the weekly Torah reading by the faculty of
“You Must Not Deviate”
Prof. Hannah Kasher
Department of Philosophy
If a case is too baffling for you to decide … you shall appear before the levitical priests, or the magistrate in charge at the time, … You shall act in accordance with the instructions given you and the ruling handed down to you; you must not deviate from the verdict that they announce to you either to the right or to the left (Deut. 17:8-11).
What content of Judaism is included in the warning “not to deviate”?  Maimonides and Nahmanides disagreed about the subject matter referred to. Interpreting on the basis of the context of this passage, Maimonides concluded that three categories are referred to (Hilkhot Mamrim 1.2; also see Sefer ha-Mitzvot, positive commandment 174):
Nahmanides’ list is quite different (Hasagot ha-Ramban, principle 1):
This prohibition – do not deviate – refers only to what the Rabbis said in interpreting the Torah, such as those things that are deduced from the Torah by Midrash halakha using any of the thirteen techniques for interpreting the Torah (B1), or interpretations derived from the [simple] meaning of the Scriptural verse itself (B2), or what was handed down from Sinai— halakha le-Moshe mi-Sinai (C).
It turns out the Maimonides and Nahmanides disagreed on whether to include two categories: A and B2. The category of “Rabbinic regulations, decrees, and practices” (A) comprises part of that which we are warned “not to deviate” from according to Maimonides, and is absent from Nahmanides’ list. Nahmanides, inter alia, based his position on the following argument:
As Scripture says, “If a case is too baffling for you to decide, be it a controversy over homicide, civil law” – that is, when something is not clearly revealed to them, and the Rabbis or judges are in disagreement as to the laws of the Torah, its proscriptions and punishments… This prohibition cannot include rabbinic regulations, such as when they say: “Kindle a Hanukkah light,” for this does not come under the rule of the Scriptural verse, “If a case is too baffling for you to decide,” rather such regulations are to be observed on the strength of the verse “Ask your father, he will inform you; your elders, they will tell you” (Deut. 32:7, also cf. Shabbat 23a).
As an exegete who tends towards the plain sense of the text, Nahmanides understands the words, “If a case is too baffling,” mean that the warning “do not deviate” pertains to rules of halakhah that are not completely clear to begin with; since the prohibition deals only with this conditional situation, it does not include regulations, decrees and practices that were independently set by the Sages (A).
The second difference between the two philosophers’ views pertains to their approach to the status of rules of halakhah that are derived from the plain sense of the text (B2). According to Maimonides, the prohibition “not to deviate” refers only to commandments from the Rabbis (de- Rabbanan), whereas commandments that come from the plain sense of Scripture are commandments directly from the Torah ( d’Oraitha): “The fundamentals that were explicitly told to Moses at Sinai, and they are the six hundred and thirteen commandments.”
According to Nahmanides’ approach, the commandment not to deviate applies to all “that the Sages said regarding the laws of the Torah, including the plain sense of Scripture”. In this respect Nahmanides also disagreed with Maimonides in his understanding of what was implied by the Sages’ saying, “Scripture does not leave its plain sense (en miqra yotze mide peshuto).” Maimonides held that this aphorism, which means one must always take the plain sense into account, does not allow us to consider as a “commandment from the Torah” (d’oraitha) any “obligation to perform specific acts or to keep away from certain things which is learned through the Midrash halakha” ( Sefer ha-Mitzvot, fund. 2).
In his glosses to Maimonides’ Sefer Hamitzvot, Nahmanides argues that both the plain sense of Scripture, and rulings learned from the applications of Midrash halakha to the verse, are both “commandments from the Torah”. In this he was applying his mystic view of the written Torah, which, he maintained, can be read in a variety of ways: “But we have its [the verse’s] Midrash along with its plain sense, and it does not escape either of them, rather Scripture tolerates them all, and both are true.” There were those who concluded from this difference of opinion that Maimonides rejected in principle the notion that the biblical text could be interpreted in a variety of ways, but this is not the case.
The two remaining categories – rules of halakhah that are derived from Midrash halakha (B1) and rules of halakhah that have been handed down by tradition (C) – occur both in the list of Maimonides and of Nahmanides. That is to say, the prohibition “you shall not deviate from” them applies to both groups. Nevertheless, there is a difference in their position regarding these two categories. In Maimonides’ view, category (C), “things received by tradition, never are a subject of controversy” (Hilkhot Mamerim 3c). Controversy (mahloket) arises in category (B1) “when many things are being examined, since each person deduces from them according to his intellectual abilities… not that they erred in a received tradition” (from the introduction to his commentary on the Mishnah).
