Thales in Harpers Dictionary of Classical Antiquities (1898)

(Θαλῆς). An Ionian, the founder of Greek philosophy. He was a contemporary of Solon and Croesus, and one of the Seven Sages, and was born at Miletus about B.C. 636, and died about 546, at the age of ninety, though the exact dates of his birth and death are not known. He is said to have predicted the eclipse of the sun which happened in the reign of the Lydian king Alyattes; to have diverted the course of the Halys in the time of Croesus; and later, in order to unite the Ionians when threatened by the Persians, to have instituted a federal council in Teos. Aristotle preserves a story of his knowledge of meteorology which was turned to a practical use (Polyb. i. 11, p. 1259). In the lists of the Seven Sages his name seems to have stood at the head, and he displayed his wisdom both by political sagacity and by prudence in acquiring wealth. In mathematics we find attributed to him only proofs of propositions which belong to the first elements of geometry, and which could not possibly have enabled him to calculate the eclipses of the sun and the course of the heavenly bodies. He may, however, have obtained a knowledge of the higher branches of mathematics from Egypt, which country he is said to have visited. In the annals of Greek philosophy he was probably the first who looked for a physical origin of the world instead of resting upon mythology. Thales maintained that water is the origin (ἀρχή) of things, meaning thereby that it is water out of which everything arises and into which everything resolves itself, and that the earth floated upon the water. Thales left no works behind him (Herod.i. 74, Herod., 170; Diog. Laert. i. 25; Aristot. Metaph. i. 3, p. 983). See Ionian School of Philosophy; Philosophia.