Yitro (5765)

From the book Mida Tova: Articles on the Hermeneutical Principles by Rabbi Michael Avraham. Translated from Hebrew using gpt-5.4 (reasoning_effort=high, batch API).

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With God’s help, Midah Tovah — Eve of the Holy Sabbath, Parashat Yitro, 5766

Interwoven Hermeneutical Principles: Kal va-homer (a fortiori inference) and Asmakhta (a scriptural support that is not a true derivation)

Questions

1. Asmakhtot for Torah laws and for rabbinic laws.
2. What is the difference between asmakhtot and supportive derivations?
3. Why must an asmakhta be a defective derivation?
4. What indications do we find in the words of the Sages that a given derivation is an asmakhta?
5. Which structural defects turn a derivation into an asmakhta?
6. Why do the Sages formulate asmakhtot?
7. Can a formal kal va-homer be an asmakhta? And what about a reason-based kal va-homer?

A. Summary of Last Year’s Article

And the Lord said to Moses: Go to the people and sanctify them today and tomorrow, and let them wash their garments.

And he said to the people: Be ready for three days; do not approach a woman.

(Exodus 19:10, 15)

As it was taught: Moses did three things on his own initiative, and the Holy One, blessed be He, agreed with him: he added one day on his own initiative, he separated from his wife, and he broke the tablets.

He added one day on his own initiative. What did he expound? “Today and tomorrow” — just as tomorrow includes its night with it, so too today includes its night with it. But the night of the present day had already passed. Learn from this: there must be two days besides the present day. And from where do we know that the Holy One, blessed be He, agreed with him? Because the Divine Presence did not rest until Sabbath morning.

He separated from his wife. What did he expound? He reasoned by a kal va-homer on his own and said: If Israel, with whom the Divine Presence spoke only once, and for whom a time was fixed, and yet the Torah said, “Be ready … do not approach,” then I, with whom the Divine Presence speaks at every moment and for whom no time is fixed — all the more so. And from where do we know that the Holy One, blessed be He, agreed with him? Because it is written: “Go say to them, Return to your tents,” and immediately after it is written, “But you, stand here with Me.” Some say: “Mouth to mouth I speak with him.”

He broke the tablets. What did he expound? He said: If with regard to the Passover offering, which is only one of the 613 commandments, the Torah says, “No foreigner shall eat of it,” then here we have the entire Torah, and Israel are apostates — all the more so. And from where do we know that the Holy One, blessed be He, agreed with him? Because it is said, “Which you broke,” and Resh Lakish said: “Well done that you broke them.”

(Babylonian Talmud, Shabbat 87a, and Yevamot 62a)

In the Talmudic passage cited above, several decisions made by Moses are presented, and God is said to have agreed with them. The passage assumes that Moses used the hermeneutical rules in arriving at those decisions, and this raises the question why it is described as something he did “on his own initiative.” The Tosafists consistently support the view that these were defective derivations — that is, derivations with a structural flaw — and therefore they were only an asmakhta in the loose sense. Moses’ decision was based not on the derivation itself, but on his own reasoning.

By contrast, according to Maimonides, reliance on derivations may itself still count as something done “on his own initiative.” Maimonides holds that the laws learned from derivations are rabbinic laws and not Torah laws, since they are not included in the written text. He assumes that the definition of the concept “Torah law” overlaps with the definition of “Written Torah” — that is, what appears explicitly in Scripture. According to most commentators, however, these two concepts belong to different conceptual domains: Written Torah is the counterpart of Oral Torah, but both of these, in terms of legal force, are included within Torah law. Rabbinic laws are a separate legal category, containing rules of lesser legal standing, such as enactments, decrees, and customs.

We noted that according to Maimonides, derivations are a tool for expanding what is already present in the Torah. What appears explicitly in the Torah, or what is deduced from it by deductive means, is Torah law; but what emerges from derivations, which are analogical in character, is an expansion of Torah law that lies outside the Torah itself. According to the Tosafists, by contrast, derivations are a tool for exposing contents hidden within Scripture itself, which a plain-sense reading cannot uncover. We also connected this to the dispute between Maimonides and Nahmanides in the second root.

