The aim of this dictionary is to provide teachers, students and laymen with clear, concise and correct definitions and descriptions of philosophical terms throughout the range of philosophic thought. In this volume, all branches of schools of ancient, medieval and modern philosophy are represented. This reissue of the 1942 edition, with scores of new entries, is an event widely heralded by both scholars and students. From Aristotelianism to Zoroastrianism, from Abbagnano to Swingli, the new edition of the classic work remains true and valid. While preserving the original material, additions include such well-known names as Martin Buber, Simone de Beauvoir, Ayn Rand, Jean-Paul Sartre, Lionel Trilling, et al.