By: Arash Daklan

I will base my discussions on one of the most important feature of dualism-supporters; David j. Chalmers. In “Consciousness and its Place in Nature”[i] he introduces three types of materialism. All of them are being discussed by the idea of some kind of metaphysical possibility of “Zombies”. Though in some articles he says that he hasn’t based his argumentation on this possibility, for example in Chalmers (2006), the idea of zombies has two deep problems. The first one is the very conceivability that has a great problem. He says “Many people hold that zombies are conceivable in principle”. (2005) Now suppose a very weak criticism against this claim. In the medieval ages there were many people who “held that the earth is the centre of the universe”. However, my criticism is about the problems that we have with conceivability. What does it mean that something is conceivable? It is clear that every conceivable phenomenon is logically coherent; this means that every conceivable idea is logically possible. Then here raise a very important question: are any logically possible phenomenon conceivable? If yes, then we can infer that conceivability is the very logical possibility. All Chalmers’ endeavor in his unpublished work “The Two Dimensional Argument Against Materialism”[ii] to define the relation between conceivability and possibility under the title of “varieties of conceivability”, it seems to me, is made to escape from this idea and I think that it is not successful. Henceforth, when we say that every conceivable matter is metaphysically possible then we are saying also that every logically possible matter is metaphysically possible. However, if it is right then we should accept that every metaphysically necessary phenomenon is logically necessary. It is evidently against Kripke. Kripke in his famous book “Naming and Necessity” has identified a posteriori necessity. If we accept that every conceivable phenomenon is metaphysically possible then we lose the notion of metaphysical necessity. I will discuss about this matter elsewhere.
One may oppose that every conceivable matter is logically possible, but it is not right that every logically possible matter is conceivable. In this way he can prevent me from the above argumentation. However, this idea cannot help. They should answer to very important questions; "why they are not conceivable?", "If they are not conceivable how do we know that they are logically possible?" It seems to me that this idea is suffering from the same kind of vagueness that the idea of “Universal set” is. Aside from this matter, for the sake of argumentation I can dismiss these problems, but I have another question. How do we know that “Zombies” are not some kind of “Logically incoherent idea” in the logical spheres that we cannot conceive them?[iii] Another problem with this argument is that it is conceivable for example that 125897/125=258, but it is not logically possible. We can find so many examples. These examples are discussed by Chalmers in his mentioned unpublished work.
However, the second matter is a very deadly problem about Chalmers’ idea in all of his articles and books. To clarify the weak point I point out one of his methodologies that it is repeated in approximately each one of his works. He has used always some thought-experiment. However, there is a very big obstacle against thought-experiment that nobody is paying attention to. To show the fault in these experiments let suppose Turing Test. Why Turing has said that we should use an ignorant judge to evaluate the outcome? That is very clear. Knowing what is going on in so many situations prevents us to explore the idea. We are addicted to use introspection. In Turing Test we use an ignorant judge to eliminate this referring to introspection. This means that you should design an experiment and the others who are ignorant about the experiment methodology should evaluate it, but in thought-experiment everybody who is demanded to evaluate it is aware of the methodology then it cannot be a good experiment to base our theories on, unless we use formal computational method. For example Ned Block[iv], who is a Type-B Materialist in Chalmers’ point of view, has represented a Homunculi-Headed Robot by imagining;
… a body externally like a human body…but internally quiet different. The neurons from sensory organs are connected to a bank of light in a hallow cavity in the head. … Inside the cavity resides a group of little men. (p.238)
All the function of a human being is going to be done by this Homunculi-Headed Robot. He goes on to say that
What makes the homunculi -headed system (count the two systems as variants of a single system) just described a prima facie counterexample to (machine) functionalism is that there is prima facie doubt whether it has any mental states at all- especially whether it has what philosophers have variously called "qualitative states," "raw feels", or "immediate phenomenological qualities." (p.241)[v]
To show what the problem with these kinds of thought-experiment is, I quote Chalmers. He says
Many people also hold that we can conceive of an inverted world: one that is physically identical to ours, but in which some conscious states differ from the corresponding states in our world.” (2006)
Let examine Putnam’s twin earth thought-experiment to see what “My zombie twin” (Chalmers, 2006) means. Suppose our earth has two twins, the both of them are molecule for molecule similar to us. Also suppose that we know that one of them is inhabited by our real twins and the other one is resides by our zombie twins; we have no other information. How can we understand that which one of them is our zombie twin? Suppose a more realistic question. In Chalmers’ idea zombies are possible. Then we can infer that it is possible to find a planet with some people, let suppose they are not some odd fearsome ugly creatures who we see in science fiction films, but they are much like us however with some difference. Suppose their difference is like white skin and red skin difference. By the light of Chalmers it is possible that they are zombies, though it is not impossible for them to have a very civilized society. By the light of Julian Jaynes[vi] at least we can be agree with Chalmers that civilization can be produced independent of consciousness. Suppose we have travelled to a new planet of this kind and we do not know that these are zombies or conscious people like us? What should we do to understand? It seems that there are no philosophical arguments to answer the question. Usually we try to contact with them, speak with them, to see their behavior, and to gather some biological information about them. In contrast to Harris and Calvert (2003, p.555) who say
…naturalism has been unsuccessful in explaining several crucial ‘natural’ phenomena: the origin of the universe, the origin of universal laws and constants, the origin of life, and the origin of irreducible complexity.
we can just rely on this naturalistic arguments. If they are not enough to answer the mentioned question of mine then the only option that we have is to accept that there is nothing as “Consciousness” or maybe we conclude that we should re-define this notion in a new way to be able to explore it by these naturalistic methodology. When Chalmers is saying that we can conceive zombies he should say us what is the difference between us and zombies. To say that they are like us but the lack consciousness is not enough. This answer begs the question. It presupposes the meaning of consciousness, the very thing that we want to know. We need to know how Chalmers discerns a creature is conscious or not? Suppose we make a very high quality robot that it does everything that humankind does, and completely similar to a humankind, but Chalmers and other anti-physicalists do not know anything about that. Suppose we have sent one of these robots to his university to work with him as a colleague. How can he understand that? This is the big challenge that all anti-physicalists should be confronted with. How they understand that a creature is conscious or not, if they know nothing about its artificiality? In this way it seems that Block’s problem has been solved also. I have answered that in the endnote No. V.