We observed that statements by the medieval authorities to the effect that a certain derivation is an asmakhta usually arise from constraints that emerge in the course of the sugya, the Talmudic discussion. Here too, Tosafot arrive at that determination because of the constraint created by the Sages’ statement that Moses did this “on his own initiative.” Other constraints may be the fact that the law in question is known to be rabbinic, in which case there cannot be a complete derivation that anchors it in verses, and so forth. There are only a few cases in which we find the claim that a derivation is an asmakhta because of flaws found in its structure. The reason is that the hermeneutical rules are not fully clear to us, and therefore we need indirect indications from the Sages, who did know those rules, that a derivation is an asmakhta. Yet it is clear that, at bottom, every asmakhta must contain a structural flaw. Otherwise, why should we not simply derive the law from that exposition after all, thereby turning it into a Torah law?

On the other hand, when Moses acted on the basis of some derivation, even if it was defective, there still had to be something genuine in that derivation that led to his conclusion. After all, the Gemara opens with the question, “What did he expound?” In other words, it assumes that the derivation did play a role in his decision.

We presented an example of a flaw of this kind — one that, on the one hand, prevents the derivation from being valid, but on the other hand leaves its internal logic intact. The example we found was the kal va-homer employed by Moses. If Moses reasons by kal va-homer from A to B, he is implicitly assuming a rationale that links them, namely that B is more severe than A. Suppose we now find a refutation of that kal va-homer. A legal refutation consists in finding a law that runs contrary to the hidden assumption of the kal va-homer, but this does not necessarily reject the underlying rationale itself. It is therefore possible that even after the kal va-homer has been refuted, the underlying reasoning remains intact.

We are inclined to understand things this way in cases where the underlying kal va-homer is not a formal one — that is, not one based on two scriptural laws that lead us to establish a hierarchy between two cases — but rather a kal va-homer based on an a priori line of reasoning. In such a situation, finding a law that serves as a counterexample and refutes the kal va-homer does not necessarily invalidate the reasoning itself.

We noted that a systematic study of asmakhtot may bear fruit and lead to a fuller understanding of rabbinic derivation. If we can characterize the derivations classified by the Sages or by the medieval authorities as asmakhta, and then search for the structural flaws found in them, we may be able to draw conclusions about the standard structures of derivations that satisfy the criteria of midrashic interpretation.

We further noted there that asmakhtot are not necessarily just a technical aid to memory, as one might infer from some medieval writers. Asmakhtot are conclusions related to the scriptural text, but not by a deductive relation; otherwise they would be Torah laws. The implicit assumption is that there are several levels of connection between laws and the scriptural text, and the degree of connection determines the legal standing of the law under discussion. If so, an asmakhta, which is a defective derivation, may appear on several different levels, depending on the degree of defect it contains, and that degree determines how far it stands from the plain meaning of the text.

B. What Is an Asmakhta?

Introduction

This week we will address the question of asmakhtot. We will try to understand what kinds of asmakhtot we find in the literature of the Sages, and what their legal standing is. What considerations lead us to characterize a given derivation as an asmakhta? And what, in general, is an asmakhta? Why say that an asmakhta must necessarily be a defective derivation?

Definition

The basis of the discussion is the system of rabbinic hermeneutics, which provides tools by which various laws can be extracted from Scripture. Laws derived from Scripture by means of the hermeneutical rules are Torah laws according to most medieval authorities. According to Maimonides, they are rabbinic laws, as noted above in the summary of last year’s article. According to everyone, however, these are not asmakhtot.

There are cases in which an inference that appears at first glance to be a genuine derivation is not actually such, and we define it as an asmakhta. According to the definition in Encyclopedia Talmudit (entry: “Asmakhta”), the basic definition is this: an ancillary derivation, by means of which the Sages attached an already known law to a verse.

