wu :: forums - Print Page


    
      
        wu :: forums
        (http://www.ocf.berkeley.edu/~wwu/cgi-bin/yabb/YaBB.cgi)
      

        riddles >> medium >> who is who: God or the Devil?
        
(Message started by: Girl_from_Mars on May 1^st, 2005, 1:19am)

Title: who is who: God or the Devil?
Post by Girl_from_Mars on May 1^st, 2005, 1:19am

A guy at work told me this riddle which he'd never been able to solve. Can you help?

You have just died. Now you are standing by a river, which has two identical bridges crossing it. Each bridge has a guard. One is God (his bridge leads to heaven), the other guard is the Devil (his bridge leads to hell), but they look the same and there is no way of telling them apart.

God can only tell the truth, while the Devil can choose whether he wants to lie or tell the truth.

What can you ask to find out which guardian is which, and ultimately, which bridge leads where??

Title: Re: who is who: God or the Devil?
Post by Icarus on May 1^st, 2005, 11:54am

Whether this is solvable or not depends on how tightly constrained the Devil is.

If the Devil is allowed to make any answer, then the problem is not solvable. Whatever test you devise, the Devil can always answer in such a way as to deceive you (otherwise, the test would be worthless in the first place).

If on the other hand, the Devil is constrained to always give an answer which is logically true, or logically false, then solutions exist. What you want is a question that answers the same if Devil tells the truth or lies. If you want ideas on what the question could be, look for Fork in the Road I thru III in the Hard Forum.

Title: Re: who is who: God or the Devil?
Post by rmsgrey on May 1^st, 2005, 12:02pm

Whether there's a solution depends on whether the Devil can make the statement "this is a lie"

If the Devil is constrained to either lie or tell the truth, then:
[hideb]
"Is it the case both that your answer to this question is true and that is the way to heaven?"

cannot be falsely answered "no" so you need only ask it at most twice - once of each - if you get the same answer twice, it must be true; if they differ, then God said "no"
[/hideb]

Title: Re: who is who: God or the Devil?
Post by Grimbal on May 1^st, 2005, 1:34pm

Just ask "does 1 equal 1"?

Title: Re: who is who: God or the Devil?
Post by BNC on May 1^st, 2005, 2:15pm

on 05/01/05 at 13:34:49, Grimbal wrote:

Just ask "does 1 equal 1"?

Both will answer "yes".

Title: Re: who is who: God or the Devil?
Post by Grimbal on May 1^st, 2005, 3:33pm

Oops, I didn't see the Devil can tell the truth. She has to be evil after all.

A possibility would be "Is either true that (1) you will lie in reply to this question and this bridge leads to Hell or (2) you will tell the truth and this bridge leads to Heaven?".

Smarter would be: "Is either true that (1) you will lie in reply to this question and you will not grant me a new life or (2) you will grant me a new life and (you will reply truthfully if and only if this bridge leads to Heaven)".
I'll leave it as an exercise. (see if I goofed somewhere).

Title: Re: who is who: God or the Devil?
Post by David on May 9^th, 2005, 12:14pm

Ask one: If I were to ask the other person which bridge leads to heaven what would that person say? THEN you do the opposite of whatever the answer is and BOM....UR in Heaven...What a miracle!

Title: Re: who is who: God or the Devil?
Post by towr on May 9^th, 2005, 12:51pm

on 05/09/05 at 12:14:55, David wrote:

Ask one: If I were to ask the other person which bridge leads to heaven what would that person say? THEN you do the opposite of whatever the answer is and BOM....UR in Heaven...What a miracle!

They can both tell the truth, in which case you'd be ending up in hell..

Title: Re: who is who: God or the Devil?
Post by Dani Penn on May 23^rd, 2005, 10:19am

It is a simple question. Ask this and see what response you'd get...

"If you lied to me, what would you say?"

God couldn't answer.
The other would be compelled to....

Random thoughts and numbers floating in the sea of Binaries....

Title: Re: who is who: God or the Devil?
Post by bobsagot on Jun 24^th, 2005, 5:18am

Answer:
you are already in hell. The devil is tormenting you with an seeming impossible situation, one that you cannot act up without resolving the riddle, and no solution exists. You spend the rest of eternity trying asking dumb questions to the devil and his twin.

Title: Re: who is who: God or the Devil?
Post by paul schmitz on Jun 30^th, 2005, 4:27am

doesn't it depend on where the devil wants you to go? i assume hell. does god know that the devil can choose to lie or tell the truth and does the devil know that god must tell the truth? i assume yes to both of these.
asking only one question to only one entity cannot give you a solution because the devil can choose to answer in a way that he knows will at least make it impossible for you to determine who is who and at most confuse you into picking hell.

if you can ask them both the same question, does the order of who responds first matter, or are you still going to get no useful information? assuming that the second entity to reply heard the first answer and if the second one is lying that they can change what they would have said after the hear the first person.

