A Man’s Word Is His Bond

We have previously discussed the derivation of Halachic and ethical principles from the moral sensibilities of non-Jews and their culture, and particularly the question of whether non-Jewish reprehension of conduct that we consider acceptable means that we must abstain from it to avoid engendering a חילול השם. I recently encountered several additional sources on this topic, which we shall consider in this and several follow-up posts, בג”ה.

The ספר חסידים forbids breaking a promise made to a captor as a condition of regaining one’s liberty, on two grounds:

  • This will engender a חילול השם.
  • The parole of Jews will no longer be trusted in future cases of captivity.

שר אחד היה רע ליהודים שבעירו והיו רוצים לברוח משם ותפשם עד שנשבעו לו שלא יברחו משם

ואם תאמר ישאלו על השבועה ויתירו להם היה חילול ד’

ועוד שלא יאמין ליהודים יותר ושמא יתפוש אחד ולא יניחו עוד בשבועה

אלא יתעסקו עם המלך או עם שר גדול לקחת אותם משם על כרחו.1

Rav Ya’akov Emden raises two objections to the חילול השם consideration:

  • An oath taken under duress is inherently void (and does not even require התרה).
  • There will be no חילול השם, as the non-Jew understands the previous point.

היה חילול השם. באמת חסידות יתרה היא זו כי שבועת אונס לא כלום היא ואפילו התרה אינה צריכה גם אין מקום לחילול השם בכך כי גם העכו”ם יודע שאין שבועה באונס שבועה2

I am somewhat perplexed by R. Emden’s language in his initial point: insofar as he concedes the basic assumption of the ספר חסידים that even in the absence of a Halachic imperative to keep one’s promise, the necessity of avoiding חילול השם can still compel one to do so, what difference does it make whether the oath is valid, requiring התרה, or not? His entire objection to the stance of the ספר חסידים seems to hinge on his latter point, that there will be no חילול השם since the non-Jew understands the illegitimacy of his position, but whether or not the oath is valid and needs התרה, or is inherently void seems irrelevant.

The latter point of the ספר חסידים touches on a moral / game-theoretical paradox with which I have long grappled:

The perpetrator of a crime realizes that his crime has been witnessed, and that his only chance to escape the consequences is by ensuring the permanent silence of the witness. The criminal can threaten to kill the witness unless he promises to remain silent, to which the latter will certainly accede, but both are perfectly aware that the witness may subsequently repudiate his oath, on the grounds that it was entered into under duress, and the criminal therefore has no choice but to kill the witness.

Both players in this ‘game’ would clearly be better off if the witness could somehow render his promise binding, or otherwise guarantee his silence – the criminal would not have to commit a second murder, and the witness would escape with his life – yet there is no apparent way for the witness to irrevocably bind himself to the mutually desired course of future (in)action.

Ultimately, this paradox is the same one that is at the heart of the Prisoner’s Dilemma:

The prisoner’s dilemma is a canonical example of a game analyzed in game theory that shows why two individuals might not cooperate, even if it appears that it is in their best interests to do so. It was originally framed by Merrill Flood and Melvin Dresher working at RAND in 1950. Albert W. Tucker formalized the game with prison sentence payoffs and gave it the name “prisoner’s dilemma” (Poundstone, 1992). A classic example of the game is presented as follows:

Two men are arrested, but the police do not have enough information for a conviction. The police separate the two men, and offer both the same deal: if one testifies against his partner (defects/betrays), and the other remains silent (cooperates with/assists his partner), the betrayer goes free and the one that remains silent gets a one-year sentence. If both remain silent, both are sentenced to only one month in jail on a minor charge. If each ‘rats out’ the other, each receives a three-month sentence. Each prisoner must choose either to betray or remain silent; the decision of each is kept secret from his partner until the sentence is announced. What should they do?

Both players would ultimately be better off if cooperation were the rational strategy – but that indubitable fact cannot make it so, and so cooperation remains irrational, and two rational players will therefore suffer suboptimal outcomes.

In our situation, too, both players would be better off if the witness’s strategy of keeping his promise and remaining silent would be the rational one – but it is not, as once the witness is out of harm’s way, it will typically be in the interest of both himself and society in general to report the crime – and both players therefore end up with suboptimal outcomes: death, in the case of the witness, and the need to further entangle himself in crime and subterfuge, in the case of the criminal. This often insoluble problem is nicely articulated in Nobel Laureate (along with our own Robert Aumann)3 economist and game theorist Thomas C. Schelling’s classic An Essay On Bargaining (the work he “believe[s] the Nobel selection committee considered [his] contribution to “understanding cooperation and conflict”” but which he “completed before [he] had more than a smattering of acquaintance with formal game theory”):

Among the legal privileges of corporations, two that are mentioned in textbooks are the right to sue and the “right” to be sued. Who wants to be sued! But the right to be sued is the power to make a promise: to borrow money, to enter into a contract, to do business with someone who might be damaged. If suit does arise the “right” seems a liability in retrospect; beforehand, it was a prerequisite to doing business.

In brief, the right to be sued is the power to accept a commitment. … The promise is a commitment to the second party in the bargain, and is required whenever the final action of one or of each is outside the other’s control. It is required whenever an agreement leaves any incentive to cheat.

