Patristics 302–318. Perception and conception, 83 n.; according to Plato, 134; in Aristotle, 177–179. Pericles 58. Periods of philosophy, the three general, 1–4; of Greek philosophy, 12–14. Peripatetics _See_ Lyceum. Persia 15, 16. Persian Wars their importance, 55–57, 62. Personality spiritual, increased importance of, in history, 277–279. Pessimism result of theory of Cyrenaics, 97. Peter the Lombard 379, 380. Phædo founder of the Elean-Eretrian school, 93. Philo Greek-Jewish philosophy of, 281–284; and neo-Platonism, 288. Philoponus 299. Philosophic skepticism _See_ Skepticism. Physical universe early Greek tendency toward scientific explanation of, 10, 11. Physics Socrates’ view of, 80; enrichment of, under Democritus, 109–111; Plato’s conception of, 142–144; Aristotle’s theory of, 194–196; of Epicurus, 238–240. Plato 104; parts of works to be read, 75 n.; his place in Greek history, 93, 98–100, 103, 104; and Democritus, their similarities and differences, 104–106; the period of his life, 119, 120; the difficulties in understanding the teaching of, 120, 121; the chronology of his dialogues, 119, 120; the life and writings of, 121, 126; his student life, 121, 122; as traveler, 122–124; as teacher of the Academy, 124–126; concerning his dialogues, 126–128; the factors in the construction of his doctrine, 128–131; his inherited tendencies, 128–130; his philosophical sources, 130, 131; the divisions of his philosophy, 131, 132; summary of his doctrine, 132; the formation of his metaphysics, 132–136; the development of his metaphysics (the development of his ideas in the two drafts), 136–141; his conception of God, 141, 142; his conception of physical nature, 142–144; his conception of man, 144–146; his doctrine of immortality, 146–150; the two tendencies in, 150, 151; Platonic love, 151–153; his theory of ethics, 153–158; development of his theory of the Good, 153, 154; the four cardinal virtues, 154, 155; his theory of political society, 155–158; a selection of passages from, for English readers, 158–165; in the Middle Ages, 331, 337, 338, 360, 363. Platonism the revival of, 279; and neo-Platonism, 287, 288. Platonists Eclectic, 285. Pleasure of Epicurus, 230–233. _See_ Happiness. Plotinus 280, 287, 288; life and writings of, 290, 291; general character of his teaching, 291, 292; the mystic God of, 292, 293; the two problems of, 293; the metaphysical problem of, 294–297; the ethical problem of, 297, 298. Pluralism tried to reconcile extremes of Milesian school, 39, 40; and hylozoism, 41.