A Talmudic Source for R. Shimon Shkop’s Principle of Consistency (Column 617)
The mishnah in Yevamot: why yibbum remains forbidden forever even after the wife’s sister dies
The essay opens with the mishnah about two brothers married to two sisters: one dies, his wife falls to yibbum before the surviving brother, but she is also the sister of the yavam’s wife, so yibbum is impossible. Even if the yavam’s wife later dies, the mishnah rules that the yevamah remains forbidden, "since she was forbidden to him for one moment." The rabbi stresses that in yibbum there is no neutral state: either there is a mitzvah that overrides the prohibition of a brother’s wife, or, if there is no yibbum, the prohibition of a brother’s wife remains in place.
The two baraitot in R. Shimon and the solution via "one prohibition does not take effect on top of another"
The Gemara brings two contradictory baraitot in R. Shimon: in one, the offender is liable only משום אשת אח; in the other, only משום אחות אישה. The explanation is that the order of the marriages determines which prohibition takes effect first: if the living brother married first, the prohibition of the wife’s sister came first; if the deceased brother married first, the prohibition of the brother’s wife came first. The second prohibition does not disappear; it simply does not take effect, because one prohibition does not take effect on top of another.
The difficulty in Rav Ashi: why the loop does not continue forever
In the case where the prohibition of a brother’s wife took effect first, Rav Ashi explains that the prohibition of the wife’s sister is "hanging in suspension": if yibbum were to override the prohibition of a brother’s wife, the prohibition of the wife’s sister would then take effect and cancel the yibbum; therefore the prohibition of a brother’s wife is not overridden. But that explanation seems to stop in midstream: if yibbum is canceled because of the wife’s sister, then the prohibition of a brother’s wife remains, and yibbum should again be able to override it, and so on endlessly. The rabbi connects this to other halakhic loops in which the Gemara or the rishonim stop a process that seems infinite.
A reminder of R. Shimon Shkop’s consistency principle: a legal effect that cannot stand if it takes hold
From here the essay returns to R. Shimon Shkop’s proposal from earlier essays: any legal effect that, if it took hold, would cancel itself does not take effect in the first place. The central example is in Gittin: a divorce on condition that she not marry a certain man, and she goes and marries him. If that marriage takes effect, it voids the divorce; if the divorce is void, the marriage itself does not take effect, and an endless loop is created. R. Shimon stops it through a meta-halakhic principle, not a logical one. For this to work, the rabbi reminds us that the stages of the loop must not be seen as actually unfolding one after another in time, but as an internal causal ordering that all occurs within a single moment of reality.
The application in Yevamot: yibbum does not take effect not because of the wife’s sister, but because it uproots itself
According to the proposal here, Rav Ashi should be read that way as well. The prohibition of a brother’s wife took effect first, on the ordinary time axis, when Reuven married Rachel. Later, when the possibility of yibbum arises, we ask hypothetically what would happen if the mitzvah of yibbum took effect: overriding the prohibition of a brother’s wife would allow the prohibition of the wife’s sister to take effect, and that would in turn cancel the yibbum. Therefore yibbum is a legal effect that uproots itself, and by the consistency principle it never begins to take effect. In a complementary formulation, one can also say that the prohibition of the wife’s sister itself does not take effect, because it too would uproot itself; in practice only the prohibition of a brother’s wife remains.
Why the final state is not contradictory, even though only the prohibition of a brother’s wife remains
At first glance this is difficult: if only the prohibition of a brother’s wife remains, why should the mitzvah of yibbum not now take effect as usual? The essay’s answer is that the absence of yibbum is not explained by an actually existing prohibition of the wife’s sister, but by a meta-halakhic rule that prevents a self-destructive legal effect from beginning. So this is not a description of a process that actually occurred and was then undone, but of a hypothetical test: if yibbum were to take effect, it would cancel itself, and therefore it does not take effect. Once one moves from a real-time description to a hypothetical one, the loop stops.
Why Yevamot is a better source than Gittin for the consistency principle
The essay concludes that in Gittin one can certainly see the need for such a principle, but there it arises from a Tosafot difficulty, and in principle one could have suggested some other answer. In the Yevamot sugya, by contrast, Rav Ashi himself seems to formulate the mechanism: one prohibition hangs in suspension, and its future activation now prevents the other legal effect from taking hold. The rabbi therefore proposes seeing this sugya as a genuine Talmudic source for the consistency principle, from which one can then return and explain Gittin as well as other halakhic loops.
The analogy to the categorical imperative: there too the solution is moving from actual action to a hypothetical test
The essay closes with an analogy to Kant: the claim that "if everyone refused to vote or evaded taxes there would be anarchy" is not really a consequentialist claim about what my act will actually do, since my act alone changes almost nothing. The force of the categorical imperative is that it shifts the discussion to a hypothetical plane: we ask what kind of world would result if everyone acted that way, and from that determine the moral character of the act. Here too, as with the consistency principle, the solution comes from moving from a real-world calculation to a hypothetical one — though the analogy is not complete, because here one does not necessarily have the same halakhic loop.
To Rivka, my dear daughter
In columns 407 and 466 I described and explained R. Shimon Shkop’s proposal for stopping halakhic loops based on what I there called the “principle of consistency.” We saw that this is not a logical principle but a meta-halakhic one (the paradox is not resolved on the logical plane but by introducing an additional meta-halakhic principle, which is a halakhic innovation). We further saw that the foundation of the solution is the assumption that the order among the events is not in real time; rather, the entire chain of events occurs at a single moment. The internal ordering between them is along the causal axis and not the temporal axis. Nevertheless, that order determines what remains in force and what is nullified.
