Anaxagoras

To understand the work of the Greek philosopher Anaxagoras, it helps to see him against the backdrop of two other philosophers: Zeno of Elea and Parmenides. Parmenides emphasized what he believed to be the unchanging nature of the universe and its basic components: if something exists, it has always existed and always will exist, because nothing can come into being out of nothing - which is to say, something does not emerge from nothing. Because things don’t come into being out of nothing, it follows (at least for Parmenides) that things don’t cease to exist, either: something cannot disappear into nothing. Parmenides further extrapolated that, because things neither enter nor leave existence, things also do not change in any meaningful way. Finally, he concluded that because things neither change, nor begin to exist, nor cease to exist, then there is essentially only one thing in the universe: what seems to us to be many things is actually a type of cosmic unity.

Zeno of Elea (not to be confused with Zeno of Citium) was a follower of Parmenides, and wanted to support his theories via a set of paradoxes. Zeno wanted to show that if one holds views which contradict the views of Parmenides, then one will wind up believing absurdities. Zeno wanted to show that motion, because it is a type of change, doesn’t really exist, despite the testimony of our sense-data: motion entails paradoxical results when one uses rigorous logic in physics. Likewise, the overarching cosmic unity of all being is consistent, but Zeno says that if we assume the existence of many things, we encounter self-contradictory results.

We arrive then at Anaxagoras. Yale’s Professor Brumbaugh writes:

Anaxagoras contributed three new ideas to Greek philosophy. First, he developed the view that matter is a continuum. This is one way to escape Zeno’s paradoxes, since it gives both space and time the property of infinite divisibility. Second, he presented a new concept of the mind and its place in the cosmic scheme, maintaining that although all other things mix together, mind remains pure. This was not yet a mind-matter dualism, but it was an important philosophic contribution. Third, Anaxagoras formulated a new way of relating these two dimensions, using mind as the motive power that sets matter in motion.

While Anaxagoras wanted to find solutions to some of Zeno’s paradoxes, he did not flatly reject Parmenides.

Impressed by Parmenides’ statement that “nothing can come from nothing,” Anaxagoras held that matter changes only through a different mixing of qualities which all things share. There is never a sudden bursting into being of something that was nothing just before. Instead there are changes in intensity of the mingled qualities that flow from one place to another. The qualities themselves, once they have separated out of the primordial state when “all things were together,” are conserved, not created or destroyed.

In this way, Anaxagoras tries to preserve Parmenides basic doctrine, while explaining the appearance of change and motion. There is something akin to modern molecular chemistry in the ideas of Anaxagoras, although he would not have thought of it that way: the individual atoms do not essentially change, but they can be recombined into different compounds.