Q&A: An A Fortiori Inference
An A Fortiori Inference
Question
In the opening passage in Bava Kamma about the three primary categories of damages involving an ox, the following attempt at derivation appears, along with its rejection: "If tooth, where its intent is not to cause damage, is nevertheless liable, then horn, where its intent is to cause damage, all the more so! It was necessary, for I might have said: it is like a manservant and maidservant—aren't a manservant and maidservant, even though their intent is to cause damage, nevertheless exempt? So too here, there is no difference. Rav Ashi said: But is the case of a manservant and maidservant not based on a major reason? Perhaps his master will anger him, and he will go and set fire to another person's stack of grain, and it will turn out that this one obligates his master to pay one hundred maneh every day! Rather, the challenge is as follows: the horn, whose intent is to cause damage, is not comparable to tooth, whose intent is not to cause damage; and tooth, which derives benefit from its damaging, is not comparable to horn, which derives no benefit from its damaging." I’m not sure I understand the logic from the outset behind the attempted refutation of the a fortiori inference from tooth to horn. Seemingly, the claim in an a fortiori inference is not that the feature possessed by the more stringent case and not by the lenient one is the exclusive feature, since the lenient case lacks it and still reaches the same result. Rather, the point is that after neutralizing the other features, the more stringent case has a feature that the lenient one does not, and therefore if the lenient one reached X, then clearly the more stringent one will as well. And so refutations too are usually made on the basis of features, by saying that the more stringent case also lacks some feature that the lenient one has, as they indeed do in the end with "it derives benefit from its damaging." Therefore it seems as though the attempt to refute from a manservant and maidservant, where there is intent to cause damage and yet there is exemption, is illogical from the outset just on the level of logic itself, aside from the explicit reason in the Mishnah that perhaps his master will anger him.
Answer
There is no a fortiori inference that is purely formal, contrary to the view of Rabbi Chaim of Brisk that is cited in the Passover Haggadah on “Who Knows One?” (“the thirteen attributes”). He cites the a fortiori inference regarding the grasses in Genesis, and we dealt with this in the first article of Middah Tovah 5765. The refutation here is entirely logical. The exemption of a manservant and maidservant is not a leniency, because it stems from an external reason: they are exempt because we do not want to give them the power to obligate their master in order to take revenge on him. Therefore, that exemption cannot be used to create a leniency and derive, by an a fortiori inference, something more stringent.
Discussion on Answer
That is exactly what the Talmud says. So what is the question?
Suppose the explicit reason in the Mishnah of "perhaps his master will anger him" were not there—would this have been a valid refutation? Because seemingly the Talmud assumes that it would, but to me that seems puzzling. Shouldn’t the discussion be not whether the feature is more stringent or not—that seems self-evident—but whether the law itself is more stringent than the other one, and that is determined by the overall set of its features? So the refutation should be by introducing new features regarding the law, not by checking whether the measured feature is more stringent or not.
As I wrote, that is what the Talmud says. Since there is a side consideration that shows the stringency remains intact. It is possible that even if they had not found an example for this, they still would have retained that stringency. The refutation is only an indication of the claim that there is no leniency here.
From the outset I don’t understand, even before bringing in the explicit reason from the Mishnah that perhaps his master will anger him, why the fact that in the case of a manservant and maidservant intent to cause damage does not create liability is a refutation of the a fortiori inference, "If tooth, where its intent is not to cause damage, is liable—then horn, where its intent is to cause damage, all the more so!" After all, the fact that a certain feature (intent to cause damage) does not generate liability in a certain case does not mean that it is not more stringent. In fact, it seems obvious to me that regarding liability for damages, intent to cause damage is more stringent than lack of intent to cause damage. Rather, it only means that it is not the exclusive cause of liability for damage caused by one’s property—and that is obvious anyway, since in the case of tooth he is liable even without intent to cause damage. But that still does not contradict the fact that tooth is the lighter case and horn the more stringent one, until we find some stringent feature present in horn that is not present in tooth.