Hylomorphism, or Something Near Enough

Abstract Hylomorphists hold that substances are, in some sense, composites of matter and form. The form of a substance is typically taken to play a fundamental role in determining the unity or identity of the whole. Staunch hylomorphists think that this role is of a kind that precludes the ontological reduction of form to the physical and thus take their position to be inconsistent with physicalism. Forms, according to staunch hylomorphism, play a fundamental role in grounding their bearers’ proper parts and that, it seems, rules out the physical grounding of form itself. This chapter develops a physicalist version of hylomorphism which, it is argued, entails many of the central theses endorsed by staunch hylomorphists. Based on Shoemaker’s notion of conditional powers, it is argued that the spatiotemporal structures of complex wholes are the conditions on at least some of the conditional powers of their bearers’ proper parts, transforming those powers into powers simpliciter. Thus, forms play a fundamental role in the dynamical evolution of the physical world, but without bestowing causal powers themselves and hence without violating any empirically plausible version of the causal closure of the physical domain. If a substance’s proper parts are taken to be individuated by their powers simpliciter, then those parts derive their identities from their places in the whole. The form of a whole thus determine the identities of its proper parts, as Aristotle claimed, but on the position defended here, it does so without intrinsic change.