This article examines Diogenes of Apollonia's doctrines of intellection (νόησις) and soul in relation to his material principle, air. It argues that for Diogenes both intellection and soul are not, as commonly thought, some sort of air (namely, warm air), even though both intellection and soul are to be understood in terms of air and the system of τρόποι of air that he has set up. These new interpretations of intellection and soul yield insight into Diogenes' claims about the ordering activity of air as intellection and a renewed appreciation for his material monism.

Diogenes of Apollonia | soul | noēsis | air | principle | monism