Posted by: Xhyra Graf | 28 January 2007

Identity Theory of Mind

 The identity theory of mind holds that states and processes of the mind are identical to states and processes of the brain. Strictly speaking, it need not hold that the mind is identical to the brain. Idiomatically we do use ‘She has a good mind’ and ‘She has a good brain’ interchangeably but we would hardly say ‘Her mind weighs fifty ounces’. Here I take identifying mind and brain as being a matter of identifying processes and perhaps states of the mind and brain. Consider an experience of pain, or of seeing something, or of having a mental image. The identity theory of mind is to the effect that these experiences just are brain processes, not merely correlated with brain processes.

 In taking the identity theory (in its various forms) as a species of physicalism, I should say that this is an ontological, not a translational physicalism. It would be absurd to try to translate sentences containing the word ‘brain’ or the word ‘sensation’ into sentences about electrons, protons and so on. Nor can we so translate sentences containing the word ‘tree’. After all ‘tree’ is largely learned ostensively, and is not even part of botanical classification. If we were small enough a dandelion might count as a tree. Nevertheless a physicalist could say that trees are complicated physical mechanisms. The physicalist will deny strong emergence in the sense of some philosophers, such as Samuel Alexander and possibly C.D. Broad . The latter remarked (Broad 1937) that as far as was known at that time the properties of common salt cannot be deduced from the properties of sodium in isolation and of chlorine in isolation. (He put it too epistemologically: chaos theory shows that even in a deterministic theory physical consequences can outrun predictability.) Of course the physicalist will not deny the harmless sense of “emergence” in which an apparatus is not just a jumble of its parts (Smart 1981).

7. Consciousness

Place answered the question ‘Is Consciousness a Brain Process?’ in the affirmative. But what sort of brain process? It is natural to feel that there is something ineffable about which no mere neurophysiological process (with only physical intrinsic properties) could have. There is a challenge to the identity theorist to dispel this feeling.

 For the full consciousness, the one that puzzles us and suggests ineffability, we need the sense elucidated by Armstrong in a debate with Norman Malcolm (Armstrong and Malcolm 1962, p. 110). Somewhat similar views have been expressed by other philosophers, such as Savage (1976), Dennett (1991), Lycan (1996), Rosenthal (1996). A recent presentation of it is in Smart (2004). In the debate with Norman Malcolm, Armstrong compared consciousness with proprioception. A case of proprioception occurs when with our eyes shut and without touch we are immediately aware of the angle at which one of our elbows is bent. That is, proprioception is a special sense, different from that of bodily sensation, in which we become aware of parts of our body. Now the brain is part of our body and so perhaps immediate awareness of a process in, or a state of, our brain may here for present purposes be called ‘proprioception’. Thus the proprioception even though the neuroanatomy is different. Thus the proprioception which constitutes consciousness, as distinguished from mere awareness, is a higher order awareness, a perception of one part of (or configuration in) our brain by the brain itself. Some may sense circularity here. If so let them suppose that the proprioception occurs in an in practice negligible time after the process propriocepted. Then perhaps there can be proprioceptions of proprioceptions, proprioceptions of proprioceptions of proprioceptions, and so on up, though in fact the sequence will probably not go up more than two or three steps. The last proprioception in the sequence will not be propriocepted, and this may help to explain our sense of the ineffability of consciousness. Compare Gilbert Ryle in The Concept of Mind on the systematic elusiveness of ‘I’ (Ryle 1949, pp. 195-8).


 Smart, J. J. C., “The Identity Theory of Mind”, The Stanford Encyclopedia of Philosophy (Fall 2004 Edition), Edward N. Zalta (ed.), URL =




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