A few days ago I learned with my daughter Rivka, may she live and be well, a sugya in Yevamot regarding the rule that a prohibition does not take effect upon an existing prohibition (ein issur ḥal al issur), and we understood that prima facie one can find there a source for R. Shkop’s principle of consistency. We will begin with the sugya itself and then return to the principle of consistency.
An Introduction on Yevamot and Mathematics
Many sugyot in Yevamot deal with complex family relationships. The “genealogy” there is a true logical delight. Suddenly you understand why the world needs families, and how boring it would be without them. A mathematical background can certainly help the learner, or at least make things easier. For example, if you speak of “the maternal brother of the son of Reuven’s uncle,” and you ask: what is Reuven in relation to him? (A very common question in Yevamot, and in Sanhedrin regarding disqualifications due to kinship.) Operator theory immediately gives you the answer: to invert the chain of relations from Reuven to Shimon and obtain the chain from Shimon to Reuven, you must reverse the order of the links in the chain and invert each one. Thus, for example, “brother of my father’s uncle” means I am “nephew (the inverse of ‘uncle’) of the son (the inverse of ‘father’) of his brother (the inverse of ‘brother’—the identity operator).” The explanation is very simple: if we assume that the relation between me (I)) and Reuven (R) is as follows:
R = ABCD (I)
Then the reverse relation is:
I = D-1C-1B-1A-1 (R)
If you substitute the previous relation you obtain an identity:
R = ABCD (I) = ABCD D-1C-1B-1A-1 (R) = R
The product of two inverse operators cancels out (nephew of uncle is the identity relation; son of father is the identity relation; etc.)[1]. Note that you can delete the middle D D-1, then delete CC-1, and so on. This is what is called “telescopic cancellation.”
It follows that the inverse of the relation I described above is the following: Reuven is the nephew of the father of his maternal brother. Anyone who has studied Yevamot and Sanhedrin can appreciate how much this simple rule can help. My friends from the “Netivot Olam” yeshiva can tell you how I saved them from these quagmires.
The Sugya of Two Brothers Married to Two Sisters
In the Mishnah, Yevamot 32a, the following simple case appears (when you study it you’ll see that even tracking the developments of this simple double chain is quite difficult):
Two brothers married two sisters. One of them died, and afterward the wife of the second died—she is forbidden to him forever, since she was forbidden to him for even one hour.
Reuven is married to Rachel, and his brother Shimon is married to Leah, her sister (always assign names—preferably from a biblical family while preserving as many relationships as possible; advice worth gold). The complication begins here with the fact that the relationship between any two of this foursome can be described in either of two ways. For example, Reuven is both the husband of Leah’s sister and the brother of her husband. The same holds for Shimon and Rachel. Alas—the worst has happened—and one of them died. As is well known, disasters come in bundles, and the wife of the deceased falls for yibbum (levirate marriage) before his brother. Now let us not forget that he is both the husband of her sister (and therefore she is his wife’s sister, according to the inversion rule above) and the brother of her husband (and she is his brother’s wife, again by that rule).
What do we do? We are not perturbed by the prohibition of “his brother’s wife,” for this is precisely the novelty of the commandment of yibbum: the prohibition of a brother’s wife is overridden by the mitzvah of yibbum. But here there is another incest prohibition: a wife’s sister. This is not overridden by the mitzvah of yibbum; rather, it cancels it. The mitzvah of yibbum applies when the only obstacle is the prohibition of a brother’s wife, but any additional incest prohibition nullifies it.
In the case described in the Mishnah, Reuven dies, and then his wife Rachel falls before Shimon for yibbum. Shimon cannot perform yibbum with her because she is also his wife’s sister (Leah). But the righteous Leah also dies in a sudden tragedy (their family name: Reuven and Shimon of the House of Hard-Luck), and now Rachel would be permitted to Shimon (for one’s wife’s sister is not forbidden to him after his wife’s death). Nevertheless, the Mishnah states that since at the moment Reuven died and Rachel fell for yibbum, yibbum was not possible (because Leah was still alive), then even if Leah dies afterward, the mitzvah of yibbum is already void; therefore even now Shimon cannot perform yibbum with Rachel (note that if there is no obligation of yibbum, there is an incest prohibition, for she is his brother’s wife. In the realm of yibbum there is no neutral state of permission: either there is an obligation to perform yibbum, or doing so is prohibited).
The Gemara brings a Tannaitic dispute regarding one who had relations with his wife’s sister (Rachel) while his wife (Leah) is alive:
Our Rabbis taught: If he had relations with her, he is liable on account of his brother’s wife and on account of his wife’s sister—these are the words of R. Yose. R. Shimon says: he is liable only on account of his brother’s wife.
According to R. Yose, he is liable for both wife’s sister and brother’s wife. According to R. Shimon, he is liable only for brother’s wife. R. Yose’s position is more readily understood, for if there is no mitzvah of yibbum then not only the prohibition of wife’s sister exists here, but also that of his brother’s wife (it is not overridden, since there is no mitzvah of yibbum). But R. Shimon’s view is puzzling, for he leaves one prohibition in place—and specifically the prohibition of brother’s wife, which one might have thought would be overridden by the mitzvah of yibbum. The prohibition of wife’s sister, which one would expect to remain, does not appear according to him.
The Gemara brings a contradictory (and more intuitive) baraita in R. Shimon’s view:
But isn’t it taught: R. Shimon says, he is liable only on account of his wife’s sister.
And resolves:
Not difficult: here (the first source) is where the living [brother] married first and afterward the dead [brother] married; there (the baraita) is where the dead [brother] married first and afterward the living [brother] married.
