We ought not to listen to those who exhort us, because we are human, to think of human things....We ought rather to take on immortality as much as possible, and do all that we can to live in accordance with the highest element within us; for even if its bulk is small, in its power and value it far exceeds everything.
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.
The virtues [moral excellence] therefore are engendered in us neither by nature nor yet in violation of nature; nature gives us the capacity to receive them, and this capacity is brought to maturity by habit.
Friends hold a mirror up to each other; through that mirror they can see each other in ways that would not otherwise be accessible to them, and it is this mirroring that helps them improve themselves as persons.
For as the interposition of a rivulet, however small, will occasion the line of the phalanx to fluctuate, so any trifling disagreement will be the cause of seditions; but they will not so soon flow from anything else as from the disagreement between virtue and vice, and next to that between poverty and riches.
Nor need it cause surprise that things disagreeable to the good man should seem pleasant to some men; for mankind is liable to many corruptions and diseases, and the things in question are not really pleasant, but only pleasant to these particular persons, who are in a condition to think them so.
The male has more teeth than the female in mankind, and sheep and goats, and swine. This has not been observed in other animals. Those persons which have the greatest number of teeth are the longest lived; those which have them widely separated, smaller, and more scattered, are generally more short lived.