Anaxagoras (lived c. 500–428 BC)

Greek cosmologist and pre-Socratic philosopher. He speculated that everything consisted of ‘seeds’, which contained a little of every natural substance. Changes in things occurred by the exchange of portions of seeds. In the beginning, all natural substances were mixed together and Mind (‘finest of all things and purest’) started a rotation that formed the Earth by vortex action.

Anaxagoras was born in Clazomenae, on what is now the Turkish coast, and studied under Anaximenes. He taught in Athens for 30 years (c. 480–c. 450 BC), and his pupils included the politician Pericles, the playwright Euripides, and possibly the philosopher Socrates. He was prosecuted for impiety and banished because he described the Sun as a white-hot lump of stone.