Kim on Mental Causation and Causal Exclusion

Abstract

For three decades Jaegwon Kim has articulated and defended the view that mental properties are distinct from physical properties, are supervenient on physical properties, and are causal properties figuring in supervenient causation. But he has increasingly come under the influence of a problem, the causal exclusion problem, which threatens to undermine any kind of psychophysical property dualism, thus leaving type-type identity as the only viable form of realism about the mind. In this paper I will focus on the increasingly central role of the causal exclusion problem in Kim's philosophical work.' I will argue that if we seek to accommodate causal-exclusionary considerations, as he does-rather than firmly repudiating them as mistaken-then we are inevitably driven toward a psychophysical type/type identity theory. This is where Kim's intellectual trajectory is leading him, although he has not yet embraced the view. The appropriate form of the identity theory is one that also accommodates species-relative multiple realization-despite the fact that multiple-realization considerations are commonly thought to undermine type-type psychophysical identities altogether. Ironically, the relevant version of the identity theory is not new at all; in its essentials, it is the position of D.M. Armstrong (1968, 1970, 1977) and David Lewis (1966, 1972), as amended in an important and insufficiently appreciated way in Lewis (1980). Although I will suggest that the Armstrong/Lewis version of the psychophysical identity theory is the position that Kim himself should adopt, given his own philosophical attitude toward the problem of causal exclusion, I do not believe it is the right view. I favor a version of nonreductive materialism that (i) asserts that mental properties can be physically multiply realizable not just across different species but within creatures of the same species, (ii) repudiates psychophysical type-type identities, and (iii) maintains that causal-exclusionary reasoning is mistaken. In the final section I will briefly explain my own position on the matter of causal exclusion.