To: Hakeem G.
From: Geoffrey Klempner
Subject: P.F. Strawson's criticisms of Cartesian dualism
Date: 8 February 2007 12:29

Dear Hakeem,

Thank you for your email of 30 January, with your University of London essay in response to the question, 'Explain and assess Strawson's reasons for thinking (i) a Cartesian is committed to thinking that a dualist reduction or analysis of the idea of a person is possible and (ii) that such a reduction or analysis is not possible.'

This is a good essay with which I have few real disagreements.

There's nothing to be embarrassed about in agreeing with a philosopher whose theory or claims you have been asked to critique. You have considered possible objections and responded to them, and you have given a reasonably clear exposition of the view in question. That's all you needed to do.

Of course, I am somewhat biased in my judgement here because I think that Strawson is right, at least in his negative criticisms of Cartesianism.

Elsewhere, in chapter 3 of his book, 'Individuals: an essay in descriptive metaphysics' Strawson argues for a stronger conclusion - that the concept of a person is 'primitive', a view which raises questions about the coherence of materialism as a solution to the mind-body problem. But that is not something you are required to discuss.

It seems uncontentious that a Cartesian is committed to thinking that a dualist reduction or analysis of the idea of a person is possible. However, it would be consistent with Descartes' remark in the Meditations that 'I am not lodged inside my body as a pilot in a ship' to argue that it is in fact essential to having a concept of myelf that I seem to have a body, even if I allow that the evil demon might be deceiving me. In other words, there is room here for a weaker, 'phenomenological' claim that the character of experience is such that an experience disembodiment is inconceivable. Interestingly, don't know of any place where Descartes actually addresses the question of disembodied souls or what their experiences are like. He does remark in Meditation 1 that the soul is not a 'wind or a vapour', pouring cold water on Spirtualist notions of disembodied ghosts made of insubstantial 'ectoplasm'.

A soul has no spatial characteristics, no location, and therefore the only connection that it has to a given body is through mind-body interaction. So, of course, one would not expect to find any other way of referring to souls other than by referring to the bodies of which they are the souls.

In your account of Strawson's argument over identity at a time and identity over time, my feeling was that you allowed yourself to talk too generally. The argument was very clear in your mind when you wrote the essay, but you don't convey it to the reader. I would have thought that exposition requires that you give the argument rather than merely report about it. It can help if you imagine a reader who isn't as knowledgeable as the examiner, who needs to be persuaded that Strawson is right.

In other words: you know what the argument is. Spell it out as persuasively as you can.

I do remember, as a second-year undergraduate student many years ago, not being persuaded by Strawson's worries about identity. My objection was along the lines of Leibniz's identity of indiscernibles. Given that souls are not individuated by any spatial means, their individuation is purely a matter of their mental properties. So why isn't it just logically absurd to imagine, e.g. that there might be two 'GK souls' thinking about what to write to HK and interacting with GK's body in order to make these words appear on the screen? Why isn't that a good objection?

One possible answer would be to point out the difference between this claim, in the context of Cartesian dualism, and the claim made by Leibniz - who originally propounded the identity of indiscernibles - about 'monads' in his monadology.

In Leibniz's theory, monads are all that exist. There is no physical 'matter' as such. That is how he is able to claim that each monad is uniquely identified by its mental properties (the way it 'represents' the rest of the universe). Whereas, in Cartesian dualism, the soul has a causal effect on something outside it, and receives causal input from the same source. Once this mental-physical bridge is introduced, there is nothing to prevent the hypothesis that two (or two hundred) soul substances are transmitting the same instructions to my pineal gland at the same time, or receiving the same visual experiences.

Similarly, there is nothing to prevent the hypothesis of a series of soul substances conveying their states to one another like a line of colliding billiard balls. This is in fact Kant's objection to Cartesian dualism in the Critique of Pure Reason (in 'The Paralogisms of Transcendental Psychology'). So Strawson is not being original in putting forward this argument and wouldn't claim to be.

Interestingly, Strawson shows recognition that Leibniz's theory requires a separate argument in 'Individuals'. This is added evidence that the problem has to do, not just with the notion of 'soul substance' as such, but rather with that notion in the context of an interactionist theory.

All the best,

Geoffrey