Presentation on theme: "Causal Theories of Mental Representation. RECAP Metasemantics A theory of mental representation tells us: “Why [in virtue of what] do mental representations."— Presentation transcript:
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.
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?
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.
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!
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 CO 2, H 2 O, 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.
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!”
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 ?
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 ✓
C.O.A.D.N. Don’t Cause “Horse!” Horse! 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.
Robustness Causes Why doesn’t “pepper” mean pepper-or-“salt”?
Proximal Stimuli Why doesn’t “dog” mean dog-or-doggy-image? Causes
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.