. And just before it reaches the ground, a breeze may come and take it back up and then blow it down the street. Still before it reaches the ground, a hand may catch it and the dollar bill is stuffed in a pocket and taken away. There seems to be a lot more than just physics here. The defender of physics, however, might claim that all these other sciences arc ultimately reducible to physics so what justifies the use of causal examples entirely from physics is that physics ex­plains everything else. But, as has already been said in chapter 4, this itself is a theoretical commitment and one for which there is as yet no conclusive philosophical argument or empirical evidence. Fundamen­talism, as Cartwright (1999: ch.l) calls it, is more a hope, or act of faith: that when physics and aU the other sciences arc complete, the others will all be reducible. Economics might be reducible to sociol­ogy, for instance, which in tum is reducihle to psychology, then biology, chemistry and finally physics. The only thing that feeds such a hope is that a few instances have been found where one phenomenon has appeared to be reducible to another. In chapter 4, however, it was argued that it is preferable not to prejudge the truth of reductionism in our philosophical theory of causation. Some fonn of emergentism should remain at least a live option. To take all our examples from physics, or disproportionately so, is thus to prejudge as to the sale impOltance of physics to causation. Causation in psychology or sociol­ogy may be just as impoliant to us and their ncglect seems justified only if physical fundamentalism is true. We have no strong reason yet to believe that it is.

Second, causation in physics is often atypical or misleading if then generalized outside physics. Physics has become a technical, theoretical and abstract discipline, which at times can bear little resemblance to the macroscopic world with which we are familim' and for which we have created our conceptual distinctions. Consider lhe table, for instance, that puzzled Eddington so (see Ayer 1973: 82-3). This table was, contrary to the appearance of solidity and stability, almost entirely empty :)pacc and what wa:) in that space was in a constant statc of flux and movement. Should we conclude that this is the real table and nothing in the world is ::;olid? It would be a mistake to do so, we argue. Solidity is a phenome­non to be found at a relatively macroscopic level. That it cannot be

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Why not physics? 21 7

found at a microscopic level is no good reason to conclude that it does not exist: that it is not really a feature of our world. The microrcductive facts might not be all the facts.

In the case of causation, it has been argued that physics shows lhere is no such thing. Macroscopic, directed causation has been replaced, we were told by Russell (1913), with symmetrical equations. Perhaps this was early Twentieth Centmy optimism in the ambitions of physics. We ought to eliminale the concept of causation because, they say, it pro­motes an incorrect view of the world: science shows us that things are otherwise. But if there is no causation in physics, would that in itself invalidate the concept of causation universally or only in physics? It does so as a whole only if all other sciences are reducible to physics, a thesis for which we still await a proof. There is no evidence meanwhile that tho:)c other sciences have eliminated their causal concepts. Indeed, causation still figures heavily in the explanations to be found in histol)'. economics, law, sociology and psychology. Physics, then, looks atypical and generalizing from it misleading, justit-ied only by the wager that all human knowledge is ultimately reducible to it.

Further, on lhe issue uf causatiuIl iIi physics, it can be argued Lhal focus on it lends unwalTanted support to the idea that causes produce their effects of necessity. One reason for this is that explanation in physics often deals with artificially limited models in which there are a finite number of inputs producing an output. Within the model, an effect can be guaranteed, usually with mathematical certainty. Once we go into the real world, however, there is always the possibility of some preventer or interferer that was not included in the original model. The antecedent strengthening argument of chapter 3 thus comes into play.

A final reason to look beyond physics is that causal examples from physics have in any case heen already given adequate coverage and a balance needs to be redressed. If we are right in what we have just argued, physics has already influenccd the philosophical understanding of causation too much in one direction. Physics is already over-repre­sented in the philosophical literature, as a result of which a number of contemporary theories of causation seek its physical reduction. For Dowe (2000), for inslance, physical causation consists in transference of conserved quantities, while Kistler (2006) reduces causation explicitly to energy transference. Examples outside of physics could be ignored on the justification, again, that they would be ultimately reducible to physics. III contrast, recall fi-om §4.3d Collins, Hall and Paul's (2004: I4) example of a kiss to the ehcek causing its recipient to blush. TIle

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blush is explained by psychological, social and biological factors, and perhaps others, and only if all those are reducible to physics can we plausibly say that all causation is energy transference. The theory of causation as exercise of powers, however, can allow the kiss to have psychological, social and biological powers, without any commitment to all of these being physically reducible.

In the Aristotelian spirit, the examples that will be offered below come from the living world. amI mainly from biology. Life is best studied in context. The causal role of a gene, for instance, must be considered in the context of an organism and an organism must be considered in context of its immediate environment. And all eeo-syst.ems are infinitely sensitive to contextual changes. Biology further allows for the large complexity of causation, where many causal factors produce the outcomc.In retunl, we will see that if biological causal mechanisms are understood in the dispositional sense, it seems to follow that reductionist views such as genetic determinism, sociobiology and evolutionary psychology calmot represent the whole truth about the causes of complex biological, social and psychological phenomena. An adequate understanding of what, for in~tance, genes uo ill biology requires acknowledgment of complexity and context-sensitivity, two key notions that aTe emphasized in the dispositional account. A crucial part of the understanding of what genes can and cannot do, we will argue, is to accept that they operate in a dispositional way, and we thus see biology as exemplifying the general nature of causation as here developed.

10.3 The central features of causal dispositionalism

In the dispositionalist theory that has been developed, we have discussed various features that we take to be central to causation. Tn the following, we will show why this dispositionalism is particularly suitable for the intcrpretation and understanding of natural processes in biology and especially genetics. We will show how eight features of the theory have a resonance in the case of biology.

1. Biological explanation invokes dispositions or powers. A gene, for instance, is something that is characterized essentially by its causal role: as a producer of inheritable traits rather than by any physical or structural property.

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Powers in biological explanation 21 9

2. Biology acknowledges the complexity of causation, which is accommodated in the dispositional account. Specifically, the poly­geny of disposltionalism is an accepted part of biology, where traits are typically produced by many genes working together.

3. A theory of causation should allow for the context-sensitivity that is to be found in biology. Genes can express themselves in different ways in different situations: they have plasticity and flexibility. The dispositional theory allows this as it does not commit to the assump­tion of the regularity theory: same cause, same effect.

4. Causation occurs without necessitation when causal powers have accumulated adequately for a threshold to he mel. There are many cases in biology where the passing of such a threshold produces some novel phenomenon, for instance, whcn greater than 40 CAG repeats in chromosome-4 produces mutant HTT, leading to Huntington's disease.

5. The powers fheory allows for the possibility of holism and emergent­ism. Although it is a transfer theory, it is not committed to reduction­ism. Many phcnomena in biology seem better understood holistically.

6. Cause and effect are simultaneous. Even though we can pick oul a part of the causal process as 'the cause' and another later part of the process as 'the effect', causation is simultaneous. The effect of a gene will be concurrent with it doing its work.

7. An account can be given of why biological prediction is defeasihle: namely that additional powers may be at work, in the laboratory or outside in nature, disposing away from the outcome predicted of the model.

8. There is an irreducible sui generis modality involved in causation, which is evident in biology. Genes dispose, and no more than dis­pose, towards certain outcomes.

The aim now is to present some biological examples that illustrate each of these points, while at the same time trying to show that this can throw some new light on how we interpret biological causal processes.

lOA Powers in biological explanation

Biology is full of attributions of powers, including many instances where something's causal powers are an essential prui of what it is. Many of our examples wlll focus on genetics and we need only

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220 A BiologicaUy Di,sposed Theory of Causation

look at the notion of a gene to s~e something that 1S characterized by its causal powers: by what it is disposed to do.

The notion of a gene retains a degree of vagueness (Moss 2003:

Carver, Waldahl and Breivik 2008). We know, for instance, what a double,belix sh'and of DNA is and we know quite precisely what a chromosome is and its constituents. Which pmts of these structures are the genes is something that is not so easy to answer, however, and this is mainly because genes are identified functionally rather than structurally. A gene is something characterized according to certain roles it can play. One such role ascribed to genes is that they are units of inheritance and another role is that they are productive of traits. Although there is some dehate about the exact causal role of genes, it seems clear that they are directly identified as causally powerful entities of some kind. Hence, we hear that there are genes for blue eyes, for depression, for curly hair, and so on: the idea being that the gene has some causal power that plays a productive role for such traits. Being a unit of inheritance, however, is also a causal or functional role for genes. Genes have the power to be inherited by biological offspring in a way that acquired characteristics of indiviuuals on the whole do not. This feature is one that makes clear how the gene is an essentially dispositional notion. 1 The gene is the unit of heredity, irrespective of wlllch structural properties play the role of being such a unit or passing on such units to offspring. The structural explanation of such a power will be in terms of some region or genomic sequence of DNA. A strand of DNA will thus contain many such genes, perhaps some of them overlapping or containing multiple repeated sequences. Such sequences arc seen as coding for traits, while other parts play regulatory functions. But genes do not seem to be easily identifiable particulars, as distinct macroscopic objects are. They seem more like bundles of powers ·coded' into the structural complexity of DNA strands.

Dispositions can be understood as essentially functional role occu­piers and it is clear that genes can be characterized in this way. Such dispositional talk pervades biological explanation, with coding parts of genes, regulatory regions, inhibitors, promoters, and so on. The same can be said of RNA, proteins and enzymes, as well as functionally defined organs such as the heart, liver and lungs. Dispositional explana­tion works by first identifying a functional role whose physical or

I It was Svein Anders Noer Lie who first brought to our attention that genes are hcst understood in disposilional tellllS.

Complexity, polygeny and pleiotropy 221

structural realization could then be further described. Any such struc­tural component parts can themselves be understood in terms of smaller powerful pruticulars, also playing a smaller functional role that contributes to the whole, and so on down many layers of structural explanation. This view has been called homuncular functionalism or homunctionalism (Mumford 1998: 210).

IO.5 Complexity, polygeny and pleiotropy

In classical Mendelian genetics, there is a one-to-one correspondence between dominant 'factors', which later became known as genes, and traits or phenotypes. Each particular gene is 'for' one particular trait, such as blood type, earwax, freckles, or, in Mendel's original exam­ples, white or purple petals on a flower. For each trait, a single causal mechanism is ventured: the gene is expressed if dominant but not expressed if recessive and hidden by a different dominant gene. A gene that is recessive can still be expressed if not hidden by a dominant gene.

In chapter 2, we saw that causation is a complex matter, with many factors involved in the production of an effect. Philosophical poJygeny is the idea of many powers working together to produce the events in the world. Such events or occurrences are polygenic where there are many powers that are productive of a single evcnt. Manifestations, for Molnar, are not polygenic. Each power has a single kind of manifestation, which dctcnnincs the identity of the power, and that manifestation should be understood as the power's contribution to an event of which it is in part productive (Molnar 2003: 195). The notion of polygeny, however, was taken from its Oliginal appearance in biology, specifically from genetics (which gives us a small but additional reason why biology is a good illustration of the dispositional theory). In genetics, polygeny is the idea that many different genes contribute to the production of a trait (Dupre 1993: J23-4), or that one protein is 'coded for' by many genes working together (Skaftnesmo 2005' 45). Examples of traits that are thought to be produced polygcnically are disorders like autism, diabetes and cancer.