If Shimon (the living one) first married Leah and afterward Reuven married Rachel, then from Shimon’s perspective Rachel was first his wife’s sister and only afterward his brother’s wife. In such a case only the prohibition of wife’s sister takes effect, and the second prohibition does not, because a prohibition does not take effect upon an existing prohibition. That is the case of the contradictory baraita. But if Reuven (the one who later dies) married Rachel before Shimon married Leah, then relative to Shimon Rachel was first his brother’s wife and only afterward his wife’s sister; in such a case only the prohibition of brother’s wife takes effect, and that is the first baraita.
Now the Gemara asks:
And according to R. Shimon, in a case where the dead [brother] married first and afterward the living [brother] married—since the prohibition of wife’s sister does not take effect, let her undergo yibbum!
In the case where Reuven married first, only the prohibition of brother’s wife takes effect and not that of wife’s sister, and the mitzvah of yibbum overrides the prohibition of brother’s wife. So why not perform yibbum in such a case?
Rav Ashi explains:
Rav Ashi said: The prohibition of wife’s sister is suspended and stands; if the prohibition of brother’s wife falls away, the prohibition of wife’s sister comes and takes effect; therefore it [the prohibition of brother’s wife] does not fall away.
R. Shimon holds that if the prohibition of brother’s wife took effect first, then the prohibition of wife’s sister remains hanging and suspended; if the mitzvah of yibbum were to push aside the prohibition of brother’s wife (as usual), then nothing would prevent the prohibition of wife’s sister from taking effect, and it would prevent yibbum. Therefore the prohibition of brother’s wife remains in place (since there is no mitzvah of yibbum to override it).
The Problem with This Explanation
This explanation seems to stop halfway. For we have now arrived at the conclusion that the prohibition of brother’s wife exists and that of wife’s sister does not; but then one can continue and say: let the mitzvah of yibbum come and override the prohibition of brother’s wife—then the prohibition of wife’s sister will take effect and neutralize the mitzvah of yibbum, which will restore the prohibition of brother’s wife, which will remove the prohibition of wife’s sister and restore the mitzvah of yibbum that will again nullify the prohibition of brother’s wife—and so on ad infinitum. I wanted to end with “Chad Gadya, Chad Gadya,” but that would be a poor ending, since in Chad Gadya there is a clear hierarchical chain and no loop. Here the problem is that there is a loop that does not stop. For some reason the Gemara chooses to stop it at a certain point, and it is not clear why.
We saw similar difficulties in columns 406–407 regarding loops that the Gemara or the Rishonim choose to stop at some point without any apparent reason. For example, a red heifer upon which a yoke was placed with the owner’s consent: if that disqualifies it, then certainly it was not with the owner’s consent; but if it was not with his consent then it is not disqualified; but then it was with his consent; and so on. Likewise regarding pesik reisha de-lo nicha lei: the person is exempt and then he does want the forbidden result; but if he wants it he is liable and then he does not want it; and so on. Likewise regarding migo: if we accept the principle, it destroys itself (for the person chooses the “weaker” claim because it is not weaker but rather better thanks to the migo), so there is no migo; but then the claim is indeed weaker; and so on.
The Principle of Consistency: A Reminder
In those columns and in column 466 I also brought Tosafot’s example in Gittin regarding Reuven who divorces his wife on condition that she not marry so-and-so, and then she goes and marries so-and-so—this cancels the divorce (for the condition was not fulfilled). But then she is still Reuven’s wife and therefore her marriage to so-and-so does not take effect; but if so she did not violate the condition and her divorce from Reuven stands; but then her marriage to so-and-so stands (for she is single), which in turn cancels the divorce; and so on.
For this loop R. Shimon Shkop innovated his principle of consistency, whose core is the following meta-halakhic rule: any legal effect (status/act) whose taking effect would uproot itself cannot take effect. In the yeshiva idiom: any effect such that “if it takes effect, it does not take effect”—does not take effect. In our case, her marriage to so-and-so cannot take effect, because if it were to take effect it would uproot itself; therefore it does not take effect. Here the loop stops. One could continue and ask: if she is divorced from Reuven, why should she not be considered married to so-and-so—after all, she is not a married woman? The answer is that she is not married to so-and-so not because she is a married woman, but because the marriage to so-and-so would uproot itself, and there is a halakhic rule that a self-uprooting effect cannot be effected. We remain with a state that seems self-contradictory (a state we did not encounter at any stage in the infinite loop): she is divorced from Reuven but not married to so-and-so—and there we stop.
I explained that this halt has no logical explanation. Logically, the loop continues to infinity. There is here a meta-halakhic assumption about the imposition of effects that uproot themselves. This assumption is not logically necessary, but halakhah presumes it (according to R. Shimon). I also noted that this meta-halakhic assumption alone is insufficient; we must add another assumption: that we view each stage in this process as if it temporally follows the previous stage. If this were not so, then even the divorce from Reuven could not take effect, for its taking effect would uproot itself (because of the marriage to so-and-so).
But if we assume there is a kind of “as-if temporal” sequence, then we begin our journey on the true time axis at the stage where she divorced Reuven. At that stage there is no problem with that divorce, and it does not uproot itself. Afterward real time moves on, and in the next stage she goes and marries so-and-so. At that stage those marriages cannot take effect because they are an effect that uproots itself (for the divorce already preceded them). How do they uproot themselves? That occurs along an internal time axis: after she “marries” so-and-so we go back “in time” and it emerges retroactively that the divorce from Reuven was canceled. But that is a mistake. We do not really go back in time; rather, we move along an internal time axis that, from the perspective of ordinary time, all occurs at a single instant (the instant she “marries” so-and-so). At that instant the marriage to so-and-so uproots the divorce from Reuven, which in turn cancels the marriage to so-and-so. But this entire process is not a real return to the time of the divorce and a forward progression back to the marriage to so-and-so. All of this occurs along a fictitious internal time axis that is entirely hidden within the moment when she “marries” so-and-so. Within that moment she as it were progresses along another, internal, axis whose ordering is causal rather than temporal: the divorce enables the marriage to so-and-so to take effect—yet the marriage to so-and-so uproots the divorce, and therefore, on this internal axis, it comes before the divorce (because causally it precedes it), even though on the external time axis the marriage to so-and-so comes after the divorce. We regard this ordering as if there were an additional (internal) time axis here, but in truth it is not time but causal order.
