“Ah, pay no heed if your enemies laugh. They'll not be able to once you lop off their heads.”
Source: Eragon, Eldest & Brisingr
Illusions : The Adventures of a Reluctant Messiah (1977)
Context: You're going to die a horrible death, remember. It's all good training, and you'll enjoy it more if you keep the facts in mind.
Take your dying with some seriousness, however. Laughing on the way to your execution is not generally understood by less advanced lifeforms, and they'll call you crazy.
“Ah, pay no heed if your enemies laugh. They'll not be able to once you lop off their heads.”
Source: Eragon, Eldest & Brisingr
“The crazy ones only laugh when there is no reason to laugh.”
“If you're going to tell people the truth, you better make them laugh; otherwise they'll kill you.”
Credited to Shaw in the lead in to the mockumentary C.S.A.: The Confederate States of America (2004) and other recent works, but this or slight variants of it are also sometimes attributed to W. C. Fields, Charlie Chaplin, and Oscar Wilde. It might possibly be derived from Shaw's statement in John Bull's Other Island (1907): "My way of joking is to tell the truth. It's the funniest joke in the world."
Another possibility is that it is derived from Shaw's characteristic of Mark Twain: "He has to put things in such a way as to make people who would otherwise hang him believe he is joking."
Variants:
If you are going to tell people the truth, you'd better make them laugh. Otherwise, they'll kill you.
If you're going to tell people the truth, you'd better make them laugh. Otherwise, they'll kill you.
Disputed
Of Laws.
Political, Moral, and Miscellaneous Reflections (1750), Political Thoughts and Reflections
Source: Blue Mars (1996), Chapter 14, “Phoenix Lake” (p. 748)