Functionalism

1. Functionalism objections

2. Functionalism Something is a functional kindiff itcan be analyzed in terms of a causal role (e.g., something is an F iff it play the F-role). F is realized by P in X iff P plays the F-role in X. A property is multiply realizable iff it can be realized by different things in different objects.

3. The Pain Role The Pain Role: (1) An internal mental state, (2) typically caused by tissue damage, (3) which can result from kicking, burning, etc. and (4) which commonly causes crying, frowning, and whimpering, as well as (5) anger, the desire for it to stop, the belief that one is in pain, etc.

4. Functionalism Realizer Functionalism: Mental states are states that play a characteristic causal role. To be in pain is to be in the state that plays the pain role. Role Functionalism: Mental states are higher-order properties, like the property of having some state or other that plays the characteristic causal role. To be in pain is to be in some state or other that plays the pain role.

5. Preview In the previous chapter we noticed that mental states can be multiply realized. In humans the state which realizes pain is (say) c-fiber firing; in squid it’s (say) d-fiber firing. Multiple realization raises a puzzle: what do old Eight-legs and I have in common when we are both in pain? It can’t be c-fiber firing because Eight-legs has no c-fibers (or so I will assume). And it can’t be d-fiber firing because I have no d-fibers (or so I will assume). In virtue of what, then, is it true that Eight-legs and I are both in pain? Functionalism provides an answer to this puzzle. Ravenscroft, p.50.

6. Realizer Functionalism Pain = R. R = c-fiber firing. [So] Pain = c-fiber firing.

7. Realizer Functionalism Pain = R. In humans, R = c-fiber firing. [So] In humans, pain = c-fiber firing. Pain = R. In squids, R = d-fiber firing. [So] In squids, pain = d-fiber firing.

8. Realizer Functionalism The Relativized Identity Theory: Mental states are identical to physical states of the brain. To be in pain-for-humans is to have C-fibers firing, to be in pain-for-squids is to have D-fibers firing, to be in pain-for-Orkans is to have activity in silicon chip E, etc.

9. Realizer Functionalism Pain = R. In humans, R = c-fiber firing. [So] In humans, pain = c-fiber firing. Pain = R. In squids, R = d-fiber firing. [So] In squids, pain = d-fiber firing.

10. Realizer Functionalism Hamlet = H. In 1990, H = Mel Gibson. [So] In 1990, Hamlet = Mel Gibson. Hamlet = H. In 1996, H = Kenneth Branagh. [So] In 1996, Hamlet = Kenneth Branagh.

11. Realizer Functionalism The 1990 Hamlet = H in the 1990 movie. H in the 1990 movie = Mel Gibson. [So] The 1990 Hamlet = Mel Gibson. The 1996 Hamlet = H in the 1996 movie. H in the 1996 movie = Kenneth Branagh. [So] The 1996 Hamlet = Kenneth Branagh.

12. Realizer Functionalism Pain = R. In humans, R = c-fiber firing. [So] In humans, pain = c-fiber firing. Pain = R. In squids, R = d-fiber firing. [So] In squids, pain = d-fiber firing.

13. Realizer Functionalism Pain-in-humans = R in humans. R-in-humans = c-fiber firing. [So] Pain-in-humans = c-fiber firing. Pain-in-squids = R in squids. R in squids = d-fiber firing. [So] Pain-in-squids = d-fiber firing.

14. Realizer Functionalism The Relativized Identity Theory: Mental states are identical to physical states of the brain. To be in pain-for-humans is to have C-fibers firing, to be in pain-for-squids is to have D-fibers firing, to be in pain-for-Orkans is to have activity in silicon chip E, etc.

15. Role Functionalism Role Functionalism: Mental states are higher-order properties, like the property of having some state or other that plays the characteristic causal role. To be in pain is to be in some state or other that plays the pain role.

16. Role Functionalism Role Functionalism: Mental states are higher-order properties, like the property of having some state or other that plays the characteristic causal role. To be in pain is to be in some state or other that plays the pain role. The Disjunctive Identity Theory: Mental states are identical to physical states of the brain. To be in pain is to either be a human and to have C-fibers firing or to be a squid and to have D-fibers firing or to be an Orkan and to have activity in silicon chip E or…

17. Role Functionalism Functionalists have often touted the phenomenon of multiple realization as a basis for the claim that the properties studied by cognitive science are formal and abstract—abstracted from the material compositional details of the cognitive systems. What our considerations seem to show is that cognitive science properties so conceived threaten to turn out to be heterogeneous disjunctions of properties after all. And these disjunctions seem not to be suitable as nomological properties –properties in terms of which laws and causal explanations can be formulated. If this is right, it would disqualify mental properties, construed as second-order properties as serious scientific properties. -Kim, p.166

18. The Master Argument If Functionalism is correct, then either (a) Realizer Functionalism is correct, or (b) Role Functionalism is correct. If (a), then the Relativized Identity Theory is correct. The Relativized Identity is incorrect. If (b), then the Disjunctive Identity Theory is correct. The Disjunctive Identity Theory is incorrect. [So] Functionalism is incorrect.