Thales

Thales lived in sixth-century BCE Miletus, a wealthy city on the coast of Asia Minor trading with Egypt and Babylon. Everything recorded about him is legend: he predicted an eclipse, measured the height of the pyramids by geometry, fell into a well while gazing at the stars and was laughed at by a servant girl, and grew rich by forecasting an olive harvest and renting every oil press in advance.

Aristotle named him the first natural philosopher because he proposed that water is the principle of all things. What matters is not the answer but the question. Thales assumed that behind the variety of appearances lies one principle that reason can grasp, and that this principle is a natural thing, not a god. He also said the lodestone has a soul because it moves iron, a remark that shows he saw the world as a living whole.

He left no writings and may never have written. But two successors in Miletus, Anaximander and Anaximenes, took up his question, and a school was born. The Greeks ranked him first among the Seven Sages.