There is no friendship towards a slave, as a slave, for, as such he is a mere animate tool (XL.).

In the relations of the family, friendship varies with the different situations.

Parents love their children as a part of themselves, and from the first; children grow to love their parents.
Brothers are affected by their community of origin, as well as by common education and habits of intimacy.

Husband and wife come together by a natural bond, and as mutual helps; their friendship contains the useful and the pleasant, and, with virtue, the good.

Their offspring strengthens the bond (XII.).