Q&A: Units of Derivation
Units of Derivation
Question
Good evening
In Sanhedrin 34, the Talmud says that it is not possible for there to be two derivations for exactly the same Jewish law. One verse may yield several reasons, but one reason does not emerge from several verses.
On the other hand, in several places the Talmud says that the practical difference between views is only in how the verse is interpreted; and in some places the Talmud also brings an additional opinion. For example, in Rosh Hashanah 20b:
Rabbi Zeira said in the name of Rav Nachman: The moon is covered for twenty-four hours. For us, six are from the old moon and eighteen from the new one; for them, six are from the new moon and eighteen from the old one. What practical difference does this make? Rav Ashi said: To challenge the witnesses. The Master said: There must be a night and a day from the new month. From where do we know this? Rabbi Yoḥanan said: “From evening to evening.” Reish Lakish said: “Until the twenty-first day of the month in the evening.” What is the difference between them? Abaye said: The difference between them is only in how the verse is interpreted. Rava said: The difference between them is midnight.
Abaye holds that, in principle, it is possible to derive the same law from two verses, and Rava disagrees in that specific case, but not about the principle.
Have you happened to deal with this topic?
Answer
It seems to me that there is no difficulty here. The rule is that the same Jewish law cannot emerge from two different verses, but it is possible for there to be a dispute between two sages about which verse it emerges from (even if the only practical difference is interpretive significance). In other words, the rule that there cannot be two sources for the same law applies within the view of a given sage himself. Each sage is supposed to derive one law from each verse: the relation between verses and laws is one-to-one. But why should there be any obstacle to their disagreeing about the source of a given law? Like any other dispute. Did I miss something?
Discussion on Answer
Absolutely, and more power to you!
But I still have some lingering thoughts. First, it seems to be proven from here that the derashot are creative, because if they were merely supportive derivations, what difference would it make to us that they give two different sources? And even if they are creative, does the interpretive toolbox still have to be singular? Maybe according to Maimonides, but according to Nachmanides?
Even supportive derivations are supposed to hold water. So there too there has to be uniqueness. Especially in light of what I once wrote about the need for supportive derivations according to Maimonides and those who hold that there are also creative derivations. I wrote that once we have found a supportive interpretation, the verse is considered occupied, and in any case it is impossible to derive from it another creative interpretation. So even a supportive midrash has practical implications, and from that it is obvious that uniqueness matters.
I didn’t understand your comment about Maimonides and Nachmanides regarding the singularity of derivations. Why should there be a difference between them? The very need for uniqueness seems completely clear to me. Each verse teaches one thing, and it is not reasonable that the same verse should teach two things, because once it is interpreted for one purpose, it is already occupied, and the second thing cannot be proven from it.
For the sake of the lesson I’m giving today, I looked again at the passage in Sanhedrin about one reason from several verses. I didn’t understand whether in the end you agreed with what I wrote, but from looking into it, it’s clear that what I wrote to you is the explanation of the passage.
The Talmud there is unwilling to combine two identical opinions from two different sources and count them as two opinions. It does not say that such a situation is impossible. On the contrary, it is certainly possible; otherwise this rule would be unnecessary. So it is clear that the situation is possible, but if it happens, the combination of the two is not counted as two opinions. And why not? Because one contradicts the other. That is, according to any one view, there must be only one source for the law; it cannot be that within the same view there are two sources. A different rationale necessarily contradicts the first, and therefore is not counted together with it. From this it follows that one sage certainly cannot maintain a law on the basis of two different sources.
Agree?