In column 407 we saw that this principle, together with the additional assumptions, stops all these loops and many others (I there referred to the fourth volume in the “Talmudic Logic” series, which surveys very many examples of halakhic loops). I also showed there a case in which the internal-time assumption alone suffices to stop the loop, even without adding the principle of consistency. For our purposes: can such a mechanism explain Rav Ashi’s words in our sugya in Yevamot?
Back to Rav Ashi
It seems to me the answer is yes. Recall that we are dealing with a case where Reuven (the one who dies) married first. In such a case, the prohibition of brother’s wife is the first to take effect on Rachel relative to Shimon. Now Shimon marries Leah, and the prohibition of wife’s sister “wants” to join and take effect on Rachel as well. But it does not take effect, for a prohibition does not take effect upon an existing prohibition. Yet, as the Gemara says, it does not dissipate and disappear; rather, it remains “hanging and suspended” (if the prohibition of brother’s wife falls away for some reason, it will take effect in its place). Now Reuven dies, and his wife Rachel falls to Shimon for yibbum. The mitzvah of yibbum “awakens” and seeks to push aside the prohibition of brother’s wife. But if the prohibition of brother’s wife disappears, the prohibition of wife’s sister will take effect and neutralize the mitzvah of yibbum. Here the loop stops, because we see that if the mitzvah of yibbum were to take effect, it would uproot itself; therefore, according to R. Shimon Shkop’s principle of consistency, the mitzvah of yibbum cannot take effect. Note that this occurs even though the prohibition of wife’s sister has not taken effect on Rachel (it is merely suspended), and therefore it is not that prohibition that “stops” yibbum. The reason it does not take effect is not the prohibition of wife’s sister, but R. Shimon’s principle of consistency: its taking effect would uproot itself (because it would remove the prohibition of brother’s wife, which would then allow the prohibition of wife’s sister to take effect and cancel the mitzvah of yibbum). As we have seen, such a mitzvah cannot take effect.
Up to this point we applied the principle of consistency to the mitzvah of yibbum. An alternative formulation applies the principle to the prohibition of wife’s sister: suppose the mitzvah of yibbum pushed aside the prohibition of brother’s wife; the neutralization of that prohibition would allow the prohibition of wife’s sister to take effect on Rachel, which would prevent the mitzvah of yibbum from taking effect, which would leave in place the prohibition of brother’s wife, which would again prevent the prohibition of wife’s sister from taking effect. In other words, the prohibition of wife’s sister uproots itself, and therefore it too does not take effect. The only status that remains in such a case is the prohibition of brother’s wife—neither the prohibition of wife’s sister nor the mitzvah of yibbum. How does this happen? The prohibition of brother’s wife took effect on the real time axis even before the whole story begins—at the moment Reuven married Rachel. At that moment, Leah is not yet Shimon’s wife, and certainly there is not yet any obligation of yibbum, so that marriage takes effect and, as a result, so does the prohibition of brother’s wife. Nothing prevents their taking effect. By contrast, both the mitzvah of yibbum and the prohibition of wife’s sister—each one, at the moment it would take effect, would uproot itself, and therefore cannot take effect.
The final state according to R. Shimon (bar Yochai, not Shkop) is that there is a prohibition of brother’s wife, but there is no mitzvah of yibbum and no prohibition of wife’s sister. This seems contradictory, for if only the prohibition of brother’s wife exists, the mitzvah of yibbum should apply (what cancels it if there is no prohibition of wife’s sister?!). But then the prohibition of wife’s sister would take effect, and so on. However, as we saw above, that is not correct. The prohibition of brother’s wife exists, and nevertheless there is no mitzvah of yibbum. There is no mitzvah of yibbum not because of the prohibition of wife’s sister, but because it is a self-uprooting effect.
The sting of this whole move is that we assume that this loop does not actually occur along the true time axis (we do not actually move back and forth in time), but along a hypothetical causal axis. If the process were real, then what would uproot the mitzvah of yibbum would be the prohibition of wife’s sister. But we are speaking of a hypothetical process—something that happens along an internal “time” axis (which is really a causal axis): when the mitzvah of yibbum “wants” to begin to take effect, we make a hypothetical calculation of what would result if it did in fact take effect, and we discover that it would end up uprooting itself. Consequently, it does not begin to take effect. It is not that it takes effect and then the prohibition of brother’s wife is uprooted and then the prohibition of wife’s sister returns. Rather, it is a hypothetical argument: if it were to take effect, it would uproot itself; therefore the entire process does not begin at all. This is why, as I wrote above, the mitzvah of yibbum does not take effect not because of the prohibition of wife’s sister, but because it is self-uprooting. No loop is formed and the earlier difficulty does not arise.
The difficulty was based on our assuming that the entire process actually occurs back and forth along the time axis, in which case there would be no way to stop it. The core of my explanation is that the process is purely hypothetical and does not occur in reality—exactly as we saw in R. Shimon Shkop’s halting of the loop. There, too, the difficulty arose because we thought everything is happening in actuality: the condition is violated and then uprooted and then reinstated, and so on. R. Shimon’s answer is that it is a hypothetical process that does not occur in reality: we merely ask, “If the marriage to so-and-so were valid, what would happen?” When we discover that it would uproot itself (and not that it actually uproots itself—since it does not actually occur), the conclusion is that it does not take effect at all. The entire chain does not begin in reality.
