Between Rabbi and Expert – Lesson 2

Table of Contents

• [0:04] The three-part model of halakhic decision-making
• [3:07] The confusion between a professional domain and a rabbinic domain
• [4:08] Eating on Yom Kippur: what the Shulchan Arukh says
• [10:04] Halakhic authority vs. factual determinations
• [11:58] Anarchism and the absence of halakhic authorities today
• [15:37] Maimonides and the Shulchan Arukh as advisory books
• [21:18] Drawing the line at age three: why three?
• [26:12] The authority of the judge in choosing experts
• [28:31] The authority of the rabbi in halakhic questions
• [31:31] The authority of the Sanhedrin and its connection to Jewish law
• [35:21] The paradox of the heap and binary determinations
• [51:58] Jewish law and the facts: change in modernity
• [53:32] The connection between logic and Jewish law
• [54:43] The prohibition against factions and communities
• [56:06] Bach’s genius and the if-then structure

Summary

General Overview

The text presents a three-stage model of decision-making in cases that contain both a factual component and a normative component, and argues that the value-based decision-maker is involved in two of the three stages, because even “determining the facts” sometimes includes drawing a value-laden line and is not merely a professional decision. The text emphasizes that people get confused when the system hands the value decision over to the expert as well, for reasons of convenience and efficiency, and then mistakenly perceive it as a professional determination. It distinguishes between the categorical question of what counts as a halakhic component and what counts as a factual component, and the question of authority—who is authorized to issue a halakhic ruling nowadays—and presents the view that binding halakhic authority exists for the Sanhedrin and for a religious court with respect to those who accepted its authority, whereas rabbis generally function as advisors in Jewish law. The text connects the confusion to two philosophical phenomena: the paradox of the heap, which shows that many concepts are continuous rather than binary, and the naturalistic fallacy, which emphasizes that norms are not derived from facts without some bridging principle.

Three Stages in a Decision and Drawing a Value-Laden Line

The text describes an approach according to which a decision is not built from two stages—“an expert brings the facts and then a rabbi applies Jewish law”—but from three stages, in which even the determination of whether a given situation is “dangerous” already requires a value judgment. It gives the example of the legal speed limit on a road, where a traffic expert can draw a risk graph, but cannot determine from what level of risk it “counts as dangerous,” because that determination is a value threshold. It argues that the value-based decision-maker, called for the sake of discussion “the rabbi,” though it could also be a legislator, a judge, or a person making a moral decision for himself, must participate both in the stage of setting the line and in the stage of applying the norm to the case.

Handing the Decision to the Expert for Convenience and the Public Confusion

The text argues that normative systems sometimes let the expert draw the value line as well, because there is no professional “expertise” in drawing such a line, and in a certain sense everyone is neither more nor less professionally qualified to set it. It presents this as an efficient choice that creates confusion, because when the system is used to handing the expert the value decision too, people think it is a professional decision, and when a value-based decision-maker stops and does not hand the decision over to the expert, there is a backlash accusing him of “interfering in a professional field.” It gives an example from Jewish law and from civil law where, for the sake of simplicity, one might decide that the halakhic threshold will be matched to the legal threshold, but emphasizes that this is a choice made for efficiency and not proof that the legal threshold is a professional determination.

Yom Kippur, the Shulchan Arukh, Most Doctors, and Fear of Heaven as a Component in Drawing the Line

The text refers to wording attributed to the Shulchan Arukh according to which one asks a doctor whether there is danger to life, and presents a custom from Pressburg in which an aliyah was given to the doctor on Yom Kippur and he was called “Maran,” as one who effectively rules in practice. It argues that drawing the line of “danger” is not a professional medical tool but a value decision, and therefore handing that determination over to the doctor is a possible systemic choice but not a necessary one. It quotes the Shulchan Arukh as a source in which the rabbi determines rules such as following two doctors against one, and emphasizes that this is an example of a halakhic determination that defines how to decide between professional opinions. It adds that the halakhic decisors themselves note that “two against one” is not an absolute rule, and that there are considerations such as degree of expertise and whether the doctor is God-fearing, because a God-fearing doctor will tend to draw the line differently in relation to the value of Yom Kippur.

Clarifying the Difference Between the Category Question and the Question of Halakhic Authority

The text clarifies that the lecture is dealing with the question of which component in a decision is halakhic and which component is factual, not with the question of who is authorized to make a halakhic ruling. It presents the possibility of saying that drawing a certain line is a halakhic determination and still not accepting the ruling of a particular rabbi because one does not recognize his authority, and it states that the discussion of halakhic authority in our time is a separate discussion. It presents the view that binding halakhic authority exists only for the Sanhedrin, whereas a rabbi who is not a Sanhedrin functions as a professional advisor who gives an opinion on what he thinks Jewish law says, similar to a law professor who is not a judge.

Legal Analogies: Judge, Religious Court, and Determining Facts as Part of a Ruling

The text distinguishes between a legal expert who gives advice and a judge who rules with authority, and argues that authority does not necessarily stem from greater expertise. It describes how a religious court can also determine facts in a way that is binding on the parties who came before it, even though from the outside one may disagree about “what really happened,” because a verdict includes a factual determination as part of the legal ruling. It argues that when a decision lies with an authoritative body, that body must decide even on matters outside its expertise, and therefore it will consult experts in order to draw the graph, but drawing the line remains within its authority.

The Rabbi as an Advisor in Jewish Law, a Sage Who Ruled, and a Proposed Model of Presenting Options to the Questioner

The text argues that even without binding authority, it is worthwhile to listen to a halakhic expert just as it is worthwhile to listen to a doctor—not because of authority, but because of professional reasonableness. It explicitly accepts the claim that Maimonides, the Mishneh Torah, and also the Shulchan Arukh are in practice advisory books, and agrees with the comment that “for Jews, advice is an ancient Jewish profession.” It presents a model according to which the one who ultimately decides in a halakhic question is the questioner, while the rabbi’s role is to draw a map of the options, the costs, distinctions such as a rabbinic prohibition and a Torah-level prohibition, pressing circumstances, and conduct beyond the letter of the law, and then the questioner chooses. It illustrates this through an example of family planning, in which the rabbi presents the commandment of “be fruitful and multiply,” “He created it to be inhabited,” sources for leniencies, and examples of circumstances, and stops before the actual decision so that the couple can determine for themselves what counts for them as a pressing circumstance.

Mara De-Atra and the Community’s Acceptance of Authority

The text argues that a mara de-atra has authority not because of an appointment “from above,” but because the community accepted him upon itself, similar to two litigants who accept a religious court upon themselves. It suggests that one might make a similar claim regarding the Shulchan Arukh and Maimonides—that their force comes from acceptance by the Jewish people—but expresses doubt as to whether such acceptance actually occurred in a binding sense. It adds that halakhic decisors of the sixteenth and seventeenth centuries ruled that “it is forbidden to rule from the Shulchan Arukh” without analysis of the Talmudic passages and the context, and that later it was said that since there are commentaries that bring sources and opinions, it is already permissible to rule through it.

The Example of the Shakh, the Jerusalem Talmud, and Criticism of “Reality Has Changed”

The text brings the Talmudic statement about “a three-year-old girl—her virginity returns,” and the question raised in the Jerusalem Talmud about a case where a religious court intercalated the year, and the Jerusalem Talmud determines that the law is set according to the determination of the religious court. It quotes the Shakh, who cites medieval authorities (Rishonim) and writes that the religious court “changes the physiology,” so that virginity returns until the age of three years and one month, and describes this as an extreme conception according to which the ruling determines reality itself. It proposes an alternative interpretation according to which this is a probabilistic continuum, where the Sages draw a line for the sake of legal simplicity, and in intercalating the year they simply set the line according to the date that was fixed, without claiming that the physiology itself changed.

