Pluralists list of later Cosmologists who were, 20; their new conception of change, 40; their new conception of the unchanging, 40, 41; introduction of conception of efficient cause by, 41; summary of similarities and differences in theories of, 41, 42; their lives span the fifth century, 42. _See_ Empedocles, etc. Plutarch neo-Platonist, 299. Political philosophy of Aristotle 202, 203. Political society Plato’s theory of, 155–158. Polytheism Homeric, 19. Polytheisms the systematizing of, 298, 299. Porphyry 291, 298, 357. Posidonius 270, 271. Primary and secondary qualities 116. Probabilism in Stoicism 262. Proclus 299–301. Prodicus 66, 68. Protagoras 66, 67; the relativism of, 69, 70; his point of view compared with that of Socrates, 81. Psychology materialistic, of Democritus, 111–114; Plato’s, 144–146; of Aristotle, 196–199; the Stoic, 248–250. Ptolemy his cosmography, 322–325. Purpose Aristotle’s conceptions of, 186–190. Pyrrho 266. Pyrrhonism 265, 266. Pythagoras 17. Pythagoreanism neo-, 281, 285–287; and neo-Platonism, 288. Pythagoreans the early, 17; the later, 44, 48, 49; their conception of Being, 49–51; their astronomy, 49, 52, 53; their dualism, 51, 52. Qualitative changes of phenomena 196–202. Rationalism defined, 104 n.; of Plato and Democritus, 104; of Abelard, 365–367. Realism 100, 104, 358, 362–365; objective, 104. Reason and dogma the relation between, 355, 356, 360–362, 365–367. Reconcilers _See_ Pluralists. Relativism of Protagoras, 69, 70; represented by the anthropologists, 103. Religion of the Greeks, organization of, 8, 9, 10; the new, perils of, 16–18; in Epicurus’s system, 236, 237; and science, the separation of, under Duns Scotus, 387, 388. Religious feeling two causes of the rise of, 272–274. Religious period of the Hellenic-Roman period 208, 209; treated, 273–301; the divisions of, 280, 281. Religious philosophies Hellenic, rise of, 280, 282; summary of history of, 281; introductory period of, 281–287; development period of, 281, 287, 288. Revival of Learning, the 375–378. Rhabanus Maurus 350. Rhetoric among the Greeks 60. Romans their conquest of Greece, 205–208. Roscellinus life and teaching, 361, 362. Rossetti, Christina _Shadow of Dante_ cited, 325 n. Rousseau and Epicurus 229. St. Ambrose 306. Salerno, University of 377. Scholasticism what it is, 355–359; of Anselm, 359–361; of Roscellinus, 361, 362; of Abelard, 363–367; classic, period of, 333, 368–394. School in early Greek philosophy, meaning of, 19.