The case of the probability of dysfunction

Françoise Longy (IHPST)

Plan

• The origin of the question

• The PHYS and ART proba of dysfunction

• Can ART proba be seen as chances ?– Intuitively– Theoretically :

Artefact kinds as non-physical(NP) real kinds

• Probabilities grounded in NP real kinds

• How to present the ART proba of dysfunction?

Origin of the question: Characterisation of function

X has function F only if : X has an (objective) property O such that:

a) X is there because of Ob) Because of O, X has proba q of doing F

X has proba p (p=1-q) to malfunction

Origin of the question: Characterisation of function

X has function F only if : X has an (objective) property O such that:

a) X is there because of Ob) Because of O, X has proba q of doing F

X has proba p (p=1-q) to malfunction

Organisms and artefacts

Origin of the question: Characterisation of function

X has function F only if : X has an (objective) property O such that:

a) X is there becausebecause of O

b)b) BecauseBecause of O, X has proba q of doing F X has proba p (p=1-q) to

malfunction

Origin of the question: Characterisation of function

X has function F only if : X has an (objective) property O such that:

a) X is there becausebecause of O

b)b) BecauseBecause of O, X has proba q of doing F X has proba p (p=1-q) to

malfunction

BecauseBecause = a causal because

Origin of the question: Characterisation of function

X has function F only if : X has an (objective) property O such that:

a) X is there becausebecause of O

b)b) BecauseBecause of O, X has proba q of doing F X has proba p (p=1-q) to

malfunction

BecauseBecause = a causal becauseThe probability is grounded in some objective feature of the world

Origin of the question: Characterisation of function

X has function F only if : X has an (objective) property Oproperty O such that:

a) X is there because of Obecause of O

b)b) Because of OBecause of O, X has proba q of doing F X has proba p (p=1-q) to

malfunction

OO = ???The probability is grounded in some objective feature of the world

Which probability is pertinent relative to the function/dysfunction distinction?

The DYSF-PHYSPHYS-proba of X ?The probability that the physical structure instantiated by X might not do F

No

X = a coffee machine, a light-bulb, … coming out of the factory

Which probability is pertinent relative to the function/dysfunction distinction?

The DYSF-ART-ART-proba of X ?The probability that X, which has been made in a bulb factory, might burn out after 5 minutes of normal use

YES

? ≠ DYSF-ART-ART and DYSF-PHYS-PHYS probabilities

DYSF-ART-ART : : the probability that X might possess (inherited) a physical make-up incapable of doing F

DYSF-PHYSPHYS : The probability that the physical structure instantiated by X might not do F

• The PHYS-proba as chances ? –No particular problem

• The ART-proba as chances ?–???

ART-Proba as chancesintuitively

• Great importance of the quality of the production

• Two opposite factors : cost/quality of production

• Market definite value of p

• The assembly-lines (machines, work procedures, control mechanisms, …) are continuously planned, verified and adjusted to maintain a stable p

X = a bulb coming out from a production plant

The probability p that X will be defective

ART-Proba as chancestheoretical arguments

Two ways of considering X

a) X as a physical object

b) X as an item of artefact kind

Physical properties/functional properties- a≠b multirealizability

- b is not definable in physical terms

ART-Proba as chancestheoretical arguments

Two ways of considering X

a) X as a physical object

b) X as an item of artefact kind

Physical properties/functional properties- a≠b multirealizability

- b is not definable in physical terms

b irreducible to a

to have a function ≠ to have a capacity

= a historical property

Organisms, = kinds defined by historical relations functional kinds

Artefact kinds and Biological species are :• historical real kinds (Millikan)• NPNP (non physical) real kindreal kind

A NP real kind

• Physical real kind (paradigm water, gold ..)A common physical micro-structure explains

• High number of universally shared properties

• NP real kind (paradigm lion, Renault 4 ..)

External mechanisms explain • Historical continuity between members

• High number of partially shared properties

A NP real kind

• Physical real kind (paradigm water, gold ..)A common physical micro-structure explains

• High number of universally universally shared properties

• NP real kind (paradigm lion, Renault 4 ..)

External mechanisms explain • Historical continuity between members

• High number of partiallypartially shared properties

1. Largely shared (Boyd, Millikan)2. Determinate proportion

A NP real kind

• Physical real kind (paradigm water, gold ..)A common physical micro-structure explains

• High number of universally shared properties

• NP real kind (paradigm lion, Renault 4 ..)

External mechanisms explain • Historical continuity between members

• High number of partially shared properties

1. Largely shared (Boyd, Millikan)2.2. Determinate proportionDeterminate proportion

Types of real kinds and

types of causes

– A physical real Kind : gold (yellow, …)

– A NP real Kind : corks (red crests, …)

Proximate and Ultimate causes

• The physiological proximate cause– Because it has such genetic code

• The evolutionary ultimate cause– Because he has inherited a cork genetic code

Why his genetic code gave rise to a red crestWhy he inherited the capacity to grow a red crest

Why has this cork a red crest ?

NP Real Kinds and probabilities resulting from ultimate causes

• Not all probabilistic properties are concerned– Only those resulting from mechanisms elected for

regulating a particular ratio

• The probability of being a female(organism)– Selected mechanisms regulate the male/female ratio

• The probability of dysfunction (artefact)– The proportion of defective items in regulated by

• Factory mechanisms

• Firm mechanisms

• The Market mechanisms

What nature hasthe DYSF-ART probability ?

It is not a real frequency– it does not result from statistical data concerning

the actual population of Xs– It corresponds to the ratio of defective items a

series of mechanisms (at factory, firm or market level) tends to produce under normal conditions

– Frequency in the actual population may differ from the one grounded in the NP-real kind mechanisms

The probability that an artefact item is defective

How to qualifythe DYSF-ART probability ?

It measures something like a propensity – It measures an objective feature of the world which is not a

frequency

However, speaking of propensity is odd – An item X could then have 2 ≠ propensities of doing F

X could have the physical propensity pphysical propensity p to do F, but the real real kind propensity qkind propensity q (q≠p) to do F !

– it is not a tendency rooted in what the item is all by itself

The probability that an artefact item is defective

How to qualifythe DYSF-ART probability ?

It is rather a property at kind (population) level– If a tendency is involved, it is a tendency rooted in the factory (firm

or market) mechanisms

However, calling it simply a frequency is misleading– The objective fact it refers to is not an effective frequency in a real

population– It is the frequency that an actual series of mechanism, involved in

maintaining a NP real kind's unity, tend to produce

Should we then say something like

"ideal frequency NP real kind mechanisms tend to produce"?

The probability that an artefact item is defective