“If you don't see the book you want on the shelves, write it.”

Variant: .

"I want my books to have their own shelves", you said, and that's how I knew it would be okay to live together.
Source: The Lover's Dictionary

Letter to his brother Jeff from Guadalcanal (28 January 1943); p. 28
To Reach Eternity (1989)
Context: I'm going to ask you something. If I do get killed, and I honestly don't see how I can help it, I want you to write that book we were thinking about when I enlisted. If I get it, it's a cinch I won't be able to do it, and it would make me feel a whole lot better to know that if not my name and hand, at least, the thot of me would be passed on and not forgotten entirely. You know, sort of put into the book the promise that I had and the things I might have written so at least the knowledge of talent wasted won't be lost... If I get it, no one will ever know to what heights I might have gone as a writer. Maybe if you wrote about the promise that was there, all wouldn't be lost.

Notebook E: Epigrams, Wisecracks, and Jokes https://books.google.com/books?id=NIhKY8SpAE4C&amp;q=%22You%20don%27t%20write%20because%20you%20want%20to%20say%20something%3B%20you%20write%20because%20you%27ve%20got%20something%20to%20say.%22&amp;pg=PA123#v=onepage, edited by Edmund Wilson (1945) <br class="br">Quoted, The Crack-Up (1936)

Source: Epigrams, p. 353

Source: If on a Winter's Night a Traveler