indexical thought

51
Indexical thought Indexical thought

Upload: beck

Post on 11-Feb-2016

39 views

Category:

Documents


0 download

DESCRIPTION

Indexical thought. Frege cases: Hesperus/Phosphorus etc. A rational subject, S, may take different (and possibly conflicting) attitudes towards the judgment that a given individual is F depending on how that individual is presented. - PowerPoint PPT Presentation

TRANSCRIPT

Page 1: Indexical thought

Indexical thoughtIndexical thought

Page 2: Indexical thought

Frege cases:Frege cases:Hesperus/Phosphorus etc.Hesperus/Phosphorus etc.A rational subject, S, may take different A rational subject, S, may take different

(and possibly conflicting) attitudes (and possibly conflicting) attitudes towards the judgment that a given towards the judgment that a given individual is F depending on how that individual is F depending on how that individual is presented.individual is presented.

To account for that sort of situation, To account for that sort of situation, Frege posited ‘modes of presentation’ in Frege posited ‘modes of presentation’ in addition to the reference of linguistic addition to the reference of linguistic expressions. expressions.

Page 3: Indexical thought

Frege’s constraint on ‘modes of Frege’s constraint on ‘modes of presentation’presentation’If a rational subject can think of some object If a rational subject can think of some object aa

both that it is F and that it is not F, that means both that it is F and that it is not F, that means that there are two distinct modes of that there are two distinct modes of presentation under which the subject thinks of presentation under which the subject thinks of aa..

Modes of presentation are whatever is needed, in addition to reference, to account for the subject’s differential behaviour in such situations.

Page 4: Indexical thought

Indexical modes of Indexical modes of presentationpresentationThey are a special case.They are a special case.

First person vs third person modes of First person vs third person modes of presentation:presentation:

My pants are on fireMy pants are on fireHis pants are on fireHis pants are on fire

Page 5: Indexical thought

Modes of presentation: two Modes of presentation: two optionsoptionsSemantic option : Modes of presentation are a

level of content additional to reference. (Fregean ‘senses’ etc.)

Syntactic option : Modes of presentation are not an additional level of content. They are ‘concepts’ qua vehicles of content. (Fodor, Sainsbury & Tye, etc.)

Page 6: Indexical thought

Arguments for the syntactic Arguments for the syntactic optionoptionMillianism: Reference is all there is to

content. No ‘senses’.Mates’s cases : There being two different

words (eg ‘psychiatrist’/‘alienist’, or ‘Greek’/‘Hellene’) is sufficient to make Frege cases possible.

Even if there is a single word (‘Paderewski’) in the language, Frege cases will be possible if the subject associates distinct ‘mental files’ with it.

Page 7: Indexical thought

Numerically distinct filesNumerically distinct files

The two ‘Paderewski’ files contain distinct bodies of information (about Paderewski the musician and Paderewski the politician respectively).

But two distinct mental files may also contain the same information.

There being two distinct mental files is sufficient to make it rational for the subject to contemplate the possibility that one object is F while the other (perhaps) isn’t.

Page 8: Indexical thought

Preliminary conclusionPreliminary conclusion

Modes of presentation = mental files.

On the syntactic construal, mental files are mental particulars.

They are not to be equated to the body of information in the file.

Page 9: Indexical thought

The reference of mental filesThe reference of mental files

Mental files serve to store information Mental files serve to store information about objects (so they are about objects about objects (so they are about objects and ‘refer’).and ‘refer’).

The reference of the file is not The reference of the file is not determined by information determined by information inin the file but the file but through through relationsrelations to entities in the to entities in the environment in which the file fulfills its environment in which the file fulfills its function.function.

Page 10: Indexical thought

ER relationsER relations

The relations on which mental files are The relations on which mental files are based, and which determine their based, and which determine their reference, are reference, are epistemically rewardingepistemically rewarding relations. relations. They enable the subject to They enable the subject to gain information from the objects to gain information from the objects to which he stands in these relations.which he stands in these relations. The The function of the file is to store information function of the file is to store information from these entities — information that is from these entities — information that is made available through the relations in made available through the relations in question.question.

Page 11: Indexical thought

An example: demonstrative An example: demonstrative filesfilesThe subject stands in a certain relation to The subject stands in a certain relation to

some object he is perceptually attending some object he is perceptually attending to.to.

