A System of Logic: Ratiocinative and Inductive, 7th Edition, Vol. I
CHAPTER XII. _Of the Explanation of Laws of Nature.
§ 1. Explanation defined 518
2. First mode of explanation, by resolving the law of a complex effect into the laws of the concurrent causes and the fact of their coexistence 518
3. Second mode; by the detection of an intermediate link in the sequence 519
4. Laws are always resolved into laws more general than themselves 520
5. Third mode; the subsumption of less general laws under a more general one 524
6. What the explanation of a law of nature amounts to 526