Please do NOT post your answer, but do say if you think you have solved the puzzle and how long it took. Solution on Monday.

Imagine that a man walks up to you and says, ‘Everything I say to you is a lie.’  Is he telling you the truth or is he lying?
I have produced an ebook containing 101 of the previous Friday Puzzles! It is called PUZZLED and is available for the Kindle (UK here and USA here) and on the iBookstore (UK here in the USA here). You can try 101 of the puzzles for free here.

1. Anders says:

These puzzles get older and older. Solved, and it took me something like -20 or 25 years, going by how long before this friday I first saw it

2. Suzanne says:

Isn’t that the Cretan paradox? All Cretans are liars said the Cretan.
I look forward to the answer 🙂

1. Cretan Liberation Front says:

I think we should attempt to eliminate Cretophobia from this site.

2. Anders says:

It is the same problem, but it’s not a paradox, despite the name of the problem

3. mittfh says:

It’s not exactly the same, since E was referring to an entire group of people rather than himself, but as with that case, Richard’s statement can lead to a conclusion based on a flawed (binary) interpretation of logic.

3. I am normal. Everybody else is insane.

1. Berhard says:

Me, too…

4. Liam says:

5. He says the truth to warn you that what will count is false

6. And… Norman short-circuits and deactivates… [Star Trek TOS episode “I, Mudd”] 😉

7. Palle Gilling says:

It took me about 10-15 seconds. It is a good way to wake my sleeping brain, not beeing much of a “morning person”. Nice week-end to all of you.

8. Duncan says:

Took just a few seconds. I was looking forward to more of a challenge.

9. You lot are so harsh. I know you get frustrated by how clever you are, but a good puzzle is never old.

1. Anders says:

if it was first published in 600BCE and discussed in every logic class since then, yes, it’s old

10. Anders says:

miffh, it is not word for word the same, but logically it is the identical problem, with the same resolution of the alleged paradox

11. Martha says:

It would work better if he said, ‘What I am saying to you right now is a lie,’ wouldn’t it?

1. No, that doesn’t produce the same results. Saying “I am lying” is a contradiction – it cannot be true or false. On the other hand, saying “Everything I say to you is a lie” can potentially be false.

2. Anders says:

maybe I am mistaken, but I have always made a difference between lying and simply being wrong. To me, lying means knowingly stating what the person believe to be wrong. e.g. if I firmly believe that 2+2 = 5, then saying that it equals 4 is both true and a lie at the same time, while saying it equals 5 is false but honest

Maybe it’s good I’ve never been a witness at a trial, I wouldn’t know what to say when asked to swear the oath.

12. “Erm.. I’m going to go with TRUE” (Wheatly, Portal 2)

1. Anders says:

how about saying “Please do NOT post your answer”. That is not a lie, although many seem to think it is

2. face recognition is an expertise aquired through familiarity and training, like dog experts or twitchers

13. Lazy T says:

I imagined him so I imagine that he is ‘lying the truth’.

1. Not an answer- a quote from Portal 2

14. Anders-Not an answer- a quote from Portal 2
And how do i delete a comment?

15. John says:

Neither. He is dead now because I shot him for saying such a confusing thing. Though I did get the real answer rather quickly.

16. John says:

Neither. He is dead now because I shot him for saying such a confusing thing. Though I did get the real answer rather quickly. This is a paradox.

17. John says:

It being a paradox is not my answer by the way. So that means I DIDN’T post my answer.

18. Anonymous says:

A man, of course he’s lying.. They all do.

19. ctj says:

i had an answer to the question as soon as i read it.

but it’s been several hours and i’m still trying to figure out what the “puzzle” is.

20. Nick says:

Ow! My brain hurts now.

21. L.Long says:

Solved in 2 sec because House is correct.

22. One Eyed Jack says:

Weak sauce, Richard, Very weak.

23. A.R. says:

It took me about two seconds.

24. Moo says:

The answer is yes, he is telling you the truth or he is lying.

25. Steve says:

I can say what the answer isn’t !

It isn’t yes or no or indeed yes and no !