In the literature of the Sages we find two primary kinds of asmakhtot:

1. Anchoring a Torah law in a verse, even though its true source is elsewhere. The source of that law may be a halakha le-Moshe mi-Sinai (a law transmitted orally to Moses at Sinai), reasoning, empirical reality, or another scriptural source:
2. An asmakhta for a halakha le-Moshe mi-Sinai. For example, the fixed halakhic measures of the Torah are a halakha le-Moshe mi-Sinai, yet they were attached to the verse “a land of wheat and barley.” See Babylonian Talmud, Eruvin 4b; Berakhot 41a; Rashi there; and Encyclopedia Talmudit, note 10 to that entry.
3. An asmakhta for a law that actually derives from another scriptural source. For examples, see Tosafot, s.v. “Shalmei Pesach,” Babylonian Talmud, Rosh Hashanah 5a, and Encyclopedia Talmudit, note 11 there.
4. An asmakhta for a law whose source is reasoning. For example, the permissibility of eating the birds of the metzora rite after they have been sent away. See Babylonian Talmud, Kiddushin 57b, Rashi, s.v. “Rava,” and Encyclopedia Talmudit, note 14 there.
5. An asmakhta for a law known from reality. For example, the rule that there is no partial placenta without a fetus. See Babylonian Talmud, Chullin 77a, Rashi there, and Encyclopedia Talmudit, note 15 there.
6. Anchoring a rabbinic law, such as an enactment or decree, in a verse. See Encyclopedia Talmudit there, from note 21 onward.

Supportive Derivations and Type 1 Asmakhtot: Halakha le-Moshe mi-Sinai

In various essays — see, for example, the page for Parashat Vayishlach, 5766 — we discussed the concept of “supportive derivations,” as opposed to “creative derivations.” Creative derivations are derivations from which we learn and thereby generate a new law. Supportive derivations are derivations formulated only after the law that is supposedly “derived” from them already exists. If so, how do we really know the law that is attached by such a supportive derivation? And what is the relation between such derivations and the concept of asmakhta?

Let us begin with a situation in which we possess a certain law by tradition, but without a source. One possibility is that this is a halakha le-Moshe mi-Sinai, in which case it indeed has no source at all in the Written Torah, but was given orally to Moses. See Maimonides, Introduction to the Commentary on the Mishnah. As Maimonides states, we will usually know of such a law that it was transmitted to Moses at Sinai — that information has to be transmitted, since according to his view there is never disagreement about such a law. A derivation that anchors such a law in Scripture, that is, type 1a, is seemingly superfluous. The law is valid, and its status is that of Torah law, even without our derivation. It is therefore reasonable to conclude that in such a case the derivation is defective. Otherwise, there would have been no need to transmit this law as a tradition from Sinai; we could simply have been left to generate it from the derivation.

However, according to Maimonides, a halakha le-Moshe mi-Sinai is a rabbinic law. But if it has a derivation that anchors it in Scripture, then its status becomes that of Torah law. See his Introduction to the Commentary on the Mishnah and the second root.¹ According to Maimonides, then, there is certainly good reason to anchor a halakha le-Moshe mi-Sinai in a supportive derivation, since that changes its legal standing. According to him, that is precisely why such a law was transmitted by tradition even though it could also be derived by the hermeneutical rules: this is necessary in order to establish its status as Torah law.

Supportive Derivations and Type 1 Asmakhtot: Reconstructing a Creative Derivation

Let us continue with the same case, in which a law is given to us without a source and we search for a derivation for it. If we do not know that the law in our possession is a halakha le-Moshe mi-Sinai, then it is unlikely that it is such. In general, laws transmitted from Sinai would be passed down from generation to generation together with their legal classification as such. See Maimonides there.

We must therefore assume that this law has some midrashic source. We search for such a source, and in the end we find a derivation from which the law in question can indeed be derived. But once we have found a reliable source for the law, there is no reason to assume that this was not also the original basis on which it was first generated. Why not assume that we are merely reconstructing the creation of the law as it was done in the past? After all, when this law was first generated — we are now assuming that it was not transmitted from Sinai — some hermeneutical rule was used. And if we have found a reliable derivation that generates this law, it is reasonable to suppose that this was the original derivation.

A midrash of this kind looks like a creative derivation, not a supportive one. It is a case in which the law was once created from some creative derivation, but that source was forgotten. We now seem to have succeeded in reconstructing the source through our own effort. Such a process therefore reflects not a supportive derivation but a reconstruction of a creative one.

