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
