(Ἀρίστιππος), son of Aritades, born at Cyrene, and founder of the Cyrenaic School of Philosophy, came over to Greece to be present at the Olympic games, where he fell in with Ischomachus the agriculturist (whose praises are the subject of Xenophon's Occonomicus), and by his description was filled with so ardent a desire to see Socrates, that he went to Athens for the purpose (Plut. de Curios. 2), and remained with him almost up to the time of his execution, B. C. 399. Diodorus (15.76) gives B. C. 366 as the date of Aristippus, which agrees very well with the facts which we know about him, and with the statement (Schol. ad Aristoph. Plut. 179), that Lais, the courtezan with whom he was intimate, was born B. C. 421.

Though a disciple of Socrates, he wandered both in principle and practice very far from the teaching and example of his great master. He was luxurious in his mode of living; he indulged in sensual gratifications, and the society of the notorious Lais; he took money for his teaching (being the first of the disciples of Socrates who did so, D. L. 2.65), and avowed to his instructor that he resided in a foreign land in order to escape the trouble of mixing in the politics of his native city. (Xen. Mlem. 2.1.) He passed part of his life at the court of Dionysius, tyrant of Syracuse, and is also said to have been taken prisoner by Artaphernes, the satrap who drove the Spartans from Rhodes B. C. 396. (Diod. 14.79; see Brucker, Hist. Crit. Phil. 2.2, 3.) He appears, however, at last to have returned to Cyrene, and there he spent his old age. The anecdotes which are told of him, and of which we find a most tedious number in Diogenes Laertius (2.65, &c.), by no means give us the notion of a person who was the mere slave of his passions, but rather of one who took a pride in extracting enjoyment from all circumstances of every kind, and in controlling adversity and prosperity alike. They illustrate and confirm the two statements of Horace (Hor. Ep. 1.1. 18), that to observe the precepts of Aristippus is "mihi res, non me rebus subjungere," and (1.17. 23) that, " omnis Aristippum deceit color et status et res." Thus when reproached for his love of bodily indulgences, he answered, that there was no shame in enjoying them, but that it would be disgraceful if he could not at any time give them up. When Dionysius, provoked at some of his remarks, ordered him to take the lowest place at table, he said, " You wish to dignify the seat." Whether he was prisoner to a satrap, or grossly insulted and even spit upon by a tyrant, or enjoying the pleasures of a banquet, or reviled for faithlessness to Socrates by his fellow-pupils, he maintained the same calm temper. To Xenophon and Plato he was very obnoxious, as we see from the Memorabilia (l.c.), where he maintains an odious discussion against Socrates in defence of voluptuous enjoyment, and from the Phaedo (p. 59c), where his absence at the death of Socrates, though he was only at Aegina, 200 stadia from Athens, is doubtless mentioned as a reproach. (See Stallbaum's note.) Aristotle, too, calls him a sophist (Metaphys. 2.2), and notices a story of Plato speaking to him with rather undue vehemence, and of his replying with calmness. (Rhet. 2.23.) He imparted his doctrine to his daughter Arete, by whom it was communicated to her son, the younger Aristippus (hence called Μητροδίδακτος), and by him it is said to have been reduced to a system. Laertius, on the authority of Sotion (B. C. 205) and Panactius (B. C. 143), gives a long list of books whose authorship is ascribed to Aristippus, though he also says that Sosicrates of Rhodes (B. C. 255) states, that he wrote nothing. Among these are treatises Περὶ Παιδείας, Περὶ Ἀρετῆς, Περὶ Τύχης, and many others. Some epistles attributed to him are deservedly rejected as forgeries by Bentley. (Dissertation on Phalaris, &c. p. 104.) One of these is to Arete, and its spuriousness is proved, among other arguments, by the occurrence in it of the name of a city near Cyrene, Βερενίκη, which must have been given by the Macedonians, in whose dialect β stands for φ, so that the name is equivalent to Φερενίκη, the victorious.

We shall now give a short view of the leading doctrines of the earlier Cyrenaic school in general, though it is not to be understood that the system was wholly or even chiefly drawn up by the elder Aristippus; but, as it is impossible from the loss of contemporary documents to separate the parts which belong to each of the Cyrenaic philosophers, it is better here to combine them all. From the fact pointed out by Ritter (Geschichte der Philosophie, 7.3), that Aristotle chooses Eudoxus rather than Aristippus as the representative of the doctrine that Pleasure is the summum bonum (Eth. Nic. 10.2), it seems probable that but little of the Cyrenaic system is due to the founder of the school. * Ritter believes that Aristippus is hinted at (Eth. Nic. 10.6), where Aristotle refutes the opinion, that happiness consists in amusement, and speaks of persons holding such a dogma in order to recommend themselves to the favour of tyrants.

The Cyrenaics despised Physics, and limited their inquiries to Ethics, though they included under that term a much wider range of science than can fairly be reckoned as belonging to it. So, too, Aristotle accuses Aristippus of neglecting mathematics, as a study not concerned with good and evil, which, he said, are the objects even of the carpenter and tanner. (Metaphys. 2.2.) They divided Philosophy into five parts, viz. the study of (1) Objects of Desire and Aversion, (2) Feelings and Affections, (3) Actions, (4) Causes, (5) Proofs. Of these (4) is clearly connected with physics, and (5) with logic.