Wednesday, May 25, 2011

Can a zombie be an epiphenomenalist?

To: Tom M.
From: Geoffrey Klempner
Subject: Can a zombie be an epiphenomenalist?
Date: 15 August 2002 09:58

Dear Tom,

Thank you for your e-mail of 7 August, with your third essay for the Philosophy of Mind program, in response to the question, ''You say that you are an epiphenomenalist, but your zombie double would say that too!' - Is that a valid refutation of epiphenomenalism?'

This is a very well constructed essay with which I cannot find anything to disagree. You have expressed the zombie argument against the epiphenomenalist clearly and succinctly. In what follows, what I am going to say should not be understood as a criticism of your essay, but rather as an attempt to find some points where there could be further fruitful discussion.

You say that if we accept epiphenomenalism then 'we must consider a particular thought as having two components: the subjective awareness we have of it and the hidden episode of brain activity it represents'. Of course, this applies to all kinds of mental phenomena, not just to episodes of thinking. So let us consider the phenomenon of pain. On this version of the epiphenomenalist theory, there is the subjective awareness of pain, and there is its physical cause: say, 'stimulation of C-fibres' (this is the standard example given by philosophers - I have no idea who was the neuroscientist who first put forward the 'C-fibre' theory). However, it could be argued that this is not what we mean when we say, 'Jones is in pain'. Although it may be true that the occurrence of such things as pain is ultimately explained by physical events in the brain, the *meanings* of mental concepts relate to human behaviour in the context of normally observable physical circumstances. 'Pain' is a concept which collects certain types of phenomena, namely, those which show themselves through speech and behaviour.

This 'behavioural' view, suitably elaborated, does give in my view a correct account mental phenomena: with two provisos. The first proviso is that it should be seen as implied by the theory that there is a 'central' physical state that accounts for behaviour. In other words, when we say that someone is in pain, it would be like saying that this is an example of a particular 'natural kind' which can be classified by its hidden physical structure, just as when we say that a piece of material is gold, what we mean is that it is an example of the natural kind which has the inner, physical structure of gold. (There is a seminal paper on this question by the American philosopher Hilary Putnam entitled 'Meaning and Depth Grammar' which you might come across.) The second proviso is we need to provide a convincing account of first-person knowledge of mental states which coheres with the behavioural view. This is the tough part. A well-known criticism of behavioural view is that 'one cannot apply it to oneself without feigning anaesthesia'.

The epiphenomenalist accepts the structure of the behavioural view but with an essential modification: the true 'inner structure' of pain is thought of as a non-physical event whose occurrence cannot be verified except by the individual in whom the event occurs. Stimulation of C-fibres is not the innermost aspect of pain. This is how the idea of 'pain' having two meanings arises: the subjective meaning and the behavioural meaning, including reference to a hypothesised inner physical structure.

You were right to consider the epiphenomenalist who claims that the non-physical aspect cannot logically be separated from inner physical states. I fully agree with you that an epiphenomenalist who makes this move deprives themself of the only way of expressing what they mean by calling epiphenomenal states 'non-physical'. However, more argument could be given here. In fact, an essay could be written on this one point. Is the only way to express the idea of the inner or the 'non-physical', one which involves thought experiments of the Cartesian variety?

Nagel will be good to read on this question. Nagel's idea, tentatively expressed, that the physical might turn out not to be the must fundamental notion for understanding reality, but rather 'concept X' where X has both physical and mental 'aspects' harks back to Spinoza's 'double aspect' account of the mind-body relation in the 'Ethics'. (As I may have mentioned, these speculations are confined to a footnote in Nagel's book 'The View From Nowhere'. There is much more to Nagel's theory of the subjective and objective, as you will see.)

I still do not see, however, how this saves dualism, as opposed to making a more sophisticated version of materialism (or rather X-ism). On the other hand, I am not totally convinced that there might not yet be a possibility which we have overlooked.

All the best,

Geoffrey