In the analysis of Anaxagoras’ physics in view of the relation between his teachings on multitude and heterogeneity, two central questions emerge: 1) How can the structure of the universe considered purely mereo-topologically help us explain that at the first cosmic stage no qualitative difference is manifest in spite of the fact that the entire qualitative heterogeneity is supposedly already present there? 2) How can heterogeneity become manifest at the second stage, resulting from the noûs intervention, if according to fragment (...) B 6 such a possibility requires the existence of “the smallest”, while according to the general principle stated in fragment B 3 there is not “the smallest” but always only “a smaller”? This paper showcases the perplexity of these two questions but deals only with the former. The answer follows from Anaxagoras’ being a thoroughgoing infinitist in the way in which no Greek physicist was: the principle of space isotropy operative in geometry is extended to physics as well. So any two parts of the original mixture are similar to each other not only in view of the smaller-larger relation but also because each contains everything that the other one contains. This in effect means that at the stage of maximal possible heterogeneity each part of any part contains infinitely many heterogeneous parts of any kind whatsoever. So, neither can there be homogeneous parts in view of any qualitative property, nor can there be predominance in quantity of parts of any kind that would make some property manifest. (shrink)

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. (shrink)

In this article, both Anaxagoras’ theory of multiple worlds and the principles of his theory of matter are examined. It is argued that the five principles, which are set out explicitly in the extant fragments, (No Becoming, Indefinite Types, Universal Mixture, Predominance, and Infinite Divisibility) form a consistent set. Further, it is argued that the principle of Homoeomereity, which Anaxagoras attributes to Anaxagoras, is consistent with Anaxagoras’ other principles and is likely to be a genuine principle of Anaxagoras’ physics.

In this article, both Anaxagoras' theory of multiple worlds and the principles of his theory of matter are examined. It is argued that the five principles, which are set out explicitly in the extant fragments, (No Becoming, Indefinite Types, Universal Mixture, Predominance, and Infinite Divisibility) form a consistent set. Further, it is argued that the principle of Homoeomereity, which Anaxagoras attributes to Anaxagoras, is consistent with Anaxagoras' other principles and is likely to be a genuine principle of Anaxagoras' physics.