Experts in Court, the Scopes Trial, and Ruling Without Scientific Tools

The text describes how choosing between experts in court is done by the judge even though he is not a greater expert than they are, because that is part of his authority to reach the bottom line. It cites the “Scopes Trial” in the United States over the teaching of evolution and creationism, in which many experts and articles were brought, and argues that the judge has no real tools for deciding which expert is right. It states that this is not a scientific decision, but after the judge rules, the decision is valid as an authoritative one within the legal framework even if it is mistaken.

The Paradox of the Heap, the Continuity of Concepts, and the Naturalistic Fallacy

The text explains that the confusion between facts and norms stems from the paradox of the heap, which shows that everyday concepts like “heap,” “bald,” “dangerous,” and “person” are not binary but continuous, and therefore any attempt to set a sharp threshold is a matter of convention. It explains that the naturalistic fallacy is the attempt to derive “what ought to be” from “what is,” and emphasizes that a norm does not emerge from facts without a bridging principle that decides to which factual situation the norm applies. It uses the example of a surgery with a five percent mortality rate to show that the expert can provide statistics but cannot determine whether it is “permitted” or “proper” to perform the surgery, because that is a moral or halakhic decision.

Determining the Age of Majority, Two Hairs, the Presumption of Rava, and Considerations of Simplicity

The text presents the determination of the age of majority as a value-laden line that does not stem from expertise, and adds that an expert can describe responsibility as a function of age, but the decision-maker has to determine from what threshold of responsibility there is legal accountability. It brings halakhic distinctions such as “a minor who knows how to hold a lulav,” which create individual tests, and opposite them the presumption of Rava that the age of thirteen is a statistical presumption for the appearance of two hairs. It emphasizes that considerations of simplicity lead systems to establish sharp rules even when reality itself is a continuum.

Jewish Law as an If-Then Function: The Presumption that a Person Does Not Pay Before the Due Date, and Changing Facts

The text argues that Jewish law is the application of norms to a given factual situation, and that clarifying the factual situation begins with consulting those who know the facts, while Jewish law itself provides the bridging principles of “if the facts are such-and-such, then the norm is such-and-such.” It cites the presumption that “a person does not pay before the due date,” and explains that if reality changes and borrowers do in fact repay early, then the factual presumption itself can change, but the normative principle that a presumption helps determine credibility and the extraction of money remains. It concludes that one should not look for “facts” in Jewish law, because the facts that appear in it are a changing substrate, whereas the halakhic determinations are transition rules connecting factual situations to norms.

Changing Circumstances, Interpretive Disputes, and the Analogy to Logic and Music

The text argues that a change in a halakhic outcome due to changing facts depends on an interpretive question—whether a given law is circumstance-dependent or fixed—and presents this as a central question in discussions of change in Jewish law. It compares Jewish law to logic in that logic does not determine the premises and does not determine the conclusions, but rather determines the rule of transition, and Jewish law is similar in being an if-then function rather than a list of facts. It offers another analogy through Bach, arguing that genius lies in the ability to generate an “if-then” of fitting a composition to a given audience, whereas when the “if” is fixed people mistakenly imagine that the product alone is what matters. Similarly, people forget that the expert supplies the “if,” while the norm and the line are determined on another plane.

Last time I dealt with the question of the relationship between Jewish law and facts, or between a rabbi and an expert, and I sketched out a kind of map of how decisions are made on a question that also involves factual determinations. I said that there are really three stages in the decision-making process, not two, and that in two of those three stages it is actually the value-based authority, not the factual authority, that is involved. In the usual picture people tend to think that the expert supplies the facts and then the rabbi comes along and determines what the Jewish law is with respect to those facts. But as I showed there, it seems to me that even in determining the facts—which are not exactly facts—the rabbi is actually involved.

I spoke, for example, about the case of the permitted speed on a road. A traffic expert can’t tell me at what speed it becomes dangerous on this particular road. What he can do is give me some kind of risk graph, tell me for each speed you drive at what more or less can be expected, one moment from now, and we still haven’t determined whether a given speed is dangerous or not, even though that seems, at first glance, like a factual determination. But no—it isn’t a factual determination. Here you have to cut the graph at some point, set a threshold, and setting that threshold is a value judgment. Let’s say the graph says that at a certain speed there is this level of risk, and at a higher speed there is that level of risk, some kind of graph. I need to decide from what level of risk it counts as dangerous. A risk of half a percent? One percent? 0.8 percent? Whatever it is—what counts as dangerous? And that determination is a value-based one. The expert has no professional tools for making that determination.

So already at the stage where we determine whether the speed is dangerous, before we apply the norm that one may not drive if that speed is dangerous—already within the determination that the speed is dangerous, the rabbi is actually involved. And I remind you again that I said this is not really specifically about a rabbi, but about any normative decision whatsoever. It can be a legal decision in the case of law, it can be a moral decision, it can be any normative decision at all. The model is always a three-stage model; you just replace the word “rabbi” with legislator, judge, a person deciding for himself in morality, or whatever moral authority he chooses for himself. So what I called the value-decider is actually involved in two of the three stages of the decision.

And I tried to show several contexts in which people get confused. People think, for example, that rabbis are intervening in areas where they are not supposed to intervene because these are supposedly professional areas—and that is not true. It is not true that these areas are purely professional areas. Rabbinic intervention definitely has meaning there, and it ought to be there. And this created some misunderstanding at the end of last time, at least that’s how I understood it from a few questions. So I thought I needed to clarify a little some of the things I said and that also came up in the questions. And if there are more things, then tell me—I’ll try to explain what I understood.

Can you give another example besides the permitted speed? It’s a little… I’ll give more examples today. I will today. But that’s not in his capacity as a rabbi. What? What is not in his capacity? If he comes and says that the rabbi’s intervention is in value matters, then he’s not acting in his capacity as a rabbi but in the capacity of… No—in halakhic matters I’m speaking about values, halakhic values. There are moral values, legal values, halakhic values, all right? I call all of those value-based planes. That’s a general term, not necessarily only morality.

Regarding eating on Yom Kippur, two things. First, in the Shulchan Arukh the wording is that one asks the rabbi—if the rabbi says there is danger to life—there’s nothing in the Shulchan Arukh saying that the rabbi decides or something. You mean the doctor. The doctor, sorry. And I heard this week that the custom in Pressburg was that they would give the doctor an aliyah on Yom Kippur and call him “Maran” or something, that he’s the decisor of Yom Kippur. So it’s a shame they didn’t hear my lecture in Pressburg.

No, because he isn’t… But the wording of the Shulchan Arukh—and this is what rabbis today do—is they say, ask the doctor, he will decide whether you eat on Yom Kippur. Look, I’ll tell you: I said this last time too. The doctor—or the traffic expert—is also no more qualified than I am to draw that line. Not more and not less. We all basically do this by intuition, or arbitrarily, however you want to put it. And because of that, normative systems very often choose the easy route. They let the expert make the value judgment too. That’s true in Jewish law regarding eating on Yom Kippur—not in Jewish law itself, but among certain rabbis—just as with determining death, or determining death, or speed limits and things like that.

Because when the expert from the Technion has drawn the graph, now I ask: who is going to draw the line? The Minister of Transportation knows no better than the expert from the Technion how to draw the line, but also no worse. There is no expertise in that domain. So very often considerations of convenience say: fine, since the expert has already drawn the graph, let him draw the line too. Understand? But in truth that is not an expert determination. It is still not a professional determination; rather, systems, for reasons of convenience and efficiency, tell the expert: you make the decision. The same thing in an area like the rabbis I mentioned who want to say that someone driving above the legal speed limit violates the prohibition of “and you shall guard your lives very carefully.” I said that is not correct, because that prohibition is a halakhic prohibition, while the legal determination is the legal determination.

