To: Maria D.
From: Geoffrey Klempner
Subject: Zombies in Philosophy
Date: 27 February 2004 10:38

Dear Maria,

Thank you for your letter of 16 February, with your first Philosophy of Mind essay (units 1-3) in response to the question, 'What is the philosophical significance of the idea of a 'zombie'?'

This is a good piece of research, which I found interesting and informative, and in parts gripping.

I was a little disappointed to find no reference to the discussion of zombies in the Pathways program (which you said you had enjoyed). However, there is no rule that students must refer to Pathways materials, and you certainly have made the best of your reading.

As a philosophy undergraduate (at Birkbeck College London). I would read extensively, but I never acquired the taste in my essay writing for systematically summarizing the views of different philosophers in the way that you have done. The danger, which you have not altogether avoided, is that after considering several very different viewpoints, there seems little left to do other than say which viewpoints one agrees with and which one disagrees with.

One way to avoid this is to *not* confine one's critical comments to the conclusion.

You evidently felt that the essay required a historical reference, hence the account of Descartes and Leibniz. This is a sound approach in principle. The problem is that Descartes as an interactionist, would *not* accept the possibility of a zombie.

According to Descartes, the 'animal spirits' are moved by impulses from a non-physical soul in the pineal gland. The movements of the animal spirits cause the body to move. Without these triggering impulses, *nothing will happen*, or, if it does, it will not be recognizable as the behaviour of a conscious human being.

In other words, the zombie hypothesis requires *epiphenomenal* mind-body dualism.

Perhaps this seemed so obvious to you that it didn't need stating. Possibly all you meant to say was that the epiphenomenalist relies on the Cartesian concept of the 'inner'.

Like you, I regard the zombie hypothesis as incoherent. I don't, however, fully agree with the view that 'Zombies are conceivable because of the inadequacy of our present concepts...'. Writers like Nagel, Dennett and Churchland in different ways are looking towards a future when we will finally *see* what we cannot see now because of the inadequacy of our conceptual vocabulary. Advances in brain or consciousness research will change our concepts so that we no longer *seem* to be able to conceive of a zombie. But I wonder whether what is required is concept change, rather than simply a clearer philosophical vision, using the concepts we have now.

The basic form of anti-zombie argument which you rely on is one which goes, 'You think you can imagine a zombie but are you really sure? Maybe your imagination is leading you astray.' The answer is, 'No I'm quite sure, nothing is so certain to me as what I am imagining now, that *you* have nothing 'inside', but merely speak and behave as a genuinely conscious subject would speak and behave.'

This is a powerful intuition, which needs to be attacked from the inside, in a way which reveals the philosophical illusion that prompts it. That is what I try to do in the Pathways Philosophy of Mind program.

There are two ways to approach this. One is via Wittgenstein's advice, 'Always get rid of the idea of the private object in this way: assume that it constantly changes, but that you do not notice the change because your memory constantly deceives you' (Philosophical Investigations Part II, p. 207). Wittgenstein is not making a sceptical point, but rather using imagination against itself. One consequence of this is that the GK who existed one second ago is as much an 'other' to me as you or anyone else. It is perfectly possible (so far as imagination will allow) that GK has been a zombie up to one second ago when consciousness miraculously came into existence.

My preferred argument, however, is the one given in the Philosophy of Mind program. As an epiphenomenalist, I believe that there could exist a zombie double of GK. It follows, however, that GK's zombie double is also a professed epiphenomenalist who speculates that I might be *his* zombie double.

As I take care to point out, the argument is not a fully knock-down refutation. It is consistent with the truth of epiphenomenalism that (for reasons which evidently have nothing to do with the truth of epiphenomenalism) my zombie double should assert the words, 'I am an epiphenomenalist.' I regard the argument more as an aid to the imagination in combating a philosophical illusion.

However, the question asked about the philosophical significance of the idea of a zombie, rather than explicitly how one would refute the zombie hypothesis or epiphenomenalism. This you have certainly done.

All the best,

Geoffrey