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.
Youth should be kept strangers to all that is bad, and especially to things which suggest vice or hate. When the five years have passed away, during the two following years they must look on at the pursuits which they are hereafter to learn. There are two periods of life with reference to which education has to be divided, from seven to the age of puberty, and onwards to the age of one and twenty.
Anything that we have to learn to do we learn by the actual doing of it; People become builders by building and instrumentalists by playing instruments. Similarily, we become just by performing just acts, temperate by performing temperate ones, brave by performing brave ones.
Bravery is a mean state concerned with things that inspire confidence and with things fearful ... and leading us to choose danger and to face it, either because to do so is noble, or because not to do so is base. But to court death as an escape from poverty, or from love, or from some grievous pain, is no proof of bravery, but rather of cowardice.
There are three things that are the motives of choice and three that are the motives of avoidance; namely, the noble, the expedient, and the pleasant, and their opposites, the base, the harmful, and the painful. Now in respect of all these the good man is likely to go right and the bad to go wrong, but especially in respect of pleasure; for pleasure is common to man with the lower animals, and also it is a concomitant of all the objects of choice, since both the noble and the expedient appear to us pleasant.