Note 103 — Chapter XXVIII · THEÆTETUS.

See the remarks on the necessity of Verification, as a guarantee for the Deductive Process, in Mr. John Stuart Mill’s System of Logic, Book iii. ch. xi. s. 8. Newton puts aside his own computation or theory respecting gravity as the force which kept the moon in its orbit, because the facts reported by observers respecting the lunar motions were for some time not in harmony with it. Plato certainly would not have surrendered any συλλογισμὸς under the same respect to observed facts. Aristotle might probably have done so; but this is uncertain.