Back to the Question of a Source for the Principle of Consistency
We have seen that Rav Ashi’s “loop” is not real but a hypothetical thought experiment we conduct: what would happen if all this were to occur? This is the meaning of the mechanism innovated by R. Shimon Shkop, and in this sense it seems to me that our sugya is an excellent source for his innovation. Without it, it is very hard to understand, for we remain with an infinite logical loop and Rav Ashi’s words are unintelligible.
Admittedly, Tosafot in Gittin itself would seem to be a source for the principle of consistency, for without it there is an infinite loop. Moreover, that is proof from the Gemara and not merely from Tosafot, since Tosafot is only challenging the Gemara. It emerges that without the principle of consistency one cannot understand the Gemara. So why is our sugya in Yevamot a better source than the sugya in Gittin itself? In Gittin it is a question, and in principle someone might have proposed another answer to resolve it. Here it appears that Rav Ashi states the principle of consistency explicitly. It is not merely the result of a difficulty and calculation within the sugya. Therefore, in my view, the Yevamot sugya is truly a source for the principle of consistency, and now we can use it to resolve the sugya in Gittin as well as all the other loops I mentioned.
Another Example of Moving from Practical to Hypothetical Reasoning: The Categorical Imperative
I wish to conclude with another example of the significance of moving from practical reasoning to hypothetical reasoning, as in the principle of consistency. In columns 122, 344, and elsewhere I discussed the categorical imperative, and I pointed out that there too a similar error occurs.
Consider a person who claims there is no point in going to vote in elections or in paying income tax because this step has no effect (I explained there why my vote will not change the outcome of the elections, and why one person’s tax evasion does not change the country’s economic situation at all). The usual response to such a person is the consequentialist one: what will happen if everyone does as you do? Clearly, if everyone evades taxes the state coffers will be empty, and if no one goes to vote there will be anarchy. His reply is that those would indeed be very undesirable states, but they will not actually occur—at any rate not because of him. After all, every person makes his own calculation privately (and does not talk about it with anyone else, certainly not regarding tax evasion): whether to evade taxes and whether to go vote. Everyone makes his own decision as he did, and the decisions of all people are not affected by what I decide. Therefore we return to the claim that my step has no effect. Even in a situation where everyone decided to evade taxes, the state’s condition would indeed be dire, but my hundred shekels would still make no difference. They did not cause everyone else’s decisions. Thus, prima facie, there is no argument here that should make me change my policy.
I explained that one can propose a solution to this in terms of Kant’s categorical imperative. The claim against such an offender is not consequentialist (“If you do this, everyone else will do so as well”). The consequentialist claim is indeed mistaken. The claim against him is philosophical-hypothetical: make a hypothetical calculation of what would happen in the hypothetical case that everyone behaved as you do (even though in reality this will not happen—at least not because of you). If the result seems bad to you, then the act in question is bad—and therefore you must not do it. If the result seems positive to you, there is no problem—do it. This is no longer a claim that can be dismissed in the same consequentialist way, since it does not deal with practical consequences. The consideration here is not what will actually happen, but what would happen in the hypothetical case that everyone decides to act thus. The hypothetical consideration does not seek to examine the consequences of your act; rather, it is a gauge for determining the goodness or badness of the act under discussion. The state that would emerge if everyone did X determines the nature of the act X. If that state is bad, then X is a bad act (even though my own X did not produce that state). If it is a bad act, it is forbidden; again, irrespective of consequences. If the state is positive, then X is a good act, and therefore there is no barrier to doing it—again, irrespective of consequences.[2]
Thus, here too, our problem arises because we raised a practical consideration regarding the actual consequences of the act in question (a consequentialist consideration). It is resolved by our moving from a practical-consequentialist consideration to a hypothetical one (what would happen if), exactly as we saw in R. Shimon Shkop’s principle of consistency.
Admittedly, there is no loop here, and therefore the similarity between the cases is not complete. But if you consider the point I raised in column 122—namely, the consequentialist consideration—you will obtain a genuine loop (there are bad consequences, but still it makes no difference to me because my act by itself has no effect; but then everyone will say it makes no difference to them for the same reason, and then there will be an effect; and so on). The way to solve the problem is to stop the loop by moving to hypothetical reasoning. Now the similarity between the categorical imperative and the principle of consistency is much stronger.
[1] There is non-uniqueness, because a person can have several brothers; therefore “brother of my brother” is not necessarily me, and likewise “son of my father” or “nephew of my uncle.” Hence such a chain does not necessarily pick out a single definite person; but in principle the chains of family relations obey these relations. I have always wondered whether it is correct to say that I am my own brother, since we have the same parents (see column 81).
[2] Admittedly, in column 122 I showed that one can translate this consideration into a consequentialist one via the Prisoner’s Dilemma. But for our purposes here that is not important.
Discussion
I don’t understand what a “suspended prohibition” means. Mitla tali, as I understand it, means that the prohibition is hanging in wait on the side: if the first prohibition is removed, it will then take effect there, but as long as the first prohibition remains in place, the second prohibition has no significance. You are suggesting that the second prohibition is constantly there at half strength—not enough to incur punishment, but enough to prevent levirate marriage. I do not see why it should prevent levirate marriage if there is no prohibition here.
