Thales

Thales of Miletus stands at the very beginning of Western philosophy. Counted first of the legendary Seven Sages, he was the first, Aristotle tells us, to seek a single natural first principle of all things — and he named it water, the moist source from which everything arises and on which the earth floats.

Tradition credits him with predicting the solar eclipse of 585 BCE, with feats of geometry and engineering, and with the saying that 'all things are full of gods'. Whether or not the stories are true, his decisive step was to explain the world by nature rather than myth — founding, with his successors Anaximander and Anaximenes, the Milesian school.