to go back and re-examine the argument, but we still need to find something wrong with the argument on independent grounds." This is exactly what materialists have done with the concept of metaphysical identityprovided a means of asserting that consciousness is physically instantiated, even though it's conceivable that it might not be. Therefore, Chalmers' argument is not sound, for it fails to rule out such a materialist theory. Because Chalmers' theory leads to epiphenomenalism, materialism remains the most plausible position to take toward consciousness. Materialists must face the difficulty of reducing consciousness to more basic physical phenomena, so that while the details may be complex, the metaphysics of our world will be simple. (There is only one type of propertyphysical properties.) There is no need to posit any additional fundamental laws or principles, and consciousness will not be epiphenomenal because the causal link between brain processes and behavior is clear. The problem materialism faces is that presently we have no idea how consciousness can be merely physical phenomena. There is an explanatory gap, as Levine puts it, between modern day physics and consciousness. Nonetheless, materialists would argue that we should not be pessimistic about the possibility that there will be a conceptual revolution in the future that will allow us to bridge this explanatory gap. While one cannot forecast the coming of a conceptual revolution in physics, physiology, and psychology which would lead to the reductive explanation of consciousness, history has shown that similar revolutions in thinking have occurred. Before Charles Darwin, people assumed that complex organisms like humans, and complex structures like eyes could only be the result of some intelligent designer. Darwin gave scientists a new way of viewing complex organism structures which illustrated how they could have evolved from simpler organisms and structures. I believ...
