The Greek natural philosopher Thales (ca. 624-ca. 545 BC) founded the Ionian school of ancient Greek thinkers.

Thales was descended, according to the historian Herodotus, from Phoenicians who had settled in Miletus, a thriving Greek seaport on the west coast of Asia Minor (now Turkey). His mother, however, bore a Greek name. Thales's interest in the heavens was so well known that the philosopher Plato picked him as the example of the impractical student: while gazing upward and scanning the stars, he fell into a well.

Thales became so famous for his practical shrewdness and theoretical wisdom that in later times he began to be honored for having made important discoveries whose true origins were not known then and in some cases are still obscure. The most spectacular of these supposed achievements was his alleged prediction of a total solar eclipse (presumably that of May 28, 585 BC), at a time...