A word originally used by Anaxagoras to mean an all-knowing, all-pervading spirit or force; in later Greek philosophy it came to mean simply mind, reason, or intellect.

NOUN: In Philosophy a. Reason and knowledge as opposed to sense perception. b. The rational part of the individual human soul. c. The principle of the cosmic mind or soul responsible for the rational order of the cosmos. d. In Stoicism, the equivalent of Logos. e. In Neo-Platonism, the image of the absolute good, containing the cosmos of intelligible beings.
ETYMOLOGY: Greek.