Multiple realization, reduction and mental properties

Abstract

This paper tries to remove some obstacles standing in the way of considering mental properties as both genuine natural kinds and causally efficacious rather than epiphenomena. As the case of temperature shows, it is not justified to conclude from a property being multiply realizable to it being irreducible. Yet Kim's argument to the effect that if a property is multiply realizable with a heterogeneous reduction base then it cannot be a natural kind and possesses only derivative “epiphenomenal” causal efficacy is not conclusive either. The fact that temperature is, but jade is not, a natural kind cannot be established by comparing the heterogeneity of their respective reduction bases, but rather by the fact that the former is and the latter is not embedded in laws of nature.