ARISTIPPUS, the founder of the Cyrenaic school of philosophy, was the son of Aritadas, a wealthy merchant of Cyrene, in Africa. Nothing is known of the early part of his life, but he appears to have been sent by his father on a voyage to Greece, and while there, attending the Olympic games, he was attracted by the fame of the Socratic teaching. He immediately proceeded to Athens, united himself to the circle of followers who surrounded Socrates, and continued with him till his death in 399. He did not, however, accept without essential modification the teaching of his master, and his conduct, in many points, was displeasing both to Socrates and to other members of the Socratic band. He had probably brought with him from the wealthy city of Cyrene habits of luxury and ostentation, which contrasted forcibly with the homely and temperate life of his master. Xenophon, in the Memorabilia, reports his conversation on the nature of temperance, in which he defends his life of ease and self-indulgence. Plato also somewhat significantly states that he was absent in the island of iEgina on the day when Socrates died. Another feature of his character, which rendered Aristippus objectionable to the other Socratics, was his tendency to adopt the theory and practice of the Sophists, among whom he is expressly included by Aristotle (Met., ii. 2). It is more than probable that in Cyrene he had been already introduced to the doctrines of Protagoras, of whose influence his own theory shows manifest traces. We are further told that he opened his school before the death of Socrates, who blamed him for receiving payment from his scholars. This story is probably inaccurate as to the time when he began to teach, but it is undoubtedly true that he took money for his lectures, and defended the practice. Aristippus resembled the Sophists in another particular; like them, he avoided the duties and ties of citizenship by wandering from city to city. He was a professed cosmopolitan. The records of his travels, particularly of his visit or visits to the court of Syracuse, and his hostile relations with Plato there, are not in all points consistent, and rest on but slender authority. He appears to have settled finally in his native city, and seems to have died there. Although nothing is known with certainty as to the dates of his birth and death, 435 B.C. for the one, and about 356 B.C for the other, may be accepted as probably accurate. The life of Aristippus is the best exemplification of his principles. True temperance, according to him, consists not in abstaining from pleasure, but in being able to enjoy it with moderation. He therefore indulged in good living, rich clothing, splendid dwellings, and in the society of the accomplished hetaerae. But in all these pleasures he remained thoroughly master of himself ; he possessed them, and was not possessed by them. At any moment he could relinquish pleasure, for he had attained an equanimity that rendered him happy under any circumstances. To make the most of life, reasonably to enjoy the present moment, and to drive off care, reflection, and forethought, were the practical precepts by which he guided himself. As might naturally be expected, Aristippus left no definite system of philosophy ; indeed, according to some accounts, he wrote nothing at all. Diogenes Laertius certainly gives a list of works ascribed to him, but some of these were no doubt spurious, and none have survived. His daughter Arete, who had received the spirit of his teaching, continued the school after his death, and in turn instructed her son, the younger Aristippus (hence called _____), to whom is attri-buted the systematic representation of the Cyrenaic doc trines, the fundamental principles of which, however, are due to the elder Aristippus.

In the Socratic theory of morals, virtue had appeared as the only human good, and reason as the indispensable condition of right action; but there was at the same time a utilitarian side to this teaching. Ethical virtues had been tested by their consequences; proof of the virtuous quality of an action had been drawn from its tendency to give pleasure; happiness or utility had been, in a certain sense, laid down as the end of action. This one-sided aspect of the Socratic theory was accepted by Aristippus, and by him carried out to its full extent. He refused altogether to consider those speculative elements, which, though in some degree rejected by Socrates himself, were nevertheless inherent in the Socratic system. Logic and Physics he thought unnecessary, for they contained nothing which bore upon the end of action, and for the same reason, as Aristotle tells us, he rejected mathematical study. But although Logic and Physics, as separate disciplines, received no attention from the Cyrenaics, yet they were admitted as supports to their ethical theory. According to Aristip-pus, knowledge is sensible perception; all that we know of anything is the impression made by it on us. These impressions are motions,—changes in our mental states; and each mental state is a purely subjective phenomenon, from which we can deduce nothing as to the constitution of external reality. Nor can we compare our knowledge with that of others; each one's sensations are peculiarly his own, and can be known only by himself. General names or conceptions, and, consequently, general proposi-tions or truths, are meaningless and absurd. Individual feeling is the sole criterion of truth. From this it follows at once that such feeling is the only means by which we can determine our actions; feeling becomes the standard both of truth and of action. Now the only difference among feelings, in their relation to action, is their pleasurable or painful quality. The change effected in us by any object is either a violent, a gentle, or a perfectly tranquil motion. The first is painful, the second pleasant, the third indifferent. The end of life, as is manifest also from expe-rience, is the attainment of pleasure, which must be positive or real, not merely absence of pain, as the Epicureans afterwards held. Further, future pleasure, as a gentle motion not yet effected, and past pleasure, as a gentle motion completed and done, cannot possibly enter into our estimate of happiness. Immediate gratification, the pleasure of the moment (//.ovoxpovos), is the end of life; real happiness consists of a succession of moments of intense pleasure. The conception of a life in which, on the whole, pain is over-balanced by pleasure, may certainly be formed, but can never furnish a satisfactory end of action. Varieties of pleasure were, of course, admitted by Aristippus, but his decided opinion seems to have been that bodily pleasures and pains are the most potent factors in human happiness or misery. As to the causes of pleasure, the means by which it was to be attained, these are in themselves indifferent; an action which gives pleasure is good, whether or not it be opposed to the religion or laws of the country. The predicates, good and bad, attached to actions indepen-dently of their consequences, are merely conventional, and not founded in nature. Yet Aristippus was compelled to admit that some actions which give immediate pleasure entail more than their equivalent of pain. This fact, he thought, was the true ground of the conventional distinc-tion of right and wrong, and in this sense regard ought to be had to custom and law. But there is quite another side of the Cyrenaic doctrine, which appears as strongly in the theory as in the practice of Aristippus. Man must not give up himself as a slave to pleasure ; he must be superior to it. True happiness can only be obtained by rational insight, prudence (_____), or wisdom. Only through this prudence, which is in truth virtue, can man make a proper use of the good things in his power, and free himself from those superstitions and violent passions that stand in the way of happiness. Through this wisdom we are enabled to preserve the mastery of pleasure, to rise superior to past, future, or even present happiness, and make ourselves independent of circumstances. True free-dom of soul, real self-sufficiency, is given by wisdom, by mental cultivation. It is evident that at this point Aristippus approximates more closely to Socrates and the Cynics; and it is a suggestive fact that his followers, who pushed his principles to their logical consequences, landed in a theory of the negation of pleasure, nearly identical with the later Cynic views.

fWendt,De Phil. Cyrenaica, 1841; H.v. Stein, De Phil. Cyren., pt. i., "De Vita Aris.," 1855; Mullach, ___. Phil. Graec., n. 397-438.