Now, true, a rabbi or a Sanhedrin, whoever it may be, can come and say: fine, but for the sake of simplicity I’m setting the halakhic threshold equal to the legal threshold. There is a lot of sense in that arbitrary determination—let’s set it by the legal threshold. No problem, that’s perfectly fine; a system can do that. But you have to remember that these are only considerations of efficiency. Therefore, in a place where the system does not make that determination—say if a rabbi comes and says, no, I’m not willing for the line to be the legal line—in the Shulchan Arukh there are various clauses: two doctors say this, one doctor says that. I don’t see there a case where two doctors say this and the rabbi says, I don’t trust the doctor. But listen to what you yourself are saying. The Shulchan Arukh says that if two doctors say one thing and one doctor says something else, we follow the two. And who said that? The rabbi. In the Shulchan Arukh. The rabbi—not the doctor. He didn’t go to the medical association to ask them what to do when there are two doctors against one doctor, right? The Shulchan Arukh said it. Which means he made a halakhic determination of where to draw the line between the doctors’ opinions. That is exactly what I’m talking about.

Now, I said—and he can say—I hand the decision over to the doctor. Sanhedrin, rabbi, Shulchan Arukh, legislator—they can all do that, no problem, and very often they do. They do it because it is more convenient, more efficient, and also because the fact that he is an expert obviously does not detract from his ability to do it. It doesn’t give him greater authority than anyone else, but also not less. So given that, then what difference does it make—if he is already sitting there drawing graphs, let him draw the line too. You understand? It is efficient. But this often causes people to get confused and think we’re dealing with a professional decision. And we’re not.

And I’ll bring examples so that you’ll see: intelligent people, experts in their fields, get confused on these matters. Therefore, when suddenly some rabbi or legislator or whoever comes along and says, wait, stop—here I am not handing the decision over to the expert—everyone gets upset: what do you mean, what are you doing interfering in that field? And that’s the point. If he does hand it over, fine, that’s his right—he wants to streamline matters and do it simply. But if he does not hand it over, that is entirely his right. The fact that he handed it over is incidental. And people, because authority is often handed over to the expert, get confused and start to think that this is a professional decision. And it isn’t.

Now, I’ll begin—I’ll return again to the point where I stopped. My feeling was that there was a bit of confusion created about the authority of the rabbi. Why one should listen to him, what one should not listen to him about. There were various questions—I don’t even remember all the details exactly—but somehow my feeling was that by the end there was confusion around this issue. So I’ll clarify it a little and then continue.

One has to distinguish between the question I asked in the previous lecture—and that question is: where, in this determination, is it a halakhic determination, and where is it a professional determination? That is the question I was addressing. I did not touch on the question of who is supposed to make the halakhic determination. That is a completely different question. I can say that the determination of where the line for the permitted speed passes is a halakhic determination, and still, if a rabbi comes and tells me the line is here, I won’t accept it. Why? Because even though it is a halakhic determination, I do not recognize that rabbi’s authority to make that halakhic determination. He is not a Sanhedrin. He is a rabbi.

And that point, it seems to me, created some misunderstandings last time, because on the one hand I said, as if, that you don’t have to listen to the rabbi, while on the other hand I said, wait, this is a halakhic determination, not a professional one. And that created some confusion, so it is very important to clarify this point. The question whether there is halakhic authority today, and whose voice one should heed—a kind of halakhic question—is a completely different question. I did not touch it in these lectures. I did not touch it at all.

Halakhic authority belongs only to the Sanhedrin. No one else has halakhic authority. A rabbi who is not a Sanhedrin is a professional consultant. We spoke about this once. He is a professional consultant; he basically says what, in his opinion, Jewish law says, and he has no authority. Just as I go to a legal expert—one second—a legal expert, a professor of law, and consult him about what, in his view, the law says in such-and-such a case. He is a professor, not a judge. I’m not talking about a declaratory judgment; I’m talking about going for consultation. Okay? He has no authority. When he tells me, he is giving me his opinion as to what the law says in this situation. That is not an authoritative determination; it is expert advice. He knows more than I do, so he tells me what it means.

When I go to a judge, the judge is not advising me. The judge tells me what the law determines in this case—that is authority. And that is not because the judge necessarily understands the law better than the legal scholar. Not necessarily. Maybe yes, maybe no. Rather, because he has authority and the legal scholar does not. What the judge determines binds the parties. What the legal scholar determines is advice. If you want, accept it; if you don’t want, don’t accept it. You may make a mistake if you don’t accept it, but that is your right. There is no authority here.

So here too. And still, the question is of course a legal question, but the scholar has no authority; the judge does. The professor does not; the judge does. The same in Jewish law: when I ask which of these three stages belongs to Jewish law and which is a professional determination, that is a categorical question about the type of determination. All right? Does this determination belong to the halakhic sphere or the factual sphere? I have not yet said anything about who should make the decision within the halakhic sphere. That is a different question, an internal halakhic question, one that concerns halakhic authority in our time, or in general.

And here I’m quite an anarchist—you’ve probably come to know me by now. I do not think there are halakhic authorities today. The Sanhedrin has halakhic authority, and a religious court has halakhic authority with respect to the two people who come before it. Suppose a religious court determined that such-and-such happened—that doesn’t mean that I, as an outside observer, am obligated to accept it because they have authority. I can disagree that that’s what happened. But the two parties must behave as if that is what happened, because the religious court, like a judge, at the point where two litigants appear before it, has the authority to determine the facts as well. But that is not authority because those are really the facts, but because this is part of the legal determination.

The religious court ruled that Reuven borrowed from Shimon. Reuven denied it, and Shimon sued him, and the court determined that Reuven did in fact borrow from Shimon. That is a factual determination. Are Reuven and Shimon obligated to obey a factual determination? What expertise does the court have in facts? Obviously they are obligated to obey, because a judgment includes within it a determination of what the facts were. There is a dispute about the facts, and the court determined what the facts were for the legal aspect.

If you now ask me as an outside observer—or even one of the two parties—what really happened: did Reuven borrow or not borrow? I have no idea. If someone comes and says that court is talking nonsense, Reuven did not borrow—that is completely legitimate. He can say that. He understands facts as well as the religious court or the civil court. It has nothing to do with that. But still, that determination is a legal determination—a factual determination within the legal framework. The question of who determines the legal determination is a completely different question, okay?

So on the one hand I can be an anarchist and say there are no halakhic authorities, and all these rabbis who talk—it doesn’t obligate anyone and one need not obey them. On the other hand, I say that when these rabbis speak, they are speaking in their own domain. It is not a professional determination; I do not obey them because I disagree with them halakhically. Not because I don’t obey them because they are meddling in facts and they are rabbis—that I rejected. That is not true. They are not meddling in facts; this is a halakhic determination. Rather, my view regarding halakhic authority is that rabbis today do not have halakhic authority, so I have a halakhic disagreement with them about what Jewish law says. But that does not mean that I disagree with them because this is a professional determination and not a halakhic one, which has not been entrusted to them. That is not correct—that claim is incorrect.

I can still argue with them if, in my opinion, rabbis today have no halakhic authority. That is another question, which must be discussed separately, but I am not dealing with it at all. Here I am dealing only with the question of which part of the decision belongs to the halakhic category and which part belongs to the factual category. That’s all. When I speak about the relationship between the rabbi and the professional, it is just a mode of expression. I mean someone who deals in Jewish law as against someone who deals in facts. Now you fill in the blank yourselves—who, in your view, deals in Jewish law—that makes no difference to me. You can say your cat, your neighbor, your rabbi, it doesn’t matter who.

