The two studies, "Indivisible Magnitudes," and "Aristotle and Epicurus on Voluntary Action," explain two doctrines in the philosophy of Epicurus, first by a detailed examination of the ancient Greek and Latin texts which describe them, and second by showing how earlier Greek philosophy gave rise to the problems Epicurus tackled. Originally published in 1967. 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.