In virtue of that relation, the subject can In virtue of that relation, the subject can gain (perceptual) information about the gain (perceptual) information about the object.object.

The demonstrative file The demonstrative file ‘that F’‘that F’ serves as serves as repository for information gained in that repository for information gained in that way.way.

Page 12: Indexical thought

Another example: the ‘self’ fileAnother example: the ‘self’ file

In virtue of In virtue of beingbeing a certain individual, I a certain individual, I am in a position to gain information am in a position to gain information concerning that individual in all sorts of concerning that individual in all sorts of ways in which I can gain information ways in which I can gain information about no one else, e.g. through about no one else, e.g. through proprioception and kinaesthesis.proprioception and kinaesthesis.

The mental file The mental file selfself serves as repository serves as repository for information gained in this way for information gained in this way (Perry).(Perry).

Page 13: Indexical thought

Mental files and the Mental files and the role/content distinctionrole/content distinctionDifferent types of file exploit different Different types of file exploit different

types of contextual relation.types of contextual relation.The type of a file corresponds to its The type of a file corresponds to its

function or role: exploiting a given ER function or role: exploiting a given ER relation.relation.

This shows that This shows that there are two levels of there are two levels of content after allcontent after all: referential content (a : referential content (a property of the file-token) and functional property of the file-token) and functional role (a property of the file-type).role (a property of the file-type).

Page 14: Indexical thought

Two levels of content: the Two levels of content: the Perry/Kaplan approachPerry/Kaplan approachIf you and I both think ‘I am tired’, there is a

sense in which we think the same thing, and another sense in which we think different things.

It would be misleading to say that the first level (the level at which we think the same thing) is ‘purely syntactic’ ; for what characterizes that level is the function or role of the files we deploy in our respective thoughts. The function or role stays constant : we both deploy a SELF file.

Page 15: Indexical thought

‘‘My pants are on fire’/’His My pants are on fire’/’His pants are on fire’pants are on fire’ There is a sense in which we think the same thing,

and another sense in which we think different things.

Same truth-conditional content, but different thoughts, with different behavioral effects.

What characterizes the difference is, once again, the function or role of the files that are deployed in the respective thoughts: a SELF file or a demonstrative file.

Page 16: Indexical thought

Summing upSumming up

Modes of presentation are mental files, construed as mental particulars.

They are not senses, but referential vehicles. Still, we must distinguish two levels of content, as

in Frege’s framework. The two levels we need correspond to Kaplan’s

character/content distinction: qua tokens mental files refer, but qua type they possess a ‘character’ corresponding to their role or function.

Page 17: Indexical thought

The indexical model for The indexical model for languagelanguage

expression typeexpression type

encodesencodes

expression tokenexpression token reference referencecontextualcontextual relationrelation

Page 18: Indexical thought

The indexical model for The indexical model for thoughtthought

mental file typemental file typehas the function ofhas the function ofstoring informationstoring information

derived throughderived throughmental filemental file referencereferencetokentoken of fileof file

contextualcontextual relationrelation

Page 19: Indexical thought

Alternative approachesAlternative approaches

Can we account for the cognitive significance of indexical thoughts without appealing to mental files and the vehicle/content distinction ?

Can we do it purely in terms of content ?Both the centered world framework and the

token-reflexive framework can be seen as attempts to do that.

Page 20: Indexical thought

Alternative approaches (1)Alternative approaches (1)Centered contentsCentered contentsInstead of introducing the vehicles into the

picture and endowing them with functional significance, Lewis proposes to make the contents themselves more fine-grained by characterizing them as sets of centered possible worlds rather than as sets of possible worlds tout court. Centering the possible worlds on an individual at a time gives us the subjective perspective which is the hallmark of indexical thought.

Page 21: Indexical thought

Centered contentsCentered contents

Centered contents are not classical propositions (which only require a possible world to determine a truth-value), but relativized propositions.

They determine a truth-value only when evaluated with respect to an appropriate index, containing the thinking subject and the time of thought in addition to the world in which the thought occurs.

The content is a property of thinker-time pairs, not a classical proposition; and it is evaluated ‘at’ the individual/time of the index.

