Anaxagoras, an Ionian from Clazomenae, came to Athens in 480 B.C. quite possibly as a member of Xerxes' invading army or navy. At this time he was probably about twenty years old. He was the first philosopher to settle in Athens and he lived there for thirty years. He was a friend and a teacher of Pericles and, probably in 450 B.C., was accused before the Athenian courts by Pericles' political opponents. The charges were that he was a pro-Persian and that his attitude to the gods was irreligious. He had taught that the sun was a red-hot stone and that the moon was made of earth. However he had not the scruples of Socrates about evading prison and, probably with the help of Pericles, he was able to leave Athens and to return to Ionia. He settled at Lampsacus and lived there for about twenty-five years. As a mark of respect to his memory, the anniversary of his death was long kept as a holiday in Lampsacus for schoolchildren.
His work was read first with enthusiasm and finally with disappointment by the young Socrates. The only fragments which survive seem to have come from the first book of this work, in which he deals with his general principles. There is still controversy among scholars about precisely how these principles are to be understood.
His approach to the problem of substance and change seems to have been like that of Empedocles (though without his mystical, Pythagorean attitude). He too accepts the view of Parmenides that nothing can be added to or taken away from what is. He too is concerned to explain motion and change. It is quite likely (see fragment 17) that he had read the poem of Empedocles. Certainly his idea of "mingling" and "separation" reminds one of the Sicilian philosopher (though this idea may also be derived from Anaximenes ).
He did not believe in either one or four "roots" or elements. Nor is he an atomist. He held the view that matter is a continuum, infinitely divisible and that, however much it may be divided, each part will contain elements of everything else. Thus the difference between, say, fire and earth, or a piece of gold or a grain of wheat, is accounted for simply by the fact that in fire there is more fire than there is in earth, and in gold more gold than there is in wheat; yet there is some fire in earth, some earth in fire, some wheat in gold and some gold in wheat. It seems probable, too, that the opposites — the hot and the cold, the moist and the dry, etc. — were also regarded as "things" and hence part of the constitution of the "seeds."
As for the problem of how these seeds ever came together into the forms we know — the problem of motion, growth and change — Anaxagoras assumes the existence of an external cause which he calls Nous or "Mind." In doing so he earned the applause of Aristotle who, simply because he made this assumption, says that he, compared with all the other philosophers whom we have been discussing, was like a sober man among a crowd of drunkards. Socrates too, according to Plato, was delighted when he first read that Anaxagoras had made Mind the cause of all things. However he was quickly disillusioned by discovering that though Anaxagoras did indeed use Mind as a kind of deus ex machina to account for the original rotatory movement which gave rise to the formation of the world, his real interests were much more what we would call "scientific." He only used Mind as a hypothesis when he could think of nothing else. We should note too that Anaxagoras' Nous, like the Love and Strife of Empedocles, is imagined as a substance (fragment 12). It is therefore impossible to maintain that Anaxagoras introduced, except verbally, anything which can be called a "spiritual" element into philosophy. The following fragments are quoted from Burnet.
4. . . . . But before they were separated off, when all things were together, not even was any colour distinguishable; for the mixture of all things prevented it-of the moist and the dry, and the warm and the cold, and the light and the dark, and of much earth that was in it, and of a multitude of innumerable seeds in no way like each other. For none of the other things either is like any other. And these things being so, we must hold that all things are in the whole.
6. And since the portions of the great and of the small are equal in amount, for this reason, too, all things will be in everything; nor is it possible for them to be apart, but all things have a portion of everything. Since it is impossible for there to be a least thing, they cannot be separated, nor come to be by themselves; but they must be now, just as they were in the beginning, all together. And in all things many things are contained, and an equal number both in the greater and in the smaller of the things that are separated off.
8. The things that are in one world are not divided nor cut off from one another with a hatchet, neither the warm from the cold nor the cold from the warm.
11. In everything there is a portion of everything except Nous and there are some things in which there is Nous also.
12. All other things partake in a portion of everything, while Nous is infinite and self-ruled, and is mixed with nothing, but is alone, itself by itself. For if it were not by itself, but were mixed with anything else, it would partake in all things if it were mixed with any; for in everything there is a portion of everything, as has been said by me in what goes before, and the things mixed with it would hinder it, so that it would have power over nothing in the same way that it has now being alone by itself. For it is the thinnest of all things and the purest, and it has all knowledge about everything and the greatest strength; and Nous has power over all things, both greater and smaller, that have life. And Nous had power over the whole revolution, so that it began to revolve in the beginning. And it began to revolve first from a small beginning; but the revolution now extends over a larger space, and will extend over a larger still. And all the things that are mingled together and separated off and distinguished are all known by Nous. And Nous set in order all things that were to be, and all things that were and are not now and that are, and this revolution in which now revolve the stars and the sun and the moon, and the air and the aether that are separated off. And this revolution caused the separating off, and the rare is separated off from the dense, the warm from the cold, the light from the dark, and the dry from the moist. And there are many portions in many things. But no thing is altogether separated off nor distinguished from anything else except Nous. And all Nous is alike, both the greater and the smaller; while nothing else is like anything else, but each single thing is and was most manifestly those things of which it has most in it.
13. And when Nous began to move things, separating off took place from all that was moved, and so much as Nous set in motion was all separated. And as things were set in motion and separated, the revolution caused them to be separated much more.
14. The Hellenes follow a wrong usage in speaking of coming into being and passing away; for nothing comes into being or passes away, but there is mingling and separation of things that are. So they would be right to call coming into being mixture, and passing away separation.
21. From the weakness of our senses we are not able to judge the truth.
21a. What appears is a vision of the unseen.