The Impossible Punishment¹

The Unexpected Hanging Sentence

A man guilty of a particularly vicious and heinous murder has been sentenced to death by hanging. The judge who presided over the trial, and must now sentence the convicted murderer, decides that a simple death is too good for the criminal, and determines to add an additional element of suffering. He sentences the criminal as follows:

“You are sentenced to be hanged from the neck until you are dead, and that it be done within the week. However, you will not know when within the next seven days the day of your death shall be. That way, you may live in fear each day until the punishment is carried out. . . . And may God have mercy on your soul.”

Taken to his cell, the murderer reasons that the sentence is impossible to be carried out. He thinks to himself that if he is to die on the seventh day, then he would know—when he was not hung on the sixth day—that he would be hung on the seventh day. That means that he would know when he would die, and so the judge cannot have meant that he would die on the seventh day.

He then thinks that if he is alive on the sixth day, then he will be hung that day. But in that case, he would know when he would be hung. Because the judge told him he would not know when he would die, he therefore could not be hung on the sixth day either.

He continues the reasoning, and applies it to the fifth, the fourth, the third, the second, and the first day after the sentence, each time concluding that he cannot die that day, for then he would know that he would die and the judge told him he would not know.

Against all this seeming logic, the criminal is hanged on the third day after his conviction and sentencing. He went to the gallows completely flummoxed, and cursing the judge for his false sentence.

Endnotes

¹ Adapted from R. M. Sainsbury, Paradoxes (Cambridge: Cambridge University Press 2007), 91. ⇑