Anaxagoras was a Greek philosopher and scientist of the fifth century B.C.E. He was born into a wealthy family from the city of Clazomenae (on the west coast of today's Turkey), but is celebrated for abandoning his inheritance to devote himself to scholarship. He is also remembered as the first thinker to introduce philosophy to Athens. As a scientist, Anaxagoras distinguished himself, among other things, as the first Westerner to correctly explain solar and lunar eclipses. He was once incarcerated for explaining that the moon reflected the light of the Sun, and that the Sun is not a god. Yet some of his theories would be disproved, including his descriptions of the Sun as a mass of fiery metal and of the stars as blazing stones.
Anaxagoras' most original contributions to philosophy concern his doctrine of "nous" ("mind") as the origin of the cosmos. He held that all things originally existed together as a boundless, homogeneous mixture. Nous formed the cosmos by causing the mixture to continuously rotate around a vortex, which in turn caused like elements within the mixture to separate out to form the various material masses that comprise the cosmos. In a second phase of separation, flesh, seeds, and other organic elements separated from the mixture and came together to form living organisms. Although scholars like Plato and Aristotle criticized Anaxagoras for presenting nous as an ethically neutral force, Anaxagoras' views were at least partly reinforced by Newtonian science.