(4) Hypotheses must agree with the laws of Nature (p. 279)
§4. Hypotheses necessary in scientific investigation 280
§5. The Method of Abstractions 283
Method of Limits (p. 284);
In what sense all knowledge is hypothetical (p. 286)


CHAPTER XIX

LAWS CLASSIFIED; EXPLANATION; CO-EXISTENCE; ANALOGY

§1. Axioms; Primary Laws; Secondary Laws, Derivative or Empirical;
Facts 288
§2. Secondary Laws either Invariable or Approximate Generalisations 292
§3. Secondary Laws trustworthy only in 'Adjacent Cases' 293
§4. Secondary Laws of Succession or of Co-existence 295
Natural Kinds (p. 296);
Co-existence of concrete things to be deduced from
Causation (p. 297)
§5. Explanation consists in tracing resemblance, especially
of Causation 299
§6. Three modes of Explanation 302
Analysis (p. 302);
Concatenation (p. 302);
Subsumption (p. 303)
§7. Limits of Explanation 305
§8. Analogy 307


CHAPTER XX