philosophy of science. Philosophy of mind Kim has defended various mind-body theories during his career. He began defending a version of the identity theory in the early 1970s, and then moved to a non-reductive version of physicalism, which relied heavily on the supervenience relation. Kim eventually rejected strict physicalism on the grounds that it provided an insufficient basis for resolving the mind-body problem. In particular, he concluded that the hard problem of consciousness—according to which a detailed and comprehensive neurophysical description of the brain would still not account for the fact of consciousness—is insurmountable in the context of a thoroughgoing physicalism. His arguments against physicalism can be found in his two latest monographs: Mind in a Physical World (1998) and Physicalism, or Something Near Enough (2005). Kim claims "that physicalism will not be able to survive intact and in its entirety." This, according to Kim, is because qualia (the phenomenal or qualitative aspect of mental states) cannot be reduced to physical states or processes. Kim claims that "phenomenal mental properties are not functionally definable and hence functionally irreducible" and "if functional reduction doesn't work for qualia, nothing will." Thus, there is an aspect of the mind that physicalism cannot capture. In his later years, Kim defended the thesis that intentional mental states (e.g., beliefs and desires) can be functionally reduced to their neurological realizers, but that the qualitative or phenomenal mental states (e.g., sensations) are irreducibly non-physical and epiphenomenal. He, thus defended a version of dualism, although Kim argues that it is physicalism near enough. As of March, 2008, Kim still saw physicalism to be the most comprehensive worldview that is irreplaceable with any other world view. In a 2008 interview with Korean daily newspaper Joongang Ilbo, Kim stated that we must seek a naturalistic explanation for mind because mind is a natural phenomenon, and supernatural explanation only provides "one riddle over another". He believed that any correct explanation for the nature of mind would come from natural science rather than philosophy or psychology. Argument against non-reductive physicalism Kim has raised an objection based on causal closure and overdetermination to non-reductive physicalism. The non-reductive physicalist is committed to following three principles: the irreducibility of the mental to the physical, some version of mental-physical supervenience, and the causal efficaciousness of mental states. The problem, according to Kim, is that when these three commitments are combined with a few other well-accepted principles,