The Mendellian idea, in contrast, is that traits are monogenic: pro­duced by a single gene. Admittedly, such genes could be repressed, if accompanied by a dominant gene, but if they are allowed to do their work, they produce their associated trait alone. But even if some traits

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222 A Biologically Disposed Theory oj Causation

are monogenic in this way, this does not mean that the traits arc produced by one single causal factor, namely the gene alone. Even for monogenic trait'), other non-genetic factors will play a role for the outcome, as Wolff describes:

Tn ontogenesis, genetic and non-genetic factors interact in producing successive states, each of which is the prerequisite, and detemlincs the conditions, for the oext one to follow. In this interplay, genes are a necessary, but not a sufficient. component. The structures already present, gradients, threshold values, posi­tional relationships, and conditions of the internal milieu, are equally essential. Thus even monofactorial traits can be considered to he multifactorial causation. and the varying borderline conditions that arise during development add 10 the complexity. From this standpoint, it is not expected that a mutation has a consistent phenotypic outcome, and the phenotype-genotype relationship may be ilTegular. (Wolf 1995: 127)

That biological causation is compJex and multifactorial is neither a new nor controversial claim, and it supports dispositionalism about causa­tion, where context and complexity is emphasized. Webster, referring to Goldschmidt (1958: 250), seems to dismiss strict monogenicity alto­gether, claiming that 'the production of a "character" involves many genes, if not all of them' (Webster and Goodwin 1996: 86).

How many genes it takes to make one trait, we leave for science to reveaL What is relevant for our purpose, however, is whether there are multiple causal factors involved, besides from the genes themselves, in the production of a trail. Let us have a look at an example where an alleged single gene is shown to cause a disease, namely, Huntington's disease, which is caused by so-called mutant HIT.

What we find here is that there is no strict one-to-one correspondence between the gene and the trait, so that whenever one has the gene, one will have the disease. For a start, at the level of the genes, there is not just a single thing. What counts as mutant HTT is a protein that is produced by a range of determinable gene kinds. Everyone has the (normal) HTT gene in chromosomc-4 and it contains a repeat of CAG (cytosine, adenine and guanine) DNA bases. This CAG repeat forms an amino acid glutamine. Typically, people have fewer than 36 CAG repeats in their glutamine. But there is variation. If someone has more than 40 CAG repeats then their HIT passes a threshold beyond which a different protein is produced that in turn produces increased decay of ncurons and, eventually, the jerky, random physical movements, known as chorea, that arc the symptoms of the disease. It is this protein that is

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Complexity, polygeny and pleiotropy 223

called mutant HTT, rather than the CAG pmts of the gene. Thus, although mutant HIT might be thought of as the single gene that produces the disease, if we look at it closer, it is actually the name for a protein produced by a range of CAG repeats above 40 in number. The range of 36 to 39 CAG repeats is even a vague area, where the patient would be classed as '+/- affected'. The common cause for all Hunting­ton's sufferers, therefore, is not a single gene but a protein produced by a determinable range of gene types, i.e. >40 CAG repeats in the short arm of chromosome-4.

There is then the further question of whether this mutant HTT would always corrcspond to the trait, so that having the gene necessitates developing the disease. Could someone have the gene without develop­ing the disease? The standard answer would be negative but this is based on certain assumptions. The disease does not usually develop until the age of thirty-six, .so clearly there can be those who die young with the gene and without developing the disease. That may seem a cheap cop out, so it is also worth noting that while there is so far no known cure for Huntington's, there are drugs being developed, such as Tetrabenazine, that aim to control its symptoms of chorea. In addition to controlling the

symptoms, there is also work to block the mutant HTT protein produc­tion by using inhibitory RNA (Harper ct al. 2005). It looks, therefore, that there is not an inevitable one-to-one relationship between the number of CAG repeats one has and the development of chorea. One could of course define Huntington's disease in terms of having greater than 40 CAG repeats. The relation between the gene and the disease would then rest only on analyticity, whereas our interest is in whether there is a causal one-to-one correspondence to be found. A drug that could control the symptoms, possibly at source by preventing the neuron decay, would then be enough for us to show that this genetic causal process could be prevented and that it is not inevitable that if one has a certain genotype, one must have a certain phenotype.

Mendellian genetics is of course fully consistent with a dispositional theory of causation, if for instance many Mendelian genes together produced the outcome. Then in some contexts with certain causal factors involved, one could have a gene without developing the trait, while in contexts involving other causal factors, the gene would produce the trail. But genes do not seem, in any direct way, to 'code' for diseases, traits or behaviour. Genes code for proteins, and one gene can even code for many different proteins. This means that the gene can play different functions in different situations, for instance, producing one protein for

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224 A Biologically Disposed Theory of Causation

one organ and another protein for a different organ (Skaftnesmo 2005: 45-6). This is called pleiotropy and relates to philosophical pleiotropy. Powers are for instance pleiotropic in the sense that one power con­tributes to produce many effects or events (Molnar 2003: 194). Which effect is produced will depend on what other powers are also operating. In the case of the genes, there arc some extreme cases of pleiotropy. A banana fly, for instance, has one gene that can code for 38,000 different proteins alone. Webster and Goodwin provide another example:

jf the production of a 'character' involves many genes it follows that a single gene may be involved in the production of more than one 'character' and, indeed, such pleiotropic effects are well known. To give one example, in Drosophila the gene morula causes abnormalities in the number of cell divisions in the facet-foffiling cells of the eye and also causes a reduction in the size of the bristles in bristle-fanning cells ... Thus the morphological effects of a particular gene depend upon the 'material' upon which the gene acts. Consequently, at the level of morphology, while the fonnula 'whenever X, then Y' is sometimes true, it is not generally true. (Webster and Goodwin 1996: 86)

Philosophical pleiotropy also involves the idea that a power makes the same type of contribution to any event of which it is a cause (Molnar 2003: 194-5). This notion is important within the powers ontology as the type of manifestation is what detennines a power's identity. We cannot, therefore, have the same power with different manifestations in different contexts. Instead, using the vector model as our guide, we can say that different contexts are only situations in which different powers are combined with our original power. That original power always makes the same type of contribution to any context, however, which in the vector model means that it must have the same direction although the magnitude may vary. Pleiotropy in this sense is also recognized in biology, but this is best covered under the heading of context-sensitivity.

10.6 Context-sensitivity, plasticity andflexibility

We saw in the quotation above from Webster and Goodwin, (1990: 86) that there is an idea of a gene being something that can do different things in different contexts: building one protein in one situation and another protein in another situation. As well as being empirically founded, this plasticity is also explanatorily useful, given the lack of COlTcspondence between genotype complexity and phenotypic complexity. To solve the

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Context-sensitivity, plasticity and flexibility 225

philosophical puzzle, which is one of explaining how different effects can be produced in different contexts while at the same time maintain­ing that there is only one kind of manifestation for each power, we have to allow that each gene has many different powers. This is plausible to maintain. A gene is a highly complex particular with many structural components, its structural complexity needed to code its great infonnational complexity.

Talk of genes coding information has to be admitted as a metaphor, the reality of which we take to be physical properties that dispose towards certain outcomes. The standard theory tells us immediately that genes have morc than one power as they have both a coding sequence and a non-coding sequence that detemlines when the gene is activated or expressed. The coding sequence can be thought of as the part of the gene that contains infonnation on how to create the trait and the non-coding sequence contains infOlTIlation on when to create the trait. But this distinction of two powers of the gene would itself be a vast oversimplification. The reality is that there arc many different coding sequences contained within the same gene and, effectively, different non-coding sequences which dctennine when the different coding se­qllences are activated. We can set aside for now t.he fU11her point that it is not traits directly that genes code but first RNA and then proteins. But we should also draw attention to the fact that coding for sllch proteins is only part of the work that genes do. They have a number of other regulatory functions, such as self-reproduction. This shows, therefore, that it is far [Tom the case that there is one causal power for each gene. There arc many different functions that a single gene can play, cOlTesponding to their physical complexity and what we interpret as a mUltiplicity of powers. Each of those powers can then make the same contribution to any event or trait of which it is a cause. Context­sensitivity can thus be squared with pleiotropy.

We saw in earlier chapters that the manifestation of dispositions is a highly context-sensitive matter. A small difference in context can result in a huge difference in outcome. We see the same feature in biology. Genes are context-sensitive both microscopically and macroscopically. At the micro-level, we find that:

Over half or the human genome consists of repetiLive sequences and most, if not all, of these consist of parasitic transpos3bk dements. Transposable elements come in fom principal varieties, three of which transpose through RNA inter­mediates and one of which transposes directly as DNA .... Far from being

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biologically irrelevant, the spacing, positioning, separations, and proximities of different elements in a complex system of distributed regulation appear to be of the essence. (Moss 2003: 191)

Hence, the relative positioning of the elements within the genome, its general micTo-context, appears to be relevant to what it docs. But then we also find that there are relatively higher-level phenomena in which differ­ing contexts produce differing outcomes and thus aTe amenable to the kind of context-sensitive interpretation provided by the dispositional account.

One experiment that exhibits this feature is the one described by Prescott et al. (2005). The aim wa~ to produce 'genetically engineered' transgenic Pisum sativum peas that were not vulnerable to the pea weevil Bruchus pisorum. The pea weevil could destroy entire crops, using the enzyme a-amylase to digest the starch from the peas. The common bean plant Phaseolus vulgaris has developed a built-in pest resistance. It has an a-amylase inhibitor that stops the weevils (tjgesting starch so that they cannot feed and kill the crop. Given the genotypic and phenotypic similarities between the peas and beans, the project was commenced of making transgenic peas, taking the a-amylase inhibitor from Phaseo{us vulgaris and injecting it into the Pisum sativum genome. The project was, however, abandoned after it was revealed that the genetically modified peas caused immunogenic responses, such as hypersensitive skin and allergic lung damage when ingested by mice (Prescott et al. 2005). Why had this happened? The gene had done its work to the extent that the peas were resistant to the weevils, but given that the primary aim was to preserve a crop that would then be ingested, the unexpected side-effect rendered the project a failure. The inhibitor protein was being manufactured by the peas but, as peas and beans produce proteins differently, it was slightly different structurally. The peas had added small groups of saccharides at places on the proteins and it was these that led to the side effects when ingested. The case shows that we cannot assume that the protein expression of genes in non-native hosts will be exactly the same. A new context, even where it closely resembles the original context, can result in vastly different outcomes.

JO.7 1'hresholds in biolog\'

The dispositionalist seeks a sharp separation of the ideas of causal production and causal necessitation. Causal dispositionalism is an

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Thresholds in biology 227

account of the fonner without the latter. Necessitation is just one account of how causal production can occur and, as we have argued at length in chapter 3, it is not a good one, In its place, we offered a threshold account. Causation occurs where there is enough of an accu­mulation of powers to make it happen, taking into account the powers that dispose towards a certain outcome and the powers that dispose away from it. Some thresholds are significant for us in that they mark a point at which some major change is triggered and, for that reason, our work as causal agents is sometimes conducted with such a threshold in mind. The most obvious example of this is the threshold at which

water boils. Tn biology, there are many phenomena that operate in this kind of

way. In the case of Huntington's disease, for instance, we saw that production of the mutant HfT protein was triggered when the number or CAG repeats was above 40, but could be triggered with a repeat number as low as 36. Threshold and trigger figure impOltantly in explanations. Human body temperature, for instance, is usually kept within a narrow 'normal' range through thennoregulation which ensures the Ill<:1intenance of cquillbriurn, Sweating when hot cools the body and shivering when cold warms it. This is vital because a body temperature above 40c,C can bc life threatening. Beyond that threshold, normal

bodily functions could start to fail. As has all'eady been argued, the possibility of prevention and inter­

ference figures prominently in biology and indeed the whole of medi­cine is premised on the idea. Treatments are typically based on the idea that biological processes need not inevitahly produce traits. But it is also clear in biology that the possibility of prevention, and thus the lack of causal necessity, does not invalidate the use of causal claims. Even when there is a threshold for which the cffect is usually achieved, there could always be the possibility of interfering powers that dispose away from and prevent the effect.

