“The world never knows, and cannot for the life of it imagine, what this man sees in that maid and that maid in this man. The world cannot think why they fell in love with each other. But they have their reason, their beautiful secret, that never gets told to more than one person; and what they see in each other is what they show to each other; and it is the truth.”

"One"
Lyrics, Achtung Baby (1991)

Colonel Richard Cantwell and Renata in Ch. 38
Across the River and into the Trees (1950)

As quoted in The Reader's Digest Great Encyclopedic Dictionary Special Supplement (1966), p. 2047

Letter Four (16 July 1903)
Letters to a Young Poet (1934)

Source: September 1, 1939 (1939), Lines 62–66

"The spirit of disobedience: an invitation to resistance"

Journal entry (1938), quoted in the Introduction to a 1994 edition of Of Mice and Men by Susan Shillinglaw, p. vii
Context: In every bit of honest writing in the world … there is a base theme. Try to understand men, if you understand each other you will be kind to each other. Knowing a man well never leads to hate and nearly always leads to love. There are shorter means, many of them. There is writing promoting social change, writing punishing injustice, writing in celebration of heroism, but always that base theme. Try to understand each other.

Narcissus and Goldmund (1930)