Tuesday, November 6, 2012

Difficulties for a materialist view of the mind

To: Andy R.
From: Geoffrey Klempner
Subject: Difficulties for a materialist view of the mind
Date: 30th October 2008 11:26

Dear Andy,

Thank you for your email of 25 October, with your first essay for the Possible World Machine, in response to the question, 'What difficulties stand in the way of a materialist view of the mind, according to which thoughts, feelings and sensations are ultimately nothing more than processes in the brain?'

You start off by making a statement which has important consequences for what follows. You say, 'The philosophy of materialism asserts that the only thing that can be truly proven to exist is matter.'

This undoubtedly describes one class of materialist: the kind of materialist who, looking at the great success of science, argues that by the principle of Occam's Razor (the principle that we should not multiply hypothetical entities unnecessarily) it would be methodologically unsound to posit mental stuff in addition to material stuff. The most famous proponents of this view are the Australian materialists Armstrong and Smart.

Given what you say about the current lack of knowledge of how exactly processes in the brain give rise to mental phenomena, it might seem a little rash to make this claim. How can we be so sure, at this relatively early stage in the scientific investigation of mental phenomena, that we will not need to admit the existence of mental entities or forces in addition to material entities and forces? The Australians will counter that, given the current state of knowledge, materialism at least offers the prospect of scientific investigation of the mind.

Recent debates in the philosophy of mind have highlighted the problems with this view. The Australian materialists don't want to go so far as to claim that they can logically prove that there cannot be such a thing as mental stuff in addition to physical stuff; merely that materialism is the best theory. They want to assert the contingent identity between material and mental phenomena. The problem is that this seems to concede too much to the dualist, because it accepts, in principle, that in some possible world dualism *might* be true.

The basis for Descartes' argument for dualism, on the basis of the 'incorrigibility' of first-person reports which you describe (how my pains feel to me, how my qualia seem to me) is that things would seem to me just as they do now even if there was no material world and I was being deceived by an evil demon, the creator of my 'dream world'. The material and the mental might be ever-so closely correlated with one another in the actual world. Nevertheless, the evil demon thought experiment demonstrates that each has a different 'essence'. That is sufficient, in Descartes' view, to prove that they are indeed two and not one.

That is why philosophers seeking to resist dualism concentrate their attack on the Cartesian notion of incorrigibility. The case from science is not strong enough. The claim which you quote from McCafferty and Beebe is seen as a target for attack, rather than, as Descartes saw it, an indubitable axiom. This is where Wittgenstein's argument against the possibility of a 'private language' comes into play. However, the jury is still out on the question of the scope and effectiveness of Wittgenstein's argument.

You cite another source of difficulty for the materialist view, in Sartre's concept of the 'transcendence of the ego'. Consciousness can never observe itself as such. Whatever I may observe, the observing 'I' always escapes. If matter is 'all there is to be observed', then it would seem to follow from this argument that the 'I' cannot be matter. If the 'I' were merely matter, then in principle it would be there for observation.

If that is the argument, I am not sure that it is effective against materialism. Why is it assumed that matter is 'all there is to be observed'? Developments in physics, for example quantum mechanics and Heisenberg's Uncertainty Principle appear to contradict this view. Not all matter or states of matter can be observed. What is there for theory, what it makes sense to posit as the 'best explanation' of given experimental data is not necessarily there for possible observation, not even for beings with the sense organs of angels (a possibility which the philosopher Locke fancifully considers when he discusses Newton's 'corpuscularian hypothesis').

In other words, since physics has given up the idea of 'observability in principle', you can't argue against materialism on the grounds that a material 'I' would be unobservable.

One view, argued for example by Dennett in his book 'Consciousness Explained' is that the mind is related to the brain as software to hardware. The 'I' is just a program. There is no reason why one would be able to 'see' thought processes when one opens up a brain, any more than one can see what program a computer is running by opening up the case and looking at the circuit boards. This would meet the worry about the unobservability of mental phenomena. However, at the present time the belief that the mind can be 'reduced to a program' is merely an article of faith. Dualists can take some small comfort from that fact.

All the best,

Geoffrey