Part ii of this book was devoted to developing an account of the material side of Aristotle's temporal theory. Previous attempts to reconstruct this theory have foundered on the relation between motion and time, and more specifically, on the question of how temporal priority and posteriority could possibly be derived from the kinetic continuum. Unable to solve these problems to their satisfaction, commentators (not surprisingly) never fully saw their way to addressing the formal side of the theory, or indeed even to recognizing that Aristotle's view is essentially hylomorphic in character. Considered in the light of this exegetical history, explicating the matter of time is of no small significance.

However, material analysis is only one half of any hylomorphic account, and it is in some sense the less important of the two. Aristotle reminds us time and again that it is form that makes something the very thing that it is, as he does in Physicsii.1: “Indeed, it [morphê – shape, form] is more the nature of a thing than its matter; for something is more accurately said to be what it is when it is in actuality rather than potentiality” (193b6–8). So while the account of time's hulê presented in the previous chapters constitutes an important first step toward the development of a fully proper understanding of Aristotle's theory of time, the more challenging portion of the project lies ahead of us.