The concept of self-motion is not only fundamental in Aristotle's argument for the Prime Mover and in ancient and medieval theories of nature, but it is also central to many theories of human agency and moral responsibility. In this collection of mostly new essays, scholars of classical, Hellenistic, medieval, and early modern philosophy and science explore the question of whether or not there are such things as self-movers, and if so, what their self-motion consists in. They trace the development of the concept of self-motion from its formulation in Aristotle's metaphysics, cosmology, and philosophy of nature through two millennia of philosophical, religious, and scientific thought. This volume contains "Self-Movers" (David Furley), "Aristotle on Self-Motion" (Mary Louise Gill), "Aristotle on Perception, Appetition, and Self-Motion" (Cynthia Freeland), "Self-Movement and External Causation" (Susan Sauve Meyer), "Aristotle on the Mind's Self-Motion" (Michael Wedin), "Mind and Motion in Aristotle" (Christopher Shields), "Aristotle's Prime Mover" (Aryeh Kosman), "The Transcendence of the Prime Mover" (Lindsay Judson), "Self-Motion in Stoic Philosophy" (David Hahm), "Duns Scotus on the Reality of Self-Change" (Peter King), "Ockham, Self-Motion, and the Will" (Calvin Normore), and "Natural Motion and Its Causes: Newton on the 'Vis Insita' of Bodies" (J. E. McGuire). Originally published in 1994. The Princeton Legacy Library uses the latest print-on-demand technology to again make available previously out-of-print books from the distinguished backlist of Princeton University Press. These editions preserve the original texts of these important books while presenting them in durable paperback and hardcover editions. The goal of the Princeton Legacy Library is to vastly increase access to the rich scholarly heritage found in the thousands of books published by Princeton University Press since its founding in 1905.