But if they have no halakhic authority, then what is the result of all this? What difference does it make? Professional determination—what do you mean, what difference does it make? He understands Jewish law. If there is no halakhic authority, in any case you don’t have to listen to them. You don’t have to listen to them, but it’s advisable. If you get advice from a professor of law who is an expert in his field, and let’s say you yourself don’t understand—that’s what it means to be an expert. When you go to a doctor, does he have authority to make you take the medicine he prescribes? Does he have authority? Are you obligated? You are not obligated. But if you don’t take it, then… So what you’re saying is that with a rabbi, you decide whether to accept his authority. Right, of course. First of all, you decide which rabbi to go to. Obviously. But I’m saying: assuming he is an expert and that’s presumably why you came to him, and you are not an expert—under those assumptions—it is very reasonable to accept what he says. Not because he has authority, but because it is reasonable, like with any professional expert. If he understands his field, then it is worth listening to what he says.

So Maimonides’ Mishneh Torah is basically a book of advice? Right, right. And also the Shulchan Arukh. Also the Shulchan Arukh? Right. We have lots of consultants. For Jews, giving advice is an ancient Jewish profession. This is where it started.

What about the authority of the mara d’atra regarding the customs of his community? So I said—about that I explained last time—the mara d’atra has authority. Why? Not because he is a Torah scholar and not because he received rabbinic authorization from the Chief Rabbinate, assuming he did, because he doesn’t need that, but because the community accepted his authority upon itself. And when a community accepts the rabbi’s authority upon itself, it gives him authority. Just as when two litigants come before a religious court, they accept upon themselves that the court will determine whether there was or was not a loan, even though they know that better than the court does. Fine, but that’s part of the process. If you accepted the authority upon yourself, then there is authority. But this is not authority conferred from above; it is authority you accepted upon yourself, and therefore you must obey it.

The same idea of mara d’atra could be said also about the Shulchan Arukh and Maimonides—that the Jewish people accepted these decisors upon themselves as the decisors by whom they go. If that’s true—but I do not think the Jewish people accepted… If the alternative is anarchy, then maybe you recommend that the Jewish people accept, but it’s not that the Jewish people actually did so. The question is whether the Jewish people, when seeking the halakhah, doesn’t open a Shulchan Arukh. No, no. But if politicians determined who the mara d’atra is… One second, let me finish answering him.

Regarding the Shulchan Arukh and Maimonides: you know that the commentators on the Shulchan Arukh, the decisors in the 16th and 17th centuries, determined that one may not issue rulings from the Shulchan Arukh. That is a rule in Jewish law. Look under the entry “halakhah” in the Talmudic Encyclopedia; he brings several sources—Bach and Maharsha, several of the foremost commentators and decisors mainly in the 16th and 17th centuries—that one may not issue rulings from the Shulchan Arukh, but only from analysis of the passages, to see where the context is, what is happening, and what it is talking about. Because to rule from the Shulchan Arukh is like what the Maharal calls “the sorcerous boors”—he said five, and immediately you… wait, look what’s going on, does it fit the passage, does it not fit the passage, does it fit your situation or not.

Today, those same decisors, somewhat later ones, say that because around the Shulchan Arukh there are commentaries that bring the various opinions and the sources and so on, now it is already permitted—permitted.

So if a politician determined who the mara d’atra is, am I obligated to listen to him? Of course not. The whole idea of mara d’atra is completely opposed to that. Not only does he not have expertise—he has authority. He determines the facts even though he doesn’t know the facts. There is a Shakh—did I mention this Shakh? Or maybe that was in Petah Tikva? The Shakh on the law that a girl under three, her virginity returns. For some reason I remember mentioning this in one of the recent lectures; I don’t remember where.

The Shakh brings the Jerusalem Talmud, where the Jerusalem Talmud says… First, the Talmud says that for a girl under three, her virginity returns. Meaning: if a little girl of two was violated, the assumption is that the hymen returns and heals until age three. After age three, not. That is the Talmud’s assumption. I’m not going into the question now of how physiologically correct that is, but that is the Talmud’s assumption.

Now the Jerusalem Talmud asks: what happens when a religious court intercalates the year—not the girl, the year. What happens in that case? So the Jerusalem Talmud says that it is determined according to the court’s ruling. Meaning that a girl of three and a month—or three according to the calendar—her virginity returns even though she is three and a month old, okay? If the year had not been intercalated.

Now, the Shakh brings several medieval authorities (Rishonim), and he himself writes this way too—which to my mind, with all due respect, is really unfounded—he writes there that the religious court, the halakhic ruling, changes physiology. Meaning, it determines the physics, the physical reality in the world. Here we see that now her virginity returns until age three and a month. This is exactly connected to what I’m talking about here. Obviously that is a very extreme view, because it says not only that rabbis or decisors have authority to determine what reality is, but to determine reality itself. That is, they determine reality itself: “the righteous decrees and the Holy One, blessed be He, fulfills.”

What is the truth there? The truth there is something entirely different, of course: around age three, more or less, that’s what happens. At age two and a half, then most girls’ virginity returns—I don’t know—80 percent; at age three, 90 percent; at age three and a half, 95 percent; at age fifty maybe 99 percent. Fine, so there is some kind of graph like that. Where do you draw the line? At age three. The Sages decided that age three sounds sufficiently reasonable. Okay, now the legal logic says that if the court intercalated the year, since this is not a sharp line, then why complicate things for people? So fine—go according to the date determined by the court. Not because something in the physiology actually changed; this is not binary physiology of up to here yes and from here no. It is a continuum. So where do you draw the line? You can draw it at age three, three and a month, two years and eleven months. Simply, the easiest thing was to draw it at age three. How did it come out exactly at that round number? What, how did that miracle happen? If they had set the year not at 365 days but a bit less, then virginity would return at age 3.2? Or at pi? It depends on the donkey. Pi years? Why? Obviously, they drew the line at three years because it’s a round number, and it’s a reasonable line to draw. It’s simple and more or less reasonable.

Now they intercalated the year. Once they intercalated the year, then true, now we are in a situation where either only 85 percent have their virginity return and not 80 percent, fine, but it is still good enough, and for us the line passes where the date determined by the court says. That’s all. That’s what is written there in the Jerusalem Talmud. And to take these things into realms as if the court changes physiology? How do those who said this even know it? Even if it were true, did they make measurements? How do they know? How do they know the explanation is not what I said?

Maybe the rabbi just now said that this is exactly the point—that all we’re dealing with is a decision in a situation of doubt, and it’s known that it could go either way. So when one says “to change reality,” he means that same reality which for purposes of ruling is treated as fixed. No, no—again, from his wording that is not what comes out. He means that the religious court changes reality. He tells stories of wonders and miracles about the court. Otherwise what’s the issue? Like the court determines the facts. A determination. Like the court determines the facts, exactly. Yes. It’s a multifaceted ruling.

All right, let’s continue with the discussion. I understand that the halakhic determination, or the factual determination, or the almost objective determination—the halakhic determination is given to the rabbi who has authority. You are claiming that the middle category, which is drawing the line, is given to the rabbi? To the value-decider. Yes—the “rabbi” as I called him there. But again, if you don’t accept the rabbi’s authority, do it yourself. It is not a professional determination. But what gives the rabbi more grounds to determine that than to determine the professional matter? In the end someone has to determine the Jewish law, the rabbi is always the one who determines Jewish law.

People ask: why does the High Court decide whether we go to war or not—why can it decide that? Say, in a place where it sees the government’s unreasonableness, it will cancel it, okay? Let’s say. Fine? Who authorized him? Is the High Court judge a general? No. But he is the jurist, and he has to decide. So if that determination also requires factual judgments, there is no choice—he is the one who decides. By the way, in a case where the issue is who is the expert—I claim he is the greater expert, and my opposing party claims he is the greater expert—who will determine who the expert is? Shall we take a poll at the association of experts? Of course not. The judge will determine; the rabbinic judge will determine. Since in the end a decision lies on his doorstep, he is the authoritative party who must issue a decision. Everything required in order to issue that decision he will have to decide about.