Take, for instance, a genetic experiment conducted by Koopman et a1. (1991) to make a chromosomally female mouse with male anatomy, The methodology was to transfer the sex-determining region of the Y -chromosome, specificaUy the testis-producjng Sry-gene, into ferti­lized eggs. Presence of the human SRY-gene has been used by the Intemational Olympic Committee for gender verification (the human version is spelled out in upper case). The so-called Sly-gene in mice is a I4-kilobase DNA fragmcnt. The experiment was declared successful in that a chromosomally female (XX) mouse was produced with testis:

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It is now shown that Sry on a I4-kilobase genomic DNA fragment is sufficient to induce testis differentiation and subseq~ent male development when intmduced into chromosomally female mouse embryos. (Koopman et aI. 1991: 117)

Even though the experimenters here claim that the DNA fragment is 'sufficient to induce testis differentiation', they do not seem to mean the same as what a philosopher would mean by sufficiency. This should be clear when we take a closer look at the details of the experiment.

The Sry-fragment was microinjected into fertilized eggs and 158 embryos obtained. 93 mice were born from these but only five had taken up the foreign DNA and become transgenic. Of the five transgenic mice, only one was chromosomally female but with testes, and these testes were small and infertile. The other four transgenic mice showed no changes: two were nonnal XY -males and two were nonnal XX­females. The two females indeed had several copies of the Sry DNA but had no sex reversal. The team concluded from this that' Although we have shown that Sry alone can promote testicular development in the absence of other Y -linked genes, sex reversal does not always occur. The most likely explanation for this is that thc Sry trans gene 1S sensitive to position effect':>' (Koopman el. al. 1991: 121). This seems to point to the context-sensitivity of causation: whether the threshold for the effect is actually met will depend not only 011 what we take to be the main causal factor, but also on what other powers are operating:

when additional transgenic mice arc analysed, we would expect to find instances of partial sex rcvcrsal due to position effects, where the level of Sry expression is close to a critical threshold. It will be important to understand what this threshold means in the process of testis detemlinatiol1. (Koopman et al. 1991: 12T)

Genes thus provide exemplary cases of causal production without necessitation. There needs to be 'enough' working with lhem and facil­itating them if they are to do their work. A lhreshold at which they are able to express must be passed. It is doubtful that the gene ever has enough on its own and will only be expressed when there are the right contextual factors for their expression. If we consider the genes for leg growth in humans, for instance, we can see how implausible it is to think that those genes alone do all the work. The nonnal development of legs and feet depends crucially on context of usage, such as staI1ing to put weight on them at the right time. Thus, the bone structure of legs and feet arc developed in the process of standing, walking and jumping. Without that extemal stimulus, in an adequate degree, infant legs and

Fmergence, holism and non-linearity 229

feet would remain weak, soft and unsteady into adulthood. The genes alone would produce only small and shrivelled legs (Holdrege 1996: 140ff.) and we see from returning astronauts how quickly muscles and bones can diminish without adequate weight being placed on them. The best interpretation is to say that the genes dispose towards development of limbs of a certain phenotypic kind but do so only if other contextual factors, comprising both those factors disposing towards and those disposing away from the effect, deliver enough to meet the threshold for such production. Given this consideration, we can sec that even if trait production was monogenic - that is, if there were a one-to-one correspondence between genotype and phenotype - this would not mean that the genes produced the trait on their own. The gene would still need a suitable environment in which to do its work.

Jo.8 Emergence, holism and non-linearity

The status of holism and place of emergent phenomena in biology is controversial. On the one hand, there is genetic detenninism. which is a reductionist project. This would be a theory that for each trait, there is a gene that produces it and does so deterministically. There are alleged genes, for instance, for mental illness (Swift and Swift 2005), intelli­gence (Burdick et al. 2006), aggression (Cases et al. 1995), violence (Ferguson and Beaver 2009; Reiss and Roth 1993), alcoholism (Pandey et al. 2008; Galanler 1993), depression (Cohen 1994), and even infidel­ity (Walum et al. 2008). As we have argued above, however, such genes. if there really are such things, would never more than dispose towards certain character traits, but would do their work only if they were placed in an appropriate context: a biological, psychological. social and cul­tural context (see, for example, Rose 1997: 275-6). Even if there were monogenetic traits, they would still be muHi-factorial according to our theory, requiring mutual manifestation partners, some of which would nol be genetic at all. This would be lo say that although there may be something genetic that disposed towards depression, for instance, it would not be enough on its own to reach the threshold at which depression starts. The stress all polygeny - the complex nature of an effect's causes - would count against any reduction of causes to one simple kind that alone was able to determine an effect.

Not all genetic explanation is intended as reductive and deteIDlinistic, however. More holistic biological explanations can be found in other

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230 A Biologically Disposed l'hcorJ' of Causation

cases, One example is that of the eyeless Drosophila (banana fly), which suggests that the organism's need for visual sensations determines new uses for its genes. The gene Eyeless is found to be the gene for eye production in Drosophila (confusingly, the gene is named after what would be the effect of its absence: if the fly lacked the l!yeless gene it would be eyeless). This gene can be mutated so that eye production is blocked, Tribes of banana flies that lacked (he Eyeless gene, and were indeed without eyes, were developed and inbred. After a few genera­tions, however, flies appeared with eyes even though they were still without the so-called Eyeless gene that had produced eyes in previous generations (Webster and Goodwin 1996: 87). The organi.sm managed to design the eye without the gene for eye production. According to Webster and Goodwin, this example:

shows that a specific genetic makeup is neither necessary nor sufficient for the production of a specific morphology .... we can say that, in Drosophila, the power (Hull's 'potential') to produce eyes is not dependent upon the presence of specific 'genetiC information' ... there can be invariance of morphology despite variation in genetic makeup; there are no constant conjunctions here. (Webster and Goodwin 1996: 87)

According to Skaftnesmo (2005: 72), a more holistic approach to the organism is what is needed to explain such a case. The Drosophila seems to be making use of its genes as a store of tools that can be called upon when required. This makes sense within an evolutionary frame­work. It is traits that are fit or not, in the evolutionary sense of fitness. It is the macro-level traits that are selected by evolutionary processes. The genes that are productive of those traits are in some sense not important, as long as they produce the trait. Hence organisms of dif­ferent specics could have the same trait in viltue of different genetic make-up. Traits can thus be understood as variably realized by different genetic processes. Evolutionary pressures work primarily at the macro­level, however. They concern scarcity of food resources, reproductive opportunities and environmental obstacles. The organism is the unit that must encounter these pressures and either overcome or succumb to them, not the genes within such organisms.

In biology, we can see that organs display many holistic causal powers, which are emergent in the sense that they could not be found at relatively lower levels. The heart has a power to pump blood, for instance, which its constituents do not. have, and the pancreas produces insulin, which its parts could not. Similarly, an animal can

Emergence, holism and non-linearity 23 1

see, but that does not mean that its constituents have the power to see (Hanson 1958: 6). The propelty or power that an animal has of being al1ve is also a prope.rty of the organism as a whole and not something we would usually ascribe separately to the parts of the organism. Where we do, it is primarily because those organs are located within an interde­pendent network of parts within a hving organism. The ascription of a power can be made at any relative level in nature and the question of whether such a power can be explained reductively can then be inves­tigated independently. Compositional pluralism allows that some phe­nomena might be explained reductively while other phenomena might be explained holistically. But we have also outlined a broad concept of emergence as a way of accounting for relatively novel macro-phenom­ena and this may be suited for many biological phenomena.

What of non-linearity? It seems that there arc many examples in biology where the relation between two variables is non-linear. Here are three. First, there was the example mentioned in §4.2 of Hunter's reaction. Ice was an anti-inflammatory for blood vessels but only for a period of five minutes. Swelling is rednced dnring (hat period but would then increase if still applied after that time. If we plotted swelling against time of application, therefore, we would get an inverted curve. Second, we could point to the relationship between temperature and population levels. Life on our planet has flourished within a narrow temperature range. If average global temperatures were to lower or rise by just a few degrees, we would see rapidly declining populations in most species. Third: an example from genetics of gene over-expression. In an experiment by Powell and Rogers, mice were injected with copies of the sheep protein for wool development ~ IF (intermedia(e filament) keratin - to study the effect of its phenotypical expression on hair structure and development. The mouse that had most copies of the IF keratin gene was the one that had the worst hair growth. It had brittle, deformed hair, which it regularly lost and then fe-grew (Powell and Rogers 1990: 1485~6). A conclusion drawn from the experiment was that over-expression of a gene could result in an imbalance, which caused the hair loss, while mice with lower levcls of the gene had nOI1l1al hair growth (Powell et a1. 1994: 617)·

In chapter 4, we explained various ways in which non-linear phenom­ena might be explained: in terms of complexity, going in and out of eqUilibrium, non-linear composition and emergence. We leave it to the science to ten us which of these explanations apply for these speci.fic cases.

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232 A Biologically Disposed TheOlY of Causa/ion

10.9 Simultaneity

Hurne had argued for the temporal priority of cause over effect (1739: l.iii.2: 75-6). He did so with reference to cases like his billiard balls, where movement of the cue ball, for instance, preceded the movement it caused in the object balL In chapter 5, we cast doubt on Hume's claim. The causation occurs not while the cue ball is moving, nor while the object ball is moving, but in between, when the balls touch. The causation, we argued, was simultaneous in that the cause and effect occur at the same time, whether that time is instant or extended. In biology, however, it might look like there are some more plausible examples of temporal priority. Someone might be born with a certain genetic defect, such as mutant HTT, which doesn't have its effect of causing Huntington's disease until they are forty years of age. The cause exists before the effect. it seems.

We have not argued, however, that there cannot be extended causal chains, the start of whlch occurs prior to the end. Such causal chains can have non-overlapping causes and effects. But each individual link in such a chain involves, on our account, simultaneous causation. In the case of Huntington's, mutant HIT, once produced, starts to have effects immediately in neural degeneration. But it still may be that visible signs of the disease, the chorea, occur only once a threshold of so many destroyed neurons has been met. "What we have is an extended process but it can still be argued that at each stage, cause and effect are simultaneous.

A way of explaining away apparenl cases of temporal priority in biological causation has been offered, but can a more positive recom­mendation of simultaneity be offered? The sorts of cases that could be offered as examples would be ones of biological components exercising their power. The heart has the power to pump blood and, when it docs so, it is a clear case of causation. The pumping movement can be considered the cause and the circulation of the blood its effect. Consid­eration of this case dearly weighs in favour of simultaneity. Typically, blood circulates for as long as the heart pumps and while the heart pumps, blood circulates. setting aside all the earlier remarks about context-sensitivity and the possibility of prevention (circulation can stop if a major artery is severed). We could say similar things about all the functions of the major organs. Their immediate effects are produced while the organs are fUIlctioning. The case of genes is a bit

Defeasible prediction 233

more complicated. however. Gcnes can have dormant periods when they do no work. Hence, one could indeed have the gene 'for' the production of a certain trait or protein but, as has already been mentioned, that would only be the coding part of the gene. The non-coding part, and other contextual factors, determine whether and when the gene is ex­pressed. If one has the gene but then develops the trail only later in life, it docs not entail the temporal priority of causation because it is likely that the gene had not been activated, or at least the threshold for a certain trait has not been met. As soon as it is activated, it starts to do its work. Such a claim, we hope to have shown during the book, is both philo­sophically and empirically plausible. Once the gene is activated, it starts to exercise its causal powers, which means that it has effects immedi­ately. There is no temporal gap betwcen the exercise ofthe gene's power and its effccts, even though those immediate effects might be just the first part of an extended and gradually unfolding process.

