Conjugal love, or the friendship of spouses, can persist even after sexual desires have weakened, withered, and disappeared.

Freud's view is that all love is sexual in its origin or its basis. Even those loves which do not appear to be sexual or erotic have a sexual root or core. They are all sublimations of the sexual instinct.

We love even when our love is not requited.

Aristotle uses a mother's love for her child as the prime example of love or friendship.

Friendship is a very taxing and arduous form of leisure activity

One of the aims of sexual union is procreation - the creation by reproduction of an image of itself, of the union.