[196] The hypothesis of the earth’s diurnal rotation had clearly been suggested by a celebrated passage in Plato’s Timaeus, though whether Plato himself held it is still doubtful. That he accepted the revolution of the celestial spheres is absolutely certain; but while to our minds the two beliefs are mutually exclusive, Grote thinks that Plato overlooked the inconsistency. It seems probable that the one was at first actually a generalisation from the other; it was thought that the earth must revolve because the crystal spheres revolved; then the new doctrine, thus accidentally struck out, was used to destroy the old one.
[197] De Coel., II., viii., 290, a, 26.
[198] Zeller, p. 469.
[199] De Sens., vi., 446, a, 26.
[200] De Coel., I., viii., 277, b, 2.
[201] De Respir., i. and ii.
[202] De Gen. An., I., xvii.
[203] Outlines, p. 30.
[204] There is a passage in the Politics (I., ii., sub. in.) in which Aristotle distinctly inculcates the method of studying things by observing how they are first produced, and how they grow; but this is quite inconsistent with the more deliberate opinion referred to in the text (De Part. An., I., i., p. 640, a, 10). Perhaps, in writing the first book of the Politics he was more immediately under the influence of Plato, who preferred the old genetic method in practice, though not in theory.
[205] Meteor., II., iii., 357, a, 15 ff.