OUR KNOWLEDGE OF THE EXTERNAL WORLD AS A FIELD FOR SCIENTIFIC METHOD IN PHILOSOPHY, By Bertrand Russell CONTENTS LECTURE PAGE I. Current Tendencies 3 II. Logic as the Essence of Philosophy 33 III. On our Knowledge of the External World 63 IV. The World of Physics and the World of Sense 101 V. The Theory of Continuity 129 VI. The Problem of Infinity considered Historically 155 VII. The Positive Theory of Infinity 185 VIII. On the Notion of Cause, with Applications to the Free-will Problem 211 Index 243 INDEX Absolute, 6, 39. Abstraction, principle of, 42, 124 ff. Achilles, Zeno's argument of, 173. Acquaintance, 25, 144. Activity, 224 ff. Allman, 161 n. Analysis, 185, 204, 211, 241. legitimacy of, 150. Anaximander, 3. Antinomies, Kant's, 155 ff. Aquinas, 10. Aristotle, 40, 160 n., 161 ff., 240. Arrow, Zeno's argument of, 173. Assertion, 52. Atomism, logical, 4. Atomists, 160. Belief, 58. primitive and derivative, 69 ff. Bergson, 4, 11, 13, 20 ff., 137, 138, 150, 158, 165, 174, 178, 229 ff. Berkeley, 63, 64, 102. Bolzano, 165. Boole, 40. Bradley, 6, 39, 165. Broad, 172 n. Brochard, 169 n. Burnet, 19 n., 160 n., 161 n., 170 n., 171 ff. Calderon, 95. Cantor, vi, vii, 155, 165, 190, 194, 199. Categories, 38. Causal laws, 109, 212 ff. evidence for, 216 ff. in psychology, 219. Causation, 34 ff., 79, 212 ff. law of, 221. not a priori, 223, 232. Cause, 220, 223. Certainty, degrees of, 67, 68, 212. Change, demands analysis, 151. Cinematograph, 148, 174. Classes, 202. non-existence of, 205 ff. Classical tradition, 3 ff., 58. Complexity, 145, 157 ff. Compulsion, 229, 233 ff. Congruence, 195. Consecutiveness, 134. Conservation, 105. Constituents of facts, 51, 145. Construction v. inference, iv. Contemporaries, initial, 119, 120 n. Continuity, 64, 129 ff., 141 ff., 155 ff. of change, 106, 108, 130 ff. Correlation of mental and physical, 233. Counting, 164, 181, 187 ff., 203. Couturat, 40 n. Dante, 10. Darwin, 4, 11, 23, 30. Data, 65 ff., 211. �hard� and �soft,� 70 ff. Dates, 117. Definition, 204. Descartes, 5, 73, 238. Descriptions, 201, 214. Desire, 227, 235. Determinism, 233. Doubt, 237. Dreams, 85, 93. Duration, 146, 149. Earlier and later, 116. Effect, 220. Eleatics, 19. Empiricism, 37, 222. Enclosure, 114 ff., 120. Enumeration, 202. Euclid, 160, 164. Evellin, 169. Evolutionism, 4, 11 ff. Extension, 146, 149. External world, knowledge of, 63 ff. Fact, 51. atomic, 52. Finalism, 13. Form, logical, 42 ff., 185, 208. Fractions, 132, 179. Free will, 213, 227 ff. Frege, 5, 40, 199 ff. Galileo, 4, 59, 192, 194, 239, 240. Gaye, 169 n., 175, 177. Geometry, 5. Giles, 206 n. Greater and less, 195. Harvard, 4. Hegel, 3, 37 ff., 46, 166. �Here,� 73, 92. Hereditary properties, 195. Hippasos, 163, 237. Hui Tzu, 206. Hume, 217, 221. Hypotheses in philosophy, 239. Illusions, 85. Incommensurables, 162 ff., 237. Independence, 73, 74. causal and logical, 74, 75. Indiscernibility, 141, 148. Indivisibles, 160. Induction, 34, 222. mathematical, 195 ff.