Diogenes of Apollonia - Works

Works

His most famous work was On Nature (Peri Physeos), some fragments of which are preserved, chiefly by Simplicius. Diogenes, like Anaximenes, believed air to be the one source of all being, and all other substances to be derived from it by condensation and rarefaction. This he modified by the theories of his contemporary Anaxagoras, and asserted that air, the primal force, was intelligent:

And it seems to me that that which possessed thought is what people call air, and that by this everyone both is governed and has power over everything. For it is this which seems to me to be god and to have reached everything and to arrange everything and to be in everything. And there is not a single thing which does not share in it.

The nature of the universe is air, limitless and eternal, from which, as it condenses and rarefies and changes its properties, the other forms come into being. Among his other doctrines, he is said to have believed that there was an infinite number of worlds, and infinite void; that air, densified and rarefied, produced the different worlds; that nothing was produced from nothing, or was reduced to nothing; that the Earth was round, supported in the middle, and had received its shape from the whirling round of the warm vapours, and its concretion and hardening from cold.

The longest surviving fragment of Diogenes is that which is inserted by Aristotle in the third book of his History of Animals. It contains a description of the distribution of the blood vessels in the human body. It is notable chiefly because "here we can read at first hand what in the case of the other Presocratics we learn only indirectly: an attempt to describe in scientific detail the structure and organization of the physical world."

Diogenite meteorites are named for Diogenes of Apollonia, who was the first to suggest an outer space origin for meteorites:

With the visible stars revolve stones which are invisible, and for that reason nameless. They often fall on the ground and are extinguished, like the stone star that came down on fire at Aegospotami.