Logic Puzzle - Raymond Smullyan

This quote was added by user71700
There is a question I could ask you that has a definite correct answer - either yes or no - but it is logically impossible for you to give the correct answer. You might know what the correct answer is, but you cannot give it. Anybody other than you might possibly be able to give the correct answer, but you cannot! Can you figure out what question I could have in mind?

Train on this quote


Rate this quote:
3.4 out of 5 based on 74 ratings.

Edit Text

Edit author and title

(Changes are manually reviewed)

or just leave a comment:


bvw 1 year, 10 months ago
My favorite logic puzzle is one from Knot Theory. It was effectively solved by an impetuos young man named Alexander from Macedonia.

Self-reference is in a way, a proof of life. I think Godel said that.
catrice 1 year, 10 months ago
Self-referential statements ruin logic. It's not interesting, though.
bvw 1 year, 10 months ago
@Hunterz1200, you understood my answer?
catrice 1 year, 10 months ago
bvw, on the other hand, perhaps people should answer, because most people don't scroll to the comments if they know they'll see what they don't want to see.
hunterz1200 1 year, 10 months ago
Yes, yes I can.
bvw 3 years, 6 months ago
Can you not answer this question, please? Let folks think about it by themselves.

Test your skills, take the Typing Test.

Score (WPM) distribution for this quote. More.

Best scores for this typing test

Name WPM Accuracy
zhengfeilong 141.63 99.2%
hunterz1200 141.15 97.6%
wolfram 140.58 96.4%
vmlm 134.58 99.7%
ze_or 132.67 98.9%
heavy.nap 132.46 98.1%
ltfigs 129.31 97.1%
user425222 126.42 98.4%

Recently for

Name WPM Accuracy
cewial 71.55 94.1%
user502993 85.86 93.5%
horblok 50.69 91.6%
admin04 64.98 83.9%
jeffraly-jz 59.70 97.1%
user89402 31.02 80.6%
wu9911 77.96 89.8%
user76509 59.13 98.4%