Monday, August 20, 2012

Are zombies conceivable?

To: Mike C.
From: Geoffrey Klempner
Subject: Are zombies conceivable?
Date: 3rd March 2008 14:07

Dear Mike,

Thank you for your email of 19 February, with your essay towards the Fellowship Award entitled, 'Are zombies conceivable?'

In answer to your question about making a living from philosophy, this is a relevant question to me, as I have taken the unusual route of trying to make a living outside the academic world, effectively running a business marketing my philosophy courses. It is true that you will find philosophy graduates doing various things related to philosophy, for example Richard Lewis and his magazine 'Philosophy Now' so I am not unique.

You want to do serious research in philosophy. Outside the academic world, that is hard to do. I find it hard to find the time or energy to do serious research. Currently I am doing original work in the philosophy of business, but that is very much on the fringes of academic life. My main audience is non-academic.

My advice would be to get a job where you can do some good -- a job which you can bear doing -- and pursue philosophy as an independent philosopher. Maybe take a WEA evening class, as I did for many years and found very satisfying.

Your essay is clearly work in progress. The standard is well up to what one would expect from a graduate student.

You may have got a bit too bogged down in criticisms of the Churchlands' eliminativism. We are considering the question is 'are zombies conceivable?' Eliminativism would be one way of rejecting zombies. However, as you show, it is not the only way. What we are looking for is a dialectical hold on the zombie theory which identifies weaknesses in that theory. You are not asking what are the consequences of rejecting zombies for our conception of the mind-body problem but rather, simply, whether the zombie hypothesis itself makes sense, whether it adds up.

What is the zombie hypothesis? If we are assuming, from the start, a creature which is physically indistinguishable, say, from me, then so far as its physical properties and behaviour are concerned, the world in which it inhabits is nomologically and not just logically possible. The psychophysical laws which determine that my brain states are accompanied by 'something within' do not belong to the laws of nature which science investigates. Who is to say how 'lawlike' they might be?

I don't get why Chalmers thinks that the China brain thought experiment is relevant. Is it that it seems so far fetched to suppose that the entire population of China could, effectively, be a 'conscious self' that we are led to conclude that consciousness is an extra add-on? But doesn't that beg the question against the functionalist?

My argument based on blind sight is, in fact, intended to put the case for the possibility of zombies -- for the sake of reductio. In other words, I am trying to shore up the zombie theorist's position in order to have something more meaty to attack. Just as we can imagine an experience of 'disembodiment', so we can imagine an experience which would convince us that we had 'become a zombie' for a while. However, the point made in the Philosophy of Mind unit is that in neither case is the possibility of a certain kind of experience sufficient to establish the logical possibility of the hypothesis of 'mind separated from body'.

What you have done is combine that thought experiment with my argument that my zombie double would say just what I (supposedly a believer in the zombie theory) would say about the imagined experience, or about the possibility of zombies. 'I know I'm not a zombie!'

This isn't a knock-down refutation. A zombie doesn't 'say' anything. It makes noises which we hear as having a meaning, but which do not have any meaning for it. That is a possible defence, although I don't find it very convincing.

However, if this is right it puts paid to the idea that zombies would 'talk differently' from us, for example, telling another zombie to 'look out' as the bus approached. If they did, they would be zombies in a different sense from the one I thought we had assumed.

Suppose, however, consciousness is a feature of normal human brains. Defective brains still work in the main, but the lack of consciousness shows in behaviour -- in the things that the subject does and says. Then it seems that we are very much in film-zombie territory. Zombies totter around, or they talk in a monotone.

Isn't that a conceivable hypothesis? Yes, but then it is not clear how this relates to materialism. We have hypothesized a physical difference, so why isn't the physical difference enough to explain the different behaviour of humans and zombies?

The only way I can make sense of Chalmers' claim is in terms of the idea that consciousness is a kind of essentially non-physical 'stuff' that normal brains produce. How do we know this? Simply by virtue of the fact that I know that there is something 'in' me or 'about' me which science can never explain. There might be another subject physically very much like me which lacked the ability to produce conscious 'stuff', and no scientific investigation would be able to discover the physical difference between us, even though by hypothesis such a difference must exist, because it shows in behaviour.

That is a more difficult position to refute. My argument doesn't work, because I have assumed that there is *no* physical difference. However, in this case, Dennett has a plausible explanation in terms of the 'fine tuning' which distinguishes a working brain from a brain which is physically almost identical but functionally incapable of realizing conscious states the way normal brains do.

All the best,

Geoffrey