Thales
（
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.
