Friday, May 4, 2012

Functionalist view of the mind and Arnaud's objection

To: Victor L.
From: Geoffrey Klempner
Subject: Functionalist view of the mind and Arnaud's objection
Date: 9 August 2007 13:41

Dear Victor,

Thank you for your email of 3 August, with your essay, 'First and Second Order of Consciousness'.

First of all, you need to correct the quote: the reference is to 3.0321 not 6.0321 as given! (Wittgenstein returns to the question of systems of representation in the 6's - I spent a while looking in vain for the quote until it occurred to me that it came from earlier on.)

There seem to be all the materials for a very good Associate essay here. However, the argument is rather condensed and the essay could certainly benefit from being expanded to something closer to the 2000-2500 target length.

I'll start with points that seem to me reasonably clear.

The general principle behind Arnaud's objection is one Descartes would fully agree with. What we imagine may not, in reality, be a state of affairs that can be realized. Imagination is not a sure guide to what is conceivable or not conceivable. That is one of the lessons from the experiment with the beeswax.

If Descartes' case for dualism were simply that he (Descartes) can imagine his mind existing in the absence of his body, then Arnaud's objection would be crushing. But that is not Descartes' argument. His case is built on the assumption that it is logically possible that - there is a possible world in which - my experiences/ perceptions are exactly as they are now but no material objects exist. The basis for that claim is the incorrigibility of the mental, my certain knowledge of how things seem to me now, which cannot be overturned by any factual consideration.

If dualism is rejected, then there must be an illusion here - as I believe there is, and as exposed by Wittgenstein's argument against the possibility of a private language.

That is not the case you are making. Your idea seems to be that there is a possibility (and it is only a possibility at the present state of human knowledge) that we could come to understand how the brain works sufficiently well to *see* - just as one sees the truth of the Pythagorean theorem when the appropriate construction line is drawn - how the processes which take place in the brain perfectly capture the 'pattern' of the mind: in Tractarian terms, in reproduce it in a different form but the same 'logical multiplicity' - just as with the music, the musical notation, the grooves in the gramophone record etc. etc.

This is the thesis of functionalism. One drawback with this is that it seems to offer a 'hostage to fortune' in respect of its assumption that we will succeed one day in unravelling the brain. Maybe the connectionists are right and we won't. In that case, you could still assert the claim about patterns but with little to back up that assertion. How strong would your argument be then? Is it enough to point out that Descartes has not proved the negative, which is what he is required to do, namely that the mind cannot be a mere 'pattern' in your sense?

An anti-reductionist (and anti-functionalist) would argue that the language of the mental is ultimately the only way to describe the physical states of affairs that obtain in the brain. This is perfectly consistent with the point about forms of representation, and also consistent with materialism.

The other things you want to say about the mind also follow. The idea that a brain thinks, feels, deliberates is nonsensical. To talk about something which thinks, feels and deliberates is to talk about a system - the human agent - and the brain is just one of the component parts of that system.

But it doesn't prove materialism. Leaving aside the question of the validity of his argument, Descartes might still be right. Maybe, as Descartes thinks, there is the physical realm and the mental realm, and the 'patterns' that are represented in the language of the mental are not repeated in the physical realm. They don't need to because they are the very essence of the soul, qua non-physical 'substance'. The brain is just a relatively crude (only relatively) relay mechanism, conveying impulses from the soul.

It is, however, consistent with this interpretation to hold (as in Christian theology) that the possibility of 'life after death' is necessarily and not contingently equivalent to the possibility of 'resurrection' - in other words, the system 'self' (or, 'Descartes') can only exist if there is something that plays a role analogous to the role that the human body plays. A disembodied, naked 'soul' is not a 'self'.

What would be sufficient to show that Descartes is wrong (i.e. demonstrate that dualism is false)? Do we have to wait until we understand the brain better (until we can prove, beyond a shadow of a doubt, that it does not function as a mere relay mechanism?).

Or, failing that, what would be sufficient to show that Descartes' argument for dualism is invalid? If you take the Arnaud line, Descartes will just reply that you are begging the question. That's why I think the materialist has no alternative to attacking the incorrigibility assumption head on.

All the best,