Anaximenes

naximenes (flourished circa 546 BC), the pupil of Anaximander, specified the boundless to have the element air, being that substance of which all is really made, also the gods and all things divine. He regarded air as this all encompassing ether, because: "Air is near to the incorporeal" and also it is never exhausted, though all are generated by breathing it.

     When the air is uniform it is not visible, but when set in motion, when turning hot or cold, when moistened, it gets perceivable shapes. It is always moving and changing, or there would not be so many things forming in it. When dissolved, it becomes fire, when compressed water, and when further condensed earth, lastly stone, its most condensed form.

     The soul, too, is air, and that which keeps the body intact. Aëtios quotes him stating:

     As our soul, which is air, holds us together, so do breath and air surround the whole universe.

     Like the cosmos of Anaximander, that of his student is in little need of the gods. The universe works by its own machinery, creating and upholding everything within it - including the gods. This is an astronomical order in no need of outward influence.

Literature
Freeman, Kathleen, Ancilla to The Pre-Socratic Philosophers, Oxford 1952.
Kahn, Charles H., Anaximander and the Origins of Greek Cosmology, New York 1960.