- ”A great deal more is known than has been proved.”
- Simple: A lot more things have been known than things which have been proved.
- ”What I cannot create, I do not understand.”
- Simple: I do not understand things which I cannot create.
- ”I think I can safely say that nobody understands quantum mechanics.”
- Simple: I think I can safely say that nobody understands quantum mechanics.
- ”I'd hate to die twice. It's so boring.”
- Simple: I would not like to die two times. It is very boring.
- ”I have to understand the world, you see.”
- Simple: You know, I have to understand the world.
- ”I don't know anything, but I do know that everything is interesting if you go into it deeply enough.”
- Quoted in The Music of the Primes : Searching to Solve the Greatest Mystery of Mathematics (2003) by Marcus du Sautoy
- On his blackboard at time of death in 1988; as quoted in The Universe in a Nutshell by Stephen Hawking
- The Character of Physical Law (1965) Ch. 6; also quoted in The New Quantum Universe (2003) by Tony Hey and Patrick Walters
- Last words, as quoted in Genius: The Life and Science of Richard Feynman (1992) by James Gleick
- Surely You're Joking, Mr. Feynman! (1985). Part 4: "From Cornell to Caltech, With A Touch of Brazil", "Certainly, Mr. Big!"
- The Pleasure of Finding Things Out (1999). From Omni interview, The Smartest Man in the World (chapter 9)