That the mind is a purely physical substance.

I. The argument from causal closure.Philochristos asserts that my axiom is question begging, because it follows from it that physicalism is true. Of course, that is precisely the point of any argument, but oh well. Still, it would appear that many substance dualists would accept this axiom, and it seems clear that mental events are caused by physical ones (e.g. the process of conception leads to the creation of a person with consciousness). In fact, lest Philocristos revert to a non-physicalist account of the origin of the universe (e.g. God) he must accept this premise.He then goes on to list four supposed problems with the conclusion of the argument, I shall deal with them in point form.a. From the account of identity physicalism I have given in part three, it does follow that mental properties are subject to third person observation. Of course, as before mentioned, this could require a perfect understanding of the brain (ie. down to each particular cell), but does not deny the possibility of it in theory.b. It is claimed that if physicalism is true, then the semantical content of our mental events must be irrelevant. This completely misses the point, consider the case of a chair, a chair is a chair because of the material, rather than immaterial, stuff that it is made out of. The semantics of the chair are derived from the physical material out of which it is made, so too is this the case with mental states such as beliefs and desires - the semantics are derived from the physical stuff out of which it is made. Finally, he states that "we should not expect evolution to have produced reliable belief-producing cognitive faculties"; this is a view towards which I can sympathise, but it is clear that on some level evolution must produce reliable belief-producing cognitive faculties. Why? Because if evolution did not produe any reliable cognitive faculties, then it is plainly absurd that we would survive and reproduce.c. It is next asserted that supervenience fails to escape the same problems faced by epiphenomenalism. This is clearly false, given that it can and does maintain that mental events do influence other physical events - we act intentionally when the mental events in question (e.g. brain states) cause our bodies to act.d. This is a reassertion of his Personal Identity Theory argument, and given that I have already dealt with that extensively, I refer voters to my third round post.e. This downright contradicts most science. I am not going to spend very much time resopnding to it - but rest assured most neurological evidence (and most neurologists) points to physicalism.II. The argument from methodological naturalismPhilocristos' statement that science does not imply physicalism is rather odd. It must of course be noted that there have historically been many things attributed to non-physical forces that now have widely accepted scientific explanations: two examples of this are the precise ordering of colours in the rainbow (which has been explained by the light spectrum), and the diversification of life (which has been explained by evolution). Science tries its very best to answer things in a physicalist way, and it has been very successful in doing so. What seems bewildering to a 15th century theologian can be widely accepted with a physicalist explanation today, and substance dualism/idealism is rapidly finding itself in a similar circumstance. Given that science has shown, time and time again, that there are physicalist explanations for what was previously thought to require a non-physicalist explanation, science continues to do so in other areas, such as the soul/no soul debate. Scientifically speaking, it would be an unreasonable leap to claim that the explanation of something is non-physical when so often we have been shown to be false in that assertion, and when there is such an overwhelming majority of things with a purely physicalist explanation.Philocristos seems to fail to grasp the concept of induction - upon which science is founded. According to induction we make general/universal claims from an existential/specific one (e.g. I have dropped a ball from my hand 1000 times, and every single time it has fallen; so if I drop it again, it will fall again). Inductively speaking, given that so much of the universe has already been shown to be physical, it would be an astonishing claim to suppose that minds are made up of an entirely distinct substance.ConclusionPhilocristos' arguments have all been shown to be faulty. Meanwhile, the argument from causal closure and the argument from methodological naturalism have both survived my opponent's rebuttal and construct a powerful case for a physicalist conception of the mind.References1 - http://www.nytimes.com...