This being the case, the Great Court of Law could possibly arrive at a pardonable error: “For Scripture does not excuse making a mistake in a decision on a point of halakhah, except for the Great Court of Law” (Guide for the Perplexed 3.41). Nevertheless the importance of the central authority remains, since were it not for such an authority, “human beings would have perished because of the multiplicity of differences of opinion and the subdivisions of doctrines (loc. sit.). Thus, for example, Maimonides was willing to assume that in determining the beginning of the months (Kiddush hahodesh) the Sages may have “inadvertently erred, … been coerced, … been mistaken (Sefer ha-Mitzvot, pos. commandment 153), yet nevertheless their determination stands to set the time of the Jewish festivals, and one would transgress “you shall not deviate” if he disagreed with their dates.
In contrast, as a mystic, Nahmanides viewed the times set for the Jewish festivals as true and sacred, since the sanctification of the new month in his opinion was always determined at precisely the correct time: whether it was sanctified “properly by the authorized court in the Chosen Land” (Nahmanides’ glosses on Sefer ha- Mitzvot, pos. commandment 153) or whether its details (C) were transmitted as a halakhah handed down to Moses at Sinai (see his commentary on the Torah, Lev. 23:44). For, like Rabbi Judah ha-Levi ( Kuzari 3.41), Nahmanides as well maintained that G-d intervenes in what happens in the Great Court of Law: “This is hinted at in Scripture where it says, ‘G-d stands in the divine assembly; among the divine beings He pronounces judgment’ (Ps. 82:1), for the Divine Presence is among them to consent with them” (commentary on the Torah, Num. 11:16). According to him, there is no chance that G-d will let a judge sentence the innocent to death (loc. sit. 19:18), or let the Sages in the Great Court of Law arrive at a decision which is substantially wrong: “For the spirit of G-d lies over those who serve to sanctify Him, and He will not abandon his followers, but will forever protect them from errors and stumbling blocks” (loc. sit., Deut. 17:1). According to Nahmanides, “The prophecy of Sages is through ways of wisdom, … they know the truth through the spirit of holiness that is within them” (Hiddushei ha-Ramban, Bava Batra 12a). In using the expression “prophecy of Sages,” Nahmanides categorizes himself in apposition to Maimonides sharp distinction between “Sages” and “prophets” as regards matters of halakhah (see Maimonides’ introduction to his commentary on the Mishnah).
Thus Nahmanides interpretation of the warning “not to deviate” must be understood in the context of his mystic approach. Nahmanides was aware that a person who dissents against the Great Court of Law is likely to be someone who is absolutely convinced of the justice of his position from the outset, and that such a person is likely to be in a difficult dilemma when about to do something which is traumatic for him: “How can I eat this things which in my opinion is entirely helev (forbidden fat), or how can I kill this innocent person?” (see his commentary on Deut. 17:11). So Nahmanides puts words in the mouth of such a person to set his mind at rest, even when he is not yet completely convinced of the truth of what the Sages said: “G-d gave us the Torah according to the understanding of the Sages, even if they be entirely wrong”. “Even if they be wrong,” is a propos of the mistaken idea held by that person. In fact, due to Divine guidance, they are never wrong.
Here we must stress that this discussion in no way pertains to the view we saw above, that sacred Scriptural text has many strata, and that both the simple peshat and the halakhic midrash are “both true.” For in category B1 which we speak of now, according to Nahmanides, “one of the views is mistaken, without any doubt” (Hasagot ha-Ramban, fund. 6), and the erroneous view is not the view which the Sages held. Indeed, Nahmanides extended the warning “not to deviate”; there is not only an affirmative obligation to obey the Sages, but also a requirement to believe that was they say is the truth: “For you must believe that they say right [as opposed to left] is right (commentary on Deut.17:1). Likewise, “One must put aside one’s own opinion and believe what they said, … that is, one must believe them by the strength of this proscription, for it obliges us to believe in the Torah according to the interpretation that they give it” (Hasagot le-Sefer ha-Mitzvot, fund. 1). Apparently, the knowledge that G-d would not let the Sages of the Great Court of Law ever make an error has the power to make a person retract his view which is refuted, even though he may have been convinced of its truth.
 For a discussion of the subject at hand, see especially: H. Henokh, Ha-Ramban ke-Hoker u-khe-Mekubal, Jerusalem 1978 (pp. 355-360); M. Idel, “R. Moshe ben Nachman – Kabbalah, Halakhah u-Manhigut Ruhanit,” Tarbiz 64 (1995), pp. 535-580; S. Rosenberg, Lo Ba-Shamayim Hi, Alon Shevut 1997; Y. D. Sillman, Kol Gadol ve-lo Yasaf, Jerusalem 1999; Y. Blidstein, Samhut u-Meri be-Hilkhot ha-Rambam, Tel Aviv 2002; Havivah Pedayah, Ha-Ramban – Hit’alut, Zeman Mahzori ve-Text Kadosh, Tel Aviv 2003; E. Wolfson, “By the Way of Truth: Aspects of Nahmanides’ Kabbalistic Hermeneutic,” AJSR XIV (1989), pp. 103-178.