By Water & Blood

Book 15, Chapter 13

'BUT the chief point and power of Plato's system, his theory of ideas, has been discredited, and abused, and insulted in every way, as far as it was in Aristotle's power. For as he was unable to conceive that things of a grand, divine, and transcendent nature require a certain kindred power for their recognition, and trusted to his own meagre and petty shrewdness, which was able to make its way through things terrestrial, and discern the truth in them, but was not capable of beholding the plain of absolute truth, he made himself the rule and judge of things above him,^[30] and denied the existence of any peculiar natures such as Plato affirmed, but dared to call the highest of all realities triflings and chatterings and nonsense.

'Rather is the supreme and final speculation of Plato's philosophy that which treats of this intelligible and eternal being of the ideas, wherein verily the utmost toil and stress is set before the soul. For a most happy man is he, who has shared in the effort and attained the end, while he who has failed from want of power to obtain an insight is left without any share at all of happiness.

'And for this reason Plato too strives earnestly in every way to show the strength of these ideal natures. For he says that it is not possible either rightly to assign a cause of anything whatsoever, except by participation in the ideas, or to have knowledge of any truth except by reference to these: nay not even a particle of reason would any have, unless they should acknowledge the existence of these ideas.

'They again who have decided to maintain the doctrines of Plato lay the chief stress of their arguments on this point, and quite necessarily. For nothing is left of the Platonic system, if one will not grant them on Plato's behalf these primary and i principal natures. For it is in these that he is especially superior to all other men.

And a disciple of his was Diogenes the 'dog,' who seemed to entertain most brutelike ideas, and attracted many followers. He was succeeded by Crates, and a disciple of Crates was Zeno of Cittium, who was established as founder of the sect of the Stoic philosophers.

Zeno was succeeded by Cleanthes, and Cleanthes by Chrysippus, and he by the second Zeno, and the rest in order. All these are said to have been especially devoted both to hard living and to dialectic. The doctrines then of their philosophy are somewhat as follows.