Anaximenes of Miletus

Anaximenes son of Eurystratus (586 BC – 526 BC), a Miletan extended Anaximander’s ideas especially in astronomy. He was a fellow citizen, friend and student of Anaximander; some say he was also a pupil of Parmenides.

Like Thales and Anaximander, Anaximenes believed that all things in nature are the various forms of one fundamental substance, from which they derive and into which they return. The ultimate essence of all things he regarded as ‘air’ rather than the ‘water’ of Thales. This air was linked up with that essence which is essential to life.

He called it penuma –literally breath – and held that in a sense the universe itself was alive: ‘As out soul, being air, sustain us, so pneuma and air pervade the whole world’.

He also said that stars move, not under the earth but round it. He used simple and econo0cmial Ionic speech.

Some aspects of his physical theory, notably his use of empirical models and his attempt to identify a cause of elemental change, constitute scientific advances.
Anaximenes of Miletus