h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Well, you're nearly there.

You're working backwards, of course.

You do, of course, need a Para Doc's.

So which one is the paradox?

B

The statement "I am a liar" is paradoxical, but it is unclear that anyone said that.

I think we'd all just like to be given the solution, Mu. Can you do that?

No.

B

Here you are then, Mu:

Okay, Major Jump is the one because paratroopers make major jumps, therefore he's a paradoc.

I do not understand the logic of that, nor do I believe it is the right answer.

B

And I don't understand the logic of your question, so I guess we're even.

Logic, schmogic... It's a "silly" question so the answer must be "WIBBLE!"

as an aside, but strangely relevant, some sources cite a detrimental side effect of fluoride being that it creates apathy in the user...

but who cares

I'm trying to decode the Field Marshall's statement, but I get lost.

"Don't bother asking the Corporal. He'll tell you that he always lies"

So, if the FM telling the truth, then the Corp would be making a paradoxical statement, in that he would, at that point, be truthfully remarking about his inability to tell the truth. Which must therefore be a lie, since he always lies. But if he was lying, then he wouldn't say that he always lies, because that would be the truth.

The only way out of this paradox is if the FM is lying, and that isn't what the Corp would say.


Geggs

I'm trying to decode the Field Marshall's statement, but I get lost.

"Don't bother asking the Corporal. He'll tell you that he always lies"

So, if the FM telling the truth, then the Corp would be making a paradoxical statement, in that he would, at that point, be truthfully remarking about his inability to tell the truth. Which must therefore be a lie, since he always lies. But if he was lying, then he wouldn't say that he always lies, because that would be the truth.

The only way out of this paradox is if the FM is lying, and that isn't what the Corp would say.

I keep thinking of the two guards, one who always tells the truth and the other who always lies, who guard two doors, behind one of which there are great riches, and behind the other is death. You can only ask one guard one question, and if I remember correctly, the question maust be "If I asked the other guard which door to take, what would he say?" and whatever the answer is the the guard gives, you take the other door.

If the guard you ask is the liar, then he will tell you the wrong door, because the other guy would tell you the right door, but if he is the truthful one, then he will accurately report the the other guy (being the liar) will tell you the wrong door. Either way, his answer will be the wrong door.

This feels like it might be relevant, but I'm not sure how.


Geggs

The one in my head is the villager in the fork of the road. One village is full of truth tellers and the other full of liars and you don't know which way to go. To find out which path leads to the village of truth all you need ask the villager is "which leads to your village". Again, regardless of which village the villager calls home, he'll tell you the path to Truth.

Same result as in Geggs' example since it requires only one question and you remove the identity of the asked entity from the problem.

However, this problem is logically inconsistent and "silly", therefore I'm sticking with my answer of "WIBBLE!"

Ah...Geggs. Nearly there. But unfortunately, if the FM is a liar, then none of that makes sense.

Is there anyone else claiming to be a liar?

B

I will side with the idea that nobody except officers should be doing surgery- therefore the ortho doc para doc will probably be the Major.
As an aside there was a star trek episode that used this same idea.
The chief robot Normon was not letting anyone beam up, but trying to use logic on the question of someone who always lies saying he is lying caused him to blow a circuit and the Enterprise crew beamed up before he got rebooted.

see post 71.

Furthermnore - the Lt. is lying when he reports what the Major said
and the Private is lying if he includes the major in saying "they are all liars" I would say that the ortho doc para doc is Major Jump.

If anyone is fascinated by logical puzzles - rather than the poorly presented nonsense offered here by Mu Beta - I would like to recommend you take a look at Raymond Smullyan's 'The Lady or the Tiger?' (1982). You won't regret it.

thank you, i will

The chapters 'Ladies or Tigers?' and 'The Island of Questioners' are particularly amusing. When I worked through them with my father, many years ago, we often ended up with tears of laughter streaming down our faces. And, of course, there are solutions with clear explanations.



Ps I see Mu has abandoned his own thread - presumably to go off and play with himself. Can't say I'm surprised.