And perhaps you mean that the prohibition of “wife’s sister” exists, only one is not punished for it? In the rule that one prohibition cannot take effect where another already applies, plainly the issue is not only punishment but the very taking effect of the prohibition itself. And so too in the simple meaning of the language in our sugya: according to that view it would have been more correct to say that the prohibition of “wife’s sister” exists (and is not suspended), except that one is not punished for it. The meaning of the expression that the prohibition is “suspended” is that it does not currently exist, but is hanging and waiting to see whether the initial prohibition will be removed. It is not “half strength,” and certainly not a full level of prohibition. It is suspended—that is, waiting and dependent on the occurrence of something else.
True, one really does need a rationale for why a prohibition that is suspended and waiting can have an effect. But one need not say that the prohibition exists and one is simply not punished; perhaps for the purposes of levirate marriage it is enough that the cause of the prohibition exists. Tomorrow I’ll look in the commentators.
The question is also what it is dependent on and what it is waiting for. Its status does not change and will not change, because it remains “suspended.”
Or perhaps “suspended” here does not mean dependent, but hanged? That is, it is hanging on a tree and not hanging on something.
Otzar HaChokhmah (“for if the prohibition of brother’s wife lapses”) immediately showers “the enduring worlds, standing in their established form.”
In the novellae of R. Shimon Shkop, Yevamot sec. 18 p. 62: “And wherever the prohibition of brother’s wife is suspended, such that if it were permitted it would be of no avail, for in any event it would revert to its prohibition, it does not lapse, as they said in the Gemara in a similar case according to R. Shimon, that the prohibition of wife’s sister does not take effect upon that of brother’s wife.” In the writings of Kehillot Yaakov, Yevamot sec. 36 p. 131: “And if because of this the bond of the first would again take effect—that cannot be said, since if the bond of the first were to take effect again, it would once more lapse because of ‘the wife of two deceased brothers.’ And in such a case it cannot take effect at all, as we say on 32a according to Rabbi Shimon: since if the prohibition of brother’s wife were to lapse, that of wife’s sister would take effect; therefore it does not lapse.
But on the other hand, R. Chaim in the stencil edition sec. 76 p. 46 says: “For although the prohibition of wife’s sister does not apply to her, the status of ervah does apply to her, because she truly is his wife’s sister, and that suffices to exempt her from levirate marriage, for an ervah exempts from levirate marriage.” And in Seridei Esh, Even HaEzer sec. 76 p. 213: “The explanation is not, as people are accustomed to say, that if we say the prohibition of brother’s wife has lapsed, then the prohibition of wife’s sister will apply to her, and therefore it is forbidden to perform levirate marriage with her, and so the prohibition of brother’s wife does not lapse. Rather, the explanation is that the fact that the prohibition of wife’s sister is suspended and pending makes her an ervah, and an ervah exempts from levirate marriage.”
And in R. Shimon Shkop I also saw in the novellae sec. 1 that “one prohibition does not take effect upon another” means that it is not in the world at all, and not merely a matter of punishment (for if the prohibition exists, why should he not receive lashes? unlike Pri Megadim). So in this too he says as you do (though I too had not proposed otherwise), and the points fit together. [And by the way, one more thing: since R. Shimon Shkop himself sees “wife’s sister” as an example of his idea of the revolving wheel, and the explanation I had thought to propose in R. Shimon Shkop regarding the wheel seems to me not to fit here, then you should not be surprised to hear that you were also right in understanding R. Shimon Shkop’s intent, unlike what I proposed there and despite my pressing his language against you. That explanation—which there received your initial approval as a possibility—I shall now draw back into my bosom.]
Is there a way to understand R. Shimon Shkop’s principle differently? That is, is R. Shimon Shkop’s reasoning compelling in itself even without proofs from the Gemara, because the Torah cannot command levirate marriage, etc., in a case where the command itself would negate the command?
Why is this principle not said in the case of migo, where on the contrary we say that even though if the migo were to take effect it would in any case lapse, we still invoke migo?
It certainly can be understood differently. That is why I wrote that this is not a logical solution but a meta-halakhic one. On the logical level, the taking effect does not uproot itself; rather, it creates a loop that simply keeps going forever.
As for migo, see my pamphlet on migo and the post I linked to here.
Why can it be understood differently? After all, the Torah has only two possibilities: either to command levirate marriage or not to command it. In a case where there is an infinite loop, the possibility of commanding levirate marriage falls away, because it is impossible to command a mitzvah such that, if we are commanded to do it, it will be nullified.
That is only in this specific situation. The general mitzvah of levirate marriage remains intact.
Here a loop is created, that’s all. You are arbitrarily choosing to stop it at the absence of a mitzvah. But that is simply your choice.
Good.
Regarding Seridei Esh and R. Chaim, who seemingly say as you do, I do not think they mean what you wrote. Their claim is that levirate marriage is prevented not by the prohibition of wife’s sister, but by the fact that she is his wife’s sister (that is, an ervah), even if no prohibition accompanies it.
In R. Chaim’s words this is almost stated explicitly. True, in Seridei Esh he speaks of the prohibition of wife’s sister, but perhaps there too it is only a habitual turn of phrase.
And one should note regarding R. Chaim and Seridei Esh: why is it that in the case of one’s brother’s wife, although the prohibition lapses because of the mitzvah of levirate marriage, the fact that she is an ervah does not lapse? And why should that fact not prevent levirate marriage?! One can of course attribute it to a scriptural decree regarding levirate marriage, but from a standpoint of reasoning that still requires clarification.
Indeed. Though afterward I wrote something about the cause of the prohibition (as distinct from the prohibition itself), and that is simply the fact that she is his wife’s sister. For there is that story in which they asked why, in a case of one prohibition upon another, he is buried among thoroughly wicked people, and R. Shimon Shkop said: because the cause of the prohibition is still present here. And the Birkat Shmuel was dissatisfied, and when they asked him to explain he said something that on its face seems rather similar (though I do not remember what it was). But later in that sugya in Yevamot, when they discuss thoroughly wicked people, I saw in Rashi that he emphasizes that this is relevant only for intentional transgression and not for inadvertent transgression, and it seems at first glance that he means to say that there is no prohibition and nothing at all—only an assessment of a person’s mindset, that from his perspective there is a greater degree of rebellion here.
