Anaximenes of Miletus is the last of three thinkers who came from the same Ionian town and whose work, according to tradition, marks the very beginning of philosophy. Yet though Anaximenes' thoughts represent the culmination of Miletian perception of the world, he has been somewhat overshadowed by Thales and Anaximander.
Nonetheless, it was to him that Theophrastus dedicated a separate treatise. According to Aristotle, Anaximenes believed the air to be the origin of all there is.
What he is best known for, however, are his concrete formulations of the processes of origin, decay, and changes in nature viewed against the background of condensation and rarefaction of the air. And though what we are familiar with are most likely later interpretations of his ideas, the strong accent on air found in doxography may partly reflect Anaximenes' actual perspective.
It was probably based on intimate aspects of life reflected in parallels between the air, the breath, and the soul. Boundless air encompassing the entire world then represents true divinity, from which 'gods and divinities come to be'.