To this we must add the Gemara’s interesting statement in Babylonian Talmud, Sanhedrin 34a, cited in our essay for Parashat Shemot, 5766:

Abaye said: For the verse says, “God has spoken once; twice have I heard this, that strength belongs to God” — one verse yields several meanings, but one meaning does not emerge from several verses. The school of Rabbi Ishmael taught: “And like a hammer that shatters rock” — just as a hammer breaks a rock into many sparks, so too one verse yields several meanings.

(Psalms 62:12; Jeremiah 23:29)

That is to say, there is here a principle that one law cannot emerge from two verses, even though it is certainly possible to derive two laws from one verse. See the examples brought there in the sugya.² Therefore the Gemara concludes that if two people derive the same law from two different verses, one of them is necessarily mistaken. See our essay there.³ The reason is that the Torah does not hide the same law in two different verses, out of considerations of optimality and economy of language.

The conclusion is that when we find a derivation that anchors a certain law in Scripture, assuming that we trust this derivation and its power to serve as a source for that law, there cannot be some other derivation from which the same law could also be generated. We must therefore conclude decisively that the original creation of the law likewise relied on that very derivation, and not on another. This is a compelling argument that a derivation of the sort described here is creative, not supportive. It is probably the original derivation that created the law in the past, and we have merely reconstructed it by means of the hermeneutical process.

It is possible to attach to a law already known from a certain derivation some other derivation as an asmakhta. In such a case, the second derivation must necessarily be defective, for otherwise we would have two different derivations from which the same law could be generated.

Derivations of the Holy One Himself

One can imagine derivations whose source is the Holy One, blessed be He, Himself. If God gave Moses a certain law together with its midrashic source in Scripture, and Moses transmitted it onward as tradition, then there is here a creative derivation in the essential sense, but it was not created by the Sages; it was created by the Giver of the Torah Himself. In such a case, if the derivation is known, it is simply an ordinary creative derivation. If it has been forgotten, then we return to the cases discussed above. Finding a derivation for such a law would be a reconstruction of the derivation that was transmitted to Moses — like the laws that were lost during the mourning period for Moses and were restored by Othniel through his dialectical reasoning. See the page for Parashat Nitzavim, 5765.

It is also possible that for such a law we may propose another derivation, parallel to the original one, as an asmakhta. That second derivation would necessarily be defective, for the same reason as in the previous section.

Supportive Derivations and Type 1 Asmakhtot: Reason, Reality, or Another Derivation

What about the other sources listed above, namely 1b-d? In those cases, the law originates in reasoning, another derivation, or an analysis of reality, and only afterward do we find it a midrashic anchor in Scripture.

With regard to a law whose source is another derivation, we must assume that the derivation now being proposed is an asmakhta, in the sense that it contains some defect. As we saw in the Sanhedrin sugya, one and the same law cannot be learned from two different derivations. Therefore, if there is a valid derivation that creates this law, then the present derivation must necessarily be defective. In itself, it could not have created the law under discussion.

With regard to a law whose source is reasoning, the existence of a valid derivation that also anchors that law is entirely possible. To be sure, at first glance the derivation seems unnecessary, since the law can be learned from reason, and the Gemara says in several places: “Why do I need a verse? It is logical.” In other words, where there is reasoning, there is no need for a verse. See the essay on Parashat Toledot, 5766.⁴ Still, in our case we are dealing not with an explicit verse but with a derivation, and therefore the difficulty is less severe. The need for the verse exists because of what emerges from its plain meaning. The derivation may indeed be unnecessary in light of the reasoning, but the verse itself is not unnecessary. Such a case is possible. The same applies to a law that emerges from reality. These two, then, are supportive derivations.

Summary: Supportive Derivations and Type 1 Asmakhtot

We have thus learned that derivations that anchor laws whose original source was itself a derivation — whether by God Himself or by Sages in earlier generations — are, in essence, acts of reconstructing the creation of the law, and therefore they are creative derivations. These are ordinary derivations that should satisfy all the standards of rabbinic hermeneutics.

There are derivations that anchor laws whose real source is known to be some other derivation. These are asmakhtot, meaning defective derivations, since there cannot be two derivations for the same law.

Derivations that anchor reasoning or reality are supportive derivations, but not asmakhtot. In other words, there is no need to assume that those derivations are defective.

