For he was also clever in discussion. But the Thirty Tyrants, as Xenophon tells us, forbade him to teach the art of arguing. Aristophanes also brings him on in comedy, making the Worse Argument seem the better. He was moreover the first, with his pupil Æschines, to teach oratory. He was likewise the first who conversed about life, and the first of the philosophers who came to his end by being condemned to death. We are also told that he lent out money. At least, investing it, he would collect what was due, and then after spending it invest again. But Demetrius the Byzantine says it was Crito who, struck by the charm of his character, took him out of the workshop and educated him. Realizing that natural philosophy was of no interest to men, it is said, he discussed ethics, in the workshops and in the agora, and used to say he was seeking "Whatsoever is good in human dwellings, or evil." And very often, we are told, when in these discussions he conversed too violently, he was beaten or had his hair pulled out, and was usually laughed to scorn. So once when he was kicked, and bore it patiently, some one expressed surprise; but he said, "If an ass had kicked me, would I bring an action against him?" Foreign travel he did not require, as most men do, except when he had to serve in the army. At other times, remaining in Athens, he disputed in argumentative fashion with those who conversed with him, not so as to deprive them of their belief, but to strive for the ascertainment of truth. They say Euripides gave him the work of Heraclitus, and asked him, "What do you think of it?" And he said, "What I understood is fine; I suppose what I did not understand is, too; only it needs a Delian diver!" He attended also to physical training, and was in excellent condition. Moreover, he went on the expedition to Amphipolis, and when Xenophon had fallen from his horse in the battle of Delium he picked him up and saved him. Indeed, when all the other Athenians were fleeing he retreated slowly, turning about calmly, and on the lookout to defend himself if attacked. He also joined the expedition to Potidæa--by sea, for the war prevented a march by land; and it was there he was said once to have remained standing in one position all night. There too, it is said, he was pre-eminent in valor, but gave up the prize to Alcibiades, of whom he is stated to have been very fond. Ion of Chios says moreover that when young he visited Samos with Archelaus, and Aristotle states that he went to Delphi. Favorinus again, in the first book of his 'Commentaries' says he went to the Isthmus.