# Telling the truth or lying?

There are two men, Bob and Dylan.

Bob says “One of the two of us is a liar”.
Dylan says “Actually, we’re both liars”.

Honest men always tell the truth and liars always lie. What are these men? Both honest? Both liars? Or one of each, and, in that case, who is who? Explain your reasoning.

• I'm pretty sure Bob's statement is unnecessary, so this puzzle isn't quite as elegant as it could be. Commented May 16, 2017 at 9:55

So let's go through all the possibilities here.

- Option 1: Not possible because both are liars and Dylan is supposed to lie, meaning at least one should tell the truth.
- Option 2: Not possible because Dylan tells the truth. But if he's right he is a liar
- Option 3: Works Bob tells the truth and Dylan lies
- Option 4: Eliminated in the same way as option 2

We're just left with one option with is #3.

Bob is truthful and Dylan is a liar

• Welcome to Puzzling! (Take the Tour!) Very nice answer to the question... good job :)
– Rubio
Commented May 2, 2017 at 19:34
• Nice explanation
– VHS
Commented Nov 14, 2017 at 19:23

Bob is telling the truth. Dylan cannot be telling the truth when he says he is a liar because that would be a paradox in this world. So he must be lying, which makes Bob's comment a truthful one. Bob's comment cannot be a lie because then THAT would be a paradox.

Bob is a truth teller, Dylan a liar. Dylan can't be a truth teller because he would be lying. As he is lying, Bob must be telling the truth.