Why, from a standpoint of reasoning, is it still in need of clarification that the scriptural decree of levirate marriage overrides everything that exists in the case of one’s brother’s wife?
One could also say that the death of his brother cancels the ervah-status of his brother’s wife (just as the death of his wife cancels the ervah-status of his wife’s sister), though the prohibition of brother’s wife remains, and only that prohibition is uprooted by the mitzvah of levirate marriage.
If the ervah-status is canceled with the death of his brother, why does the prohibition remain?
Meaning, you are saying that the fact itself is obviously a necessary condition for the prohibition, and not that these are separate planes (the fact of ervah and the prohibition of ervah) which usually go together but where there could also be a prohibition without the fact. I agree that this is more reasonable, and I retract that invention and make use of the opening you left: that the scriptural decree of levirate marriage permits everything that exists in the case of one’s brother’s wife, and has the power to permit even factual ervah-status (it can reveal that this is not an ervah, or say that this is an ervah that is permitted).
[Though perhaps one can infer something from observing the nations. If they see a problem in one’s brother’s wife, that means they identify a factual ervah-status there (similar to what you said about consecrated things that predated the Torah). And if they permit levirate marriage, that means they think that the death of the brother’s wife cancels that factual ervah-status.
But the prohibition still is not canceled, since we have no source for making the prohibition depend on the factual ervah-status, and therefore we need the mitzvah of levirate marriage. All right, I’m just flailing around here.]
But tell me: how is there radio silence among the Rishonim? What kind of thing is that? Only in the Rivan did I see someone say as you did, and everyone else put the palm of silence to their mouths.
The Rishonim are generally not sensitive to philosophical and logical questions, and are also less skilled at conceptualizing and handling them.
In Tosafot HaRosh on 13a he writes (I did not study the sugya or his words, it just came up in the search net I cast to pull up fish): “And Beit Hillel hold that although one prohibition cannot take effect upon another, and she does not bear the status of the prohibition of wife’s sister, nevertheless she is a woman who is not fit for levirate marriage, and she is an ervah, and therefore exempts her co-wife.”
Regarding hypothetical considerations, could you clarify for me how they differ from standard matters like “for if not so,” such as “one should pray for the welfare of the government, for were it not for fear of it…,” “we do not suspect that perhaps a weasel dragged it away, for if so there would be no end to the matter,” and many others like them. It seems that here you treat the hypothetical consideration as though it were some kind of mechanical matter, and therefore identify a point of hypothetical mechanical influence; but if there is a legislator with awareness here, then ostensibly it is all the same.
The hypothetical consideration is not special because it is hypothetical. The novelty is that the consideration, which on its face seems real, is in fact hypothetical. That is an interpretive novelty, not a substantive one.
I did not understand why this is merely an arbitrary choice. After all, in the end, in this particular situation we must stop the loop at some stage and decide either to obligate levirate marriage or not to obligate it (there is no other option). And since obligating levirate marriage is not possible because of the problem it creates, the last remaining necessary option is to exempt from levirate marriage.
We are repeating ourselves. Both are equally impossible. Exempting from levirate marriage is also impossible.
This is a loop with no natural endpoint.
When the second possibility is an obligation of levirate marriage that is forbidden to him because she is his wife’s sister, it is certainly possible—and called for—to exempt from levirate marriage, no? (At any rate, that is the best option we have.)
Similar to every levirate marriage involving an ervah prohibition, where on the one hand there is the value of levirate marriage and on the other hand there is the problem of an ervah prohibition, and the law is that it is preferable to forgo the value of levirate marriage rather than violate the ervah prohibition—so too here, if we obligate him in levirate marriage we will be violating an ervah prohibition, whereas if we exempt him we admittedly will not fulfill the value of levirate marriage, but we will not violate the ervah prohibition.
A. The impression is that the post presents three levels. One level is ordinary consequential assessment of what has already happened, like someone who gave a bill of divorce and then we say: divorced, divorced. A second level is a practical hypothetical consideration, where the result is in the hands of the current decision-maker who is deliberating, for example: if I go outside, I will get wet from the rain, and therefore I will not go outside. And something of this sort also applies in the case of the weasel. A third level is a virtual hypothetical consideration, where the result is not in the hands of the decision-maker, as in the categorical imperative, and similarly in the welfare of the government. The first two levels are familiar to everyone, whereas with respect to the third level there is a substantive novelty. In the loop of a taking effect that uproots itself, the claim in the post is that this is not an ordinary consequential assessment of the first level, but a practical hypothetical consideration of the second level. And in the categorical imperative, the claim in the post is that this is not a practical hypothetical consideration of the second level, but a virtual hypothetical consideration of the third level (which does involve a substantive novelty). If so, then what is the interpretive novelty in the post regarding the loop of the taking effect? Everyone understands that R. Shimon is dealing with a practical hypothetical consideration (what would happen if the taking effect took effect), not with an ordinary consequential assessment, and everyone ordinarily recognizes the force of practical hypothetical considerations.