10.10 Defeasible prediction

Defeasibility of prediction is hardly something that needs illustrating, neither in biology nor any other science. False predictions are as com­monplace as anything. The challenge was more to explain within the theory of causation why prediction is defeasible and how explanations can be wrong. This was done in chapter 6, where it was shown that predictions (and explanations) are made according to a finite modeL The model assumes only cert<lin powers to be at work, and thus not certain other powers to be at work. The problem 1s that once we apply that prediction to the real world, the model may be inadequate where some further power has influence that was not included within the model.

The example of the transgenic pea experiment of Prescott et al. is enough to illustrate this. The rationale for the experiment was the promising idea that an inhibitor found in the bean ought to transfer to the pea case, given the many similarities between the pea and the bean. But this was based on the assumption that one could take a causally powerful component from one setting, splice it into a new setting, and it would work just the same. The reason the prediction failed was, on our account, because there were other relevant causal powers :in play that were not included in the model or theory that had heen constructed. Many experiments fail on th1s basis, not just genetic ones. Where a predicted outcome docs not occur, that immediately points towards

234 A Biolof?ically Di,\posed Theory of Causation

some previously unknown causally rel~vant factor at work, opening the way for new knowledge. Alternatively, it might be that some of the powers involved compose in different ways than originally envisaged, as our antipathetic cases of chapter 4 showed.

10.1 1 Dispositional modality

The finaJ feature of our theory was that causation involved an irreduc­ible, sui generi,\' modality that we call dispositionality. The features of causation we have outlined. so far, and illustrated with reference to biology, add up to it being this modality that is involved, rather than pure contingency or necessity. Although we have argued that genes alone do not necessitate traits, we do not deny that they can dispose towards them to a greater or lesser degree. But. much else besides is required for genes to successfully produce a trait, a protein or an enzyme. Some claims of genetic det.erminism look to be misleading, therefore. We do not deny that genes have a causal role. The connection between having a certain set of genes and having a certain trait is morc than accidental. But to acknowledge that we are dealing with a natural process that manifests only under certain conditions, and is capable of being prevent.ed, is to acknowledge that we are dealing with the dispo­sitional modality.

To understand this is to sec causation in biology aright. The causal rolc of genes can be exaggerated and misrepresented. Claims that thcre are genes for homosexuality, depression or criminality that., once pos­sessed, produce such traits with inevitability, seem to be based on a simplistic and faulty model of causation. In the case of physics, the regularity principle that same cause always produces same effect seems to have some initial plausibility. But the principle is ambiguous and, where A is a cause of B, it is implausible to say that whenever A occurs, B occurs. If A and C occur together, B might yet be prevented. The case of biology should make it obvious that A can be a cause of B, even though there are many contexts in which B does not follow A. Any good understanding of the way genes work, situated within some complex and delicate context., should make this apparent.?

~ We ru:e grateful to John Almour and Thomas Bohn for many discussions of genetics.

Causation and science 235

10.12 Causation and science

In this book, we have advanced a metaphysical theory of causation. It is one we think should, and can, stand up for itself on philosophical and metaphysical grounds. But we are also aware that philosophy, and metaphysics particularly, can be regarded by others as a mere flight of fancy, without any anchor in, or impact on, the outside and everyday world. To dispel any such accusation against our own theory, we have tried to show in this chapter that our philosophical theory of causation accords with thinking in an empirical science. Perhaps we have given too much empirical detail [01' metaphysicians, and not enough dctail for scient.ists. But this has been only a start. The project of integrating the abstract thinking in philosophy with thc concrete and practical thinking of t.he sciences is barely underway. Both activit.ies will benefit, we maintain, if this integration is achieved. Our hope, therefore, is 10 sec philosophy and science work together more closely, in ru:eas such as physics, biology, social sciences and psychology, to sec what ideas of causation are in play and how they might be regiment.ed and precisified.

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We have reached the end of our investigations into the dispositional nature of causation. What conclusion shall we say we have reached? Have we made any significant progress on a topic that has already filled libraries with so much bulk of printed matter? Have we justified adding to this already vast reading list that faces the student of metaphysics?

We venture the claim that we have. For we hope to have shown that we no longer need feel ashamed of our causal engagement with the world. We should have no doubt that we indeed have such an engage­ment and that it has furnished our minds with the idea of causation. It is not a fool who sits by his fire with an iron poker and agitates it, turning over the coals. Here, he is being a caLLsal agent, feeling his way in the world with the tip of Iris device and moving things, ini tiating changes. His reward for the changes he has brought is the regrowth of the Hames that wann his body. Now he is causal patient, suffering the changes that the fire makes to him, passing on its powers. This man has every reason to believe in the reality of causation: indeed, to take it as one of the most fundamental realities in the whole of existence.

And yet philosophers have told him he is wrong. We know of Burne, for instance, who in effect denies that fire warms and water refreshes (1739: 270). Yes, consumption of water is followed by refreshment -every time, he thinks - but there was no real power in the water to produce the refreshment and correspondingly no power in the old man's fire to wann him.

Let us not allow our latter-day flumeans to pass over what flume himself through principle would not. There was no delight to be L'1ken In these sceptical philosophical conclusions. Hume was profoundly troubled by the theory of causation he had presented (1739: 263-6). He knew that it could not satisfy the purposes of everyday life and knew its ahsurdity as well as anyone has ever known it. Let us not, then, allow our modenl philosophers to rejoice and rcvel in this absurdity, as if it was the glorious news that Hurne himself most strenuously dcnied. Yet the good David Hume could find no solution to his quandary. He had to

Conclusion oj This Book 237

satisfy himself with the most unfortunate of positions. He left his Chamber, the scene of his philosophic studies, and played backgammon with his friends. Out,ide of his chamber, he knew that he was causally engaged in a powerful world. Inside his chamber, he could find no principle that could affirm what he otherwise knew. This was deeply unsatisfactory. He had one theory inside his chamber; and a different theory outside his chamber. He both knew that causation was real and empowered, and yet at other times and places knew that it was not.

This puzzle is what we hope to have resolved. We offer a single theory that suffices for the outside world, that we know to be a world of powers, and also suffices for our philosophical studies. Our concrete engagement finds its accord in an abstract philosophical theory. We have no need to put on Olle hat in our studies and replace it with another when we leave.

Causation is as real as anything we know. It is fundamen1:ElI: an actual feature of this one true world. We accept primitivism, for how could there be something even more basic in the world than causation, which might allow us to bring forth a reductive analysis? We have looked at the common sense intuitions about causation. Some of them we have embraced within our theory. But we have not been enslaved by them. In a Socratic spirit, we have been prepared to overturn those intuitions that don't bear scrutiny, but only where we have more considered intuitions that lead us in a different direction. We accept that there is no constant conjunction in our natural causal world, that the problem of induction marks causation rather than spoils it, that there is no time gap between causes and effects, that there is no counterfactual depen­dence as such, that prevcntion is not a thorn in the side of the theories of causation but something that should be central to them, that our theory can both allow a world of detcnninism, or not as the case may be, that causes may equally be stochastic or not, and that overdetenni­nation docs not require pages of obfuscation but should rather be welcomed as an old fliend. Not an of these claims adhere to the philosophical orthodoxy of the day. But we hope that some might agree with us that on reflection they make perfect sense. Some of those things that have been taken for granted might then yet be cast out.

We have taken care, though we have been ambitious. We have offered a positive theory. If we have failed, we plead the reader's forgiveness. And we trust they will agree that it has been beUer for us to have been "a good, solid corpse over which others can step and climb on, than in the safe role of heaping the obstacles over with rhetorical or other flowers' (Ducasse 1924: 2).

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BIBLIOGRAPHY

Anscombe, G. E. M. (1971) 'Causality and Determination', Metaphysics and the

Philosophy (~fMind, Oxford: Blackwell, 198J: 133-47· Arislotle, Metaphysics, H. Lawson-Tanered (trans.), London: Penguin, 1998. Armstrong, D. M. (1962) Bodily Sensations, London: Routledge and Kegan

Paul. __ (1968) A Materialist Theory of the Mind, revised edition, London: Rou-

tledge, 1993. __ (1978) A Theory of Universals, Cambridge: Cambridge University Press. -- (1983) What is a Law of Nature?, Cambridge: Cambridge University

Press. __ (1989) A Combinatorial Theory of Possibility, Cambridge: Cambridge

University Press. -- (1997) A World of States of Affairs, Cambridge: Cambridge University

Press. __ (2004) Truth and Trulhmukers, Cambridge: Cambridge University Press. ____ (2005) 'Pour Disputes About Properties', Synthese, 144: 309-20. Armstrong, D., Martin, C. B. and Place. U. T. (1996) Dispositions: A Debate.

T. Crane (cd.), London: Routledge. Ayer, A. J. (1936) Language, Truth and Logic, London: Victor Gol1ancz Ltd. Bacon, F. (l16zo] 2000) The New Organon, J .• Jardin and M. Silverthorne (eds),

Cambridge: Cambridge University Press. Baldwin, T. (1998) 'Objectivity, Causality, and Agency', in J. Bennudez (ed.),

The Body and The Self, Cambridge, MA: MIT Press, pp. 107-25. Barnes, B. and Dupre, J. (zo08) Genomes and What to Make of Them, Chicago,

IL: University of Chicago Press. Beebee, H. (2003) 'Seeing Causing', Proceedings of the Aristotelian Society,

103: 257-80. __ (2007) 'Hume on Causation: the Projectivist Interpretation', in H. Price

and R. Corry (Gds), Causation, Physics. and the Constitution of Reality, Oxford: Oxford University Press, pp. 224-49·

Bennett, A. F., Dao, K. M. and Lenski, R. E. (1990) 'Rapid Evolution in Response to High--Temperature Selection', Nature, 346: 79-81.

Bennett, J. (1987) 'Event Causation: The Counterfactual Analysis', Philosophi­

cal Perspectives, J: 367-86. Bergson, H. (1889) Time mui Free Will: An Essay on the Immediate Data of

Consciousness, F. L. Pogson (trans.), New York: Dover Publications Inc ..

2001.

r ,

Bibliography 239

Bhaskar, R. (1975) A ReaList Theory of Science, Leeds: Leeds Books Lillllted. -- (1993) Dialectic: The Pulse oj Freedom, London: Verso. Bigaj, T. (zo08) 'On Temporal Becoming, Relativity and Quantum Mechanics', in

D. Dieks (ed.) The Ontology ofSpacetirne If, Amsterdam: Elsevier, pp. 229-44· Bird, A. (1998) 'Dispositions and Antidotes', Philosophical Quarterly.

48: 227-34· -- (2007) Nature's Metaphysics, Oxford: Oxford University Press. B(-ihn,1'. (2007) 'Invasion of Exotic Species', in T. Traavik and L. C. Lim (eds).

Biosafety First, Trondheim: Tapir Academic Press, pp. TH9-204· Braehet, J. and Alexandre, H. (1986) Introduction to Molecular Emhryology,

Berlin: Springer Verlag. Braithwaite, R. B. (1953) Scient({ic Explanation, Cambridge: Cambridge Uni­

versity Press. Brand, M. (1979) 'Causality', in P. D. Asquith and H. E. Kyburg (cds), Currenl

Research in Philosophy of Science, East Lansing, Michigan: Philosophy of

Science Association, pp. 251---81. -- (1980) 'SimuHaneous Causation', in P. van Inwagen (cd.), Time and

Cause, Dordrech1: Reidel, pp. 137 '53· Brentano, F. (1874) Psychology from an t;mpirical Standpoint, L. I . McAlister

(cd.), Atlantic Highlands, NJ: Humanities Press, 1973· Brody, B. A. (1972) 'Towards an AIistotelian Themy of Explanation', Philusu­

phy ofScienre, 39: 20-31. Burdick, K. E., Lencz, T., Funke, B., Finn, C. T., Szeszko, P. R., Kane, J. M ..

