Friendship is the greatest of worldly goods. Certainly to me it is the chief happiness of life. If I had to give a piece of advice to a young man about a place to live, I think I shd. say, 'sacrifice almost everything to live where you can be near your friends.'

Letter to Arthur Greeves (29 December 1935) — in They Stand Together: The Letters of C. S. Lewis to Arthur Greeves (1914–1963) (1979), p. 477