"Toxin X is a substance that will make you violently ill for a few hours. However, it has no long term effects of any kind. As an experiment in psychology, I'm offering you a million dollars if tonight at midnight you fully intend to drink toxin X by tomorrow at noon. You don't actually have to drink the toxin; all you have to do is to intend to drink it. Your intention will be tested by a device similar to a polygraph which my people have developed and which has been shown to be 100% accurate. If at midnight you have the intention, a million will be wired to your bank account. The only other conditions are that you are to make no bets, do anything that will cause you to become irrational, or arrange for any way to avoid the effects of the toxin."

Suppose you decide that being ill for one day is a reasonable price to pay for a million dollars. Your first thought is to therefore agree to the proposal. It then occurs to you that you won't even have to become sick in order to win the money. All you have to do is to intend to drink the toxin. You don't actually have to carry out your intention.

But now if you know ahead of time that you don't actually have to drink the toxin, then you can't really intend to drink it. So you tell yourself you really do have to drink it. But then if at midnight you really did intend to drink the toxin, and you got the million, then come the next day you would no longer have any reason to drink it: you've already been paid and drinking the toxin would make you unnecessarily sick.

Is there any way for you to win the money?

But if you drink the toxin, right at midnight, you won't have "an intention to drink the toxin" ("intend to drink" means "in the future") duing the succeeding lie detector test, and will flunk it. But if you resolve to drink the toxin after the test, then during the test you will realize that as soon as you pass the test, you won't have to drink the toxin, so you will flunk the test. This puzzle is trickier than it appears.  

You can only win the money by being, or becoming, masochistic, and looking forward to the sickness. I can see that. Some of the fondest memories of my youth were my many glorious hangovers.....

:-)

Edited on April 19, 2004, 10:33 am

Posted by Penny on 2004-04-19 10:19:23