Note 11 — Chapter VIII · LUCRETIUS AND HIS READERS

Philodemus, περὶ σημείων, ed. Gomperz, 1865, with additional readings from the papyrus by Philippson in Rhein, Mus. (1909). See Weltring, Das σημεῖον in der Aristotelischen, Stoischen und Epikureischen Philosophie (Bonn, 1910). Philodemus anticipated some of the difficulties that later troubled Mill, noticing that in some inductive problems a single observation provided valid conclusions, whereas in others very many were required (Gomperz, 19, 13); he knew that many fallacies were due to the use of insufficient instances (Gomp. 30, 2; 35, 15), that it was well not only to observe nature but to conduct systematic research and to employ the observations of others (Philippson, loc. cit., 13), that the observer must choose essential similarities in using the mode of “agreement” and must exclude conclusions as soon as a refuting instance appeared (Gomp. 13, 1; 17, 30; 20, 32), and he emphasized the need of employing the principle of difference (Gomp. 18, 15; Phil. p. 28). This treatise which probably draws lavishly on Zeno, has not yet been fully restored, and being a defense against Stoic attack it is not to be considered a formal and complete exposition of inductive logic. But in germ it contains most of the essential observations of J. S. Mill.