It could be argued that Friendships are of practical value to the Community. Every civilised religion began in a small group of friends.
Mathematics effectively began when a few Greek friends got together to talk about numbers and lines and angles. What is now the Royal Society was originally a few gentlemen meeting in their spare time to discuss things which they (and not many others) had a fancy for. What we now call “the Romantic Movement” once was Mr. Wordsworth and Mr. Coleridge talking incessantly (at least Mr. Coleridge was) about a secret vision of their own. Communism, Tractarianism, Methodism, the movement against slavery, the Reformation, the Renaissance, might perhaps be said, without much exaggeration, to have begun in the same way.
C.S. Lewis, The Four Loves (1960; Harcourt Brace: 1991) 68.