This need for promises is more than incidental; it has an institutional importance of its own. It is not always easy to make a convincing, self-binding, promise. Both the kidnapper who would like to release his prisoner, and the prisoner, may search desperately for a way to commit the latter against informing on his captor, without finding one. If the victim has confessed to an act whose disclosure could lead to blackmail, he may confess it; if not, he might commit one in the presence of his captor, to create the bond that will ensure his silence. But these extreme possibilities illustrate how difficult, as well as important, it may be to assume a promise. If the law will not enforce price agreements; or if the union is unable to obligate itself to a no-strike pledge; or if a contractor has no assets to pay damages if he loses a suit, and the law will not imprison debtors; or if there is no “audience” to which one can pledge his reputation; it may not be possible to strike a bargain, or at least the same bargain that would otherwise be struck.4

The ספר חסידים sidesteps this whole issue by pointing out that our situation is actually analogous to the Iterated Prisoner’s Dilemma, in which cooperation may indeed be the optimal, perfectly rational strategy; as Schelling puts it:

The tactic of decomposition applies to promises as well as to threats. What makes many agreements enforceable is only the recognition of future opportunities for agreement that will be eliminated if mutual trust is not created and maintained, and whose value outweighs the momentary gain from cheating in the present instance. Each party must be confident that the other will not jeopardize future opportunities by destroying trust at the outset. This confidence does not always exist; and one of the purpose of piecemeal bargains is to cultivate the necessary mutual expectations. Neither may be willing to trust the other’s prudence (or the other’s confidence in the first’s prudence, etc.) on a large issue. But if a number of preparatory bargains can be struck on a small scale, each may be willing to risk a small investment to create a tradition of trust. The purpose is to let each party demonstrate that he appreciates the need for trust and that he knows that the other does too. So if a major issue has to be negotiated, it may be necessary to seek out and negotiate some minor items for “practice”, to establish the necessary confidence in each other’s awareness of the long-term value of good faith.5

R. Reuven Margolis’s characteristically erudite gloss to the above passage from the ספר חסידים includes a reference to an interesting responsum of Rav Yehudah Assad, who was asked about a Jewish barkeeper who sued a non-Jewish customer for a claimed unpaid tab of “one hundred and thirty three gold in money” (!). The customer denied one hundred of the claim, and the court ruled that the Jew could collect if and only if he took an oath to the veracity of his claim, which he was reluctant to do, since it was his family members who had actually served the patron, and his tally was based on their reports, so he could not be quite certain of its accuracy. After an intricate discussion of the laws of oaths taken under undue duress and the possibility of voiding an oath by the instantaneous articulation (either mental or sotto voce) of its nullification, the Mahari Assad rejects any possibility of taking an oath that may not be wholly true, ruling that the plaintiff may only swear to the sum that he is absolutely sure he is owed, even if this will result in the forfeiture of the entire claim. In addition to his technical halachic arguments, he adds that “Regardless, it is prohibited to publicize to an ignoramus any sort of permission in this matter, and a wise man’s eyes are in his head”:

ועל דבר שנשאל שאינו יהודי שתה יין אצל חנוני מוכר ישראל בהקפה וכשבא לתבוע חובו סך קל”ג זהב כסף כפר לו מאה זהב ונתחייב ישראל בדיניהם שבועה והוא ירא מלשבע לפי שב”ב [בני ביתו] נתנו לו והוא כתב על פיהם בפנקס שלו ואולי טעה ורצה היהודי לפשר עמו ואינו רוצה האינו יהודי בשום אופן רק שישבע הישראל …

[ועיין שם שהאריך לפלפל בסוגיא דשבועת אונסין וביטול בלחש ובלב, והעלה:] מכל הלין טעמי אין אני מסכים עם הדר”ג ני’ בדין זה לא למעשה וגם לא להלכה

מלבד זה אסור לפרסם לעם הארץ שום היתר בזה הענין וחכם עיניו בראשו

אלא על סך מה שהוא ישער בעצמו שודאי אצלו ממש בברי גמור ישבע עליו והשאר יפסיד ואם גם יפסיד כל המנה לא יכניס את עצמו בהיתר הביטול

וכבר הוי עובדא בק”ק שאדם גדול בישראל ידוע זצוקלה”ה שנפסקה לו שבועה בערכאות ונתיעץ עמי על רזא דנא ושמע לדברי ועצתי ועלתה בידו לטובה כי ד’ הי’ בעזרו.6

  1. ספר חסידים (ירושלים תשי”ז) סימן תכ”ג []
  2. מגדל עוז אבן בוחן פנה א’ סימן קי”ד – קשר, צויין בשו”ת זכר יהוסף אה”ע סימן נ’ סוף ד”ה והנה מה שנוגע, ועיין בפירוש מקור חסד על הספר חסידים []
  3. The two were awarded the Bank of Sweden Prize in Economic Sciences in Memory of Alfred Nobel in 2005. []
  4. Thomas C. Schelling, An Essay On Bargaining, in The American Economic Review, Vol. 46 No. 3 (Jun. 1956), pp. 299-300 – (PDF), (PDF). []
  5. Ibid. pp. 300-01. []
  6. תשובת מהרי”א / יהודה יעלה יו”ד סימן שכ”ז, הובא במקור חסד שם []