As for derivations that support a halakha le-Moshe mi-Sinai, according to Maimonides one must distinguish between an asmakhta for a halakha le-Moshe mi-Sinai, which is apparently a defective derivation — for otherwise we would not classify the law as one transmitted from Sinai, since it would have a source in the Torah — and an asmakhta for a law transmitted by tradition that turns the law into a Torah law and thereby removes it from the category of halakha le-Moshe mi-Sinai. According to the other medieval authorities, it seems that in either case we are dealing with a defective derivation, that is, an asmakhta.

Why Does One Formulate a Type 1 Asmakhta, That Is, an Asmakhta for a Torah Law?

We have seen that derivations of type 1 divide into two kinds: supportive derivations and asmakhtot. The reason there is a need to engage in supportive derivations and examine them was discussed at length in our essay for Parashat Toledot, 5766. The natural question here is why the Sages saw any need to formulate asmakhtot. These are defective derivations that do not serve as a valid source for the law attached to them, and so they would seem to be superfluous.

The commentators discuss this question. See Encyclopedia Talmudit there, note 16 and onward.⁵ Some explain that this is simply a mnemonic device, or a kind of sign. One must remember that until the redaction of the Talmud most of the Oral Torah was transmitted orally — see the sugya in Babylonian Talmud, Gittin 60a — and there was a need to establish memory aids in order to prevent forgetting.⁶

Even so, this approach is puzzling. Many of these asmakhtot are quite intricate, and it is hard to regard them as devices that genuinely make memorization easier. This is especially true of derivations that anchor laws whose true source is another derivation. Why not simply rely on the real derivation? Beyond that, the need to remember what is an asmakhta and what is a genuine derivation itself burdens the memory and creates considerable confusion. We know many cases in which the medieval authorities disagreed over whether a given derivation is an asmakhta or not. See Encyclopedia Talmudit there, notes 77-78, and many more. Moreover, as we saw in the essay for Parashat Toledot, 5766, the question of the scriptural source of various laws has many meanings and even practical legal consequences. The use of defective derivations therefore greatly complicates the preservation of the true sources of the laws.

Such an understanding of the significance of asmakhtot points to an approach that holds that the source of laws has no significance whatsoever, and certainly no legal significance. That approach is problematic, in light of everything we presented in the essay for Parashat Toledot, 5766. Below we will suggest an alternative explanation.

Type 2 Asmakhtot

The second type of asmakhta consists of derivations that supposedly “anchor” rabbinic laws in verses. Here there is no doubt that we are dealing with defective derivations. Otherwise the laws in question could genuinely be derived from those expositions, in which case they would be Torah laws. When we see a midrashic anchor for a law that we already know to be rabbinic, we can immediately conclude that we are looking at an asmakhta, that is, a defective derivation.

Why formulate asmakhtot of defective derivations for such laws? Here too many commentators explain that they function as mnemonic devices. In this case that solution is even more problematic, since it directly creates confusion between rabbinic laws and Torah laws.

Some have explained that the purpose of the asmakhta is to give the public the impression that these are Torah laws, so that people will not come to be lenient about them. So writes Mahari”l in Likkutim; see Encyclopedia Talmudit there, note 26. This approach is puzzling, because at least according to Maimonides such an act would itself violate the Torah prohibition of “do not add.” See Maimonides, Hilkhot Mamrim 2:9.⁷

The Explanation of Ritva and Maharal: Asmakhtot as Genuine Derivations

In last year’s essay we mentioned the words of Ritva, Babylonian Talmud, Rosh Hashanah 16a, and Maharal, Be’er HaGolah, Be’er I, who write that asmakhtot are not mere mnemonic devices. Ritva goes so far as to say that Heaven forbid one should think otherwise, and that such a thought is heresy. According to them, a rabbinic law that has an asmakhta in Scripture is indeed derived, to some extent, from the text, and the asmakhta is not a mere mnemonic game. True, it is not a complete derivation, since the laws are still rabbinic laws; but the reason is that the derivation from the text is not unequivocal. There is some connection to the text. The law emerges from the spirit of the text in some way, but not in the full and necessary way that characterizes a complete derivation.