Kucherlapati, R. and Malhotra, A. K. (2006) 'Genetic Variation in DTNBP1 Influences General Cognitive Ability', Human Molecular Genetics, IS: 1563-8.

Burks, A. W. (1951) 'The Logic of Causal Propositions', Mind, 60: 363-82. -- (1955) 'Dispositional Statements', Philosophy of Science, 22: 175----93· Butterfill, S. (2009) 'Seeing Causes and Hearing Gestures', Philosophical

Quarterly, 59: 405-28. Carnap, R. (1936) 'Testability and Meaning 1', Philosoph.-", of Science.

3: 420-71. Carroll, L. ([1865] J962) Alice's Adventures in Wonderland, London: Puffin. Cartwright. N. (1983) How the Laws oj Physics Lie, Oxford: Clarendon Press. -- (1989) Nature's Capacities and Their Measurement, Oxford: Oxford

University Press. -- (1993) 'In Defence

Fraassen's Laws and Research, 53: 423---9.

of "This Worldly" Causality: Symmetl}", Philosoph.v and

Comments on van Phenomenological

.- (1999) The Dappled World, Cambridge: Cambridge University Press . ... (Z007) Hunting Causes and Using Them, Cambridge: Cambridge Univer-

sity Press.

! ,

Bihliography

Carver, R., Waldahl, R. and Brelvik, J. (2008) 'Frame That Gene: A Tool for Analysing and Classifying the Communication of Genetics to the Public',

EMBO Reports, 9: 943-7· Cases, O. Soif, L, Grimsby J., Gaspar, P., Chen, K., Poumin, S., MillIer, D., Aguet,

M., Babinet, c., Shih, 1. c., and Dc Maeyer, E. (1995) 'Aggressive Behavior and Altered Amounts of Brain Serotonin and Norepinephrine in Mice Lacking MAOA', Science, 268: 1763-8.

Chalmers, D. (2006) 'Strong and Weak Emergence', in P. Clayton and P. Davies

(cds) The Re-emergence of Emergence, Oxford: Oxford University Press,

PP·244-54· Choi, S. (2008) 'Disposjtional Properties and Counterfactual Conditionals',

Mind, 117: 795-841. Cohen, D. B. (1994) Out of the Blue: Depression and Human Nature, New York:

Simon & Schuster. Collins, J., Hall, N. and Paul, L. A. (2004) 'Countcrfactuals and Causation:

History, Problems, and Prospects, in Causation and CounterJactuals, Cam­bridge, MA: MIT, pp. I-57·

Crick, F. H. C. (J958) 'On Protein Synthesis', Symposia oj the Society Jor Experimental Biology, XJI: 139--"63.

_.- (1970): -Central Dogma of Molecular Biology', Nature, 227= 501-3. Davidson, D. (1967) 'Causal Relations', Journal oj Philosophy, 64: 691-7°3. Dawkins, R. (1976) The Selfish Gene, Oxford: Oxford University Press. Dowe, P. (2000) Physical Causation, Cambridge: Cambridge University Press. -- (2001) 'A Counterfactual Theory of Prevention and "Causation" by Omis-

sion', Australasian Journal of Philosophy, 79: 216--26. Ducassc, C. J. (1924) Causation and the Types of Necessity, New York: Dover,

1969. -- (1965) 'Causation: Perceivable? Or Only Inferred?', Philosophy and

Phenomenolofiical Research, 26: I73-9. Dummett, M. (1954) 'Can an Effect Precede its Cause?', Proceedings oj the

Aristotelian Society, 28: 27-44. Dupre, J. (1993) The Disorder of Things: Metaphysical Foundations oj the

Disunity of Science, Cambridge, MA: Harvard University Press. Eagle, A. (2009) 'Causal Structuralism, Dispositional Aetualism, and Counter­

factual Conditionals', in T. Handfield (ed'), Dispositions and Causes, Oxford: Oxford University Press, 2009, pp. 65-99.

Ehring, D. (1985) 'Simultaneous Causation and Causal Chains' Analysis,

45: 98- 102. Ellis, B. (200 I) Scientific Essentialism, Cambridge: Cambridge University Press. -- (2002): The Philosophy of Nature, London: Acumen. Fara, M. (2005) 'Dispositions and HabilUals', NO/Is, 29: 43-82. Ferguson C. J. and Beaver, K. M. (2009) -Natural Born Killers: The Genetic

Origins of Extreme Violence', Aggression and Violent Behavior, 14: 286--94.

Bibliography 241

Frankel, L. (1986) 'Mutual Causation, Simultaneity and Event Description', Philosophical Studies, 49: 361-72.

Frege, G. (1879) 'Begriffsschrift', in P. Geach and M. Black (eds), Translations from the Philosophical Writings of Gottlob Frege, Totowa, NJ: Barnes and Noble, pp. 1-20.

Galanter, M. (cd.) (1993) Recent Developments in Alcoholism, New York: Plenum Press.

Gasking, D. (1955) 'Causation and Recipes', Mind, 64, 479-87. Geach. P. 1'. (1961) 'Aquinas', in G. E. M. Anscombe and P. T. Geach, Three

Philosophers, Oxford: Blackwell, 1961: 65-125· Goldschmidt, R. B. (1958) Theoretical Genetics, Berkeley, CA: University of

California Press. Goodman, N. (1955) Fact, Fiction and Forecast, Indianapolis: Bobbs-Merrill

Co., 2nd edition, 1965. Groff, R. (ed.) (zo08) Revitalizing Causality: Realism ahout Causality in Phi­

losophy and Social Science, London: Routledge. Hall, N. (J994) 'Two Concepts of Causation', In J. Collins, N. Hall and I" Paul

(cds), Causation and Counterfactuals, Cambridge, MA: MIT Press, 2004,

PP·225-76. Hanson, N. R. (1958) Pallerns of Discovery, London: Cambridge University

Press. Hardy, A. C. (1965) The Living Stream: A Restatement of Evolution Theory and

its Relation to the Spirit of Man, London: CoIlins. Harper, S. Q., Staber, P. D., He, X., Eliason, S. L., Martins, 1. H., Mao, Q., Yang,

L., Kotin. R. M., Paulson, H. L. and Davidson, B. L. (2005) 'RNA Interfer­ence Improves Motor and Neuropathological Abnormalities in a Huntington's Disease Mouse Model', PNAS, 102: 5820-5·

Harre, R. and Madden, E. H. (1973) 'Natural Powers and Powerful Natures', Philosophy, 48 (185): 209-30.

-- (1975) Causal Powers: A Theory of NaturaL Necessity, Oxford: Blackwell. Hart. H. L. A. and Honon5, T. (1959) Causation in the Law, OxJord: Oxford

University Press, 2nd edition, 1985. Hausman, D. M. (1984) 'Causal Priority', Nous, 18: 261-79· Hedman. C. G. (1972) 'On When There Must Be a Time-Difference Between

Cause and Effect', Philosophy of Science. 39: 507-1 I. Heidegger, M. (1925) History of the Concept of Time, T. Kcisel (trans), Bloo­

mington, IN: Indiana University Press, 1985. Hempel, C. (1965) Aspects oj Scientific Explanation and Other Essays in the

Philosophy of Science, New York: Pree Press. Hitchcock. C. (2006) 'What's Wrong with Neuron Diagrams?', in 1. K.

Campbell, M. O'Rourke and H. Silverstein (cds), Causation and Explanation, Cambridge, MA: MIT Press, 2006, pp. 69--92.

"I,

,

, ' , ,

~ I, I

"I II'

"I I,

242 Bibliography

Hitchcock, C. (2009) 'Causal Models', in H. Beebee, C. Hitchcock, and P. Menzies (ed~), The OAjord Handbook of Causation, Oxford: Oxford University Press, 2009, pp. 299-314.

Ho, M.-W. (2000) Genetic Engineering - Dream or Nightmare?, New York: The Continuum Publishing Company.

Hobbes, T. (lI6SI]ly8S) [.eviathan, London: Penguin. ~- ([1655J 1839) Elements of Philosophy Concerning Body, In W. Molesworth

(ed.), The Fngiish Works of Thomas Hobbes ofMalmesbury, i, London: Bohl1. Holdrege, C. (1996) Genetics & the Manipulation of Life: The Forgotten Factor

of Context, Hudson, NY: Lindisfarnc Pre~s. Huemer, M. and Kovitz, B. (2003) 'Causation as Simultaneous and Continuous',

The Philosophical Quarterly, 53: 556 .. 65. Hume, D. (lT739J 1888) A Treatise of Human Nature, L. A. SeJby-Bigge (cu.),

Oxford: Clarendon Press. -- (lI740] 2007) 'Abstract of a Trealise of Human Nature', in P. Millican

(ed.). An Enquiry Concernillg Human Understanding. Oxford: Oxford University Press, pp. 133-45.

-_.- (l1748] 2007) An Enquiry Concerning Human Understandillg. P. Millican (ed.). Oxford: Oxford University Press.

John~ton. M. (1992) 'How to Speak of the Colors', Philosophical Studies. 68: 22I--<>3.

Kant. L ([178rl 1929) Critique of Pure Reason, N. Kemp Smith (lrans.), London: Macmillan.

Kim, J. (1973) 'Cam;ation, Nomic Subsumption, and the Concept of Event", Journal of Philosophy, 70: 217-36,

-- (2006) 'Being Realistic about Emergence', in P. Clayton and P. Davies (eds), The Re-emergence of Emergence, Oxford: Oxford University Press, pp. 189-202.

Kistler, M. (2006) Causation and Laws of Nature, New York: Routledge. Kline, A. D. (1980) 'Screening--{)ff and the Temporal Asymmetry or Explana­

tion'. Analysis, 40: 139-43· --- (I980) 'Are There Cases of SimultaneoLls Causation'?', Proceedings of the

Biennial Meeting 4the Philosophy QI"Science Association, 1: 292--301. Koopman, P., Gubbay, J., Vivian, N., Goodfellow, P. and Lovell-Badge,

R. (1991) 'Male Development of Chromosomally Fcmale Mice Transgenic for Sry', Nature, 351: J 17-21.

KrimpenJort, P., Rademakers, A., Eyestone, W., van der Schans, A, van del' Broek, So, Kooiman, P., Kootwijk, E., Plalenhurg, G., Pieper, F., Strijker. R. and dc Boer, II. (1991) 'Generation of Transgenic Dairy Cattle Using "in Vitro" Embryo Production', Nature Biotechnology, 9: 844-7.

Kripke, S, (19~o): Naming and Ncces.Hty, Oxford: Blackwell. Langton, R. and Lewis, D. (1998) 'Defining Intrinsic', Philosophy and

Phenomenologicai Research, 58: 333-45·

Bibliography 243

Leibniz, G. W. (17 14) 'PrinCiples of Nature and Grace, Based on Reason', in R. S. Woolhouse and R. Francks (eds), G. W. Leibniz Philosophical Texts. Oxford: Oxford University Press, 1998, pp. 258-66.

Le Poidevin, R. (1991) Change, Cause and Contradiction, New York: St Martin's Press.

Lcwis, D. (1973) 'Causation', in Philosophical Papers, ii, Oxford: Oxford University Press, 1986: 159-213.

