Definition: Thales was a Greek Pre-Socratic philosopher from the Ionian city of Miletus (c. 620 - c. 546 B.C.). He predicted a solar eclipse and was considered one of the 7 ancient Sages. Aristotle considered Thales the founder of natural philosophy. He developed the scientific method, theories to explain why things change, and proposed a basic underlying substance of the world. He started the field of Greek astronomy and may have introduced geometry into Greece from Egypt.
Together with Anaximander and Anaximenes, Thales formed the Milesian school of philosophy.
Main Source: IEP Thales.
