Friday, September 9, 2011

Difficulties for a materialist view of the mind

To: George T.
From: Geoffrey Klempner
Subject: Difficulties for a materialist view of the mind
Date: 28 October 2004 10:59

Dear George,

Thank you for your email of 19 October and also for your email of 28 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?'

I was curious about what you intended to establish in the first paragraph, 'the experience of mind functions all over the body... so the mind can be said to be present all over the body.' Suppose the essay question had been, 'Blah blah... processes in a physical body.' Is that all that would be required to meet this difficulty?

Consider the well documented case of phantom limbs. Someone who had never heard of the phantom limb phenomenon before might indeed find it hard to believe that a subject could experience pain in a leg that wasn't there, a pain located apparently in empty space. There is a conceptual difficulty here, but it is easily overcome. The spatial location of the physical cause of a sensation does not necessarily coincide with its apparent location from the subject's point of view. Extending this, it seems at least logically possible that a head separated from its body and kept alive might, with suitable stimulation of the brain undergo the experience of 'having a body'.

After a discussion of Plato and Aristotle, you go on to say that dualism is given an 'initial plausibility' because we have 'difficulty understanding how a purely physical thing, such as the brain, could give rise to the complex patterns of feeling and thought which we call consciousness.' What kind of difficulty is this, exactly? Suppose someone was shown a television set for the first time and told that on the screen were images of events happening now, many thousands of miles away. There would be difficulty comprehending how such a thing could be possible, a difficulty which can be overcome by a careful explanation of how television works (it might be quite a long explanation, if the questioner has no knowledge of physics).

Yet it seems that this is not the kind of difficulty we face when confronted with the claims of materialism. Having learned what an amazing organ the brain is and what it can do, we are still not convinced, because there is a philosophical difficulty here, not just lack of knowledge.

I liked your account of Descartes' argument for mind-body dualism in Meditation 6, and his speculations about the pineal gland in The Passions.

There are two points to make here. A crucial claim made in the argument of Meditation 6 is, as you say, mind and body 'are capable of being separated, at least by God'. Why does Descartes think he is entitled to assert this? Certainly not on the basis of popular belief, since it is the idea that soul is separable from body which he is seeking to provide a logical argument for. The claim is in fact based on the thought experiment conducted in Meditation 1, where Descartes considers the possibility that he is being deceived by an evil demon into thinking that a physical world exists. My thoughts, feelings and sensations would be just as they are now if, instead of my being located in a physical world, my mental states were caused directly by an 'evil demon'.

You are careful to talk of the 'localisation of the soul's contact with the body in the pineal gland'. It would not be correct to say that, for Descartes, the soul is located in the pineal gland, because the property of spatial location is not consistent with the properties which essentially characterize the soul. The Cartesian soul has no spatial dimensions, nor is it spatially located. (In Meditation 1, Descartes scornfully rejects popular notions of the soul as 'a breath of wind, a vapour'.)

Although the essay does not explicitly ask for this, we might consider how serious the difficulties raised are. As we have seen, the first difficulty, concerning location of sensations around the body, does not seem on reflection to pose a serious challenge to materialism.

More needs to be said about the 'initially plausible' difficulty of conceiving how consciousness could consist of brain processes, in order to show why it is a philosophical or conceptual difficulty, not just lack of knowledge which can be remedied by going to the text books.

The third difficulty, which you seem to lay most weight on, is the challenge posed by Descartes' argument for mind-body dualism. Is the argument valid? or might there be a way for the materialist to challenge the argument? Something to think about.

An excellent first essay, well done!

All the best,

Geoffrey