To: Max T.
From: Geoffrey Klempner
Subject: Problems for materialism and the nature of space
Date: 21 March 2002 12:02

Dear Max,

Thank you for your e-mail of 22 February, with your third essay for Possible World Machine, 'Difficulties of Materialist View of Mind', and for your e-mail of 14 March, with your fourth essay, 'In What Ways Does the Nature of Space Pose a Problem for Philosophy?'

Essay on mind

This essay benefits from your judicious choice, first, of Smart as a proponent of the mind-brain identity theory, and secondly the objections by Jackson and Kripke, which represent two of the most serious obstacles that a defender of the mind-brain identity theory needs to overcome.

One point that might be brought out in your account of Smart is that in presenting the mind-body identity claim as 'a matter of scientific enquiry to be settled by experiment and observation', Smart does appeal to an a priori principle: namely the principle of Occam's Razor.

A brain researcher with dualist leanings who accepted all the scientific findings might claim that even though the account of the workings of the brain is sufficient to account causally for everything human beings do and say, the possibility is left open that in addition to the physical aspect of a sensation of orange, which accounts for the subject's ability to discriminate oranges from apples, or their saying things like, 'I see an orange light', there exists a non-physical object, the 'quale' or 'raw feel' of orange, which is brought into existence by the brain processes, but does not itself have any causal effects. The name for this position is 'epiphenomenalism'.

Smart's view is that this violates Occam's Razor. It is unscientific because it posits an extra 'object' which plays no part in scientific explanation.

Frank Jackson's thought experiment of Mary in the black and white world seems to me quite powerful. We are assuming, of course, a future world where the explanation of why we see colours as colours has been discovered. Mary knows all this, she knows the total explanation, yet is unable to imagine what seeing colour would actually be 'like'. How is that possible? We can understand that Mary might be at a loss to identify colours, despite her vast knowledge, because there is something she doesn't *know how* to do, namely discriminate colours. But Jackson would reply that we are merely talking about a physical process of discrimination, not about the experience itself.

I fully go along with Kripke's claim that the identity must be necessary and cannot be contingent. I do not, however, see this as an insuperable obstacle for the materialist. The error which Smart makes is his reliance on Occam's razor. A satisfactory refutation of mind-body dualism needs to meet the idea of qualia head on, e.g. appealing to the private language argument.

Essay on space

From the point of view of understanding how there can be such a thing as experience, the task which Kant set out to accomplish in the first part of the Critique of Pure Reason, one arguably needs a lot less than the fully fledged concept of three dimensional, infinitely extended space within any given finite portion of which there exist a non-denumerable infinity of spatial positions.

It is clear that *our* experience is far richer than the minimal kind of experience which would be sufficient to justify an objective, spatial (or quasi-spatial) interpretation.

So, a simple model of 'experience' might be moving around fixed positions on a finite, two dimensional matrix. The description of the subject's progress is given by the experiences it enjoys at each fixed position, and the 'theory' which describes the matrix and the perceptible qualities which are to be found at each fixed position.

That would be sufficient to justify a statement like, 'The subject perceives that the quality at position, x, y is blue.'

Mathematics tells us that the more complex, infinitely extended and non-denumerably subdivided space is possible. But there is no way, other than by appeal to experience to demonstrate that this more complex space is the space of the actual world. Just as there is no way to demonstrate that space is Euclidean or non-Euclidean other than by appeal to empirical scientific theory.

I notice that you list Foster's 'Case For Idealism' as one of your references. One connection with the previous essay which you might not have noticed is the way that Foster presents an analysis of matter and space which is the *inversion* of Smart's analysis of mental phenomena. Foster makes the point that Smart's idea of a 'topic neutral description' is an equally powerful weapon in the hands of the idealist.

So, when Smart says, 'I can tell you what "having an experience of red" means in purely physical terms', Foster (or Berkeley) can say, 'I can tell you what "the cat sitting on the mat" means in purely experiential terms.' Just as there are objectors who beat their breasts (ineffectively, in Smart's view) and shout 'what about qualia!' so there are objectors to Berkeley's theory who beat their breasts and shout 'what about matter!'

The materialist, and the idealist, each claim to have told us everything about 'what there is', leaving nothing out.

All the best,

Geoffrey