INDEX 



467 



Planck, M., 28, 81 n., 132, 148, 175 n., 

 378, 379 and n., 382, 393, 418, 419, 

 432-7. 



Plato, 5, 224, 405, 408, 448. 



Poincare, H., 28, 74, 148, 150, 160-3, 

 164, 171, 176, 284 n., 286, 311, 335, 

 346. 



Poinsot, L., 244. 



Pointing, method of, 244-5, 249-50. 



Positivism, 8-9, 10, 86-7, 148, 149- 

 50, 170, 351; as theory of percep- 

 tion, 84-5; see Descriptive science; 

 Logical positivism; Modified pos- 

 itivism; Operationalism ; Strict em- 

 piricism. 



Pragmatism, 44. 



Prediction, 218-23. 



Price, H. H., 102. 



Primitive concepts, 248-9. 



Probability, 359-63. 



Progression, 259, 267. 



Propositions; analytic and synthetic, 

 142-3, 210-1; in descriptive science, 

 141-2; integrating, 141, 209-10; 

 underived and derived, 140, 209. 



Psychology of discovery, 178-81. 



Quality, distinguished from quantity, 

 15-8. 



Quantity, 253, 271-8; empirical foun- 

 dation of, 271-4; operational deri- 

 vation of, 274-6; relativity of, 271- 

 3; scientific content of, 276-8; and 

 measurement, 274-6; and order, 

 273-4; and quality, 15-8, 271; see 

 Measurement. 



Rationalism, 149, 170. 

 Realism, see Scientific realism. 

 Reality, see Nature of reality. 

 Relativity of motion, 313-4. 

 Relativity theory, 25-6, 303-11. 

 Retrospective inference, 106. 

 Reversible processes, 288-9. 

 Ribot, T., 249 n., 252. 

 Richards, I. A., 62 n., 63, 67 n., 77. 

 Richardson, E. C, 408 n., 417. 

 Riemann, G. F. B., 24, 25. 



Rignano, E., 195. 



Ritchie, A. D., 38, 60, 112 n., 230, 

 384. 



Rueff, J., 213. 



Russell, Bertrand, 20, 51 and n., 52, 

 54, 60, 70 n., 102, 148, 170, 184, 

 238, 243, 248, 252, 253, 255 n., 261, 

 263 and n., 264 n., 271 n., 278, 299 

 and n., 300, 311, 315, 316 n., 320 n., 

 321 n., 323, 341 n., 345, 388. 



Russell, H. N., 437. 



Rutherford, E., 169 



Saunders, F. H., 334 n. 



Schlick, M., 11, 148. 



Science, Chap. I; as analysis, 18-9; 

 as descriptive, 8-11; as factual, 

 13-5; as factual description, 11-3; 

 as never purely descriptive, 104-5; 

 as quantitative, 15-8; as resting 

 upon data, 80-1; as reducible to 

 quantity, 312-3; as selective of 

 events, 78-9; basic entity of, 50; 

 broadest definition of, 128; con- 

 tradiction in, 24-6; empirical study 

 of, 43-6; limiting of, 49-50; prag- 

 matic explanation of, 44-5, 78- 

 80; self-criticism of, 23; social 

 aspects of, 27; specialization of, 

 29-30; subject matter of, 50; task 

 of, 78; and sensitivity of organ- 

 isms, 79; see Descriptive science; 

 Explanatory science. 



Sciences, classification of, see Classi- 

 fication of the sciences. 



Scientific cognition, 47, 48; see 

 Kno wer ; Knowing ; Knowledge ; 

 Known. 



Scientific concepts, analysis of, 30-1, 

 Chap. XII; definition of, 235-7; 

 difficulties of, 233-4; general char- 

 acter of, 234-43; task of, 237; and 

 empirical foundation, 243-5; and 

 operational derivation, 250-2; and 

 scientific content, 245-50. 



Scientific discovery, Chap. IX; act 

 of, 175-8; mystery of, 173; spon- 

 taneity of, 176-8; twofold char- 



