[173] Diogenes Laert. ii. 9. τὰ δ’ ἄστρα κατ’ ἀρχὰς θολοειδῶς ἐνεχθῆναι, ὥστε κατὰ κορυφὴν τῆς γῆς τὸν ἀεὶ φαινόμενον εἶναι πόλον, ὕστερον δὲ τὴν (γῆν) ἔγκλισιν λαβεῖν. Plutarch, Placit. Phil. ii. 8.
His geology, meteorology, physiology.
Besides these doctrines respecting the great cosmical bodies, Anaxagoras gave explanations of many among the striking phenomena in geology and meteorology — the sea, rivers, earthquakes, hurricanes, hail, snow, &c.[174] He treated also of animals and plants — their primary origin, and the manner of their propagation.[175] He thought that animals were originally produced by the hot and moist earth; but that being once produced, the breeds were continued by propagation. The seeds of plants he supposed to have been originally contained in the air, from whence they fell down to the warm and moist earth, where they took root and sprung up.[176] He believed that all plants, as well as all animals, had a certain measure of intelligence and sentiment, differing not in kind but only in degree from the intelligence and sentiment of men; whose superiority of intelligence was determined, to a great extent, by their possession of hands.[177] He explained sensation by the action of unlike upon unlike (contrary to Empedokles, who referred it to the action of like upon like),[178] applying this doctrine to the explanation of the five senses separately. But he pronounced the senses to be sadly obscure and insufficient as means of knowledge. Apparently, however, he did not discard their testimony, nor assume any other means of knowledge independent of it, but supposed a concomitant and controlling effect of intelligence as indispensable to compare and judge between the facts of sense when they appeared contradictory.[179] On this point, however, it is difficult to make out his opinions.
[174] See Schaubach, ad Anax. Fr. p. 174-181.
Among the points to which Anaxagoras addressed himself was the annual inundation of the Nile, which he ascribed to the melting of the snows in Æthiopia, in the higher regions of the river’s course. — Diodor. i. 38. Herodotus notices this opinion (ii. 22), calling it plausible, but false, yet without naming any one as its author. Compare Euripides, Helen. 3.
[175] Aristotel. De Generat. Animal. iii. 6, iv. 1.
[176] Theophrastus, Hist. Plant. iii. 2; Diogen. Laert. ii. 9; Aristot. De Plantis, i. 2.
[177] Aristot. De Plantis, i. 1; Aristot. Part. Animal. iv. 10.
[178] Theophrastus, De Sensu, sect. 1 — sect. 27-30.
This difference followed naturally from the opinions of the two philosophers on the nature of the soul or mind. Anaxagoras supposed it peculiar in itself, and dissimilar to the Homœomeries without. Empedokles conceived it as a compound of the four elements, analogous to all that was without: hence man knew each exterior element by its like within himself — earth by earth, water by water, &c.