Prudence and ethical virtue are both necessary for one another. Continence and incontinence are concerned with bodily pleasures just like temperance and intemperance, but are distinct from them. The incontinent man is disposed to do what he knows is bad because of his passions. The continent man knows that his desires are bad but does not follow them because of reason. The difference between continence and temperance lies in the fact that for a temperate man his desires are in line with his reason.
Friendship is a necessary part of the good life.
Only the last type is genuine friendship. Friendships based on usefulness and pleasure tend not to be very enduring, since they only last as the long as each party derives the usefulness or pleasure he desires from the relationship. Friendship based on virtue is based on wishing the good for the other person. This genuine friendship is necessary for self-knowledge and helps both of the friends to grow in virtue. Friendship presupposes justice and goes beyond it.