We explained this by means of the heap paradox, which showed us that everyday concepts have intermediate cases. A law’s connection to the text can exist in various strengths and degrees. The full degree is a Torah law explicitly written in the text. A high but not full degree is an ordinary derivation, which according to Maimonides has the standing of a rabbinic law. A lower degree is an asmakhta, which according to all views remains a rabbinic law. And the absence of any connection yields a rabbinic law of a lower order still.

This conception can be applied to both types of asmakhtot discussed above. In both cases we are dealing with defective derivations, but the defect is of such a kind that some significance still remains to the derivation. Different degrees of defect in a derivation lead to different legal standings for the laws that are “derived” from Scripture by means of those defective derivations.

Legal Ramifications

We find in several medieval authorities a distinction between the legal standing of rabbinic laws that have an asmakhta in Scripture and rabbinic laws that do not.

In Tosafot, s.v. “Tanna,” Babylonian Talmud, Rosh Hashanah 12a, a distinction is drawn between a complete asmakhta, clearly implied by the verse, and an incomplete one. They also distinguish between the tithe of fruits, which has scriptural support, and the tithe of vegetables, which does not. And in Tosafot, s.v. “Lo Kashya,” Babylonian Talmud, Shabbat 34a, they write, in the name of Rashi, Rabbenu Chananel, and the Jerusalem Talmud, that we are stringent concerning eruv techumin because it has support from Scripture. The author of Pri Megadim writes likewise, in the introduction to Orach Chayim, part I, letters 20-21, regarding muktzeh.

In Rabbi Sheilat’s book Be-Torato shel R. Gedalia (Nadel), p. 28, these same ideas are cited in the name of Rabbi Gedalia Nadel. By means of them, he also explains the fact that scriptural sources are brought for conduct beyond the strict letter of the law — “You shall be holy,” “You shall do what is right and good,” “the deed that they shall do,” “so that you may walk in the way of the good,” and so forth. At first glance, such sources should turn that conduct into the strict letter of the law, since the Torah itself obligates us to it. But he explains that the connection to Scripture here is only by way of asmakhta. The spirit of the text directs us to act in this way, but this is not truly a Torah law. Encyclopedia Talmudit, note 32 there, cites the same idea in the name of Shelah.

All of these claims show us that asmakhtot are not merely memory aids. They are incomplete derivations, but they point us to the spirit of the text and teach us that the obligations emerging from them can be connected to Scripture on some level. If asmakhtot were only mnemonic devices, there would be no room for greater legal stringency regarding rabbinic laws that have asmakhtot than regarding rabbinic laws that do not. Tosafot in Rosh Hashanah even distinguish between a complete asmakhta and one that is not. Their words prove plainly that they understood the matter as Ritva did.

It is not necessary to explain all types of asmakhtot in the same way. See, for example, Kiryat Sefer, introduction, chapter 4. It is reasonable that some asmakhtot are merely memory aids and do not indicate any connection whatsoever to Scripture. Laws supported by such asmakhtot would not be more stringent than ordinary rabbinic laws.

Close Analysis of Asmakhtot

Sometimes the Gemara deals with a dispute among the Sages over the interpretation of verses, and, as is its way, it asks each side what it does with the verse and derivation of the other side. It is commonly assumed that when such give-and-take appears, we are dealing with a full derivation and not with an asmakhta. At first glance there is no point in analyzing scriptural asmakhtot so closely. Such indeed is the view of Tosafot, s.v. “VeRabbi,” Babylonian Talmud, Sotah 32b. However, in Tosafot, s.v. “Minayin,” Babylonian Talmud, Bava Batra 147a, the opposite is stated: even in the case of asmakhtot, it is the Gemara’s way to analyze and debate them as though they were complete derivations.

How are we to understand Tosafot in Bava Batra? There is no doubt that they view the asmakhta as a defective derivation that still carries meaning, and not as a mere memory aid. It is possible that Tosafot in Sotah understand the matter similarly, except that in their view it is still not justified to scrutinize defective derivations in the same way as ordinary derivations.

Asmakhtot as Defective Derivations

Asmakhtot are not always derivations based on the hermeneutical rules. Sometimes they are interpretations of verses that do not satisfy the criteria of plain-sense interpretation. In both kinds of case, we must look for defects in the interpretation or in the derivation under discussion. Otherwise these would be complete derivations or valid interpretations, and the laws supported by them would be Torah laws.

