Intelligence test

[Losty]

Under "at least one of us", why can't statement one and two be true at the same time?

If both always told the truth, we'd have to believe the first guy, who claims that one of them always lies. This contradicts the original assumption that both tell the truth

But it doesn't say always.

[Alex K]

If both always told the truth, we'd have to believe the first guy, who claims that one of them always lies. This contradicts the original assumption that both tell the truth

But it doesn't say always.

Sorry, see my edit (which I had to add because you started it )

[Losty]

Under "at least one of us", why can't statement one and two be true at the same time?

If both always told the truth, we'd have to believe the first guy, who claims that one of them always lies. This contradicts the original assumption that both tell the truth

Edit: I indeed assume an "in this conversation, consistently", which is not written but traditionally assumed in such Paradoxes which have a long tradition going back to ancient Greece (The lying guy from Crete comes to mind). If we drop this restriction, the problem tends to become simply undeterminable from the existing information.

Consistency yes, but use "sometimes" or "often" instead of always. If you don't assume anything that isn't specifically stated, the answer is clearly that both are telling the truth. If you assume "always" or "right now", then it's impossible to answer neither of them can be telling the truth or lying because none of the combinations fit.

[GrandizerII]

Something I cooked up to test your logical thinking skills. Ask any question you feel you need to pertaining to the question.

Two brothers walk up to you.

Man 1 says "One of us tells lies"

Man 2 says "And one of us tells the truth".

Man one states an undeniable fact.

Which one lies, and which one tells the truth?

Determine all of what you know, don't think one has to tell lies and one has to tell the truth.

Can an omnipotent being create a being more powerful than itself? Can you divide by zero? Am I a married bachelor or not?

[Pyrrho]

The question which remains is now - did the poster understand the implications of their own riddle?

Good question.  We will have to wait and see.  If I were going to place a bet... [I will let you use your imagination to finish the sentence].

[Alex K]

Losty, ok.

If we allow for a sometimes, the main part of the riddle becomes (in my first reading)

1. Exactly one of us sometimes lies

2. Exactly one of us sometimes tells the truth

The riddle itself has the extra info (which renders it a bit stupid) that the first guy is right in this instance. This means that one of them does not sometimes lie, i.e. that one of them *always* tells the truth.

I) Let this be the first person.
Assume the second one were lying in this instance, we invert his statement and the truth would be that it is not exactly one of them who sometimes tells the truth. One of the remaining possibilities is that both of them sometimes tell the truth, *but not in this instance*.

It is therefore a consistent hypothesis even with the additional stupid comment that *in this instance*, the first person tells the truth and the second person lies.

[Angrboda]

Too much fuzzy.

[robvalue]

Just because they say one lies and one tells the truth, it doesn't mean that is actually the case. So I've no reason to try and sort out which is which, because I don't believe any of it until I have evidence. One truth does not demonstrate continued truth, nor does one lie demonstrate continued lies.

[Little lunch]

This is great fun!
I cooked one up meself.

Two nuns in a dark room.

Nun 1 - Where's the candles?
Nun 2 - Yes, it does, doesn't it.

Which Nun is masterbating with a candle?
Keep in mind, it could be both!
:-)

[I_am_not_mafia]

Something I cooked up to test your logical thinking skills. Ask any question you feel you need to pertaining to the question.

Two brothers walk up to you.

Man 1 says "One of us tells lies"

Man 2 says "And one of us tells the truth".

Man one states an undeniable fact.

Which one lies, and which one tells the truth?

Determine all of what you know, don't think one has to tell lies and one has to tell the truth.

Both men are telling the truth and it could be either of them that lies.

'One of us tells lies' is not the same as saying that one person is lying all the time. Man 1 could easily be admitting that he also lies at times.

'One of us tells the truth' is true because the statement by man 1 is an undeniable fact according to the puzzle. That doesn't mean to say that man 2 doesn't also lie.