Q&A: Prototype Derivation
Prototype Derivation
Question
There is a well-known dispute between Rashba and Maimonides regarding Torah-level doubts. One of Rashba’s proofs is from the fact that one needs a special verse to permit a doubtful mamzer, which shows that ordinarily a doubt is forbidden. Seemingly, this contradicts the rule of prototype derivation as I understand it, namely: when the Torah states a principle, it is true for the entire Torah unless there is reason to say it was meant only there. Am I understanding the principle correctly? And if so, must we say that according to Rashba there is some specific rationale that in the case of a doubtful mamzer, doubtful cases are permitted unlike the rest of the Torah? It’s possible I wasn’t precise in the example—I haven’t looked at the passage right now—but it seems to me that this question comes up in many places in the Talmud. Thanks.
Answer
You’ve burst through an open door. Maimonides himself, in a responsum, brought proof for his view from the law of a doubtful mamzer.
As for your actual question: there are situations in which we make a prototype derivation, and there are situations in which we learn the opposite—that from the fact that a source was needed, we infer that this is a particular case and the general rule is the reverse. In one of my lectures on Yevamot I tried to explain the criterion for when we do this and when we do that. It probably has to do with the question whether the novelty is reasonable or unusually novel. If it is reasonable, then we make a prototype derivation; if it is unusually novel, then the rule is: you have in it only its own novelty, that is, only the context in which it was introduced.
Discussion on Answer
Indeed.
The logic is self-evident. If there is a novelty, we restrict it as much as possible. We say it only in a place where we are compelled to say it.
https://mikyab.net/%D7%A9%D7%95%D7%AA/%d7%9c%d7%99%d7%9e%d7%95%d7%93-%d7%a2%d7%9c-%d7%99%d7%93%d7%99-%d7%91%d7%A0%D7%99%D7%9F-%D7%90%D7%91%E2%80%8E
So according to this, Rashba holds that being lenient in a Torah-level doubt is not reasonable, while Maimonides holds that it is? And by the way, what is the logic of the rule “you have in it only its own novelty”? Because we don’t understand the logic of the law, we say that presumably it was stated דווקא here, even though there’s no apparent reason to say that the verse was written where it was written?