Apart from physical science, we learn that Anaxagoras was a close friend and adviser of the great Athenian statesman, Pericles; and we have by chance an account of a long discussion between the two men about the theory of punishment—whether the object of it is to do "justice" upon a wrong-doer apart from any result that may accrue, or simply to deter others from doing the same and thus make society better. The question is the subject of a vigorous correspondence in the Times while these words are writing. We can understand what an effect such a teacher as this would have on the eager young man from Phlya. One great word of liberation was already in the air and belongs to no one sophist or philosopher. This was the distinction between Nature on the one hand and Custom or Convention on the other. The historian Herodotus, who was no sophist but loved a good story, tells how the Persian king, Darius, called some Greeks and some Indian tribesmen together into his presence. He then asked the Greeks what payment would induce them to eat the dead bodies of their fathers. "Nothing in the world," they cried in indignation. "They would reverently burn them." He proceeded to ask the Indians what they would take to burn their fathers' bodies, and they repelled the bare thought with horror; they would do nothing but eat them with every mark of love and respect. "Fire burns in the same way both here and in Persia," the saying was, "but men's notions of right and wrong are not at all the same." The one is Nature; the other is man's Custom or Convention. This antithesis between "Phusis" and "Nomos" ran vividly through the whole of Greek philosophy, and awoke with renewed vigour in Rousseau and the radical writers of the eighteenth century. It is an antithesis against which conformist dialecticians have always turned their sharpest weapons. It has again and again been dissected and refuted and shown to be philosophically untenable: but it still lives and has still something of the old power to shatter and to set free. All the thinkers of Greece at the time we are treating were testing the laws and maxims of their day, and trying to find out what really rested on Nature and what was the mere embroidery of man. It is always a dangerous and exciting inquiry; especially because the most irrational conventions are apt also to be the most sacrosanct.
This whole spirit was specially incarnate in another of Euripides' teachers. We hear of Protagoras in his old age from that enemy of the sophists, Plato. But for this sophist even Plato's satire is kindly and almost reverent. Protagoras worked not at physical science, but at language and philosophy. He taught men to think and speak; he began the study of grammar by dividing sentences into four kinds, Optative, Interrogative, Indicative, Imperative. He taught rhetoric; he formulated the first theory of democracy. But it was as a sceptic that he struck men's imaginations most. "About the Gods, I have no means of knowing either that they are or are not. For the hindrances to knowledge are many, the darkness of the subject and the shortness of man's life." Numbers of people, no doubt, went as far as this, and without suffering for it as Protagoras did; but his scepticism cut deeper and raised questions still debated in modern thought. "Man is the measure of things"; there is no truth to be had beyond the impression made on a man's mind. When this given object seems one thing to A and another thing to B, it is to each one exactly what it seems; just as honey not only seems sweet but is sweet to a healthy man, and not only seems bitter but is bitter to a man with jaundice. Then you can not say, we may ask, that one or other impression is false, and will prove false on further inquiry? No: he answers; each impression is equally true. The only difference is that each state of mind is not equally good. You cannot prove to the jaundiced man that his honey is sweet, for it is not: or to the drunkard that he does not desire his drink, for he does: what you can do is to alter the men's state of mind, to cure the jaundice or the drunkenness. Our cognition flows and changes. It is the result of an active impact upon a passive percipient. And, resulting from this change, there are in practice always two things to be said, a pro and a con. about every possible proposition. There is no general statement that cannot be contradicted.
Other teachers also are represented as having influenced Euripides; Archelaus, who tried to conceive Anaxagoras's "Mind" in some material form, as air or spirit—for spiritus, of course, means "breath"; Prodicus, who, besides his discoveries in grammar, is the author of a popular and edifying fable which has served in many schoolrooms for many centuries. It tells how Heracles once came to some cross roads, one road open, broad, and smooth and leading a little downhill, the other narrow and uphill and rough: and on the first you gradually became a worse and worse man, on the second a better one. There was Diogenes of Apollonia, whose theories about air seem to have had some effect on Euripides' writings; and of course there was, among the younger men, Socrates. Socrates is too great and too enigmatic a teacher to be summed up in a few sentences, and though a verse of ancient comedy has come down to us, saying, "Socrates piles the faggots for Euripides' fire," his influence on his older friend is not very conspicuous. Euripides must have caught something from his scepticism, his indifference to worldly standards, his strong purpose, and something also from his resolute rejection of all philosophy except that which was concerned with the doings and feelings of men. "The fields and trees will not talk to me; it is only the human beings in the city that will." That saying of Socrates might be the motto of many a dramatist.
The greatness of these philosophers or sophists of the fifth century does not, of course, lie in the correctness of their scientific results. The dullest and most unilluminated text-book produced at the present day is far more correct than Anaxagoras. Their greatness lies partly in the pioneer quality of their work. They first struck out the roads by which later workers could advance further. Partly in the daring and felicity with which they hit upon great and fruitful ideas, ideas which have brought light and freedom with them whenever they have recurred to men's minds, and which, as we have seen, are to a great extent still, after more than two thousand years, living issues in philosophic thought. Partly it lies in the mere freedom of spirit with which they set to work, unhampered by fears and taboos, to seek the truth, to create beauty, and to improve human life. The difference of atmosphere between the sophists of the Periclean circle and the ordinary backward Attic farmer must have been visible to every observer. If more evidence of the great gulf was needed, it was supplied emphatically enough in the experience of Euripides. He was himself prosecuted by Cleon, the demagogue, for "impiety." The same charge had been levelled even against his far less destructive predecessor, Aeschylus. Of these three special friends whom we have mentioned, Euripides did not live to see Socrates condemned to death and executed. But he saw Anaxagoras, in spite of the protection of Pericles, accused of "impiety" and compelled to fly for his life. He saw Protagoras, for the book which he had read aloud in Euripides' own house, prosecuted and condemned. The book was publicly burned; the author escaped, it is said, only to be drowned at sea, a signal mark in the eyes of the orthodox of how the gods regarded such philosophy.
Thought was no doubt freer in ancient Athens than in any other city within two thousand years of it. Those who suffered for religious advance are exceedingly few. But it was not in human nature, especially in such early times, for individuals to do such great service to their fellow men and not occasionally be punished for it. They induced men for a time to set reason and high ideals above the instincts of the herd: and sooner or later the herd must turn and trample them.
One of the ancient lives says that it was this sense of the antagonism between Anaxagoras and the conservative masses that turned Euripides away from philosophy. One need scarcely believe that. The way he took was not the way to escape from danger or unpopularity. And when a man shows extraordinary genius for poetry one need not search for the reasons which induced him not to write prose. He followed in the