"Lovers seek for privacy. Friends find this solitude about them,

this barrier between them and the herd, whether they want it or not. They would be glad to reduce it. The first two would be glad to find a third.

In our own time Friendship arises in the same way. For us of course the shared activity and therefore the companionship on which Friendship supervenes will not often be a bodily one like hunting or fighting. It may be a common religion, common studies, a common profession, even a common recreation. All who share it will be our companions; but one or two or three who share something more will be our Friends. In this kind of love, as Emerson said, Do you love me? means Do you see the same truth? - Or at least, "Do you care about the same truth?" The man who agrees with us that some question, little regarded by others, is of great importance, can be our Friend. He need not agree with us about the answer.

Notice that Friendship thus repeats an a more individual and less socially necessary level the character of the Companionship which was its matrix. The Companionship was between people who were doing something together - hunting, studying, painting or what you will. The Friends will still be doing something together, but something more inward, less widely shared and less easily defined; still hunters, but of some immaterial quarry; still collaborating, but in some work the world does not, or not yet, take account of; still travelling companions, but on a different kind of journey. Hence we picture lovers face to face but Friends side by side; their eyes look ahead.”

- C.S. Lewis, from ‘The Four Loves”