Wednesday, December 17, 2008

The Rabbi and the Norse King

Leo Rosten, in his (delightful) The Joys of Yiddish, tells the following story:

An official brought the chief rabbi of a town before the Court of the Inquisition and told him, "We will leave the fate of your people to God. I am putting two slips of paper in this box. On one is written 'Guilty.' On the other is written 'Innocent.' Draw."

Now this inquisitor was known to seek the slaughter of all the Jews, and he had written "Guilty" on both pieces of paper.

The rabbi put his hand inside the box, withdrew a slip of paper—and swallowed it.

"What are you doing?" cried the Inquisitor. "How will the court know—"

"That's simple," said the rabbi. "Examine the slip that's in the box. If it reads 'Innocent,' then the paper I swallowed obviously must have read 'Guilty.' But if the paper in the box reads 'Guilty,' then the one I swallowed must have read 'Innocent.'"

It's a clever trick, but I had heard it before:

… it was determined, with the consent of all parties, that lots should be thrown into a box, and the Greeks and Varings should draw which was first to ride, or to row, or to take place in a harbour, or to choose tent ground; and each side should be satisfied with what the drawing of the lots gave them.

Accordingly the lots were made and marked. Harald said to Gyrger, "Let me see what mark thou hast put upon thy lot, that we may not both mark our lots in the same way." He did so. Then Harald marked his lot, and put it into the box along with the other. The man who was to draw out the lots then took up one of the lots between his fingers, held it up in the air, and said, "This lot shall be the first to ride, and to row, and to take place in harbour and on the tent field." Harald seized his hand, snatched the die, and threw it into the sea, and called out, "That was our lot!" Gyrger said, "Why did you not let other people see it?" Harald replies, "Look at the one remaining in the box, -- there you see your own mark upon it."

Haraldsaga was written in the 13th century and describes events in the 11th century—Harald, after serving as the commander of the Varengian guard, returned to Norway, became king, in 1066 invaded England and died at the battle of Stamford bridge. So it is unlikely that either Harald or Snorri Sturluson, the author of the saga, got the idea from Leo Rosten or his unnamed rabbi. The most likely explanation is independent invention; it's a clever idea that could have occurred to two different people.

My preferred explanation, however, is that the inquisitor had the bad luck to pick on a rabbi with a taste for reading the Icelandic sagas.


At 3:13 PM, December 17, 2008, Blogger Milhouse said...

There's a big difference, though. In the saga, Harald is the cheat. In the Jewish version, the rabbi is merely defending himself against a potential cheat; if his adversary was honest then there should be no problem.

At 4:01 PM, December 17, 2008, Blogger Robert Wenzel said...


That's kind of how I bet on three card monte games. When it is down to two cards, to win, I pick the card I don't think it is.

Of course, it also helps to be big enough to collect.

At 12:33 AM, December 18, 2008, Blogger marevalo said...

The only problem of this story is the that it increases the "Black Legend" that is mainly false, I would move it to the Witch Hunts epoch... but, then again, there would be no court, nor any official, nor any option to a innocent veredict, and so no story at all. :-)

At 5:34 AM, December 18, 2008, Anonymous Anonymous said...

"The only problem of this story is the that it increases the "Black Legend" that is mainly false,..."

Then we just continue the story this way:

Then the Inquisitor drew out the lot that was left, and, behold, the legend it bore was "innocent", for the Inquisitor, knowing the cunning and deceitfulness of the Rabbis of the Jews, had replaced both lots beforehand, and marked them both "innocent". And so the guilty Rabbi received his just deserts and went to Hell, while the Inquisitor went to Rome and got promoted to Cardinal.

At 5:41 AM, December 18, 2008, Anonymous Anonymous said...

And the moral of that is the interesting games theory question: is there any strategy that will guarantee both parties a fair shake?

At 3:42 AM, December 19, 2008, Anonymous Anonymous said...

I meant, of course, any strategy that works even if either or both sides can pull shenanigans with the lots. If they can't there's no problem.

At 8:29 AM, December 19, 2008, Blogger Arthur B. said...

This is reminiscent of the trick used to share something between two people. Have a cutter and a chooser. Here, the Rabbi was the chooser.

At 1:38 PM, December 19, 2008, Blogger phosphorious said...

Disjunctive syllogism. . . protector of the innocent!

At 6:23 PM, December 21, 2008, Blogger Jared said...


For the given shenanigans, the Nash equilibrium is for the Rabbi to decide at random with even probability whether to eat the lot, and of course to pick the lot itself evenly at random, and for the Inquisitor to decide between fair lots, both "guilty", and both "innocent" such that both "guilty" and both "innocent" have the same probability.

One might realistically imagine that the Rabbi could look quickly at the lot, and then eat it if, and only if, it says "guilty". Then the equilibrium is for him to do that and for the Inquisitor to always use fair lots.

Both these scenarios give an even probability to each verdict. Then the question becomes whether we can imagine shenanigans where the equilibrium strategy does not give an even probability to each verdict.

At 4:34 AM, December 22, 2008, Anonymous Anonymous said...


I'm not sure this quite works. If the Rabbi has the opportunity to look at his lot before deciding whether or not to destroy it, he will obviously destroy it only if it says guilty; and the Inquisitor knows this. So won't the Inquisitor then destroy the other lot unread, on the grounds that the Rabbi's lot must have read guilty or he wouldn't have destroyed it? The Inquisitor then wins whenever he marks both lots guilty (or marks them fairly and the Rabbi has bad luck).

The only way I can then see for the Rabbi to get back to an even chance is if - before drawing - he openly states whether or not he will destroy the lot unread (making that choice randomly with even probability either way), and then observably does so.

At 12:31 PM, December 23, 2008, Blogger Gary McGath said...

Why not just put both lots, and the inside of the box, open to inspection before the lots are placed in it?

At 2:55 PM, December 23, 2008, Anonymous Anonymous said...

Unfortunately, I don't see how the lots could be allowed to remain visible while they're being chosen, which opens it all up to trickery again (think of how stage magicians work). For that matter, I suppose the Rabbi could just palm the lot he picks and replace it with his own. So now we've got the Inquisitor demanding to see the other lot, to make sure the Rabbi isn't cheating! As yet, I'm far from convinced there's any truly foolproof general solution.

At 4:05 PM, January 02, 2009, Blogger Damien Sullivan said...

Public examination of the lots before *and* after selection seems like a good start at fairness verification. See that G and I go in, and tip out the remaining lot in conjunction with examining the selected lot, so that G and I come out (but by different paths.)

At 9:04 PM, January 06, 2009, Blogger gcallah said...

Very funny, except:
"The Inquisition, as an ecclesiastical tribunal, had jurisdiction only over baptized Christians."

So no rabbi would have been brought before the Inquisition.

At 12:26 AM, January 12, 2009, Anonymous Anonymous said...

... UNLESS he was a Jewish rabbi who was caught pretending to have converted to Christianity. (I think.)

At 5:47 AM, January 12, 2009, Blogger gcallah said...

Right, Steve, the conversos did have trouble.

At 7:37 PM, January 14, 2009, Blogger Harold Feld said...

Indeed Your Grace. It was very fortunate that I had met this Rabbi's son when he passed through Cairo on his way to the Holy Land. I told him the story which, I believe, I had heard from you at your fire some years before. Obviously, he must have written to his father and included the tale.

In service,


Post a Comment

<< Home