Chapter 18

HYPOTHESES

Sec.1. Hypothesis defined and distinguished from Theory 266 Sec.2. An Hypothesis must be verifiable 268 Sec.3. Proof of Hypotheses 270 (1) Must an hypothetical agent be directly observable? (p. 270); _Vera causa_ (p. 271) (2) An Hypothesis must be adequate to its pretensions (p. 272); _Exceptio probat regulam_ (p. 274) (3) Every competing Hypothesis must be excluded (p. 275); Crucial instance (p. 277) (4) Hypotheses must agree with the laws of Nature (p. 279) Sec.4. Hypotheses necessary in scientific investigation 280 Sec.5. The Method of Abstractions 283 Method of Limits (p. 284); In what sense all knowledge is hypothetical (p. 286)