[i] - David J. Chalmers, Phenomenal Concepts and the Explanatory Gap, In (T. Alter & S. Walter, eds) Phenomenal Concepts and Phenomenal Knowledge: New Essays on Consciousness and Physicalism. Oxford University Press, 2006. Consciousness and its Place in Nature, In (S. Stich & F., Warfield, eds) Blackwell Guide to Philosophy of Mind. Blackwell, 2003. Also in (D. Chalmers, ed) Philosophy of Mind: Classical and Contemporary Readings (Oxford University Press, 2002). Reprinted (abridged) in ( W. Lycan & J. Prinz, eds) Mind and Cognition: A Reader (Blackwell, 2007). (His articles are available on his homepage: http://consc.net/papers.html)

[ii] - This Unpublished work is Available on website: http://consc.net/papers/2dargument.html

[iii] - I will discuss about epistemological problems with accepting the idea of “inconceivability of some logical possible state of affairs” elsewhere.

[iv] - Ned Block, Troubles with Functionalisms. In Readings in philosophy and Cognitive Science, By Alvin A. Goldman. MIT Press, 1993.

[v] - I am not comparing Block and Chalmers. But there are some kinds of problems that Block has referred to them regarding functionalism. I think that some of them are not the problem of functionalism at all. For example in page 241 of the mentioned book he replies to the objection that the mentioned system works so slowly, by saying “it is hard to see why the systems’ time scale should matter…” Aftermath he has given an example to support his idea, but unfortunately, or maybe fortunately, his example opposes his conclusion; “When we observe the creatures, they seem almost inanimate. But when we view the time-lapse movies… .” Does not it mean that we are observing the functions and behavior? We think that a creature is animate if and only if we observe the function of an animate creature.

[vi] - Julian Jaynes, 1990. The Origin of Consciousness in the Breakdown of Bicameral Mind, Houghton Milfflin Co., Boston.