[212] Diog. L. ii. p. 92.
The Kyrenaics did not admit that there was anything just, or honourable, or base, by nature: but only by law and custom: nevertheless the wise man would be sufficiently restrained, by the fear of punishment and of discredit, from doing what was repugnant to the society in which he lived. They maintained that wisdom was attainable; that the senses did not at first judge truly, but might be improved by study; that progress was realised in philosophy as in other arts, and that there were different gradations of it, as well as different gradations of pain and suffering, discernible in different men. The wise man, as they conceived him, was a reality; not (like the wise man of the Stoics) a sublime but unattainable ideal.[213]
[213] Diog. L. ii. p. 93.
Their logical theory — nothing knowable except the phenomenal, our own sensations and feelings — no knowledge of the absolute.
Such were (as far as our imperfect evidence goes) the ethical and emotional views of the Kyrenaic school: their theory and precepts respecting the plan and prospects of life. In regard to truth and knowledge, they maintained that we could have no knowledge of anything but human sensations, affections, feelings, &c. (πάθη): that respecting the extrinsic, extra-sensational, absolute, objects or causes from whence these feelings proceeded, we could know nothing at all. Partly for this reason, they abstained from all attention to the study of nature — to astronomy and physics: partly also because they did not see any bearing of these subjects upon good and evil, or upon the conduct of life. They turned their attention mainly to ethics, partly also to logic as subsidiary to ethical reasoning.[214]
[214] Diog. L. ii. p. 92. Sextus Empiric. adv. Mathemat. vi. 53.
Such low estimation of mathematics and physics and attention given almost exclusively to the feelings and conduct of human life — is a point common to the opposite schools of Aristippus and Antisthenes, derived by both of them from Sokrates. Herein Plato stands apart from all the three.
The theory of Aristippus, as given above, is only derived from a meagre abstract and from a few detached hints. We do not know how he himself stated it: still less how he enforced and vindicated it. — He, as well as Antisthenes, composed dialogues: which naturally implies diversity of handling. Their main thesis, therefore — the text, as it were, upon which they debated or expatiated (which is all that the abstract gives) — affords very inadequate means, even if we could rely upon the accuracy of the statement, for appreciating their philosophical competence. We should form but a poor idea of the acute, abundant, elastic and diversified dialectic of Plato, if all his dialogues had been lost — and if we had nothing to rely upon except the summary of Platonism prepared by Diogenes Laertius: which summary, nevertheless, is more copious and elaborate than the same author has furnished either of Aristippus or Antisthenes.
Doctrines of Antisthenes and Aristippus passed to the Stoics and Epikureans.
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.