Only to decide arbitrarily is foolish. You can’t draw the graph yourself; you don’t understand it. So ask the professional to draw you the graph. But in principle even that is your request to him. Meaning, in the end you are the one who has to make the decision, so there is no choice—you will make the decision. You will consult, listen, ask, but even though it is not your field of expertise, it is your field of authority.

Regarding the example you gave of two against one—then the rabbi’s ruling is only in the third category. Because he goes by majority in Jewish law—there are two doctors; he doesn’t relate to the line at all, he doesn’t draw the line. Each doctor draws his own line. It’s not a problem of line. In the third category, because it’s not a problem of line. There the problem is another problem. It could be that each doctor has a different line—he doesn’t get into that at all. Could be.

But let’s say that’s the whole point: what the Shulchan Arukh says is—he doesn’t say to the rabbi, go in and examine the line of each of the doctors, but rather, follow halakhic rules that with two against one you follow the majority. As I said before, very often this can be done for reasons of efficiency: I simply adopt the doctor’s line because I don’t understand the matter. Or it’s arbitrary. He says, fine, let it be the doctor—like that age three example. But according to that, in a case of doubt, go into the line and examine each doctor’s line. First of all, the decisors themselves say that that is indeed correct. And two against one is not a binding rule. Look and see what the level of risk is; see if that doctor is God-fearing, for example. It is written explicitly in Jewish law—there are disputes, there are distinctions depending on whether it is a God-fearing doctor or not. What difference does that make? Because a God-fearing doctor knows what counts as dangerous. He values Yom Kippur enough not to decide that a one-percent risk is “dangerous”—that’s a risk every one of us takes every morning. But a doctor who doesn’t care about Yom Kippur—what does he care? He’ll put the line at one percent. He wants to come out okay, or that his client, his patient, should come out okay. He equated—I don’t mean… but he doesn’t care about Yom Kippur. That is exactly what shows that you are indeed involved in the line.

By the way, you know, Jewish law in the Shulchan Arukh—that’s the whole idea of the Shulchan Arukh: to determine what is binding for everyone without getting too complicated. That is what the Shulchan Arukh took heat for. We talked about that—the codification controversy. But the Shulchan Arukh itself is right from its point of view; I mean, that is the simple way to determine it. The rabbi also is no less expert than I or he is—the Shulchan Arukh—in determining the line. So let’s set the doctor’s line, sorry. So why should I argue with him? It is much simpler to set the halakhah that way.

But it says explicitly in the decisors: if you have two doctors and one is more expert, then you follow the expert. And who determines that—does he have an expert certificate from the association, a professional association? No, no, of course not. You simply decide that in your eyes he seems more reliable. By the way, this happens every day. In the monkey trial in the United States—it happens every day, maybe yes, almost every day. What do you mean every day? This happens every day dozens of times in every court. Right, exactly. They bring experts and also cross-examine them. Exactly. And the judge has to decide which expert is more convincing to him. What, is he a bigger expert than the two experts brought by the defense and the prosecution? The answer is no. But it is within his authority to decide. That is exactly the point.

In the end he has to make the decision. Everything required in order to make that decision is, by definition, within his authority. Not within his expertise, but within his authority. And that is exactly the point. Now this creates a lot of problems. I began with the monkey trial. In the monkey trial there, the monkey trial—the retrial of the monkey trial—there were trials in both directions: whether to remove evolution from the curriculum or to add it to the curriculum in the United States. So there they brought before the judge some expert witness on behalf of the creationists. Some expert witness who explained that in his opinion evolution is not a scientific theory and creationism is also a scientific theory, and both should be taught.

Then they brought many experts from the other side, many more experts from the other side, who said that was not true—that this is a scientific theory and creationism is not scientific, and so on. Now the judge—listen—they also brought him dozens of articles. There is no chance he read them all. The judge doesn’t understand. Can a person read all the articles written there? What—you didn’t read those articles at all, so how can you form an opinion? They also didn’t read his articles. But the judge there had to make the decision as to which experts he believed. Now it’s no wonder that when many experts came to him with all kinds of important hats, academic robes and the like, he ruled in their favor. He has no tools to do that. I also tried to explain in the book on evolution why this is not a scientific decision at all. Not only were those experts right—not only that, but that expert wasn’t right either, and the judge wasn’t right either. Nobody there was right, because it wasn’t a scientific question they were discussing.

But on the other hand, once the judge ruled, that is his authority. Because he is the one who has to make the decision even if he was mistaken. Not because he is more expert than the others, but because he has to reach the bottom line, and to reach the bottom line he has to decide which expert to believe. There’s no choice. And that decision is made by the judge, or the rabbi, or the religious court, or the normative authority—not the professional authority.

Okay, but when you go to a rabbi—if it’s not your community rabbi, say—and you ask him a halakhic question, then the answer is only a recommendation, it’s not really… Look, in my opinion yes. But it is accepted in Jewish law that once a sage has ruled, another sage may not permit. And that’s not only a community rabbi; it’s any sage whom you approached with a question. Now if you ask him a question meaning “decide for me,” then it is accepted in Jewish law that that binds you, and another sage is even forbidden to permit for you after the first one prohibited.

The question whether that also binds you yourself is a good question—I’m not sure. Because that law speaks about rabbis: you should not contradict one another’s words. Whether you are obligated to obey his voice, I am not sure. But if you ask him for an opinion—not “decide for me” but an opinion—then, as I explained once I think, the one who decides in every halakhic question is the questioner, not the rabbi. The rabbi has to map out the options. He has to say what the halakhic options are. This is a rabbinic prohibition, this is a Torah-level prohibition, this is permitted, this is beyond the letter of the law, this has such-and-such costs, this has such-and-such costs, this is permitted in exigent circumstances, this is forbidden even in exigent circumstances, and give you examples of what counts as exigent circumstances. All the expertise. From that point on, you decide which option you choose. And if you act that way, then there is no problem at all.

Then the whole issue that once one sage prohibited, another sage may not permit, doesn’t arise, because the sage does not prohibit and permit; the sage gives you the options. And I once told the story that they came to me—actually they didn’t come to me, it was a hypothetical question—about family planning. There was some conference of rabbis, what to do about all sorts of such matters, and they asked me to write a responsum on the issue: how to guide people in matters like delaying pregnancy and all those things. There I tried to explain this approach, and I said that if such a couple comes to me, then all I can really do is map out the halakhic landscape for them. I can tell them there is the commandment of “be fruitful and multiply,” which means to have at least a son and a daughter. After that there is “He formed it to be inhabited,” which is a sort of commandment from the Prophets, and it applies to both the woman and the man; the first commandment applies only to the man. “He formed it to be inhabited.”

You need to know that there are cases in which these things can be delayed. This appears in the Talmud and in all the decisors. Until the hysteria after the Holocaust, people did not relate to it in such a crazed way as they do today. There are many possibilities to permit. And one can give examples of this: what does justify it, what doesn’t justify it. And that’s it—stop there. Now the questioner will decide what costs he is willing to pay and what not. How hard is it for him and his wife right now? Is this exigent circumstances for them? I cannot decide that for him. They know how hard it is for them, how much it bothers them, and what matters to them. How can I decide for him whether this counts as exigent circumstances or not? I can’t. What I can do is map the landscape for him. I am a professional consultant.

If that is so, then I did not rule for him at all, so there is no issue of another rabbi permitting what I prohibited, because I didn’t prohibit. I merely mapped the landscape for him, and he will decide.

What is the meaning of the verse “do not deviate from all that they instruct you, right or left,” regarding the Sanhedrin? Does the Holy One, blessed be He, not expect me to accept the authority and decision of that deciding body? If you ask me—if the Sanhedrin decrees a public fast, then of course that is binding. What do you mean? A ruling of the Sanhedrin is something completely different. I’m talking about a rabbi, not the Sanhedrin. The Sanhedrin is something entirely different. The Sanhedrin has “do not deviate”—that is how I began the whole discussion. The Sanhedrin has “do not deviate.”