Page 22: Indexical thought

‘‘That object is round’That object is round’

The content is the set of all possible worlds that are centered on an individual who is seeing a round object. That is the property of seeing an object that is round.

The subject who judges ‘that object is round’ self-ascribes that property (‘force’ component).

The self-ascription is true iff the subject of thought is actually seeing a round object at the time of thinking.

Page 23: Indexical thought

Lewisian DescriptivismLewisian Descriptivism

The objects that are represented in the content of the thought (e.g. the round object) are represented descriptively.

They are described as bearing such and such relations to the ‘center’, i.e. to the subject of thought (at the time of thinking).

The acquaintance relations are ‘internalized’ and reflected into the content of one’s thought.

Page 24: Indexical thought

Centered contents and Centered contents and DescriptivismDescriptivismIf I see something, I think of it descriptively

as ‘what I see’ – the object that bears a certain perceptual relation to me. (Searle, Jackson...)

In general, the objects we are acquainted with are represented descriptively as bearing such and such acquaintance relations to the subject.

Page 25: Indexical thought

The limits of Lewisian The limits of Lewisian DescriptivismDescriptivism A qualification: The description ‘what I see’ is not

fully appropriate. In ‘what I see’, there is an occurrence of the first

person. It corresponds to the subject in the contextual index, and the subject is not represented in the content : it is externalized and directly provided by the context.

The subject is not represented but, qua subject of the thought episode, it is involved pragmatically in the process of ‘self-ascription’ through which Lewis characterizes the attitudinal mode.

Page 26: Indexical thought

The Lewisian asymmetryThe Lewisian asymmetry

Those objects of thought that belong to the contextual index are treated completely differently than the objects of thought that are represented in the content of the thought.

The objects of thought in the content are represented descriptively as bearing such and such relations to the ‘center’.

In contrast, the entities in the contextual index are ‘externalized’ and directly provided by the context.

Page 27: Indexical thought

Problems with the viewProblems with the view

• I deplore the descriptivist construal of the content of thought and the internalization of acquaintance relations.

• I also deplore the asymmetry and its solipsistic/idealistic flavour.

(As Chisholm puts it, ‘There is one sense in which the believer can be said to be the object of his believing’.)

Page 28: Indexical thought

Multiple anchorsMultiple anchors

In the Lewis-Chisholm framework, everything is thought of descriptively, except for a single element which is externalized and serves as universal anchor for all the content.

Why not appeal instead to multiple anchors, corresponding to all the acquaintance relations in which we stand to objects of thought?

Multiple anchors are precisely what the mental file framework gives us, thus doing away with both the asymmetry and Descriptivism.

Page 29: Indexical thought

Multiple anchors in the centred Multiple anchors in the centred world frameworkworld frameworkMultiple anchoring can be achieved also in

the centred world framework by putting sequences of objects in the contextual index (Ninan’s ‘sequenced worlds’)

If we do that, however, we have to introduce modes of presentation (mental files) into the picture. We lose the benefit of Lewis’s successful appeal to the attitudinal mode to capture the first person perspective.

Page 30: Indexical thought

Sequenced worlds: the mode of Sequenced worlds: the mode of presentation problempresentation problemIf the objects of thought are fed into the

contextual index, what will determine how the objects in question are thought of ?

The descriptivist packs the modes of presentation into the content, but if we don’t do that, we need some other way of pairing the objects with the right modes of presentation.

Page 31: Indexical thought

The attitudinal mode and its role The attitudinal mode and its role in the Lewis frameworkin the Lewis framework In Lewis’s original framework, there is a

(nondescriptivist) way of pairing the subject in the contextual index with the right mode of presentation (the ‘self’ mode of presentation).

An attitudinal state is analysed into content and mode. The content, for Lewis, is a property. The belief mode itself is analysed by saying that to believe a content (analysed as a property) is for the subject of thought to ‘self-ascribe’ that property.

Page 32: Indexical thought

What is it to ‘self-ascribe’ a property? It is not just to ascribe that property to oneself. There are different ways in which one can ascribe

a given property to oneself, corresponding to different modes of presentation of oneself.

The thinker can think of himself that he is tired, when seeing himself, looking tired, in the mirror (without realizing that he is looking at himself). Or he can think that he is tired on the grounds that he feels tired. Only in the latter case does Lewis analyse the content of the thought as the property of being tired, which the subject ‘self-ascribes’.

