CHAPTER XIII. THE RELIGIOUS PERIOD, 273 THE TWO CAUSES OF THE RISE OF RELIGIOUS FEELING, 273 THE NEED OF SPIRITUAL AUTHORITY, 275 THE RISE OF THE CONCEPTION OF SPIRITUALITY, 277 THE REVIVAL OF PLATONISM, 279 THE DIVISIONS OF THE RELIGIOUS PERIOD, 280 THE HELLENIC RELIGIOUS PHILOSOPHIES, 282 THE INTRODUCTORY PERIOD OF HELLENIC RELIGIOUS PHILOSOPHY. THE TURNING TO THE PAST FOR SPIRITUAL AUTHORITY, 282 1. The Greek-Jewish Philosophy of Philo, 282 2. Neo-Pythagoreanism, 285 THE DEVELOPMENT PERIOD OF HELLENIC RELIGIOUS PHILOSOPHY. THE TURNING TO THE PRESENT FOR SPIRITUAL AUTHORITY. PLATONISM AND NEO-PLATONISM, 287 NEO-PLATONISM AND THE TWO INTRODUCTORY PHILOSOPHIES, 288 NEO-PLATONISM AND CHRISTIANITY, 288 THE PERIODS OF NEO-PLATONISM, 290 THE ALEXANDRIAN SCHOOL. THE SCIENTIFIC THEORY OF NEO-PLATONISM. THE LIFE AND WRITINGS OF PLOTINUS, 290 THE GENERAL CHARACTER OF THE TEACHING OF PLOTINUS, 291 THE MYSTIC GOD, 292 1. The Supra-Consciousness of God, 292 2. The Conception of Dynamic Pantheism, 293 THE TWO PROBLEMS OF PLOTINUS, 293 THE WORLD OF EMANATIONS.――THE METAPHYSICAL PROBLEM OF PLOTINUS, 294 THE SPIRIT, 294 THE SOUL, 295 MATTER, 295 THE RETURN OF THE SOUL TO GOD.――THE ETHICAL PROBLEM OF PLOTINUS, 297 THE SYRIAN SCHOOL.――THE SYSTEMATIZING OF POLYTHEISMS.――JAMBLICHUS, 298 THE ATHENIAN SCHOOL.――RECAPITULATION.――PROCLUS, 299 CHAPTER XIV. PATRISTICS.――THE HELLENIZING OF THE GOSPEL, 302 THE EARLY SITUATION OF CHRISTIANITY, 302 THE PHILOSOPHIES INFLUENCING CHRISTIAN THOUGHT, 305 THE PERIODS OF EARLY CHRISTIANITY, 306 THE APOLOGISTS, 307 THE GNOSTICS, 310 THE REACTION AGAINST GNOSTICISM.――THE OLD CATHOLIC THEOLOGIANS, 312 ORIGEN AND THE SCHOOL OF CATECHISTS, 314 BOOK II. THE MIDDLE AGES (476–1453)