Anaxagoras of Clazomenae (a major Greek city of Ionian Asia Minor), a Greek philosopher of the 5th century B.C.E. (born ca. 500–480), was the first of the Presocratic philosophers to live in Athens. He propounded a physical theory of “everything-in-everything,” and claimed that nous (intellect or mind) was the motive cause of the cosmos. He was the first to give a correct explanation of eclipses, and was both famous and notorious for his scientific theories, including the claims that the sun is a mass of red-hot metal, that the moon is earthy, and that the stars are fiery stones. Anaxagoras maintained that the original state of the cosmos was a mixture of all its ingredients (the basic realities of his system). The ingredients are thoroughly mixed, so that no individual ingredient as such is evident, but the mixture is not entirely uniform or homogeneous. Although every ingredient is ubiquitous, some ingredients are present in higher concentrations than others, and these proportions may also vary from place to place (even if they do not do so in the original state of the cosmos). The mixture is unlimited in extent, and at some point in time it is set into motion by the action of nous (intellect). The mixture begins to rotate around some small point within it, and as the whirling motion proceeds and expands through the mass, the ingredients in the mixture are shifted and separated out (in terms of relative density) and remixed with each other, ultimately producing the cosmos of apparently separate material masses and material objects, with differential properties, that we perceive.