1. Attention: We have put together a thread with tips and a tutorial video to help with using the new software. Please take a moment to check out the thread here: Trapshooters.com Tutorial & Help Video.
    Dismiss Notice

Philosophy Question - Life or Death ?

Discussion in 'Off Topic Threads' started by amboy49, Aug 13, 2009.

Thread Status:
Not open for further replies.
  1. amboy49

    amboy49 Well-Known Member

    Joined:
    Jul 23, 2007
    Messages:
    1,158
    Location:
    out in left field
    Here is the scenario:

    You are in a room with two doors. Standing in front of each door is a guard. Passing through one door will result in the most horrible death you can imagine. Passing through the other door will result in nirvana.

    You are allowed to ask the guards one question.

    One guard always tells the truth.

    One guard always lies.

    What do you ask to decide which door to choose ?

    I don't have the answer - need help for a philosophy homework question ! !

    Noel
     
  2. timb99

    timb99 Well-Known Member

    Joined:
    Jan 29, 1998
    Messages:
    7,330
    Location:
    Shawnee, Kansas, USA
    You ask one of them, "If I ask the other guard which door leads to nirvana, what will he tell me?"

    Regardless of the answer, you choose the door opposite what he tells you.
     
  3. wdr-NY

    wdr-NY TS Member

    Joined:
    Jul 29, 2008
    Messages:
    581
    Correct.

    Walker
     
  4. crusha

    crusha TS Member

    Joined:
    Jan 29, 1998
    Messages:
    5,762
    Extra credit: what are your assumptions, in choosing the above answer?
     
  5. timb99

    timb99 Well-Known Member

    Joined:
    Jan 29, 1998
    Messages:
    7,330
    Location:
    Shawnee, Kansas, USA
    No assumptions.

    You have two doors, we'll call them N to nirvana, and H to hell.

    You have two guards, we'll call them T for the one who always tells the truth, and L for the one who always tells a lie.

    If you ask T the question I posed above, he will tell you the truth, that is, he will say "L will tell you that door H is the door to nirvana."

    If you ask L the question, he will tell you a lie, that is, he will say "T will tell you that door H is the door to nirvana."

    In either case, you get the same answer, so you don't need to know which guard is the honest one and which is the liar.
     
  6. miketmx

    miketmx Well-Known Member

    Joined:
    Jan 29, 1998
    Messages:
    2,964
    In life the only thing that is certain is that nothing is certain. If that statement is True, it is also False.
     
  7. W.P.T.

    W.P.T. TS Member

    Joined:
    Jan 29, 1998
    Messages:
    8,371
    MikeTMX,

    Thats true to a point, but not beyond that point ... WPT ... (YAC) ...
     
  8. timb99

    timb99 Well-Known Member

    Joined:
    Jan 29, 1998
    Messages:
    7,330
    Location:
    Shawnee, Kansas, USA
    This exercise is a little more difficult, but not terribly so, if the question you ask the guard must be a yes/no question.
     
  9. amboy49

    amboy49 Well-Known Member

    Joined:
    Jul 23, 2007
    Messages:
    1,158
    Location:
    out in left field
    I have learned that timb99's answer is correct.

    But today we also learned there is a second solution. If you ask the same question to either guard but ask which door leads to Hell - the choice will then be to select the door you are instructed to take rather than the opposite door.
     
  10. wolfram

    wolfram Well-Known Member

    Joined:
    Jul 17, 2007
    Messages:
    6,258
    Two nice catches in one week? Way to go Tim.
     
  11. crusha

    crusha TS Member

    Joined:
    Jan 29, 1998
    Messages:
    5,762
    Assume, for the purposes of this question, that the guard knows what is behind the door.
     
  12. timb99

    timb99 Well-Known Member

    Joined:
    Jan 29, 1998
    Messages:
    7,330
    Location:
    Shawnee, Kansas, USA
    Buzz,

    You are correct. I overlooked that. But I guess its kind of understood. If you don't make that assumption, the entire exercise is reduced to pure chance.


    Amboy,

    Yes, that solution is also correct.
     
  13. dmarbell

    dmarbell Active Member

    Joined:
    Aug 26, 2006
    Messages:
    1,572
    It appears to me the answers are in the matrix below. First is the question, not "yes or no," you can ask. The second and third sets are yes and no questions you can ask. The answers that will lead you to Nirvana are in the left hand column. For simplicity, the questions are framed "what will liar tell me" or "what will truth teller tell me" when in fact you would ask "what will he tell me."

    The door is at the top, and the guard is next, then the question and the answer.

    Danny

    <a href="http://s188.photobucket.com/albums/z16/dmarbell/Trapshooters/?action=view┬Ąt=PhilosophyQuestion.gif" target="_blank">[​IMG]</a>
     
Thread Status:
Not open for further replies.