Editor’s Note: Last week we presented the first part of Rabbi Shmuel Kadosh’s essay concerning possible revocation of rabbinic law. He explained at length that fundamentally post-Talmudic authorities are not empowered to cancel any rabbinic legislation. This week, Rabbi Kadosh continues this discussion by noting that the Rishonim debate as to whether there exists some flexibility in regards to observing rabbinic rules whose reasons no longer seem to apply.
The Tosafists employed a number of strategies in arguing that certain Talmudic laws are void because their reasons no longer apply. In each instance where they claim that the law is void, Rambam maintains that it is still binding. In this section, we will examine three such examples.
A. Mayim Megulim - Drinking Uncovered Liquids
The Mishnah (Terumot 8:4) prohibits the consumption of certain drinks that have been left uncovered for a period of time, and strongly implies that the reason is because of a concern that snakes will deposit venom in the liquid. The Tosafot (and their intellectual heirs) employ three distinct rationales for permitting drinking such liquids. (1) Mayim Megulim was enacted because of a concern (Cheshash), and such laws are revocable once the concern has passed (Beitzah 6a s.v. VeHaIdna DeIka Chaveirai). (2) The Sages initially prohibited Mayim Megulim only in places where snakes are common. (Avoda Zara 35a s.v. Chada Katani). (3) Mayim Megulim is not a law enacted by a majority, and can thus be repealed by any court. (Rosh, Beitzah 1:5). In contrast, Rambam (Hilchot Rotzeiach 11:5-6) simply codifies the prohibition of the Mishnah, and provides no exemption for individuals living in locales without snakes. The Shulchan Aruch (Yoreh Dei’ah 116:1) adopts Tosafot’s second approach, holding that it is permitted to drink uncovered liquids because snakes are not common. 
B. Clapping and Dancing on Shabbat
The Mishnah (Beitzah 36b) states that it is Rabbinically prohibited to clap or dance on Shabbat. The Talmud (Id.) explains that clapping is prohibited because the Rabbis were concerned that one would become so enthusiastic that he or she would begin to play a musical instrument to accompany the clapping, and should the instrument break, fix it on Shabbat. The Talmud (Id. at 30a) further states that many people violated this law, and therefore the Rabbis did not publicize it, employing the principle of “Mutav SheYihyu Shogegim,” “Better they err in ignorance rather than willfully.” Tosafot (Id., s.v. Tenan Ein Mitapchin) comment that in the present day, it is permitted to clap and dance on Shabbat because people do not know how to fix musical instruments, and therefore, the concern animating the Rabbinic prohibition does not apply. Rambam (Shabbat 23:4) codifies the prohibition of clapping, as does the Shulchan Aruch (Orach Chayim 339:3). The Rama in contrast, employs two distinct rationales to permit clapping and dancing on Shabbat. The first justifies the practice by claiming that the people will not listen to the Rabbis and “better that they err in ignorance rather than willfully.” The second permits the practice because the prohibition ceased once its reason was void, namely since people no longer had the ability to fix musical instruments.
The distinction between the first and second approaches in the Rama emphasizes that the Tosafot affirmatively believed they had the authority to abrogate Rabbinic law when the reason did not apply, and were not simply finding some way of justifying communal practice. With regard to clapping on Shabbat, Tosafot had a more conservative legal option available to them to “justify” communal practice – an option that did not involve the abrogation of any laws and was suggested by the Talmud – namely, “better that they err in ignorance.” The choice not to employ that Talmudic principle, and rather argue that the law is void indicates that they believed they had the ability to abrogate Talmudic laws. Put differently, if Tosafot’s only goal were to justify communal practice, they could have simply employed Mutav. By not choosing the rationale offered in the Talmud, and instead choosing to completely abrogate the law, Tosafot demonstrate their belief in their ability to abrogate Rabbinic laws.
C. Transacting Business with Idolaters on their Holidays
The first Mishnah in Avodah Zarah declares that it is prohibited to transact business with idolaters. The reason for the prohibition is because the Rabbis were concerned that the idolater would give thanks to his deity because of the successful business transaction, and that as a result, the Jew would indirectly be promoting idolatry. Shmuel limits this prohibition in the Diaspora to the day of the festival itself, but identifies Sunday as a day on which it is prohibited to transact business. (Avodah Zarah 7b). The Talmud later recounts that two Amoraim, Rav Yehudah and Rava, sent gifts to gentiles on their holiday (despite the possibility that they might give thanks to their deity) because they personally knew the gentiles, and were certain that they were not idolaters. (Id. at 65a). Tosafot (id. at 2a, s.v. Assur LaTet) first suggests that the reason why people in the present day do transact business with idolaters on Sunday is because of a concern for Eivah or hatred. Should the Jews refrain from doing business with the idolaters, they will come to hate the Jews, and persecute them. Tosafot rejects this reason as insufficiently explaining the scope of the permitted action. There are many circumstances where the Jew could provide a plausible excuse as to why he was not conducting business on Sunday – such as claiming that he did not have a particular item in stock – in which case no Eivah would be generated. Rather, Tosafot assert that the reason why it is permitted is because the gentiles in Northern France were not idolaters, and since the reason for the Mishnaic law did not apply, the law did not apply either. In making this argument, Tosafot point to the action of the Amoraim who accepted gifts from gentiles as precedent for this argument. A comparison with Rambam’s codification of these laws illustrates the innovative assertions Tosafot are making.