--- (1973a) Counterfactuals, Oxford: Oxford University Press. -- (1986) On The Plurality QfWorlds, Oxford: BlackwelL

-- (1986a) Philosophical Papers, ii, Oxford: Oxford University Press. -- (I986b) 'Events', in Philosophical Papers, ii, Oxford: Oxford University

Press, 1986: 241---69· ,-- (I986c) 'Postscripts to "Causation"', in Philosophical Papers, ii. Oxfonl:

Oxford University Press, I986: 172-213. -,.-- (I997) 'Pinkish Dispositions', Philosophical Quarterly, 47: 1 43-:,)X. -- (2004) 'Void and Object', in 1. Collins, N. Hall and L A. Paul (cds),

Causation and Counterfac/uals, Cambridge, MA: Mff Prcss, 2004, pp. 277 <)(1.

-- (2004) 'Causatiun as Influence', in 1. Collins, N.lIall and I.. A. Paul (cds), Causation andCounterfactuals, Cambridge, MA: MIT Press, 2004, pp. 75- 106.

.- (2009) 'Ramseyan Humility', In D. Braddon-Mitchell and R. Nola (eds), Conceptual Analysis and Philosophical Naturalism, Cambridge, MA: MIT Press, pp. 203-22.

Lipton, P. (1999) 'All Else Being Equal', Philosophy, 74: 155-68. Lombard, L. (1986) Events: A Metaphysical Study, London: Routledge and

Kegan Paul. Locke, 1. ([1690J 1975) An Essay Concerning Human Understanding. Oxford:

Clarendon Press. Lowe, E. J. (1982) 'Laws, Dispositions and Sortal Logic'. in: American Philo-

sophical Quarterly, 19: 41-50. -- (1987) 'What Is The "Problem of Induction"'?', Philosophy, 62: 325-40. -- (1989) Kinds of Being, Oxford: Blackwell. -- (2006) The Four-Category Ontology, Oxford: Oxford University Press. Luisi, P. L. (2006) The Emergence QfL{fe, Cambridge: Cambridge University Press. Mackie, J. L. (196S) 'Causes and Conditions', in E. Sosa and M. Tooley (cds),

Causation, Oxford: Oxford University Press, 1993, pp. 33-55· .-- (1973): Truth, Probability. and Paradox, Oxford: Oxford University

Press. -- (1980) The Cement of the Universe, Oxford: OxJord University Press. McMullin, E. (1978) 'Structural Explanation', American. Philosophical Quar­

terly, 15: 139-47· Macpherson, C. B. (1962) The Political Theury of Possessive Individualism,

Oxford: Oxford University Press.

I'

244 Bibliography

Manley, D. and Wasserman, R. (Z007) 'A Gradable Approach to Dispositions', Ihe Philosophical Quarterly, 57: 68~75.

Martin, C. B. (1994) 'Dispositions and Conditionals', The Philosophical Quar­terlY,44: 1-8.

-- (1972) 'The Sufficiency Thesis', Philosophical Studies, 23: 205--1I. -- (1997) On the Need for Properties: The Road to Pythagoreanism and Back,

Synthese, I12: 193-23I. -- (2008) The Mind in Nature, Oxford: Oxford University Press. Mellor, D. H. (1971) The Matter afChance, Cambridge: Cambridge University

Press. -- (1974) 'In Defense of Dispositions', Philosophical Review, 85: 157---81. -- (1988) 'On Raising the Chances of Effects', Matters of Metaphysics,

Cambridge: Cambridge University Press, 1991: 225-34. -- (1995) The Facts of Causation, London: Routledge. Miah, A. (2004) Genetically Modified Athletes, London: Routledge. Michotte, A. (1946) The Perception of Causality, T. R. Miles and E. Miles

(trans.), London: Methuen, 1963. Mill, J, S. (1843) A System of Logic, London: Parker. Moliere, I.-B. ([J682] 1926), 'La Malade Tmaginaire', The Pla)'s o/Moliere, viii,

A. R. Waller (trans.), Edinburgh: John Granl. Molnar, G. (2003) Powers: A Study in Metaphysics, S. Mumford (ed.), Oxford:

Oxford University Press. Montague, R. (1962) 'Detenninistie lheories', Decisions, Values and Groups,

2: 325-70. Moore, G. E. (1903) Principia Ethica, Cambridge: Cambridge University Press. Moore, M. K. (2009) Causation and Responsibility, Oxford: Oxford University

Press. Moss, L. (2003) What Genes Can't Do, Cambridge, MA: MIT Press. -- (2006) 'Redundancy, Plasticity and Detachment: The Implications of

Comparative Genomics for Evolutionary Thinking', Philosophy oj'Science,

73: 930-46. Mumford, S. (1998) Dispositions, Oxford: Oxford University Press.

(2000) 'Nom13live and Natural Laws', Philosophy, 75: 265-82. -- (2004) {,al-vs in Nature, Abingdon: Routledge. -- (2006) 'The Ungrounded Argumenl', Synthese, 149: 471-89. -- (2007), 'Negative Truth and Falsehood', Proceedings of the Aristotelian

Society, lOT 45-7I. --- (2oo7a) 'Filled in Space', in M. Kistler and B. Gnassounou (eds),

Dispositions and Causal Powers, Aldershot: Ashgate, pp. 67-80. -- (2007b) David ,1rmstrong, Stockfield: Acumen. -- (2008) 'Powers. Dispositions, Properties, Or: A Causal Realist Manifesto',

in R. Gron (ed.), Revitalizing Causality: Realism about Causality in Philoso­phy and Social Science, London: Routledge, pp. 139--51.

-- (2009) 'Passing Powers Around', The Monist, 92: 94-111.

Bibliographv 245

-- (2oo9a) Powers and Persistence', in L. Honnefelder, E. Runggaldier and B. Schick (eds), Unity and Time in Metaphysics, Berlin: Dr Gruytcr, pp. 223-36. -- (20II) 'Les Lois etLeurs exceptions', Etudes de Philosophie, 9/10: 47-65·

Mumford, S. and Anjum, R. (2009) 'Double Prevention and Powers', Journal of Critical Realism, 8: 277-93. -- (2010) 'A Powerfullbeory of Causation', in A. Marmadoro (ed.), The Metaphysics of Powers: Their Groundings and their Realizations, London: Routledge, pp. 143-159.

--- (20Ila) 'Dispositional Modality', in C. F. Gelhmann (cd.), Lebenswelt und Wissenschaff, Deutsches fahrbuch Philosophie 2, Hamburg: Meiner Verlag.

Pp·380-94. ------. (2011 b) 'Spoils to the Vector', The Monist, 94: 55-XI. Nagel, E. (1961) The Structure of Science: Problems in the Logic 0/ Scientific

Explanation, London: Routledge. Nijhout, II. F. (T990) 'Metaphors and the Role of Genes in Development',

BioEssays. I2: 44I-6. O'Shaughnessy, B. (1980) The Will, Camhridge: Cambridge University Press. Pandey, S. c., Uga1c, R., Zhang, H., Tang, L. and Prakash, A. (200S) 'Brain

Chromatin Remodeling: A Novel Mechanism of Alcoholism'. The l(mrnal of

Neuroscience, 2X: 3729-37. Pearl, 1. (2000) Causality: Models. ReasoninK, and Inference, Camhridge: Cam­

bridge University Press. Plalo (1961) Sophist, F. M. Cornford (trans.), in E. Hmnilton and H. Cairns (eds),

The Collected DialoKucs of Plato, Princelon, NJ: Princeton University Press.

Pp·957- 1017· -- (1951) Symposium, W, Hamilton (trans.), London: Penguin. -- (1997) Meno, in J. M. Cooper (ed.) Complete Works, transI. by G. M. A. Grube, Indianapolis: Hackett, pp. 870-97.

Pollock, J. L. (I976) Subjunctive ReasoninK, Reidel: Dordrecht. Popper, K. (1959) The Logic a/Scientific Discovery, London: Hutchinson. -- ( r 972) Ohjective Knowledge, Oxford: Clarendon Press.

Powell, B. C. and Rogers, G. E. (T990) 'Cyclic Hair-LDss and Regrowth in Transgenic Mice Overexpressing an Intennediate Filament Gene', EMBO

fournaL, 9: 1485--93. PowelL B. c., Walker, S, K., Bawden, C. S., Sivaprasad, A. V. & Rogers,

G. E. (1994) 'Transgenic Sheep and Wool Growth: Possihilities and Currenl Status', Reproduction, Fertility and Derelopment, 6: 615 23.

Prescott V. E .. Campbell P. M., Moore A., Mattes J., Rothenherg M, E, hlSll'1

P. S., Higgins T. J. V., Hogan S. P. (2005) 'Transgenic Expression or Ikan Alpha-Amylase InJ1ibitor in Peas Resulls in Altered Stlllcture and Immllll\1 gcnicity', Journal of Agncultural and Food Chemistry, 53: 9023 _W

r'

i.1 ,

'i

I'

~1

Bibliography

Price, H. (2007) 'Causal Perspectivalis_m', in H. Price and R. Corry (cds), Causation, Physics, and the Cunstitution of Reality, Oxford: Oxford Univer­sity Press, pp. 250--92.

Price, H. and Corry, R. (2007) Causation, Physics, and the Constitution of Reality, Oxford: Oxford University Press.

Prior, E. (1982) 'The Dispositional/Categorical Distinction', Analysis, 42: 93--6. -- (1985) Dispositions, Aberdeen: Aberdeen University Press. Prior, E., Pargetter, R. and Jackson, F. (1982) 'Three Theses about Dispositions',

American Philosophical Quarterly, 19: 251---7.

Psillos, S. (2002) Causalion and Explanation, Chesharn: Acumen. -- (2010) 'Causal Pluralism', in R. Vanderbeeken and B. D'Hooghc (cds),

Worldviews, Science and Us: Studies of Analytical Metaphysics, London: World Scientific, pp. 13I-5I.

Putnam, H. (1975) 'The Meaning of "Meaning''', in Mind, J.anguage and Reality: Philosophical Papers, ii, Cambridge: Cambridge University Press, pp. 21 5-7I.

Quine, W. v. O. ([I951] 1953) 'Two Dogmas of Empiricism', From a Logical Point of View, Cambridge, MA: TIarvard University Press, pp. 2(}-46.

Raji, C. A, Ho, A. 1., Parikshak, N. N., Becker, 1. T., Lopez, 0. L, Kuller, L. H., Hua, X., Leow, A. D., Toga, A. W. and Thompson, P. M. (2009) 'Brain Structure and Obesity', Human Brain Mapping, 31: 353-64.

Reid, T. (1788) 'Essays on ti1e Aetivc Powcrs of Man' ,in R. E. Beanblossom and K. Lehrer (eds), Inquiry and Essays, Indianapolis: Hackett, 1983: 297-368.

Reiss, A. and Roth J. (1994) Understanding and Preventing Violence, Washing­ton, DC: National Academic Press.

Rose, S. (I997) Lifelines - Biology, Freedom, Determinism, London: Penguin Books.

Rosenberg, A. (1975) 'Propter Hoc, Ergo Post Hoc', American Philosophical Quarterly, 12: 245-54.

Rosenberg, J. F. (1998) 'Kant and the Problem of Simultaneous Causation', International Journal of Philosophical Studies, 6: 167-88.

Rothschild, L. 1. (2006) 'The Role of Emergence in Biology', in P. Clayton and P. Davies (eds), The Re-emergence of Emergence, Oxford: Oxford University Press, pp. 151-65.

Russell, B. (1913) 'On the Notion of Cause', Proceedings of the Aristotelian Society, 13,1912-1913: 1-26.