Title: Re: who is who: God or the Devil?
Post by Icarus on Jun 30^th, 2005, 3:03pm

If the devil can respond in any fashion he chooses, then it is impossible, by any number of questions, to ever tell which is which. All the devil has to do to keep you confused is to remain consistent in his answers.

The only way the problem is solvable is if the devil is constrained to give answers that are either true or false. In this case, a single question of a single being is sufficient to determine which is the way to heaven (though you will still not know which is God and which is the Devil).

Title: Re: who is who: God or the Devil?
Post by Abigail H. on Aug 2^nd, 2005, 12:24pm

Oh, I know the answer! You ask each one this question: What would the other tell me was the safe road? The Devil would lie and say that God would tell you Heaven was at the end of the road to Hell. God would tell the truth and say that the Devil would lie and say that God would tell you Heaven was at the end of the road to hell. In other words, they would both point to the road leading to Hell. So you merely walk down the opposite road.

Title: Re: who is who: God or the Devil?
Post by River Phoenix on Aug 2^nd, 2005, 7:14pm

I think that this is solvable no matter what the devil can say. Even if the devil can make statements which are not logically true or false, we already know that God only makes statements which are logically true. So if one of the two makes a statement which is neither logically true nor logically false, then it must be the Devil.

Title: Re: who is who: God or the Devil?
Post by rmsgrey on Aug 3^rd, 2005, 5:48am

on 08/02/05 at 19:14:02, River Phoenix wrote:

But the Devil could then continually make statements that would be logically true if the bridges were the other way round.

In that situation you have two possibilities: either person A is God and bridge A leads to heaven or person B is God and bridge B leads to heaven (where the labels are chosen so that person A's answers indicate that bridge A leads to heaven, and similarly for the B's)

The only way of preventing this is to have some things that the Devil cannot say (but that God could if the bridges were switched)

Title: Re: who is who: God or the Devil?
Post by cyrus on Nov 18^th, 2005, 5:56pm

Ok!

I am a newbie guys;D

I think wou can solve this by this premise that God will know if you tell a lie but the devil, no matter how smart, would not.
so based on this assumption, we can ask a trick question , find our way to heaven:

Ask this question from any of the twins ;D

" I asked the other guy if your bridge leads to heaven and he told "NO". would you agree??

if he is God he would say somethikg like this:

" you are lying, o my son ;D.."

but if itwas the devil would not know that you
are tricking him , so he will give an akswer one way or the other.

Title: Re: who is who: God or the Devil?
Post by rmsgrey on Nov 22^nd, 2005, 8:58am

So the "Father of Lies" wouldn't know if you were lying?

Title: Re: who is who: God or the Devil?
Post by towr on Nov 22^nd, 2005, 9:00am

Can the devil hear your prayers (if you pray to god). Because otherwise there's a simple answer..

Title: Re: who is who: God or the Devil?
Post by Three Hands on Nov 22^nd, 2005, 10:00am

That's assuming that God responds to your prayer...

Title: Re: who is who: God or the Devil?
Post by towr on Nov 22^nd, 2005, 10:07am

on 11/22/05 at 10:00:09, Three Hands wrote:

That's assuming that God responds to your prayer...

Well, yes.
But if they don't have to respond to your question, it doesn't matter what you ask.

Title: Re: who is who: God or the Devil?
Post by Three Hands on Nov 22^nd, 2005, 10:18am

Well, God might just not reward that method of distinguishing. After all, the riddle states that there is no way to tell them apart...

Title: Re: who is who: God or the Devil?
Post by BaH on Dec 28^th, 2005, 3:38pm

I hope this isn't too far out of whack, but I thought you went to heaven or hell based on your life, not on your riddle asking abilities at the end of it

Title: Re: who is who: God or the Devil?
Post by towr on Dec 28^th, 2005, 3:52pm

on 12/28/05 at 15:38:31, BaH wrote:

I hope this isn't too far out of whack, but I thought you went to heaven or hell based on your life, not on your riddle asking abilities at the end of it

That depends on your brand of faith. For some it doesn't at all matter what you did in life, you just need to repent at the end, or just believe, or have been chosen.
This isn't really a theological puzzle though.

Title: Re: who is who: God or the Devil?
Post by Hawk on Mar 13^th, 2006, 2:59pm

If the Devil can choose to answer honestly or dishonestly.. then this riddle is NOT possible to answer correctly.

I think it was just told wrong to begin with. Thats prolly why the original poster hasnt been able to figure it out.

Title: Re: who is who: God or the Devil?
Post by Icarus on Mar 13^th, 2006, 3:33pm

As I said in the first reply, if the devil is constrained to give an answer to your question which when examined logically is either true or false (as opposed to being undecidable, or contradictory, or irrelevant to the question), then a solution does exist.

I am sure that is the interpretation the original poser of this problem intended. But there are other, far broader definitions of what it means to lie (in particular, "to attempt to cause someone to believe somthing is true that you believe is false"). The best liars seldom if ever tell falsehoods. They just present the truth in such a way as to mislead the listener. A careful examination of political punditry will turn up numerous examples.