The only change which the reader will find in the revision of this volume is in the form of presentation of the philosophies of the earlier cosmologists (Chapter II). HERBERT E. CUSHMAN. WEST NEWTON, February, 1918. CONTENTS INTRODUCTION――THE THREE GENERAL PERIODS OF THE HISTORY OF PHILOSOPHY, 1 THE COMPARATIVE LENGTHS OF THE THREE GENERAL PERIODS, 1 THE REAL DIFFERENCES OF THE THREE GENERAL PERIODS, 1 TABLE OF THE SUBDIVISIONS OF THE THREE GENERAL PERIODS, 4 BOOK I. ANCIENT PHILOSOPHY (625 B. C.–476 A. D.) CHAPTER I. THE EARLY GREEK IN ANCIENT PHILOSOPHY, 5 THE DIVISIONS OF ANCIENT PHILOSOPHY, 5 THE LITERARY SOURCES OF ANCIENT PHILOSOPHY, 6 THE ENVIRONMENT OF THE EARLY GREEK, 7 1. His Geographical Environment 7 2. His Political Environment 7 THE NATIVE TENDENCIES OF THE EARLY GREEK, AS SEEN (1) In the Development of his Religion, (2) in his Reflections upon Physical Events, and (3) in his Interest in Human Conduct, 9–11 THE THREE PERIODS OF GREEK PHILOSOPHY, 12 CHAPTER II. THE COSMOLOGICAL PERIOD: THE PHILOSOPHY OF NATURE, 15 THE PERIL IN THE GREEK POLITICAL SITUATION: PERSIA AND CARTHAGE, 15 THE PERIL IN THE NEW RELIGION: THE MYSTERIES AND PYTHAGORAS, 16 CHARACTERISTICS OF THE COSMOLOGISTS, 18 TABLE OF COSMOLOGISTS, 20 HOW THE PHILOSOPHICAL QUESTION AROSE, 20 MAP SHOWING THE CITIES WHERE THE COSMOLOGISTS LIVED, 21 SUMMARY COMPARISON OF THE MONISTIC PHILOSOPHIES, 22 1. THE MILESIAN SCHOOL, 24 THE MILESIAN PHILOSOPHY, 25 2. XENOPHANES, THE RELIGIOUS PHILOSOPHER, 26 THE PHILOSOPHY OF XENOPHANES, 27 3. HERACLEITUS, “THE MISANTHROPIST” AND “THE OBSCURE,” 28 a. Heracleitus’ Doctrine of Absolute and Universal Change, 28 b. Fire is the Cosmic Substance, 29 c. The Definite Changes of Fire, 30 d. The Practical Philosophy of Heracleitus, 31 4. THE ELEATIC SCHOOL, 32 a. PARMENIDES, 32