The so-called Pythagoreans, who were the first to take up mathematics, not only advanced this subject, but saturated with it, they fancied that the principles of mathematics were the principles of all things.
Now that practical skills have developed enough to provide adequately for material needs, one of these sciences which are not devoted to utilitarian ends [mathematics] has been able to arise in Egypt, the priestly caste there having the leisure necessary for disinterested research.
One can aim at honor both as one ought, and more than one ought, and less than one ought. He whose craving for honor is excessive is said to be ambitious, and he who is deficient in this respect unambitious; while he who observes the mean has no peculiar name.
Therefore the good man ought to be a lover of self, since he will then both benefit himself by acting nobly and aid his fellows; but the bad man ought not to be a lover of self, since he will follow his base passions, and so injure both himself and his neighbors. With the bad man therefore, what he does is not in accord with what he ought to do, but the good man does what he ought, since intelligence always chooses for itself that which is best, and the good man obeys his intelligence.