Friendship

"And the possibility of going through life without the experience is rooted in that fact which separates Friendship so sharply from both the other loves. Friendship is- in a sense not at all derogatory to it- the least natural of loves; the least instinctive, organic, biological, gregarious and necessary. It has least commerce with our nerves; there is nothing throaty about it; nothing that quickens the pulse or turns you red and pale. It is essentially between individuals; the moment two men are friends they have in some degree drawn apart together from the her. Without Eros none of us would have been begotten and without Affection none of us would have been reared; but we can live and breed without Friendship. The species, biologically considered, has no need of it. The pack or herd-the community- may even dislike and distrust it. Its leaders very often do. Headmasters and Headmistresses and Heads of religious communities, colonels and ships' captains, can feel uneasy when close and strong friendships arise between little knots of their subjects."

-C.S. Lewis, The Four Loves (pg. 58)