To: Robert D.
From: Geoffrey Klempner
Subject: Identity and the mind-body problem
Date: 22 January 2002 12:20

Dear Bob,

Thank you for your e-mail of 5 January, with your second essay for the Philosophy of Mind program, discussing the claim, 'Whereas one could trace a path from the Morning Star to the Evening Star, or from the North side of Everest to the South side, there is no path one could trace from the inside of the mind to the outside.'

First of all, please accept my apology for keeping you waiting more than two weeks for my reply. I have no excuse, other than the difficulty of getting my mind into gear after the Christmas/new year break!

In your essay, you describe two hypotheses about the causal connection between panic attacks and physiological changes in the body, and how the hypotheses might be tested.

As you describe it, it seems highly plausible that one could, in principle, through close physical examination determine whether the observed physical changes are the trigger for panic attacks, or whether, on the contrary, the panic attacks cause the observed changes.

The first thing to note here is that it is not necessary for the researchers to have any views about the philosophical debate between materialism or mind-body identity theory, and mind-body dualism, provided that the supporters of the dualist theory accept the truth of 'epiphenomenalism': that the causation between physical events and mental events is always one-way, from physical to mental.

The materialist and epiphenomenalist brain researchers might discover that physical changes in the body cause the events in the brain which lead the subject to report a panic attack; or they may discover that it is events in the brain which cause the changes in the body. Their views about the metaphysics of the mind-body problem have no role to play.

As you rightly conclude, the final, definitive experiment still leaves the question of materialism vs. dualism open.

The reason is that the experimental 'path tracing' had nothing to do with the question of discovering identity/ difference. What we are dealing with is two quite different notions of 'tracing a path'. In the described experiment, what is at stake is the account of causes and effects. In the case of verifying identity claims, what is at stake is something quite different. In a non-metaphysical case, such as the discovery that the Evening Star is the same heavenly body as the Morning Star, what is discovered is that *if* you were to take up an ideal vantage point (e.g. by travelling by rocket into space) then you would discover that the two aspects are aspects of one and the same object. In the metaphysical case, however, there is no ideal vantage point, no ideal path that one can trace. That is because, as you rightly note, there is a fundamental discontinuity between the subjective and the objective views, that arises from 'our intimate knowledge of ourselves, of our own mental states'.

Ought we to conclude then, that the claim of mind-body identity cannot be upheld, on the grounds that, in the absence of any account of what it would *mean* to trace a path between the subjective and objective standpoints, - i.e. give a single vantage point which brought both standpoints into a single view - no sense can be given to the claim of identity?

The non-dualist has a response to this: namely to question whether in fact there is such a thing as 'subjective knowledge of one's own mental states' that cannot be accounted for in objective terms. This is the upshot of Wittgenstein's private language argument.

In other words, the argument that starts with the quote, 'Whereas one could trace a path..' fails because there are not two views, the view from the 'outside' and the view from the 'inside'. In my self-knowledge, in my knowledge of my own mental states, objective knowledge of the world and my place in it is intricately woven in a way that cannot be factored out to produce a purely 'inner' knowledge to set against 'outer' knowledge that is available to others.

You might, however, be interested to look at my paper 'Truth and Subjective Knowledge' at:

http://sophist.co.uk/glasshouse/documents/shap.html

In this paper, I try to vindicate *a* sense of subjective knowledge which is consistent with Wittgenstein's rejection of a private language. However, it turns out that this sense of subjective knowledge is full acceptable to the materialist.

All the best,

Geoffrey