Interesting that, meanwhile, they do indeed call all those women halakhic advisors from Nishmat “yo’atzot halakhah”—that is their precise title. Okay, halakhic advisors—but it turns out that all rabbis are basically halakhic advisors. Right. Nice point. Even rabbinic judges are halakhic advisors sometimes. Right, right. And that’s only a matter of semantics. No, it’s not a matter of semantics; it’s a matter of essence. The only question is where you take that essence. I say there is a difference between a rabbi and a halakhic advisor—only I claim that all rabbis are really halakhic advisors, although they don’t function that way.

But rabbis decide when someone comes to ask them, and they say permitted, forbidden. They don’t say, look, these are the options, these are the costs. And someone who gets asked a lot also can’t afford to do that. I’m not a rabbi whom people are constantly asking. Once in a while someone comes, so I can afford to talk to the person, show him the options, and say, look, these are the options—decide. Someone who gets asked five questions a minute can’t. In an SMS he says permitted, forbidden. No, I’m not belittling that. There’s nothing to do—he has to answer. He can’t give all the options in an SMS to every inquirer. Fine, so true, constraints sometimes force something else. But in my view this is an evasion of responsibility on the part of the questioners.

You’re saying that the Sanhedrin has all the authority and the rabbi is an advisor. But when there is no Sanhedrin, the question is whether the authority didn’t descend to a lower level? I don’t think so. Where would that come from? I know of no source for it. Doesn’t the abolition or disappearance of ordination affect that? Yes, it affects it greatly. When ordination was abolished, that means there is no authority. But if the chain of ordination had continued? Then there would be a Sanhedrin—not just ordained individuals, yes? No, not Sanhedrin—just ordained individuals. There was ordination after the Sanhedrin was abolished. It’s not entirely clear what exactly counts as the abolition of ordination; there are difficult articles about that. Some carry the break in ordination down to the 12th century. There were ordained people in Babylonia in the time of Maimonides. But according to most understandings, that is not the ordination that goes back to Moses our teacher. It is ordination like we have today—rabbinic certification. Some claim it is, yes; the question of where exactly that ended is historically very unclear.

There was Rabbi Hillel the last one in the Land of Israel, who fixed the calendar according to Maimonides—that he fixed the calendar—and supposedly that was a status like the Sanhedrin, and we’re talking, I think, after the Talmud already. There really was a supreme religious court in the Land of Israel. It wasn’t a Sanhedrin of seventy-one, but a supreme religious court in the Land of Israel that had a status like a Sanhedrin. At least that is Maimonides’ claim, and Nachmanides disputes it. Historically, it’s very unclear what happened there.

Okay, so that is regarding the clarifications between the categorical question and the question of authority. Category means the question of which component is halakhic and which component is factual. The question of authority is: who is the authority responsible for Jewish law and for facts? That is an orthogonal question—two completely different questions.

Now, three more comments just to summarize this point, this chapter. Basically, what lies behind the confusion regarding halakhic and factual determinations are two philosophical phenomena. One phenomenon, which I already discussed, is the heap paradox. That is to say, everyday concepts do not really work according to binary logic, but in some continuous form. I’ll just remind you briefly: one pebble is not a heap. If I have a pile that is not a heap and I add one pebble, I have not changed the situation. Right? It doesn’t change the status of the pile. But a million pebbles are a heap. How can that be? Those three statements don’t fit together. One pebble is not a heap, and adding one pebble doesn’t change the situation—so when on the way to a million did it become a heap?

Or a person with one hair on his head is bald. If you add one more hair, that doesn’t change his status. A person with one hundred thousand hairs on his head is not bald. So again, when does it happen? From when is it already afternoon? There are several examples of this sort of thing. Basically, every everyday concept is non-binary. And what this means is that when we talk about a heap, or bald, or dangerous, or a human being—any concept you take, any everyday concept you take—you can’t determine it at the level of yes or no. What you can determine is to what extent. That is, how much “heapness” there is here. It’s not whether it is a heap or not a heap, but 0.1 heap, 0.5 heap, 0.88 heap. And the degree of heapness is a more precise expression than saying this is a heap or not a heap. The same with the degree of humanity—how human is it? Say an embryo that begins from a drop of semen—or egg—and little by little develops until it becomes a person. At exactly what point does it become a person? I don’t know. All you can say is to what extent it is a person at each stage. There is no way to set a threshold and determine “person.”

But if you say it is 0.5 heap, then there is a definition of heap because it is 0.5 of it. I didn’t say “heap”; I said heapness. Heapness? So there is a definition of heapness. I take 0.5 of it. Right. So there is a definition of heapness? No, it’s heapness at a certain level. A million is certainly a heap. That’s absolute heapness—a million hairs, say. Okay. So then with half a million, will you say yes heap or no heap? No—it’s half a heap. There are situations where I know that it is already a heap. That’s exactly the problem. There are situations where I know yes; there are situations where I know no. What happens all the way in between? When does it cross over? My answer is that it crosses over continuously—it does not cross via a step function. All right?

So here this is of course connected to what I said earlier: putting the line—where to cut the graph—is not a binary question. We are trying to turn a continuous question into a binary question. There is no choice; in Jewish law or in legal systems one must determine binary levels in order to answer the relevant questions. To decide whether it is an offense or not an offense, whether it is dangerous or not dangerous—there is no choice. A legal system works in terms of permitted and forbidden. So you must draw a line. But drawing that line is some kind of model of reality. In reality there is a continuum, and that is the graph. Cutting the graph is not a professional decision but a value decision, some sort of convention. That is one point.

A second point: we also spoke once about the naturalistic fallacy. The naturalistic fallacy basically means deriving an ought from an is—deriving what is desirable from what exists. Meaning, I say that this wall is brown and therefore it is beautiful. The fact that the wall is brown is a fact. The fact that the wall is beautiful is a judgment—an aesthetic judgment in this case. Okay? A judgment never comes out of facts. You cannot get an ought from an is. And this is basically what lies behind the fallacy of expertise. The fallacy of expertise is all those confusions I spoke about—those who think this is an expert determination, those charlatan claims that supposedly interfere. What lies behind it is that people ignore the fact that an expert deals in facts. He is an expert in facts, while the normative system deals in norms. A norm never emerges from facts. Never. Meaning, there must always be some bridging principle that says to which factual state such-and-such a norm applies. And that principle is not in the expert’s jurisdiction. Therefore an expert cannot determine a normative position. Logically it is simply impossible. It cannot be. There must be some stage along the way where someone intervenes who moves us from the plane of facts to the plane of… normative judgment.

For example, one comes to represent… What, can’t that be the expert himself? It can be the expert, yes. It can be yes and it can be no. But then it is not a determination in his capacity as an expert.

So what is the difference between a fact and a norm? What is a norm? Things that are not fact. Judgment. An aesthetic norm, an ethical norm, a halakhic norm, a legal norm. These are determinations of what is proper or improper, not what is true or false. But here too there are statistical determinations—for example what today is called the wisdom of crowds, or even with a person, say, in the decision about vaccination. So true, a certain very small percentage will be harmed by the vaccine, and a larger percentage—some kind of weighing is done. Expertise is not only facts; it is also weighing a great many statistical factors, even socio-norms… Expertise is not weighing. Weighing is done by the decider. Expertise is collecting the data and building the statistics—that is the graph.

But statistics—not, that’s not the graph. I’m talking about statistics such that, for example, an expert will come and say that in a certain ruling, in most countries of the world this thing is considered… a certain surgery is dangerous. Five percent of people die in this surgery. Fine? That is what the expert says. Now I ask whether to do this surgery. To do it or not? The expert cannot say. That’s it. That is what I’m saying. The expert gives me the statistics. He says—he gathers the facts—he says look, more or less—and even that is often hard to do—but at least that is within his expertise. Okay? But the decision in the end is always yours, because you have to determine whether five percent is already called dangerous, whether a person in such a situation may undergo a dangerous surgery—all those are moral or halakhic questions. Meaning, they are not professional questions.

