ABSTRACT
This chapter supports the view that the category of substance is necessary for an account of human thinking about reality. Building on arguments by Hilary Putnam, the chapter argues that substances are not self-identifying objects but rather unities that emerge through the processes with which we stretch our concepts to know the world, as it surfaces in our experience. Substance-concepts, then, do dependent both upon structures existing in the world and upon the trajectories of our epistemic enterprises. This is a form of direct, non-naïve realism: our epistemic efforts allow us to grasp some structures present in the world, although we can never know whether those structures are exhaustive and what the fundamental structures of the world are like. The upshot is that hylomorphism is true, but there might be a variety of formal principles and only in some cases is the formal principle a real essence.
