There has, however, been a move in general philosophy of science that, if acceptable, would transform the relationship between the taxonomic and explanatory features of species. This move was influentially initiated by Richard Boyd (1999a). It begins with the claim that the attempt to define natural kinds in terms of spatiotemporally unrestricted, intrinsic, necessary and sufficient conditions is a hangover from empiricism that should be abandoned by realist metaphysics. Instead, natural kinds s