Basically, these are the two phenomena behind the fallacy of expertise. One phenomenon is the naturalistic fallacy—people think that a professional or factual determination can determine the norm, and it cannot. The second fallacy is the fallacy of binary thinking. Thinking that says we deal in legal concepts in terms of either yes or no: yes dangerous or not dangerous; yes a person, no not a person; yes a wayward wife, no not a wayward wife; or things of that sort—when in fact we are dealing with a threshold, and crossing it is not a professional matter but a value matter.

Who decided, for example, that the age at which a person becomes an adult is thirteen or eighteen? That’s exactly what I’m saying: that is drawing a line, a classic example of drawing a line that is value-based, not factual. No expert can explain why it is so. The expert can tell me to what extent the person is responsible for his actions as a function of age. At age thirteen he has this level of responsibility; at age fifteen this level of responsibility; at age ten this level of responsibility. Now a decisor, legislator, whoever it may be, has to come and say: okay, from what level of responsibility is he legally responsible in my eyes? Fine? And that is not an expert’s determination.

The truth is, I once heard from Rabbi Sherlo that really there are two stages here. At the first stage, after all, the Mishnah says “a minor who knows how to hold a lulav.” Then it’s individual; it’s not talking about age thirteen. And even then, what does “knows” mean? What does “knows how to hold a lulav” mean? Even then. Chazakah d’Rabba is the age thirteen thing. But even then, what does “knows” mean? What does “knows how to hold a lulav” mean? Even then. And then in order not to start examining this child whether he is twelve… No, actually age thirteen—Chazakah d’Rabba is the presumption that he has produced two hairs. There is a criterion: two hairs. Which is itself a presumption. No, no, no—the analytical Talmudists deal with the question whether two hairs are a sign or a cause. If you assume it’s a sign, then it’s a sign that you are already mature enough. Some argue it is a cause, meaning that this is the definition of maturity—two hairs. Never mind right now what cognitive level that expresses. Then at age thirteen… No—now at age thirteen there is a statistical presumption that generally people have developed two hairs. We return to a story not of mental maturation but of the probability that you have developed two hairs. Meaning, this is physiology. Fine, I think that plainly you are of course right that it is a sign and not a cause, but fine.

All right, I want to… Also then, every separate law would get a different threshold. Yes, certainly. Many times there are considerations of simplicity here. It’s simply considerations of simplicity, and that is perfectly fine. It is not a criticism. There’s nothing to do—systems work this way.

I’ll maybe bring… all right, I’ll leave that for next time. I’ll finish by expanding this point. Basically what this picture says is that Jewish law means applying norms to a given factual situation. Clarifying the factual situation begins with discussion with an expert or someone familiar with the facts. Setting a line, in a case where a line needs to be set, is done by the halakhic authority. Then determining the norm that applies to the factual situation. Jewish law, for example, does not say that a speed of eighty is a dangerous speed. Jewish law says that if you are in such-and-such a level of danger, then it is forbidden to drive. Now decide: what speed puts you in such-and-such a danger? That determination is an expert determination, right? I tell him: look, my rabbi’s threshold is one percent. From one percent on, that is a danger I do not halakhically permit driving in. And what counts as one percent? That of course does not belong to the decisor. That will be said by people who understand these matters and who will tell me from what speed, on this particular road, there is a one-percent risk. Maybe it’s simplistic, but I’m saying that broadly speaking that is the model.

What this really means is that Jewish law does not deal with facts at all. I’ll remind you of something I once spoke about—I think when we discussed Choshen Mishpat, I think it was then. I brought the Talmud in Bava Batra, for example—not important, every Talmudic passage is like this: “there is a presumption that a person does not repay before the due date.” The Talmud there says that if I claim money from so-and-so within thirty days—say an ordinary thirty-day loan—and I demand the money from him within the thirty days, after two weeks say, and he says “I paid,” he is not believed. Because there is a presumption that a person does not repay before the due date. A person does not pay as long as he does not have to pay.

Now suppose that in a certain situation the facts change. There is a place where people do repay before the due date. For example, with us, with mortgages—if a person has money, often he will repay the mortgage. He wants to get it off his mind, and he will repay the mortgage even though the time has not yet arrived; he could drag it out further. Now suppose the bank sues him in a religious court and says, listen, you did not repay the mortgage, and he says, what are you talking about, I paid, I paid. Is he believed or not? Within the period? In principle yes. Meaning, if the reality is that a person does repay within the period, then he will be believed. So what about the Talmud that says a person does not repay before the due date? That is a factual determination: there is a presumption that a person does not repay before the due date. Again, a factual determination after drawing the line, of course. There are people who repay and people who don’t, but a sufficient percentage do not repay before the due date for us to set this as a presumption.

Okay, so that is a factual determination. The Talmud does not deal in facts. If the Talmud needs a factual determination, it is only as a substrate for the halakhic determination. In the end, what the Talmud says is—suppose I ask today, say that the reality is that a person does repay before the due date—does it make sense to study that Talmudic passage? That passage can be erased from the Talmud, Bava Batra 5a. Is there any point in studying it? What’s the point? They tell me facts; those facts are no longer true, so that’s it—what is there to learn there? The Talmud there is not teaching the presumption that a person does not repay before the due date. For that, go to the street, to the psychology department, to whoever, and check the facts and see whether a person repays or does not repay before the due date.

The Talmud teaches the bridge principle that says: if there is a presumption that a person does not repay before the due date, then if he claims “I paid,” he is not believed and money can be extracted from him. Meaning that a presumption is effective in extracting money from one in possession. That is what the Talmud says. What is the presumption? When is there a presumption and when not? Go to the psychology department and see when there is a presumption. But how do you know which part of the presumptions or all the factual rules connected to sociology or the facts in the Talmud is consultation with experts? I have no idea. But what difference does it make?

But in this case it makes a huge difference. Because “there is a presumption that a person does not repay before the due date” came from the rabbis’ own local observation then of behavior. Obviously they didn’t go to experts in this field. It doesn’t matter, doesn’t matter how they did it, but they determined it. Right. And if reality changes, Jewish law changes? Yes. You can copy this concept to almost everything. In principle you assume that this was the reason, but maybe not. Then what? They invented the idea that a person does not repay before the due date? They looked around and saw that a person does not repay before the due date. Human nature. When do you not look around and say that Jewish law is fixed? Always with respect to facts I look around. There is no factual determination that is supposedly absorbed from heaven. Whoever called it “kadd” and “chavit”—in a place where they call a jug by one name and a barrel by another—when you want to know what reality is, you need to look at reality and see what reality is. There is no other source for determining reality. Or rumor—a rumor you heard—that’s a fact. Well, yes. That doesn’t stop taking… if suddenly something that was a rumor changed? Yes, then it won’t be a rumor, obviously. Rumor is something else. Yes. Or there won’t be an ox established as dangerous at all—the ox there is, by the way, another example of an arbitrary line. Why after three times? Why not after five? Again and again in Jewish law it’s three times: menstrual cycles, a barren woman, one who was married and had no children, all kinds of things like that. After three times there is a presumption. Why? Is that an expert determination? No. It’s a legal determination that after three times that seems enough to me. And how do you know it isn’t a tradition from Sinai? Fine, maybe it is a tradition—and if it’s not true, then what help is it that you received it? Suppose there was a tradition that we received from Moses our teacher that it’s three. Fine. It’s from the Torah; obviously it is from the Torah—it says in the Torah: “yesterday, the day before, and the third day.” They learn it from the verse. That’s clear. And then it changes? If it changes, then it changes. What do you mean? If you see that… But the Torah said. The Torah says that if there is an ox established as dangerous, then after three times you can decide. But if I reached the conclusion that there is no such thing as an ox established as dangerous—there are genes of lambs, a lamb looking at grass, they don’t gore. Fine. So even if it gored three times, the assumption is that there’s no such thing, it isn’t dangerous-by-pattern. You have to imagine the situation in which it did gore three times. Genetic manipulation. Yes. After three times that it gores they do genetic manipulation on it, and then it is no longer dangerous-by-pattern; they reset its brain. Yes. In fact, that is what is written in the Torah and in the Talmud. If after three times that it gored—or three times that it did not gore—it returns to its original status as harmless.

