To: Walter F.
From: Geoffrey Klempner
Subject: Mind-body problem and the concept of identity
Date: 28 September 2005 10:50

Dear Walter,

Thank you for your email of 14 September, with your second essay for the Philosophy of Mind program, in response to the question, 'What is identity? What is the relevance of a definition of identity to the problem of the relation between mind and body?'

Although rather short and condensed, this is a well thought out essay which manages to touch on many key issues surrounding the question of the proposed 'identity' between mind and body.

'You say, There are no identity criteria that allow us to say that mind and body are either entirely separate or entirely the same.' - The first question to ask is, what exactly is a 'criterion of identity' (or what are 'criteria of identity')? Why do we need identity criteria when there is a perfectly good logical definition of identity in the formula, 'A=B if and only if everything true of A is true of B and vice versa' (Leibniz Law)?

One can assert the 'identity' of anything with anything. Make up whatever concepts you like. My ear and the moon. If my ear is the moon then everything true of my ear is true of the moon and vice versa. The fact remains that nothing that Neil Armstrong did in his famous moon walk has any discoverable relation to the state of my ear, nor is a rock circling the world a quarter of a million miles away affected in any way when I get earache.

More to the point - and this is where Wittgenstein's considerations on language become relevant - there is no way anyone could learn the concept 'my ear and the moon' without first acquiring the concepts 'ear' and 'moon' and then artificially sticking the two together to make a composite 'object'.

In a similar way, putting 'my sensation of red' and 'brain event E' together and calling it a single 'mental event' does not make one out of two. Nothing turns on the distinction (as you note) between an ever-so-close relationship between my sensation of red and brain event E, and the identity of my sensation and the brain event. In other words, asserting 'identity' is just an empty mouthing of words.

In these terms, it looks as though we have no choice but to embrace some form of dualism. The assertion of 'identity' is empty, meaningless.

However, something you say in your last paragraph points to a different solution. It is one thing to talk of 'mind' and 'body'. It is perfectly reasonable to take the view that psychology (the science of minds) is irreducible to physics (the science of bodies). The different scientific disciplines cut up the world in different ways, but this is fully consistent with saying that all that ultimately exists are physical entities. As a simple illustration of non-reducibility, there is no physical explanation, in terms of atomic structure, why you can't put a square peg in a round hole.

It is something entirely different when we identify mind with peculiar 'objects' like 'my red sensation'. It does not follow from the fact that people enjoy sensations of red, that there exist 'mental objects' which can be identified in a Cartesian manner independently of how things are in the physical world. The point of Wittgenstein's argument against a private language is that there are no such 'private objects'. There are only statements that we make, whose truth conditions necessarily refer to both first- and third-person criteria, to what both I and others are able to know.

If there are no ontologically independent 'mental objects' then the question of the identity or non-identity of such objects with physical objects or events does not even arise.

That is where many philosophers would leave the problem. Of course, the Wittgensteinian move does not save us from the hard work of explaining how the mental arises from the physical. However, I am thinking of a different problem. Granted that the phenomenon of consciousness as such can be 'explained' (as Dennett believes) there remains the seemingly intractable question of what it means to have THIS unique point of view, what it means to *be* GK, or WF, or TN. In other words, Nagel's problem of the meaning of 'I'.

I have struggled with this in my book Naive Metaphysics, and also towards the end of the Philosophy of Mind program. But I don't have a 'solution'. It seems to me that there is no room for a 'theory' here. There is nothing to 'explain'. There is only the sheer inexplicable fact - as Descartes recognized but perhaps failed to see the full significance of - that I exist.

All the best,

Geoffrey