causal theories of mental representation

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