B. You wrote that if the process actually occurs back and forth along the timeline (the first level; ordinary consequential assessment), then there is no way to stop it. I understand that in your opinion even meta-halakhic principles would not help in such a state. I ask why you reject the following mechanical explanation: in actual fact, levirate marriage takes effect and cancels the prohibition of brother’s wife and awakens the prohibition of wife’s sister; then the levirate marriage is canceled and reawakens the prohibition of brother’s wife, which cancels that of wife’s sister; and then we again arrive at levirate marriage, and now it refuses to take effect, due to a meta-halakhic principle that since levirate marriage sees that previously (on the axis of logical causality) it was in exactly the same state and already took effect and was canceled, it now refuses to take effect a second time. That is, let us formulate R. Shimon’s principle such that any legal effect which has already taken effect and uprooted itself and returned to precisely the same state does not take effect again. And this is no longer exactly a hypothetical consideration, but an ordinary mechanical matter that has all sorts of rules dependent on the past. [Perhaps one could say that as a mechanical matter there is no wheel here, because something that has lapsed does not reawaken (without a legal act of applying a new legal effect). Meaning: after levirate marriage takes effect and cancels the prohibition of brother’s wife, there is no longer any prohibition of brother’s wife in the world (until the deceased brother marries her again); and after wife’s sister comes down from the tree and cancels the levirate marriage, there is no longer any obligation of levirate marriage in the world (until the deceased brother dies again). Then we would be left only with the prohibition of wife’s sister (even when the deceased married first and afterward the living brother married).]
I will answer for the last time. If you exempt him from levirate marriage, then the prohibition of brother’s wife remains in force, and accordingly the prohibition of wife’s sister is nullified. If so, she is subject to levirate marriage, and it is forbidden for her to marry without it.
That’s it. I’m done.
A. You lost me. Our loop is of the third type, like the categorical imperative.
B. I do not see the gain or the logic. You have invented a different meta-halakhic principle. One might just as well say that anything beginning with yod (the mitzvah of yibbum) is nullified.
A. So that I did not grasp. In our loop there is just an ordinary standard hypothetical consideration: we won’t go outside because there we will get wet (we won’t apply the legal effect because it will be uprooted). How is that similar to the special hypothetical consideration in the categorical imperative—“if everyone were to act this way”—which is something not even actually on the table?
B. There is no more gain or logic than in the description you gave (that from the outset levirate marriage does not take effect), but it illustrates the point that the hypothetical consideration is a side issue and unnecessary here, and one can use a version of the consistency principle even without hypothetical considerations.
A. Not at all. This is hypotheticality of the third type. Since if we were to go out, the going out would be nullified, therefore we do not go out. It is not that one decides not to go out. Going out is impossible. If when we were to apply the legal effect it would uproot itself, then such a legal effect cannot be applied at all (so in any case it does not uproot itself; rather, the process never begins). Exactly like the categorical imperative: if we were to behave in a certain way, the world would be bad, therefore that is an immoral way to act.
B. The principle of consistency is itself a hypothetical consideration. That is its definition.
I really am unable to understand this entire discussion.
I think I understood your answer in A. You are saying that because there is no possibility of applying the legal effect in a way that will endure, but only a possibility of initiating a loop in which the legal effect takes effect and lapses and takes effect again, etc., therefore you call this hypotheticality of the third type. I am dropping B, because it is a side twist and unimportant.
Donkeys understand fruit soup just as much as secular people like me understand halakhah (or logic). Still, I felt like becoming a bit donkey-like, and I am willing to bear the consequences. With love.
I tried to understand this convoluted move, and for some reason the moves of Russell and Gödel popped into my head.
In my donkeyish mind, it seemed to me that the meta-halakhic ruling proposed here as a solution could be interpreted like Russell’s technical-formal attempt to impose a solution in an overly aggressive way. Russell, to the best of my understanding, did not really provide a philosophical solution to the loop that confronted him when he created type theory, though he certainly tried to do so. Gödel, by contrast, acknowledged the principled inadequacy of a closed symbol-system to solve the problem in a technical-formal way, but precisely because of that he succeeded philosophically in grappling with it very well (mathematicians, logicians, and philosophers accept what he says).
Now, if I have correctly characterized the two different strategies for handling the problem, which of the two is, in your opinion, closer to Shkop’s move?
Actually, that is not a bad analogy. Russell too tries to stop the loop by means of an artificial meta-logical principle that he imposes on the system. I do not think Gödel offered a solution, but rather proved that there is no such solution within the system.
And Shkop’s solution is closer to Russell’s proposal or to Gödel’s? Or to neither of them?
Russell. Gödel is not a solution.
I will burden his honor with one last question. If from Gödel’s point of view there is no solution (and if you yourself accept that), doesn’t that create a theoretical problem for Shkop? As though there is a lacuna in halakhah that nevertheless cannot be overcome. And if there is such a lacuna, does it have practical significance?
There is no solution within the system. In the meta-system everything is fine. There is a proof of Gödel’s theorem, and it is a constructive proof; that is, one constructs a statement that is necessarily true and has no proof. And that itself is proven—but outside the system.
Test
Is that really the explanation of Rav Ashi’s words? Why not explain it in a more straightforward way: Rav Ashi says that although the suspended presence of the prohibition of “wife’s sister” is not enough to warrant punishment, it is enough to exempt from levirate marriage, and therefore the prohibition of “brother’s wife” does not lapse. No revolving wheel (and fixed sevarot). How a suspended presence can have an effect is open to suggestions, like the case of burying him among thoroughly wicked people. Etc.
[And why am I itching to explain the Gemara the way you nicely explained it? Because the explanation I think I understand in R. Shimon Shkop—which I proposed in the comments to that post 407, and which does not require the additional innovation of the axis but rather concerns something else, namely simplifying components after looking at the possible outcomes, and which I still maintain is a possible explanation in R. Shimon Shkop—is an explanation that I cannot fit into this sugya according to your interpretation of it. So I am left with no choice but to suggest a different interpretation in the Gemara. And indeed, apropos of illusory correlations, that is actually how I simply understood it in Yevamot even without its helping me for other things.]