Abstract

Aristotle's definition of time in Physics IV.11 as "a number of motion with respect to the before and after" is often claimed to be viciously circular, since it is thought that 'before' and 'after' are terms that cannot be explicated independently of temporal concepts. My project in this dissertation is to defend Aristotle's theory against this charge of circularity and, further, to argue that it succeeds where some modern theories of time fail. ;The centerpiece of my interpretation is an explication of theoretical entities that Aristotle calls 'the before and after in motion', entities that I have dubbed 'kinetic positions'. Kinetic positions are instantaneous happenings within a movement that can be specified as functions of a moving object's actual spatial location and the telos, or end, of the movement. On Aristotle's view, time is an aspect of motion, and kinetic positions are the lower-level metaphysical counterparts of instants. It is in this sense that Aristotle's account is reductionistic: time derives its existence and structure from that of motion, and motion derives its existence and structure from that of spatial magnitudes. ;The success of my project requires that I: establish that Aristotle's kinetic theory can be explicated independently of temporal concepts; explain how the asymmetrically-ordered kinetic continuum derives from the symmetrically-ordered spatial continuum; show that my interpretation of kinetic positions is consistent with Aristotle's claim in Physics VI that motion in an instant is impossible; explain the significance of Aristotle's placement of time within the genus number; justify Aristotle's claim in IV.14 that time would not exist if there were no perceptive souls; how that Aristotle's account integrates temporal passage, the "flow" of time, in such a way as to be immune from devastating arguments, devised by McTaggart and others, against its possibility. ;I conclude that Aristotle ultimately conceives time to be an unmistakable perceptible feature of motion, and in so doing manages to develop a coherent theory that preserves a conception of time first given full philosophical dress by Plato, while refining and extending it in significant ways