So I return for a moment to the presumption that a person does not repay before the due date. What the Talmud taught us there was not the fact that there is a presumption that a person does not repay. That is a matter for an expert. Or an expert, or not necessarily expertise here—look around you and see roughly what human nature is. Fine. But the determination is that if there is a presumption, then it is effective to extract money from one in possession. The one in possession will not be believed to say “I paid.” And that remains forever because it is a normative determination. What the presumption will be—that is a factual determination. One has to examine every matter each time on its own merits.

What does that basically mean? It means: in Jewish law, don’t look for facts. All the facts that appear in Jewish law are cases—just a case. It can be this way, and it can change in another place or another time. What I learn in Jewish law is the bridge principle: if the facts are such-and-such, then the norm that applies to them is such-and-such. And whether the facts are such-and-such or not—that is now. People often get confused here because they think this is Reform, changes in Jewish law, and the Torah says… The Torah does not state facts. The Torah says what to do with any given set of facts. What the facts are—you decide for yourself.

“It is preferable for a woman to dwell as two rather than to dwell alone”—that a woman wants to marry just about anyone, even if he has boils, I don’t know what, or some defect or something like that. It may be that in the time of the Sages this was true—apparently that is what they said. But in our day it is not true. There is no sanctity to that. They did not determine the factual determination. They only determined that if there is such a factual determination, then one cannot say “she did not marry on that understanding”—that she did not become betrothed on the assumption that he would strike her—because a woman does want that. But if today the fact changes, then the halakhah will change too. Because Jewish law is not the facts, and Jewish law is also not the bottom line. Jewish law is the if-then. If the facts are such-and-such, then the norm is such-and-such. Now plug in the facts relevant to your environment, and you get from the function the halakhic result. Jewish law is the function. It is not the domain and not the range. Meaning, it is neither the independent variable nor the dependent variable. All right?

Can I ask you a question? According to Jewish law, a daughter does not inherit. Yes. But then her brothers have to go begging in order to give her money, right? To support her. Circumstances changed. So today daughters will inherit? No. If you become convinced interpretively that this was a halakhic ruling according to that period because of that and because of what was there—the obligation of the brothers… Here the question of interpretation comes in. Very often there can be interpretive disputes: is some halakhic determination of the Sages or the Torah dependent on circumstances, such that if the circumstances change it could change? We discussed that when I spoke about changes in Jewish law. The big question is whether the rule that a daughter does not inherit is a result of the circumstances that prevailed then. If so, it is certainly possible to change it today. If not, then not. So that is an interpretive dispute. One has to examine whether yes or no.

Notice that in this respect this is very similar to logic. What is logic? Logic says: if every X is Y and A is an X, then A is Y. Right? Did logic determine that A is Y? No. Logic also did not determine that every X is Y. Logic determined that if every X is Y and A is an X, then A is Y. The transitive rule—that is logic. Put in whatever premises you think are true, and then from the logic you will get the relevant results. But logic does not state either the premises or the results; it states only the if-then. Okay?

You yourself wrote that something that only establishes a bridge is empty of content. Right. So what are you saying exists now in Jewish law? It is empty of factual content, not empty of content. Empty of factual content, right. Jewish law has nothing to do with facts at all. The facts are transparent to Jewish law, and it is transparent to them. These are two planes that do not speak to each other. Jewish law is only bridge principles, exactly like logic. Jewish law is the if-then. If the facts are such-and-such, then the norm is such-and-such. That is Jewish law, and that is not supposed to change. Okay? But the facts can change, and the bottom line can also change.

But what Tzvika said is the punchline here, because in the Torah—and explicitly—and in your Torah it does not change, one cannot change it. So what? In the Torah it says “do not form separate factions”—do not make separate factions. I think I also spoke about this once. “Do not make separate factions”—it is forbidden to have two synagogues in one city. Do you know Ra’anana? How many synagogues are there here? Why? It says in the Torah “do not form separate factions,” and we learn from that not to make separate factions. In one community there should be one synagogue, and in two communities there should be two synagogues. I don’t care that they are within one municipal authority, what we today call one city in our language. But in the Torah the man gives the woman the divorce document, and that did not change. And today it isn’t… No, today it isn’t, no. Things changed here… Who said the things changed? Who said the things changed? It depends on what. What do you mean it depends? The fact that the man gives the woman the divorce document—if you show on the interpretive level that when a man gives the woman the divorce document it is because of circumstances that existed then and today have changed, then indeed there could be a claim that this law should change. The question whether it is because of that—that is the million-dollar question. I don’t know how to answer that; maybe yes, maybe no, I don’t know. A lot more than a million—is that your consulting fee? Heaven—for those things they all get a lot more than a million.

So therefore I say there is here the same thing as—maybe I said this once, I no longer remember. I once thought: what is so genius about a musician like Bach? Bach—what? What is so genius? I can do that too. I have no musical ability at all, just so you know. I can do that too. I’ll make a composition, compose some piece of my own, and now I’ll create creatures such that for them this is the perfect work. After all, a perfect work is a function of the audience, right? So in principle I can also do that. It’s just my bad luck that the music I make somehow does not hit the exact point for the people around me, whereas Bach happened by luck to land exactly on what is perceived as sublime music in people’s eyes. And that is only a matter of how we are built, right? So in what sense does Bach have more musical ability than I do? And apparently he does. But that doesn’t solve this issue.

I want to tell you that Bach’s talent is that he did it straight, not backwards. What do I mean? When I make the composition, I need to produce the audience; that is, I need to produce listeners such that they will enjoy it. And in principle it is possible to produce them; when they hear my music they will be in heaven. They really have to be mutations, but it is possible to produce such mutations. Over there, yes, exactly. But someone wants to build over there—she has a startup—a school for orphans, so as not to have to deal with the parents. That’s what people always say: the university could have been perfect without students, and the hospital would be perfect without patients. Those people just interfere.

In any case, what I really want to say is that Bach did it straight and not backwards. Meaning, he had a given data set of an audience—they were already here—and he succeeded in fitting them music that seemed perfect to them, right? That I don’t know how to do. Do you understand that this ability is an if-then ability? I believe that if Bach was a musical genius—and apparently he was—then in a completely different population, if he had reached them, understood their mindset, and entered their culture, he would have made better music for them than I could. Because his ability is not the music he wrote, but the ability to write music given that the audience is given. Musical genius is also a genius of if-then, only we don’t notice it because the “if” is given. We are here. We don’t replace ourselves; we are here, people are built as they are, so we forget that there is some “if” here. We are used to the “then.”

As always: every human being is mortal, that’s obvious, and therefore if Socrates is human, then Socrates is mortal. Nobody remembers that logic is if-then, because we all know that every human being is mortal—it’s not up for discussion. Therefore it is obvious that logic says that Socrates is mortal, but that is not correct. Logic does not say that. Logic says that if every human being is mortal, then Socrates is mortal. Only very often, because the premises are so simple, we forget the if-then, okay?

So here too in the factual realm, we are used to professionals determining norms, and we forget that this is really only an if-then determination. Professionals determine the “if,” but usually…