Page 33: Indexical thought

What is it to ‘self-ascribe’ a property? There is no possibility of ‘self-ascribing’ a

property under a 3rd person mode of presentation of oneself (say, as the man seen in the mirror).

It is the attitudinal act of ‘self-ascription’ itself which determines a particular mode of presentation of the subject to whom a property is ascribed.

In other words, the first personal mode of presentation is built into the self-ascriptive relation.

Page 34: Indexical thought

What happens when we enrich the contextual index by feeding it a sequence of objects? Each object in the sequence can be thought of

under a number of distinct modes of presentation. So we need a way of pairing the objects with the appropriate modes of presentation.

But we can’t use the Lewis trick. There is a single self-ascriptive mode. On that mode we can base a special mode of presentation in Lewis’s original framework because a single individual occupies the center, and it is that individual that we need to pair with the right mode of presentation to avoid mirror-type counterexamples.

Page 35: Indexical thought

What happens when we enrich the contextual index by feeding it a sequence of objects?

When we multiply the individuals in the contextual index, what we need is not a single mode of presentation, but a sequence of modes of presentation corresponding to the sequence of objects. Appealing to the attitudinal mode is of no use here!

Conclusion: once we revise the framework so as to get rid of the asymmetry, we can no longer account for cognitive significance purely in terms of content. We need to add modes of presentation.

Page 36: Indexical thought

Alternative approaches (2)Alternative approaches (2)Reflexive contentsReflexive contentsThe token-reflexive framework (Searle, Perry,

Garcia-Carpintero, Higginbotham) also appeals to a special sort of truth-conditional content, in order to deal with indexical thought.

Page 37: Indexical thought

Alternative approaches (2)Alternative approaches (2)Reflexive contentsReflexive contents Objects are thought of as bearing certain relations

not to the subject at the time of thinking but to the occurrence of the thought in which they are represented. Each thought or utterance is therefore ascribed a reflexive content that is about that thought or utterance itself.

For example, an occurrence u of ‘I am tired’ in speech or thought means something like ‘the utterer/thinker of u is tired at the time of u in the world of u’.

Page 38: Indexical thought

A problem for ReflexivismA problem for Reflexivism

If I say or think ‘I am tired’, and this is analysed as ‘the utterer/thinker of u is tired at the time of u in the world of u’, then I have referred to myself under the descriptive-relational mode of presentation ‘the utterer/thinker of u’.

Every object of thought is referred to under such a descriptive-relational mode of presentation which exploits the object’s relation to u. But what about u itself ? Under which mode of presentation is it referred to ?

Page 39: Indexical thought

‘‘This very occurrence’This very occurrence’One option for the reflexivist is to say that u is thought

of as ‘this occurrence’, where ‘this’ is understood reflexively (‘this very…’)

But such a reflexive mode of presentation cannot itself be given a descriptive-relational analysis.

If ‘this occurrence’ were analysed as ‘the occurrence that is identical to this’, we would be using the analysandum, namely the reflexive ‘this’, in the analysans. If it were analysed as ‘the occurrence that is identical to u’, we would be back to where we started and would still be in need of a mode of presentation for u.

Page 40: Indexical thought

An alternative: Super-direct An alternative: Super-direct referencereferenceReminiscent of Russell’s strong notion of

acquaintance (with ourselves and our sense data).

In super-direct reference, there is no mode of presentation. The object itself is directly recruited as a thought constituent.

This of course cannot be done with many objects, but with mental occurrences arguably it can.

Page 41: Indexical thought

Super-direct referenceSuper-direct reference

Super-direct reference is supposed to be ‘transparent’ (in contrast to ordinary direct reference): under super-direct reference, no Frege cases are possible.

The idea of super-direct reference tends to surface in discussions of phenomenal concepts. See e.g. Chalmers’s statement that, in the phenomenal case, ‘the referent of the concept is somehow present inside the concept’s sense in a way that is much stronger than in the usual case of direct reference’ (Chalmers 2003).

