Anaximenes of Miletus (11 juin 585 av. J.-C. – 12 déc. 528 av. J.-C.)

Description:

There is very little surviving texts written by or referencing Anaximenes; meaning there is little we know of his philosophy. The main doctrine which has survived in vague references, is his belief that air was the source of all things - opposing Anaximander who is speculated to be his contemporary and most likely his student.

Anaximenes states:

[Air] differs in essence in accordance with its rarity or density. When it is thinned it becomes fire, while when it is condensed it becomes wind, then cloud, when still more condensed it becomes water, then earth, then stones. Everything else comes from these. (DK13A5)

The latter quotation is taken to be of essential importance as Anaximenes supports his argument with empirical evidence - of a sort. He also seems to be conveying knowledge of weather systems. There have been a number of suggestions in speculating why Anaximenes believed air to be the original substance of all things. Perhaps his argument was support by the basic fact that people need air to breathe, supposing that it was the essential source of life.