We saw above that there are several indications that a derivation or interpretation is an asmakhta. If the law is known to us as rabbinic, then the derivation or interpretation must necessarily be an asmakhta. Some have written that if the scope of the law differs from what should have emerged from the derivation, that is an indication that the derivation is not its true source and that it is therefore an asmakhta. See Encyclopedia Talmudit there, notes 66-73. The same may perhaps be inferred from an overly elaborate give-and-take in the Gemara, although, as noted above, the medieval authorities disagreed about that as well.

All these are only indications that the derivations in question are asmakhtot. But as we already noted, these are only indications. The derivations themselves are supposed to be defective. Someone who fully knew the hermeneutical rules ought to be able to identify defective derivations even without such indications — that is apparently what the Sages themselves did — and determine that they are asmakhtot. As we have already noted, we hardly ever find in the writings of the medieval authorities or in the Talmudic discussions examples of derivations being classified as asmakhtot because of problems in the structure of the derivation itself. This apparently stems from our incomplete acquaintance with the hermeneutical rules.

A reconstruction of those hermeneutical rules could give us the tools to identify derivations that are asmakhtot. The defects may be of several different types. One example would be the application of a hermeneutical rule in a way that does not follow the rules governing that very rule.

Example: a Reason-Based Kal va-homer with a Refutation

In last year’s essay we saw that Tosafot, in the sugya in Babylonian Talmud, Shabbat, determines that a certain kal va-homer is an asmakhta because it can be refuted. We saw there that when a kal va-homer is based on reasoning — see the page for Parashat Noah, 5765, on the three types of kal va-homer — then the existence of a refutation does not invalidate the reasoning. By contrast, in a formal kal va-homer, based on a comparison between two scriptural laws, there is no independent rationale for the hierarchy between the source case and the target case, and therefore the existence of a refutation can pull the ground out from under the hierarchy itself.

A kal va-homer based on reasoning therefore illustrates a case of a derivation that is not fully valid by the criteria of hermeneutics, yet still retains substance. The reasoning that underlies that kal va-homer may remain valid despite the refutation, but we cannot use it as a complete derivation. By contrast, a formal kal va-homer that can be refuted collapses entirely.

According to our explanation above, following Ritva and Maharal, an asmakhta is a case in which there is a defective derivation, but it has not lost all of its significance. One can still use it as reasoning with partial force, indicating some level of connection to the text. If so, a reason-based kal va-homer with a refutation is an excellent candidate to be regarded as an asmakhta in Ritva’s sense.

One of the derivations brought in Babylonian Talmud, Shabbat 87a, that Moses made on his own initiative is the derivation that led him to separate from his wife. He expounded as follows:

If Israel, with whom the Divine Presence spoke only once, and for whom a time was fixed, and yet the Torah said, “Be ready … do not approach,” then I, with whom the Divine Presence speaks at every moment and for whom no time is fixed — all the more so.

And in Tosafot, s.v. “Mah Yisrael,” it is written that this derivation is an asmakhta because it can be refuted: perhaps in Israel’s case they were commanded in this way because of the Ten Commandments, which were unique in their level and therefore required separation. This is a kal va-homer based on reasoning, and it has a refutation. That is exactly the kind of case that fits an asmakhta.

On the other hand, in Tosafot, s.v. “Ve-kava lahem zeman,” which comes immediately after the Tosafot just cited, a difficulty is raised against the Gemara: why does fixing a time tilt the law toward the absence of separation? At first glance, that consideration should tilt precisely in the opposite direction, toward a greater need for separation. See there for the answer. At first glance it is unclear why Tosafot challenge the reasoning at the basis of the kal va-homer, since it has already been clarified that this is not a fully valid kal va-homer. Rather, it is proven that a reason-based kal va-homer with a refutation reaches a state in which the reasoning remains intact even though the kal va-homer is not fully valid. This is the classic example of an asmakhta.

Of course, much more remains to be investigated regarding all the cases of asmakhtot based on the hermeneutical rules in rabbinic literature, in order to see which defects cause derivations to leave the category of a complete derivation and enter that of an asmakhta. But this is not the place.

Footnotes