Date: w. 350 B.C.
"This is what led Democritus to say that soul is a sort of fire or hot substance; his 'forms' or atoms are infinite in number; those which are spherical he calls fire and soul, and compares them to the motes in the air which we see in shafts of light coming through windows."
preview | full record— Aristotle (384-322 B.C.)