causal theories of mental representation
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Causal Theories of Mental Representation. recap. Metasemantics. A theory of mental representation tells us: “Why [in virtue of what] do mental representations have the contents they do, rather than some other content, or no content at all?”. Last Time. - PowerPoint PPT PresentationTRANSCRIPT
Causal Theories of Mental Representation
RECAP
Metasemantics
A theory of mental representation tells us:
“Why [in virtue of what] do mental representations have the contents they do, rather than some other content, or no content at all?”
Last Time
Idea theory: mental representations are ideas– little colored pictures in the mind.
Resemblance theory: the ideas represent what they resemble
Problems for Resemblance Theory
1. Can’t distinguish concepts and propositions.2. Resemblance is an equivalence relation,
representation is not.3. Resemblance is in some ways more and in
some ways less determinate than representation.
4. Even photos and paintings don’t represent what they resemble.
CAUSAL THEORIES: MOTIVATION
The Success of Causal Theories
• Knowledge (Dretske): X knows proposition P = the information that P causes X to believe P.
• Action (Goldman): X performs action A = X’s beliefs and desires cause A.
• Perception (Grice): X perceives object O = O causes an experience in X.
• Representation?
Motivations
Why think causation has anything to do with mental representation?
The Mirror Universe
Secondary Qualities
Possibility of Massive Error
Causation has the Right Structure?
Representation Resemblance CausationNon-reflexive Reflexive IrreflexiveAsymmetric Symmetric AntisymmetricIntransitive Transitive Transitive
THE CRUDE CAUSAL THEORY
Crude Causal Theory
Attempt #1: Mental representation R represents object [property] O in virtue of the fact that O causes R.
Proximal Causes
The Disjunction Problem
Horse!
Robustness
Causes
Robustness
Represents
RESTRICTING CONDITIONS
Restricting Conditions
A common direction for solving problems with the crude causal theory is to find a value for C:
Mental representation R represents object [property] O in virtue of the fact that O causes R under conditions C.
Dretske (1981)
Mental representation R represents object [property] O in virtue of the fact that O causes R during the initial learning of R.
Initial Learning
Horse!
Subsequent Experience
Horse!
Problems
First off, there probably isn’t a defined learning period for our concepts. But this isn’t the worst problem Dretske’s idea faces…
The Qua Problem
When Scotty learns HORSE, the things that cause him to think HORSE are all:
• Mustangs on Johnson’s farm• Horses• Animals• Physical objects
Causal Theory vs. Qua Problem
The crude causal theory says that anything that would cause HORSE is a horse. So HORSE doesn’t mean “animal” because many animals would not cause HORSE. And it doesn’t mean “quarter horse on Johnson’s farm” because many things other than quarter horses on Johnson’s farm would cause HORSE.
Dretske vs. Qua Problem
Dretske can’t say this!
He can’t say anything that would cause HORSE during the learning period counts as a horse.
Why? Because cows-on-a-dark-night would cause HORSE!
THE TELEOLOGICAL THEORY
Biological Functions
• The heart has the biological function of pumping blood.
• The polar bear’s coat has the biological function of being white.
• Chlorophyll has the biological function of synthesizing sugars from CO2, H2O, and light.
Not Biological Functions
• The heart does not have the biological function of making a thump-thump noise.
• The polar bear’s coat does not have the biological function of being heavy.
• Chlorophyll does not have the biological function of making plants green.
Biological Functions
F is the biological function of trait T := organisms that now possess T do so because their ancestors had T’s that performed F.
Normal Conditions
Traits don’t always perform their biological functions.
The conditions under which they do perform their functions we call Normal conditions.
The Teleological Theory
Mental representation R represents object [property] O in virtue of the fact that O causes R in Normal conditions.
Normal Conditions
Horse!
AbNormal Conditions
Horse!
AbNormal?
AbNormal?
Causes
Teleological Theory
Score:
Proximal Stimulus ProblemDisjunction ProblemHandles Robustness
THE ASYMMETRIC DEPENDENCE THEORY
The Disjunction Problem
Horse!
Causes
Causes
Jerry Fodor
Fodor wants us to consider the hypothetical scenario where horses do not cause you to think “Horse!”
Horses Don’t Cause “Horse!”
Horse!
Causes
Causes?
Horses Don’t Cause “Horse!”
Fodor argues that cows cause you to think “Horse!” only because you mistake them for horses.
But if horses can’t cause you to think “Horse!” clearly “Horse!” doesn’t represent horses. So even if you mistook a cow for horse, that wouldn’t make you think “Horse!”
Horses Don’t Cause Horse
Horse!
Causes
Causes
Horses Don’t Cause Horse
Horse!
Causes
Causes
Depends
Jerry Fodor
Fodor now wants us to consider a new hypothetical scenario.
In the new scenario cows on a dark night (C.O.A.D.N.) do not cause Scotty to think “Horse!”
C.O.A.D.N. Don’t Cause “Horse!”
Horse!
Causes
Causes
?
C.O.A.D.N. Don’t Cause “Horse!”
If cows on a dark night don’t cause “Horse!” what’s going on?
Presumably, you have better eyesight and can see that it’s really a cow.
C.O.A.D.N. Don’t Cause “Horse!”
But does this mean horses won’t cause “Horse!”? Of course not!
Just because your eyesight gets better does not mean you can’t recognize a horse as a horse!
C.O.A.D.N. Don’t Cause “Horse!”
Horse!
Causes
Causes
✓
C.O.A.D.N. Don’t Cause “Horse!”
Horse!
Causes
Causes
Does Not Depend
Asymmetric Dependence
We can say that the causal connection between cows-on-a-dark-night and “Horse!” asymmetrically depends on the causal connection between horses and “Horse!”
The first connection requires the second, but not vice versa.
Asymmetric Dependence Theory
Concept C represents property P in virtue of the fact that(i) Things with P cause C(ii) Things without P that also cause C only cause
C because things with P cause C, and not vice versa.
Asymmetric Dependence Theory
The concept “Horse!” represents the property of being a horse in virtue of the fact that(i) Horses cause “Horse!”(ii) Non-horses that also cause “Horse!” only
cause “Horse!” because horses cause “Horse!,” and not vice versa.
RobustnessCauses
Causes
Why doesn’t “pepper” mean pepper-or-“salt”?
Proximal Stimuli
Why doesn’t “dog” mean dog-or-doggy-image?
Causes
Causes
Proximal StimuliCausesBark!
Hit on the Head with a Hammer
There’s one objection that Fodor cannot answer however. I call it the “hit on the head with a hammer” objection.
Suppose there’s a particular part of your head where, if I hit it, you will think of a penguin.
Hammer Objection
Causes
Causes