Caring for but never trying to own may be a further way to define friendship.

Peace, commerce and honest friendship with all nations entangling alliances with none.

Friends show their love in times of trouble, not in happiness.

Let there be no purpose in friendship save the deepening of the spirit.

The friend is the man who knows all about you, and still likes you.

I don't need a friend who changes when I change and who nods when I nod my shadow does that much better.

There are no rules for friendship. It must be left to itself. We cannot force it any more than love.

Depth of friendship does not depend on length of acquaintance.

Friendship is the source of the greatest pleasures, and without friends even the most agreeable pursuits become tedious.

Laughter is not at all a bad beginning for a friendship, and it is far the best ending for one.