HoPwaG: Anaxagoras

Anaxagoras as featuring in Plato's Phaedo, as the spur to theory of Forms, an improved version of Anaxagoras' thesis that mind is the fundamental cosmological principle.

Doctrines:

• universal mixture: "everything is in everything", except mind;
• mind as purest thing, central in forming cosmos.

So want to know how mind and the universally mixed physical substances interact.

Mind as infinite, and controls everything that lives (cp. Xenophanes or Heraclitus' fire): something divine (or near-divine).

What Socrates wanted: if mind in charge of cosmos, looks like that leaves room to explain design of cosmos. But that's what he found lacking: Anaxagoras gives explanations in terms of physical principles.

But Socrates may have been looking for too much. Note the limitation: mind controls living things, leaving room for non-living things (rocks, etc.) to have explanations in non-mind terms.

Another limitation: things have different shares of mind: some humans > other humans > mammals > insects. So Anaxagoras' mind looks less like a "creator" mind, more of an explanation of why some things are as they are. Mind is an unequally distributed ingredient in the cosmos.

So now want to know: how does this distribution work? Doctrine of universal mixture:

• pre-cosmos, there were two substances--mind and, substance two, a mixture of everything else;
• the mixture of everything else has seeds of differentiated substances (air, water);
• mind over and above the things it's going to control; it's unmixed;
• mind initiates the cosmos, a rotation of the other substances, and by rotational forces, lighter stuff is sifted from heavier stuff, giving celestial bodies etc (note similarity to Anaximenes' doctrine of substances, combined with Xenophanes' doctrine of God);
• but difference from Anaximenes: nothing ever gets completely sifted.

Aristotle wants to see this in the light of Parmenidean reasoning: he interprets Anaxagoras as:

• accepting the Parmenidean claim that being can't come from non-being--call that the Parmenidean constraint--but also;
• accepting the Atomist doctrine that motion and change are real.

So the Atomists get around the Parmenidean constraint by having atoms be eternal and unchanging, and conglomerating in different combinations. Anaxagoras, says Aristotle, is getting around the Parmenidean constraint in a different way: no absolute change required because everything is everything else. [So changes, I think, are just variations of the proportions of one segment of the universal mixture.]

Example: eating bread replenishes body; Anaxagoras' explanation is that bread contains bits of bone, flesh, etc. So every bit of matter really contains bits of everything else. Different appearances of material objects explained by different proportions.

Question: what are these ingredients? This matter of interpretive dispute: one idea is that it's a short list of ingredient attributes, like hot, cold, moist, dry, etc. So this doesn't sound so odd; it's just that Anaxagoras is talking in physical mixture language. But another interpretive idea (e.g. held by Aristotle) is that the ingredients really are other physical things--not necessarily specific objects, but the constituents of any object. Or maybe he could be relaxed about what the ingredients are, but say that whatever they are, the doctrine of universal mixture applies.

Anaxagoras as initiating the problem of mixture: what is it for one object to be mixed with another? We think that when water and wine get mixed, what happens is just a jumbling--a juxtaposition, not a fusing. Atomists agree with the jumbling answer; Anaxagoras (and other ancients) take the fusion route.