Rambam (Avoda Zara 9:1-2) states that it is forbidden to transact business with the gentiles on their holidays. He carves out a narrow exception of sending gifts to gentiles that one knows personally are not idolaters. In essence, Rambam simply codifies the exemption of the Talmud in the narrowest possible terms. In contrast, Tosafot expand the Talmudic precedent on two levels. First, they expand the exception from sending gifts to gentiles to transacting all forms of business with them. Second, they expand an exemption that is local, and rooted in the Jew’s individual knowledge of a specific gentile to a broad, societal exemption that in essence asserts that there is not a single religious Christian in all of Northern France. Another possibility is that Tosafot are passing judgment not on the religiosity of the Christians of Northern France, but on the religion. In other words, Tosafot might be arguing that the gentiles of Northern France are not idolaters because Christianity is not idolatry. Either of these two understandings of Tosafot seemingly abrogate some part of the Talmudic prohibition – either Shmuel’s ruling that the Christians are idolaters, and that the Christian Sunday is an idolatrous holiday, or that the only exception to this rule is for gifts to individuals you personally know.
The Shulchan Aruch (Yoreh Dei’ah 148) starts by codifying the Rambam and prohibiting business with idolaters on their holidays, but concludes in §12 by quoting a minority opinion which limits the prohibition to Talmudic times, but permits it in the present because they are not idolaters. Rav Isserles extends this leniency to situations where you know that the money will go to priests because the priests use the tithes for food and drink, and not for church ritual.
In a variety of laws, the Tosafot argue that the law is void because the reason for its enactment no longer applies. Rambam consistently applies the law found in the Talmud. The Shulchan Aruch usually follows Rambam in upholding the Talmudic laws. Other times, he cites Tosafot’s rationale as a minority opinion, while codifying Rambam as normative. Finally, in rare circumstances, he adopts the rationale of Tosafot and voids Talmudic laws whose reasons do not apply. In situations where the Shulchan Aruch sides with the Rambam in upholding the Talmudic law, Rama will cite the Tosafot’s rationale as a reason for permitting the law which the Mechaber asserted was forbidden.
The debate between Tosafot and Rambam about this fundamental aspect of Halachah did not cease in medieval times. On the contrary, discussions regarding the revocability or permanence of Talmudic laws are ever-present in the discussions of modern poskim. For example, the Talmud rules that milk requires Jewish supervision, out of a concern that non-kosher milk will be mixed in. (Avoda Zara 39b). The Shulchan Aruch and Rama both agree that this supervision is required even in situations where it is extremely unlikely that non-kosher milk will be mixed in, such as where there are no non-kosher animals in the area (Yoreh Dei’ah 115:1). Yet, contemporary poskim still debate whether Jewish supervision is required in such a situation. Rav Moshe Feinstein argues famously that the government regulations ensuring that no non-kosher milk is mixed in is a sufficient form of supervision, and that Jewish supervision is not required (Responsa Igrot Moshe, Yoreh Deah 1:47, et seq.). Other Poskim strongly disagree and argue that the Talmudic law applies even where the reason does not. (See Responsa Chatam Sofer 2:107.) Many other examples of this abound. Far from being a settled point of law, the question of when and how laws in the Talmud can be abrogated when their reason no longer applies is still alive and present in our day.
 The Talmud (Avodah Zarah 30b) implies that uncovered waters were enacted because of a concern (Cheshash). It is plausible that Tosafot limits this rule to laws that are explicitly identified in the Talmud as being enacted due to a Cheshash.
 The Rosh does not point to any language in the Mishnah or Talmud that implies that Mayim Megulim is of a lower status than other laws. On the contrary, the Mishnah records it simply as Asur.
 Rabbi Isaiah Horowitz (1560-1630), living in the same city a mere generation after Rav Yosef Caro, strenuously rejects the permissive approach towards uncovered water. He writes that it is insane to drink uncovered water, and applies the verse of “God guards the fools” (Tehilim 116:6) to those who do. See Rabbi Isaiah Horowitz, Shenei Luchot HaBerit, Sha’ar HaOtiyot Kuf – Kedushat Achilah. The debate between Rav Caro and Rav Horowitz cannot be a fact dispute about whether it was actually dangerous to drink uncovered drinks. They lived in the same city (Tzefat) a mere generation apart. It is extremely unlikely that snakes were uncommon in Tzefat in 1570 (thus making it safe to drink uncovered water), during Rav Caro’s life, yet suddenly became prevalent fifty years later when Rav Horowitz lived in Tzefat. Rather they must be arguing about principles of jurisprudence – namely, can the law be revoked even though the reason for its enactment is void? In contrast, one can argue (although I do not believe this to be the case) that many of the times that the Rambam and Tosafot argue about whether a law is still binding, they are addressing different factual scenarios. For instance, their different rulings regarding uncovered water may reflect the reality that snakes could have been common in 12th century Egypt but not in 13th century Northern France.