Kavka's toxin puzzle - Wikipedia

• An eccentric billionaire places before you a vial of toxin that, if you drink it, will make you painfully ill for a day, but will not threaten your life or have any lasting effects.
  
• The billionaire will pay you one million dollars tomorrow morning if, at midnight tonight, you intend to drink the toxin tomorrow afternoon.
  
• He emphasizes that you need not drink the toxin to receive the money; in fact, the money will already be in your bank account hours before the time for drinking it arrives, if you succeed.
  
• All you have to do is...intend at midnight tonight to drink the stuff tomorrow afternoon.
  
• You are perfectly free to change your mind after receiving the money and not drink the toxin.

(Hat-tip to Puck Daddy, whose commenter invoked Kavka.)

Gregory Kavka was a moral philosopher whose work dealt with what he called paradoxes of (nuclear) deterrence, some (many? all?) of which dealt with the concept of intent. In the case of the famous toxin, Kavka's argument (if I am qualified to paraphrase it, which I'm probably not) you can't actually intend to do something later, in order to receive a pay-off now, when you know that when "later" arrives, there will no rational reason to do what you "intended" to do, because the pay-off has already occurred and can't be retracted.

Related to Kovalchuk, Kavka -- if he were a sports lawyer for the NHL, and not a deceased moral philosopher on the topic of mutually assured destruction -- would argue, not only is it not possible for him to promise to do something that he has no reasonable expectation of being able to do, but it's not possible for him to intend to do it either.

Shorter Kavka: get paid up front.