Naturalism about the mind is often taken to be equivalent to some form of physicalism: the existence of mental properties must be shown not to compromise the autonomy of the physical realm. It is argued that this leads to a choice between reductionism, eliminativism, epiphenomenalism or interactionism. The central aim of the paper is to outline an Aristotelian alternative to the physicalist conception of natural bodies. It is argued that the distinction between form and matter, and an ontology which treats individual natural bodies as real, unified things, rather than as complexes, enables us to achieve the non-reductionist, non-epiphenomenalist and non-interactionist position which eludes the post-Cartesian.