C.S. Lewis, The Four Loves

"In friendship...we think we have chosen our peers. In reality a few years' difference in the dates of our births, a few more miles between certain houses, the choice of one university instead of another...the accident of a topic being raised or not raised at a first meeting--any of these chances might have kept us apart. But, for a Christian, there are, strictly speaking no chances. A secret master of ceremonies has been at work. Christ, who said to the disciples, "Ye have not chosen me, but I have chosen you," can truly say to every group of Christian friends, "Ye have not chosen one another but I have chosen you for one another." The friendship is not a reward for our discriminating and good taste in finding one another out. It is the instrument by which God reveals to each of us the beauties of others."

"Friendship is unnecessary, like philosophy, like art... It has no survival value; rather it is one of those things which give value to survival."

"In God there is no hunger that needs to be filled, only plenteousness that desires to give."

"Those who cannot conceive Friendship as a substantive love but only as a disguise or elaboration of Eros betray the fact that they have never had a Friend. The rest of us know that though we can have erotic love and friendship for the same person yet in some ways nothing is less like a Friendship than a love-affair. Lovers are always talking to one another about their love; Friends hardly ever about their Friendship. Lovers are normally face to face, absorbed in each other; Friends, side by side, absorbed in some common interest. Above all, Eros (while it lasts) is necessarily between two only. But two, far from being the necessary number for Friendship, is not even the best. And the reason for this is important... In each of my friends there is something that only some other friend can fully bring out. By myself I am not large enough to call the whole man into activity; I want other lights than my own to show all his facets... Hence true Friendship is the least jealous of loves. Two friends delight to be joined by a third, and three by a fourth, if only the newcomer is qualified to become a real friend. They can then say, as the blessed souls say in Dante, 'Here comes one who will augment our loves.' For in this love 'to divide is not to take away."

"Friendship arises out of mere Companionship when two or more of the companions discover that they have in common some insight or interest or even taste which the others do not share and which, till that moment, each believed to be his own unique treasure (or burden). The typical expression of opening Friendship would be something like, "What? You too? I thought I was the only one." ... It is when two such persons discover one another, when, whether with immense difficulties and semi-articulate fumblings or with what would seem to us amazing and elliptical speed, they share their vision - it is then that Friendship is born. And instantly they stand together in an immense solitude."

"To love at all is to be vulnerable. Love anything and your heart will be wrung and possibly broken. If you want to make sure of keeping it intact you must give it to no one, not even an animal. Wrap it carefully round with hobbies and little luxuries; avoid all entanglements. Lock it up safe in the casket or coffin of your selfishness. But in that casket, safe, dark, motionless, airless, it will change. It will not be broken; it will become unbreakable, impenetrable, irredeemable. To love is to be vulnerable."