-- (l918) 'The Philosophy of Logical Atomism', in The Collected Papers of Bertrand Russell, Vol. VIII, London: George Allen & Unwin, pp. 160-244.

Ryle, G. (1949) The Concept a/Mind, London: Hutchinson. Saarimaa, H. (1976) 'Combination of Clonidine and Sotalol in Hypertension',

British Medical Journat, 1(6013): glO.

Bibliography 247

Saflford, D. H. (1976) 'The Direction of Causation and the Direction of Con­ditionship', The Journal of Philosophy, 73: 193-207.

Schaffer, 1. (2003) 'Is There a rundamental Level?', Nails, 37: 498-517. -- (2004) 'Causes Need Not be Physically Connected to Their Effects: the

Case for Negative Causation', in C. Hitchcock (cd.), Contemporary Debates in Philosophy of Science, Oxford: Blackwell: 197-216.

-- (2oo4a) 'Trumping Preemption', in J. Collins, N. Hall andL. A. Paul (cds), Causation and COllnteJjactuals, Cambridge, MA: MIT Press, pp. 59-73.

Schrenk, M. (2008) 'Hie Rhodos, hic Salta. From Reductionist Semantics to a Realist Ontology of Forceful Dispositions', in G. Damschen, R. Schnepf and K. Stneber (eds), Debatifl~ Dispositions: Issues in Metaphysics, Epistemology and Philosophy of Mind, Berlin: De Gruyter, pp. 145-67.

-- (20ID) 'The Powerlessness of Necessity', Nails, 44: 725-39. Scriven, M. (1966) 'Causes, Connections, and Conditions in History', in

W. Dray (cd.), Philosophical Analysis and History, New York: Harper & Row, pp. 238-64.

Searle, J. (1980), 'Minds, Brains and Programs', Behm'ioral and Umin ,,'cit,tln's,

3: 417-57· Shalkowski, S. A. (J992) 'Supervenience and Causal Necessity'. Synthcsc.

90: 55-87· Shoemakcr, S. ([1980] 2003) 'Causality and Properties', Identity, Cause and

Mind, expanded edition, Oxford: Oxford University Press, pp. 206-33. -- (1998) 'Causal and Metaphysical Nccessity', Pacijic Philosophical Quar­

terly, 79: 59-77· -- (1999) 'Self, Body, and Coincidence', Proceedings of the Aristotelian

Society, 73: 287-306. Singer, P. (2002) One World, New Haven, CT: Yale Universily Press. Skaftnesmo, T. (2005) Genparadigmets Fall: Sammenbruddet av Det Sentrale

Downet, Oslo: Antropos. Skyrms, B. (1980) Causal Necessity: A Pragmatic Investigation of the Necessity

of' £lWS, New Haven, CT: Yale University Press. Sober, E. ([1985J 1990) 'Putting the Function Back into Functionalism', in W.

G. Lycan (ed.), Mind alld Cognition, Oxford: Blackwell, pp. 97-106. Sosa, E. (1980) 'Varieties of Causation', in E. Sosa and M. Tooley (cds),

Causation, Oxford: Oxford University Press, pp. 234-42. Spinoza, B. ([1677J 1955) The Rthics, R. II. M. Elwes (ed.), New York: Dover. Stalnaker, R. (1968) 'A Theory of Conditionals', in N. Resehcr (ccl.), Studies in

Logical Theory, Oxford: Blackwell. Steele. E. J., Lindley, R. A. and Blanden, R. V. (1998) ',amarl'k's Sigllature.

How Retrogenes Arc Changing Danvin's Natural Selection l'a!"(j(ligfll,

St Leonards, NSW: Allen & Unwin. Strawsol1, P. F. (1952) Introduction to I,ogical Them)', London: Mdhucll.

Ii

II

Bihliographv

Suits, B. (200'5) The Grasshopper: Gqmes Life and Utopia, 2nd edn, Peterbor­ough, Ontario: Broadview Press.

Suppes, P. (1970') A Probabilistic Theory of Causality, Amsterdam: North­Holland Publishing Company.

Swain, M. (1980) 'Causation and Distinct Events', in P. van Inwagen (cd.), Time and Cause, Dordrecht: Reidel, 1980': 156-7·

Swift, M. and Swift R. G. (20'0'5) 'Wolframin Mutations and Hospitalization for Psychiatric illness', Molecular Psychiatry, 10',799-80'3.

Talbott, S. (200'5) 'Logic, DNA, and Poetry', The New Atlantis, 8: 61-72. Taylor, R. ([1966J 1973) Action and Purpose, New York: Humanities Press, 2nd

edn. Tooley, M. (1987) Causation: A Realist Approach, Oxford: Clarendon Press. -- (1997) Time, Tense, and Causation, Oxford: Clarendon Press. Tuomela, R. (ed.) (1978) Dispositions, Dordrecht: Reidel. Unger, P. (zo06) All the Power in the World, Oxford: Oxford University Press. van Inwagen, P. (ed.) (1980) Time and Cause, Dordrecht: Reidel. Vendler, Z. (1967) 'Causal Relations'. Journal oj Philosophy, 64: 704-13· Walum, H., Westberg, 1.., Henningsson, S., Neiderhiser, J. M., Reiss, D., IgI, W.,

Ganiban, 1. M., Spotts, E. 1.., Pedersen, N. L., Eriksson, E. and Lichtenstein. P. (zo08) 'Genetic Variation in the Vasopressin Receptor Ia Gene (AVPRIA) Associates with Pair-bonding Behavior in Humans', PNAS, lOS: 14153-6.

W31Ten, S., Ebert, E., Swerdlin, A-H., Steinberg, S. and Stone, R. (1979) 'Clooidine and Propranolol Paradoxical Hypertension', Archives afInternal

Medicine, 139: 253· Webster, G. and Goodwin, B. (1996) Form and TransJormation: Generative and

Relational Principles in Biology, Cambridge: Cambridge University Press. Weissman, D. (1965) Dispositional Properties, Carbondale, IL: Southern

Illillois University Press. Whitehead, A. N. (1929) Process and Reality: An t.'ssay in Cosmology, Cor­

reeled Edition, D. R Griffin and D. W. Sherburne (eds), New York: Free Press.

1978. Wilson, 1. (2009) 'The Causal Argument Against Component Forces', Dialec­

tica, 63: 525-54. Wittgenstein,1.. (1953) Philosophical Investigations, Oxford: Blackwell. Wolf, U. (1995) "Ine Genetic Contribution to the Phenotype', Human Genetics

95' 127-48. Woodward, J. (2003) Making Things Happen: A Theory of Causal Explanation,

Oxford: Oxford University Press. Wright, L. (£973) 'Functions', Philosophical Review, 82: 139-68.

Wright, A. (199I) 'Dispositions, Anti-Realism and Empiricism', Proceedings (?f the Aristotelian Society, 91: 39-59·

INDEX

ability 5, 186-8 second-order 187

absences 143-9 causation by ix, II, 12, 131, 143---8, 169 causation of 144 See also equilibrium denial 146-8 empowcnncnt 145, 146 reification 144, 145

abstraction 69 action at a distance 12 I

agency viii, 201-12 anccstty 128 Anderson, J. 144 Anscombe, G. E. M. 15,50,51,53,58,71,

75,76, 170 anteceUent strengthening 56-63, 66-70,

84, 191 antidotes 58,61. 191

antipathy 90-2 Apollo I 33 a priori reasoning 48 Aquinas, S1. T. vii Aristotle vii, 51, 52, 214 Armour, J. 234n Armstrong, D. M. 2,3,5,6,14, (5, 17· 34,

54,67,68, 144, 179, 188,202,203. 206, 207, 209

asymmetry 10 Ayer, A. J. 216

background condition 31"~3, 173, l79 background knowledge 2 hackwards light conc 13, 66 Bacon, F. 141 balance 196, 207 Baldwin, T. 205,210 Barker, S. 75n Beaver, K. M. 229 because 161, 162

Bcehec, H. 16, 198,202 13emlett, J. 171, 173 Bergson, H. 52 bestowal 3 Bigaj, T. 121 billiard balls 6,108-10.201 hiology 2 J 8-34

Bird, A. 4,8,17,58,61,63,82,191. 192

bodies 201,209

13~1hn, T. 234n Brand, M. 119 Brentano, F. I8S Brody, B. I 14 Burdick, K. E. 229 Butteriill, S. 196 butterfly effect 90, 94-0

Carroll, L. 145 Cartwright", N. 4,24,35, 3X,,!j.}, 1')7 l)

197, 21 5,216 Cascs, 0. 22()

categorical statements 163 5, 174 causal basis 191 causal chain 110,115, 118, I24-7, I 67-73 causal claims I3-I5,I59-63

occurrent general 142, 143 particularized 164 tensed IS

causal cone 110, 126-8 back wards 126-8 forwards r 28

causal graphs 22

causal loops 118 causal necessitation viii, 48-53, 71, 82-6.

226-<) causal necessitalianism 50-53,58, 6L

63,66-8,73·-6, 180

causal patients 201"3,2°9,210.212 causal production viii, 53, 70-4 ceteris paribus clause 154, 166, 167.

191,192 Chalmers, D. 92, tol change 23.25,26, 100, 10:\ S('{' al.I·(I

subject of change chaos 90, 97, 104, 105 Choi, S. I93 circularity 8 classification r62, r65' '7 clonidine 91 clusters of powers 3,99, [0.1, [}.n Cohen, D. 13. 229

coincidences 9 Collins, J. 102,2f7

_C7~"""",,"

!;

! I I

Index

combinatorialism 179, 182

complexity 12,22,31,44,45,54,96, 218,224--6

component powers 38~44, 86 composition 43,44 compositional pluralism 86,87,

96--101, J05, 231

composition of causes 12, 27-30, 38~41, 86--8 See also component powers; non-linearity; principle of additive composition

conceivability 59 conditional analysis (of dispositions) 8,176,

190-3 modally strengthened 192 revised 191 simple 191

conditionals 159--61,179,190-2 material J 79

conditions (vs causes) f73 consciousness 101 constant conjunction vii, viii, 7, 9, 48-5 1,

53,66,71,76,107, II7, 149, 153, 154,197-9,202-4,21I

aceiucutal 50, 53 necessary condition of cause 54 sufficient condition of cause 53 well-conflIIned 9

context-sensitivity 174, 2 r8, 224--6 contiguity 7, 10,48-50, I07 contingency JO, 22, 63, 175, 179, 182 continuity J 10, 124, 200, 205 Corry, R. 16 counterbalance 30, 41 counterfactual dependence vii, I I, 12, 20,

41,42,68,108,117, J31, 149-52, 170, 173

Euthyphro question 151

countelfactuals 12, f46. 148~55 countervailing powers!causes 20, 22, 3 L

33,37,80

Davidson, D. 52 deduction 166 deductivism 131,138-40 defeasibility 139,140,154,166,233,234 degree 2 I dense space-time 120 detenninism 74--6, 178, 179

genetic 229 deviant causal chains 31, 130, 169 dispositional mooality viii, 10, 12, 175-94·

209-13,234

distinct existences 22, 42, 112, 200 DNA 220 double prevention 152,153 Dowe, P. 102, 118, 144, 146, 217 Ducasse, C. J. 32,52, ren, 201, 212, 213, 237 Dupre, J. 221 Dybvig, D. D. 99

Eagle, A. 58, 183 Eddington, A. 216 efficient cause 32 Einstein, A. 119 Eleatic principle 145 eliminativism 16 Ellis. B. 4,37,53,58,63,82-4, 142, 164,

