Dualism has become so associated with RenT Descartes that it is usually referred to as Cartesian dualism, as if this were the defining approach to the issue. Dualism is the theory that the mind and the body, that mind and matter, are two distinct things. Descartes considered the issue of the location of the mind and found that the mind was separate from the body. He says that he is a subject of conscious thought and experience and thus cannot be nothing more than spatially extended matter. The mind, or the essential nature of the human being, cannot be material but must be non-material. This non-corporeal entity may be intimately associated with the body, but it is not itself a material entity as is the body. Descartes offered several arguments for this belief, one of which was the conceivability argument which necessarily involves a degree of tautology. Descartes says that the separate existence of the mind and body is conceivable and so is possible. If it is possible for two things to exist separately, he says, they cannot be identical. The mind is here conceiving of itself and holds that the mere fact that it can conceive of itself as existing separately from the body means that mind and body are two different things. The picture that Descartes created of the relationship between mind and body is one that has plagued philosophy ever since. It has also involved scientific inquiry as the argument is made as to whether the brain can be considered different or identical with the mind and whether the mind can exist separately from the brain. The issue has been linked with questions about the electronic brain of the computer as well, for explorers of Artificial Intelligence are asking whether a machine can think, and if it can think, whether this means that it has a mind. The issue is broader than the conceivability argument offered by Descartes, but that argument in particular is suspect and raises as many issues as it purpo...