Women should marry when they are about eighteen years of age, and men at seven and thirty; then they are in the prime of life, and the decline in the powers of both will coincide.
Neither should men study war with a view to the enslavement of those who do not deserve to be enslaved; but first of all they should provide against their own enslavement, and in the second place obtain empire for the good of the governed, and not for the sake of exercising a general despotism, and in the third place they should seek to be masters only over those who deserve to be slaves.
That in the soul which is called mind (by mind I mean that whereby the soul thinks and judges) is, before it thinks, not actually any real thing. For this reason it cannot reasonably be regarded as blended with the body
Excellence or virtue is a settled disposition of the mind that determines our choice of actions and emotions and consists essentially in observing the mean relative to us ... a mean between two vices, that which depends on excess and that which depends on defect.
Not every action or emotion however admits of the observance of a due mean. Indeed the very names of some directly imply evil, for instance malice, shamelessness, envy, and, of actions, adultery, theft, murder. All these and similar actions and feelings are blamed as being bad in themselves; it is not the excess or deficiency of them that we blame. It is impossible therefore ever to go right in regard to them - one must always be wrong.
Metaphysics is universal and is exclusively concerned with primary substance. ... And here we will have the science to study that which is, both in its essence and in the properties which it has.
In the human species at all events there is a great diversity of pleasures. The same things delight some men and annoy others, and things painful and disgusting to some are pleasant and attractive to others.
If there is some end of the things we do, which we desire for its own sake, clearly this must be the good. Will not knowledge of it, then, have a great influence on life? Shall we not, like archers who have a mark to aim at, be more likely to hit upon what we should? If so, we must try, in outline at least, to determine what it is.