166, 181. 182 embodiment See bodies emergence 88,92-4, roo-s, 216, 229,

230,231 modest kind 102 weak vs strong 92

empiricism 195, 199 Encinas, M. J. G. 60n endurance 116 epistemology 14,33, It;, 130, 131 equations 16 equilihrium 29-30,32,37,93,94 escalation 9°,94--6 essentialism 63,64,81-4, 142, 164-7 event causation 2, 3 events ix, 1-3, 10,20,21,23,26,113,200

See also two event model co-located 26 distribution of 78-8 I 'non-existent' 29, 30 property exemplifications 23 static JI6 uncaused 2,75

exceptions 165, 166 exercise of power 2,6,24,25 experience 9, 10, 14, 194-2J 3

error theory 198 feedback 208, 209 'thick' causal 197, 198,213

experiment 44, 69 explanation 12, 13G-4, 137~40,

146-8, 162 deductive-nomological 138~40 hypothetico-structural 133

facts 1,2 fallibilism 136, 137 falsification X65

/lIdl"l .' family resemblance 158 Fara, M. 4 Ferguson, C. 1. 229 finks 43,61,177,180,191 flux 26 forces 24,38-43,102, 119 Frankel,L 115,118 Frege, G. 163 functions 98, 99 flUldamentalism 216 fundameutallevel 17,18. 100

Galanter, M. 229 Gasking, D. JI4 Geach.P. T, 44,53,56,58, 166 general causal claims 13-15,71

See also types general statements 162,163 genes 218~34 Goldschmidt, R. B. 222 Goodman, N. 180 Goodwin, B. 222, 224, 230 gravitational attraction 96

I-Iall, N. 102,152,217 Hanson, N. R. 231 Harper, S. Q. 223 Harre, R. 4,7,26,51,82,83 Heidegger, M. 205 Heil, J. I22n Hitchcock, C. 19,22 Hobbes, T. 65, 102 Holdrege, C. 229 holism 87, 101,229-31 homeostasis 89 homuncular functionalism 221 Hllemer, M. 114, JI6, 119,120 Hume, D. viii, 2, 6, 7, 9, II, 47-5°,

53,58,59,82,84,106--9, JI2, Jl3, II5, Jl6, 120, 141, 142, 149, 153, 165,196,198-2°5,207,209,232, 236,237

Humc's trap 49 Humeanism 20,76, 197 Hume-world vii Hunter's reaction 89,94,231 Huntington's disease 222,223,232 hypersensitivity 97, 100, 104, J74 hypertension 91 hypothetical st8tcments 163-·5

ideas 9, I I identity 165-7

It I·,'J (,I

mdc\nlllllll:,1H ',H. It,. HI IIldlldl<l1l X.~. 1.1" \. If,l,

mllihitioll .~ I

illstant 2(), \)h instaJltancous callsa!i(1l1 I ()'). I I j. I I .>

instrumentalism 43,44 intensity 20-22, 24 intentionality 176, J85-9 interference 12,53--6,60,63,64,211,227

See also prevention additive 62,62, 191-3 subtractive 22,31,62, 191

mtllitions 10, I I

inus-condition 52

Jackson, F. 8 Johnston, M. 58, 191

Kant, I. 52, 114,122,123, 163, 164,201 Kerry, R. 89B Kiw, J. 23,92, 101, 102 Kistler, M. 217 Koopman, P. 227,228 Kovitz, B. 114, II6, IJ9, 120 Kripke, s. 57,81

laws of nature 14,63,82,99,150 Lewis,D. 2,11-14,19,20,22,2],68,69, r 13,

131,132,145,149-52,179, ISo, 191

liability 5 linearity 89, 90 Lipton, P. 154, 167 Locke, J. 9, J95, 197,201,20::;, 205 \,nmbarcL L. 2]

Lowe, 1.. J. :~1I, LI, IX'I, IHh

Mackie,.l.I .. X,,\/,').'./o.// Macpherson, ('. I~. 10.'.

Madden, E. II. ,1, '1, }.('. ') I, X.' .. H \ manifestation .1.,5,), X, I.'), .J.}. I .\'",. </{.\."

mutual manifestatillll spontaneous 35, 36

Martin, C. B. 4, 16,34,43, y8, 100, ! I,),

124,180, 191 two triangles example 98, 124

masking 58,84, 177, 191 mathematics J 0

Matheson, C. 28 McDonald, G. 17n McMullin, E. 133 Melior, D. H. 2, 15, nn, 77, 180 Mendel, G. J. 221,223

252 Index

Menu paradox 10 mereological sum 87, 98 metaphysics 17,13°,131,214,215,234 Michotte, A. 196 l\.1iU, J. S. vii, 11-13,27,28,31. 38-41,

52,53,58,59,65-9, 132 mind-dependence 16 modality 10,175-93 See also

dispositional modality models, causal 12,13,19-46,54,62,72-4,

78-80,86,88-93,96, (36,137,217 Moliere, I.-B. 8 Molnar, G. 4,7,8,10,12,27,118,144,

156, 185,186, r88, 189,210,221. 224 moment 26, 27 monogcnicity 22 I. 222

monotonicity 57, 59, 69 Montague, R. 76 Moore, G. E. 9 Moore, M. S. 7,8,95, 126. 152, 169-71

Moss, L. 220, 225, 226 mutual mmlifestation ix, 12,34-8, J22-7

pnrtncrs 35 Myrstad, J. A. 164u

naturalism 187, 188 natural kinds 83 necessary connection 47,59 necessity 10, 47-BS, 176-9, 182 Sec (llso

causal necessitation logical 48, J 94

negative causes 65, 66 See also causation by absence

negative truth 67 Neurath, O. 215 neuron diagrams 12, 19-22 Newton's first law 36 Newton's second law 114,120 Noer Lie, S. A. 187n,22on non-linearity 87-90,96-101, ras, 23 1

non-monotonicity 57, 174 non-negligible probability f8I nonnativity 176,183-9

objects 1

ontology 3 O'Shaughnessy, H. 205

overdetermination 12,43.151-3 overdoses 88, 93, 94

Pandey, S. C. 229 pandispositionalism 3,5,6, 18,45,103,

125, 134

paradox of analysis 9 Pargetter, R. 8 parsimony 3 particulars 10,26, 27

active/dynamic 26 passivism 37 Paul, L. A. 102, 217 Pearl, J. 22 Perceptibility of cause 14. 113 perdurance 116 See also temporal part persistence 26 perspectivalism 16 petenng out 170, 17 J

Pettit, P. 170 physics J6-'18,24, lOI, 1[9-21, 2J5

ideal 101 Plato ra, 145 pleiotropy {28, 224, 225 pluralism, causal vii, 157. 158 Pollock, J. JIg polygeny 12,27,3 1,35,54,72 ,87,128.

221,229 Popper, K. R. 50, 141. 165 possibility 63, 179--R3

natural 181-3 possible worlds vii, 68, 69, 149,

150, 179 potency 8 Powell, B. C. 2}1 pragmatic;; 32, 33 prediction 1}0, 131, 135, 136, 139, 174

predictive failure 136, 137 pre-emption 21,151, 152 Prescott, V. E. 226,233 prevention 12,21,53--6,60.63,64, 165.

166,177,227 additive 55-8, 60-3 subtractive 55, 62

primi.livisOl 7--11,158.176,237 principle of additive composition 87--90.

104 Plice, H. r6 Prior, E. 3, tI, 8 private language 102 probabili;;tic causation 77-8 I

disjunctive 78 probability, negligible 181 probahility-raising 71. 77 process ix, r07, 109, u6, 1 L7, 119. 122-8.

156.200, 205, 209,211 production 8 projectivisrn 16 properties 1-3,5,6. 10,45· 82

Index 253

categorical 3, 6, 178 sparse 17

proprioception 196,21YJ-II proxirnity 100 Psillos, S. 157, 158 Putnam, H. 8 r Pythagoreanism 16

quality space 23--6,122 multi-dimensional 44,45

Randall, M. 911l reali;;m 16 reciprocal causation See symmetric

causation recombination See combinatorialisrn reductionism 17,101-4, II7, 2J6 reductive analy;;is (of causation) 7-1 L

reflective equilibrium 215 Reid, T. 197,201 Reiss, A. 229 reflexive causation 16x relat.ion, asymmetric J \ 7 relation, causal 20, 2X, 23, 106 relation, part-whole 42, 43 republicanism 16, 17 resultant powers 38-44 revisionary theories 10, II

Rogers, G. E. 231 Rose, S. 229 Roth. J. 229 Rothschild, 1,. J. 103 Russell, B. A. W. 16,51,58,59,66,67,

71,110, III, 120, 217 Rytc, G. 8, 190,206

Saarimaa, H. 91 scepticism 198,236 Schaffer, J. 17,143, 145 Schrenk, M. 58, J 97n. 20 I n science 214,215,235 Searle. J. J88 selection function 176, 189, 190 Shalkowski, S 51 shape 3 Shoemaker, S. 3, 10,82 simultaneity ix, 106 -29,200,206,

.209, 232, 233 sine qualquibus non 33, 52, 173 siugJc/loncJy powers 35-8, 80 singular causal claims 13-15,72 See also

tokens singularism 71,72

Skyrms, D. 51 Skaftnesmo, T. 221,224,230 Sober, E. J 84 sociobiology 102, 2 I 8 sociology 102 Socrates 10, II, 237 soctium chloride 103 Spinoza, B. 52 spontaneous powers 35, 36 Stalnaker, R. 149 stimulation/stirnulu;; 21,36, 106, 134 Strawson, P. F. 142, 166 sttuctural equations 22 subject of change 100 subordination 167, 168 substance causation 1, 1.

success IS succession SN tellllHll"al Plilllily sufficient cOIl<iilillll 'j.'.,.'1 \

Suits, B. 11

Sl.IperVl'l1il'lln· 10/1, I 1 I Suppes, 1'. 77 Swift, M. 221)

Swift, R. G. 229 symmetric causation 117, II!), 15()

Taylor, R. 114, II9 temporal gap 106, Ill, 112

regress I r r temporal part 26, 116 temporal priority viii, 7, 9, 48-50, IOfi-29,

199,200,206, 2°7,232 tendency viii, 4, 5

probabilistic 80,81 theory-dependence 196,213 rhresholds 72-4,88,94--6,222,223, 226----g tIpping point 95 tokens 14, IS, 34 Tooley, M. 119 top-down causauon 10)"

total cause II~· 13, 31, I 1'2

totality fact (q--9 touch 195, 196 traits 220--2, 23() transfer theory 101., I(q

transitivity ix, I l. 13, 1 (17 I)

limited I70 truthmaking 2,67,68 Tughy, M. 67U Tllomela, R. 4 two-eventrnodel 23,106-8,112. II 3, n6,

120. 122, 200 types 14, 15,34,53

I ,I il!

I

I ,I

254 Index

ubiquity 31 Unger, P. 3 ungrounded powers 100

uniformity of nature principle 142 universal generalizations 67,68 universals 14, IS

immanent realism 15, 34 unprediclability in principle 97

vectors 12, 24-46, 96 additioll 27-30,38-42, 44, 89 direction 24,45 double/multi-headed 78,79 intensity/degree/magnitude 24,45, 46 resultant 28-3 f, 89 zero resultant 29,30, 32

verification transcendence 43

Vetter, B. 38n virtus dormitiva 8, 133 volition 203-7

Walum, II. 229 Warren, S. 91 Webster, G. 222,224,230 Weissman, D. 4 \Vhitchead, A. N. vii. ix-

26, ,15 will See vulition Wilson, J. 42,43 Wittgenstem, L. ! 02

Wolf, U. 222 Woodward, J. 47 Wright, A. 195 Wright, L. 184