John William Draper,
History of the Intellectual Development of Europe…
“ The doctrines of Anaximenes received a very important development in the hands of Diogenes of Apollonia, who asserted that all things originate from one essence, which, undergoing continual changes, becoming different at different times, turns back again to the same state. He regarded the entire world as a living being, spontaneously evolving and transforming itself, and agreed with Anaximenes that the soul of man is nothing but air, as is also the soul of the world. ”
