to the attitude of mind now called _materialism_, because in them the atoms, endowed with the material properties of solidity, shape, and weight alone, are conceived to be the only true existences, all others being secondary and derivative. This materialism (with some significant qualifications) was a century later the central doctrine of Epicurus, and is of importance to us by reason of its sharp contrast with the Stoic system of physics. [Sidenote: Socrates.] =44.= The value of these scientific speculations was not for the time being fully recognised at Athens. It was in the atmosphere of sophistic discussion, not free from intellectual mists, but bracing to the exercise of civic and even of martial virtue that SOCRATES of Athens (circ. 469-399 B.C.) grew to maturity. He set to his fellow-citizens an example of the vigorous performance of duty. As a soldier he was brave almost to rashness, and took an active part in three campaigns. As a magistrate he discharged his duty unflinchingly. After the battle of Arginusae the ten Athenian generals were said to have neglected the duty of succouring certain disabled ships and the people loudly demanded that all should be condemned to death by a single vote. Socrates was one of the presiding senators, and he absolutely refused to concur in any such illegal procedure[56a]. Again, when Athens was under the rule of the Thirty, Socrates firmly refused to obey their unjust orders[57]. But when himself condemned to death, he refused to seize an opportunity for flight which was given him; for this, he said, would be to disobey the laws of his country[58]. His private life was marked by a firm self-control. Athens was now wealthy, and its leading citizens frequently gathered together for festive purposes. Socrates joined them, but showed the greatest moderation in eating and drinking: such a course, he said, was the better for health and also produced more real pleasure. Over the grosser temptations of the senses he had won a complete victory[59]. His temper was calm and even; he was not put out by the violences of his wife, nor did he allow himself to break out into rage with his slaves. His personal habits, though simple, were careful: he did not approve any neglect either of bodily cleanliness or of neatness in dress. Thus Socrates gave an example of a life of activity and self-control (ἰσχὺς καὶ κράτος); and by his character, even more than by his speculation, exercised an influence which extended widely over many centuries. [Sidenote: His teaching.]