Who is telling the truth?

[KrazyHorse]

Plausible is not the same as a rigorous proof. In this context, rigorous proof may only be obtained by contradiction. Proving that the assumption that any of the alternate answers are correct leads to a logical impossibility.

[The Emperor Fabulous]

Ok, dick.

[KrazyHorse]

I've had a hard day. See my car troubles thread.

[Donegeal]

Originally posted by Winston
What if the sheriff is lying?

NEVER!!!!

[Locutus]

Different approach:

If A is true, then all statements are true. If C is true, then at least one other statement is true as well. If D is true, then 4 statements are true. Knowing only 1 statement can be true, A, C and D must be false.

This leaves only B, E and F.

Since C is false, either A and B are both true, or both false. They can't both be true (since only 1 statement can be true), so they must both be false. B is false.

If F is true then A-D are false, which makes E true, but F states E is false. This is a contradiction, so F can't be true.

This only leaves E.

Validation: if E is true, A-D must be false, which they are, and F can be either true or false. If F is false this holds true and also meets the precondition of only 1 true statement.

So E is the only true statement.


This approach shows that it's not really a good riddle: three of the answers directly contradict the precondition and that C renders B false is an all-too-obvious consequence. If A and D were replaced by something more interesting it would be okay. (Hey, once a game designer, always a game designer )

[Agathon]

Creekdweller's utterance is neither true nor false – it's the liar paradox, since he just spoke.

So the last statement can't be true either, since Creekdweller neither lied nor didn't.

[KrazyHorse]

That's a matter of interpretation. I interpreted his statement as not including any judgment on his statement itself. If you choose to be dense and interpret his statement as referring to itself as well as the 4 previous statements then the conditions of the problem are unfulfillable.

[Agathon]

Originally posted by KrazyHorse
That's a matter of interpretation. I interpreted his statement as not including any judgment on his statement itself. If you choose to be dense and interpret his statement as referring to itself as well as the 4 previous statements then the conditions of the problem are unfulfillable.

If you chose to read what he actually says, he fulfils the liar paradox. It he had said "before me" it wouldn't. But that's not what he said.

If you want to interpret what he says by appealing to his intention rather than the meanings of his words (i.e. by claiming that "so far" is vague), then you ruin the game, since you are just assuming he's sincere rather than proving it.

[KrazyHorse]

Originally posted by Agathon
If you want to interpret what he says by appealing to his intention rather than the meanings of his words (i.e. by claiming that "so far" is vague), then you ruin the game, since you are just assuming he's sincere rather than proving it.

"So far" is vague. In this context, such a sentence would, in fact, normally be interpreted as meaning "prior to myself", not "prior to and including myself"...

[KrazyHorse]

Welcome to natural language, aggie. You run into sentences with multiple possible interpretations every day...

Even gramatically perfect English does not guarantee a well-defined mapping from written/spoken sentence to meaning.

[Agathon]

Originally posted by KrazyHorse
Welcome to natural language, aggie. You run into sentences with multiple possible interpretations every day...

In fact, you run into them every time you attempt to interpret someone. Such is the nature of semantic holism.

But if I was a runner who said "So far, no-one has run a sub 9 second 100m" that would mean no-one had, including me. On the other hand, if I said "before me" it would be different. The lesson here is that you shouldn't just reinterpret the game so it makes sense – some games defy rational interpretation. Of course the scientists just assume that nothing does, and you were beautifully hoodwinked if that is the case.

And it doesn't change the fact that if you are going to appeal to his intentions to resolve the vagueness, you are violating the point of the game (since you are just making him tell the truth to make the game solvable).

[KrazyHorse]

Originally posted by Agathon


In fact, you run into them every time you attempt to interpret someone. Such is the nature of semantic holism.

But if I was a runner who said "So far, no-one has run a sub 9 second 100m" that would mean no-one had, including me.

And if you said it while you were in the middle of running the sub 9 second 100 meter?

That's the situation we have to deal with here.

[KrazyHorse]

What I'm saying, aggster, is that his phrase requires interpretation. Your interpretation is no less an interpretation than mine is. In fact, when everts speaks the words "so far", he has not yet made a statement at all. He doesn't do so until the moment he completes the word "truth"

[Agathon]

Originally posted by KrazyHorse
What I'm saying, aggster, is that his phrase requires interpretation. Your interpretation is no less an interpretation than mine is. In fact, when everts speaks the words "so far", he has not yet made a statement at all. He doesn't do so until the moment he completes the word "truth"

Not really. If I or anyone said, "so far no-one has completed a sub 9 second 100m", I might be in the middle of doing so (although how I'd manage to say it while doing it is phyiscally problematic), but then it wouldn't be true when I said it. But if I said it when I finish, I would be misusing the words.

But you're missing the point. My point was that it does require a certain interpretation to make the game solvable. But there's no reason the game ought to be solvable, and it's more interesting if it isn't, since the answer is so transparently evident if it is.

Your attempt to weasel out of it is pretty bad (the "he has not yet made a statement at all" thing). If I said "On Tuesday, such and such happened", did I not really mean Tuesday until I finished the statement? What if I had been killed just before I could utter "such and such happened", would no-one know what day I was referring to?

[notyoueither]

Bring back Asher.