In the history of the Greek mind these two last-mentioned philosophers (though included by Cicero among the _plebeii philosophi_) are not less important than Plato and Aristotle. The speculations and precepts of Antisthenes passed, with various enlargements and modifications, into the Stoic philosophy: those of Aristippus into the Epikurean: the two most widely extended ethical sects in the subsequent Pagan world.--The Cynic sect, as it stood before it embraced the enlarged physical, kosmical, and social theories of Zeno and his contemporaries, reducing to a minimum all the desires and appetites--cultivating insensibility to the pains of life, and even disdainful insensibility to its pleasures--required extraordinary force of will and obstinate resolution, but little beyond. Where there was no selection or discrimination, the most ordinary prudence sufficed. It was otherwise with the scheme of Aristippus and the Kyrenaics: which, if it tasked less severely the powers of endurance, demanded a far higher measure of intelligent prudence. Selection of that which might safely be enjoyed, and determination of the limit within which enjoyment must be confined, were constantly indispensable. Prudence, knowledge, the art of mensuration or calculation, were essential to Aristippus, and ought to be put in the foreground when his theory is stated. [Side-note: Ethical theory of Aristippus is identical with that of the Platonic Sokrates in the Protagoras.] That theory is, in point of fact, identical with the theory expounded by the Platonic Sokrates in Plato's Protagoras. The general features of both are the same. Sokrates there lays it down explicitly, that pleasure _per se_ is always good, and pain _per se_ always evil: that there is no other good (_per se_) except pleasure and diminution of pain--no other evil (_per se_) except pain and diminution of pleasure: that there is no other object in life except to live through it as much as possible with pleasures and without pains;[215] but that many pleasures become evil, because they cannot be had without depriving us of greater pleasures or imposing upon us greater pains while many pains become good, because they prevent greater pains or ensure greater pleasures: that the safety of life thus lies in a correct comparison of the more or less in pleasures and pains, and in a selection founded thereupon. In other words, the safety of life depends upon calculating knowledge or prudence, the art or science of measuring. [Footnote 215: Plato, Protag. p. 355 A. [Greek: ê)\ a)rkei= u(mi=n to\ ê(de/ôs katabiô=nai to\n bi/on a)/neu lupô=n? ei) de\ a)rkei=, kai\ mê\ e)/chete mêde\n a)/llo pha/nai ei)=nai a)gatho\n ê)\ kako/n, o(\ mê\ ei)s tau=ta teleuta=|, to\ meta\ tou=to a)kou/ete]. The exposition of this theory, by the Platonic Sokrates, occupies the latter portion of the Protagoras, from p. 351 to near the conclusion. See below, ch. xxiii. of the present work.