On Nature

Anaxagoras of Clazomenae, who taught in Athens for roughly thirty years and reportedly influenced Pericles and Euripides, wrote a treatise On Nature surviving in fragments quoted mainly by Simplicius, proposing that the world originated from an infinitely divisible primordial mixture in which everything contains a portion of everything else, distinguished only by which ingredients predominate in a given thing. He argued that Mind (Nous) alone is pure and unmixed with anything else, and that this Mind initiated the cosmos's rotation, separating out its constituents into the ordered world we observe, an idea Plato's Socrates praised in the Phaedo as promising but ultimately criticized for failing to explain things teleologically, by what is best, rather than merely mechanically. Anaxagoras was prosecuted at Athens for impiety, reportedly for claiming the sun was a red-hot stone rather than a god, and fled into exile.