Everything is air, thickening and thinning. The first attempt to explain change by a single measurable process.
The third of the Milesians took a step his teacher Anaximander would have called a retreat, and yet it was an advance. Anaximenes returned to a definite substance, air, but added the mechanism the others lacked. Air rarefies into fire and condenses into wind, cloud, water, earth, and stone. One stuff, one process, the whole world explained by how tightly it is packed. Breath is the soul, and as breath holds a person together, air holds the cosmos together. It is the first clear case of explaining quality by quantity, the seed of every physics that followed.
“Just as our soul, being air, holds us together, so breath and air encompass the whole world.”
Born in Miletus, the third of the great Milesian thinkers and a student of Anaximander.
Argued that one substance, air, becomes all things by condensing and thinning, the first attempt to explain quality through a measurable process.
Anaximenes was the pupil of Anaximander and the third of the Milesian thinkers.
Anaxagoras inherited the Milesian project of explaining the whole cosmos from a single material starting point.