_Antisthenes_ was older than Plato; though the exact time of his birth is uncertain: but he fought at the battle of Tanagra, B.C. 420, though then very young. He became a disciple of Gorgias, and afterwards of Socrates, at whose death he set up a school in the Cynosarges, a gymnasium for the use of Athenians born of foreign mothers, near the temple of Hercules, from which place of assembly his followers were called Cynics. He lived to a great age, though the year of his death is not known, but he certainly was alive after the battle of Leuctra, B.C. 371. In his philosophical system, which was almost confined to ethics, he appears to have aimed at novelty rather than truth or common sense. He taught that in all that the wise man does he conforms to perfect virtue, and that pleasure is so far from being necessary to man, that it is a positive evil. He is reported also to have gone the length of pronouncing pain and infamy blessings rather than evils, though when he spoke of pleasure as worthless, he probably meant that pleasure which arises from the gratification of sensual or artificial desires; for he praised that which arises from the intellect, and from friendship. The _summum bonum_ he placed in a life according to virtue. In a treatise in which he discussed the nature of the Gods he contended for the unity of the Deity, and asserted that man is unable to know him by any sensible representation, since he is unlike any being on earth; and demonstrated the sufficiency of virtue for happiness, by the doctrine that outward events are regulated by God so as to benefit the wise and good. _Diogenes_, a native of Sinope in Pontus, who was born B.C. 412, was one of his few disciples; he came at an early age to Athens, and became notorious for the most frantic excesses of moroseness and self-denial. On a voyage to Ægina he was taken by pirates and sold as a slave to Xeniades, a Corinthian, over whom he acquired great influence, and was made tutor to his children. His system consisted merely in teaching men to dispense with even the simplest necessaries of civilized life: and he is said to have taught that all minds are air, exactly alike, and composed of similar particles; but that in beasts and in idiots they are hindered from properly developing themselves by various humors and incapacities of their bodies. He died B.C. 323, the same year that Epicurus came to Athens.