Brains, Persons, and Society *** ABSTRACTS
Cervelli, Persone e Società ***ABSTRACTS
Realizability and Identity
It is generally held that type-identity theories of mind have been definitively discarded by the multiple realizability argument. In this paper I would like to conditionally challenge this opinion. The multiple realizability argument, in fact, is generally taken to show that identity statements between mental properties (say, have pain) and their realizers (C-fibers firing) are not necessarily valid. These are contrasted with statements such as heat = molecular motion, which are taken as necessarily true. However, after briefly introducing the dialectics, I point out that these latter identity statements are subject to the same kind of multiple realizability.
On the one side, as already noticed by many authors, the concept of heat can be applied to different states of the matter (gases, solids, plasma, …) so engendering different “identities”; on the other hand, even if applied to a very specific state of the matter (say, gases), it is nevertheless multiply realized. Secondly, I argue that the way in which this problem can be fixed with respect to the purely physicalistic identity statements (heat = molecular motion) can be extended to mentalistic identities too, a solution originally advanced by Jaegwon Kim.
In particular, Kim holds that mental and physical properties are biunivocally correlated (a thesis weaker than identity) under the heading of a condition. The logical form of his correlation thesis is Sx→(Mx↔Px), that is, If x has structure S then x has Mental property iff x has Physical property. In the last part of my paper, I modify Kim’s definition both to buttress it toward identity and in order to avoid one difficulty concerning deviant causal chains. Having set all this, I will conclude that this is enough to vindicate the identity theory of mind.