Page 42: Indexical thought

Reflexivism in Lewisian clothesReflexivism in Lewisian clothes

This idea can be couched in Lewis’s framework, by externalizing the occurrence u and letting it be directly provided by the context. Everything is then described relative to u, but u itself is given, it is not represented.

In this framework as in Lewis’s:(i) acquaintance relations are internalized : relational

descriptions provide the modes of presentation under which objects are thought of.

(ii) there is an exception : the occurrence in terms of which everything (else) is descriptively characterized!

Page 43: Indexical thought

Reflexivism in Lewisian clothesReflexivism in Lewisian clothes

On this mixture of the two frameworks (centered worlds and reflexivism):

• The content of a mental occurrence is a property of occurrences.

• That content is evaluated with respect to a contextual index containing the occurrence itself.

Page 44: Indexical thought

Reflexivism in Lewisian clothesReflexivism in Lewisian clothes

To judge something by assertively tokening a certain representation is to ascribe to the token the property that is its content.

Here reflexivity is guaranteed by the pragmatic architecture of the act of judgment.

When you think ‘I am tired’, the content of the thought is the property an occurrence has just in case the thinker of that occurrence is tired at the time of the occurrence in the world of the occurrence. To think the thought (or to think it assertively) is to ascribe that property to the current occurrence u you are producing.

Page 45: Indexical thought

Problems with the view (the Problems with the view (the same as for the Lewis picture)same as for the Lewis picture) Descriptivism: Everything is thought of

descriptively, except for a single element which is externalized and serves as universal anchor for all the content.

Dramatic asymmetry between different objects of thought, i.e. between the universal anchor and the rest, motivated by some kind of extreme Cartesian picture. (The mind’s transparent access to itself serves as the foundation for all our knowledge.)

Page 46: Indexical thought

My pictureMy picture

• Objects are thought of (either descriptively or) under modes of presentation which are mental files.

All objects -- so no asymmetry!• Mental files are based on acquaintance

relations, but to think of an object through a mental file you don’t have to think of the relation on which the file is based. No descriptivism!

Page 47: Indexical thought

Attunement (Perry)Attunement (Perry)

Objection: Acquaintance relations are not external to the mind. We we are ‘attuned’ to the relations which determine what we’re thinking about. Yes but:

‘‘there is a difference between being able to there is a difference between being able to think of a thing or person in virtue of some think of a thing or person in virtue of some role it plays in one’s life, and being able to role it plays in one’s life, and being able to articulate that role in thought or speech and articulate that role in thought or speech and think of it as the thing or person playing think of it as the thing or person playing that role in one’s lifethat role in one’s life’ (Perry 1997)’ (Perry 1997)

Page 48: Indexical thought

Reflexivism without Reflexivism without DescriptivismDescriptivismTo protect Reflexivism from the charge To protect Reflexivism from the charge

of Descriptivism, one can introduce (as of Descriptivism, one can introduce (as Perry actually does) a multi-level Perry actually does) a multi-level framework, with the reflexive content framework, with the reflexive content occurring at one level and the referential occurring at one level and the referential content at another.content at another.

Then one can say that the reflexive Then one can say that the reflexive content is not represented even though content is not represented even though the ‘attunement’ relation holds.the ‘attunement’ relation holds.

Page 49: Indexical thought

Getting rid of DescriptivismGetting rid of Descriptivism

The recipe:

• go two-dimensional• distinguish between two distinct ‘grasping’

relations.

Attunement counts as the grasping relation appropriate to reflexive content (vs referential content)

Page 50: Indexical thought

Attunement againAttunement again

‘‘Attunement to the relation that our self-notions have Attunement to the relation that our self-notions have to ourselves, or our perceptions have to the object to ourselves, or our perceptions have to the object they are of, does not require belief or thought they are of, does not require belief or thought about the relation ; it requires know-how, not about the relation ; it requires know-how, not knowledge thatknowledge that’ (Perry 2012 : 99).’ (Perry 2012 : 99).

It’s a matter of function or role.It’s a matter of function or role.- Function of role of - Function of role of what?what?- How can we answer that question without bringing

the vehicles into the picture? (Indeed, Perry himself appeals to mental files: they are ultima-tely the tokens in his token-reflexive framework.)

Page 51: Indexical thought

ConclusionConclusion

No clear alternative to the mental fileNo clear alternative to the mental file framework.