Responsa Rema, No. 10
[Isserles devotes the first part of his responsum to ruling that the laws of Noah, those basic rules that, under Jewish law, are deemed to apply to non-Jews, require that non-Jews comply with the same precepts of commercial law that apply to Jews, at least in their dealings with Jews.]
Now that we have clarified and proven that we judge Gentiles according to the laws of Israel and that a Gentile is judged with an Israelite as are two circumcised people, let us jump to the place to which our words are leading and speak about the incident that has occurred. Here is a man in a foreign land who is known throughout the world. He has drawn water from a deep well, and his water is sweet. He issues decrees and fulfill them, and may the Lord bless him. He is the giant tree whose fruit is sustenance and whose leaves cure our ills. His statements are pure. He is the Gaon [an honorific meaning an esteemed, highly learned rabbinic authority] Our Teacher and Rabbi Meir [Katzenellenbogen] of Padua [known in Jewish tradition as the Maharam of Padua]. And here, he has applied his course of study, ideas, and thoughts and joined with one of the important persons of his land, a [Venetian] patrician [Alvise Bragadini], who is one of the publishers of books. They agreed to publish together the great composition, the Mishneh Torah, which was written by the true, all-encompassing rabbinic authority, Our Rabbi Moshe ben Maimon [Moses Maimonides, known in Jewish tradition as the Ramban]. And just as the Maharam of Padua had planned, so he and the Italian printer undertook their joint project with God’s help and saw their mission to completion. And the Maharam of Padua proofread the manuscript with his pure wisdom until there was “no straw remaining in the field” and “no stone left in the path.”
Lo and behold, a person [Marc Antonio Giustiniani], who is also a patrician from among the wealthy of his land, arose against the Maharam of Padua, and said “I will also produce for revenue for my family and I shall also print the Mishneh Torah.” And so he did. And the important thing is that the one who undertook this deed, does so without the participation of the abovementioned Gaon [in other words, the Maharam of Padua], and he does so for spite and in order to exhaust the Gaon’s money, Heaven forbid. Because it is obvious that if the Gaon will not be successful in selling the books, his financial burden will be overbearing.
And I am here to judge according to the laws of Israel, as if these were two Israelite people according to our holy Torah, and we will prove that the abovementioned Gaon has been successful on the merits of the case. This result is based upon four separate pillars, and upon these four foundations we shall build the matter. And I declare that the law is with the Gaon: that he shall sell his books first. And although, because of our many sins, we are unable to enforce our Torah [on Gentiles] we shall not abandon our own and [thus we] say that all Israelites, and whosoever by the name of Israel shall be called, shall not buy any of the newly printed books of the Mishneh Torah unless they were published and distributed under the auspices of the abovementioned Gaon or his agents. This ruling is due to four reasons.
The first, simple foundation is in the chapter Lo Yaḥpor [in the Babylonian Talmud, Tractate Bava Batra 2: 21b]:
Rav Huna said: A resident of an alley erected a mill [to provide the service of grinding wheat for a living] and a fellow resident comes and erects another mill, the first to erect a mill may prevent the second-comer because he can claim “you are interfering with my livelihood.”
We can deduce [from Rav Huna’s teaching] that the second-comer acted knowingly and that the first can prevent him from erecting the mill. Therefore, it is clear that according to our law the second patrician [Giustiniani] may not print the Mishneh Torah at all, and the abovementioned Gaon holds the right to prevent him from doing so as we have just proven already. Such is the divine commandment on all rabbinic judges to rule accordingly. Alas, although the idol worshipers rule over us, we must rule according to the law that I have interpreted.
Granted, the Rif [Isaac ben Jacob Alfasi (1013 - 1103)] and the Rosh [Asher ben Yeḥiel) (1250 or 1259 – 1327)] ruled that the law is not in accordance with Rav Huna because his was a lone opinion [dissenting from the majority rule in the Talmud that the first resident to erect a mill may not prevent competition from the second-comer]. But I say that there is a way to reconcile these opposing views. As cited by a later authority, it is written in Avi’asaf [a work of commentary on the Talmud, written by the German rabbinic scholar Eliezer ben Joel Ha-Levi (1140-1225)] “In the case of a dead end alley, closed on three sides and open for entry on only one side, when Reuven lives [and is the first to erect a mill] near the closed end and Shimon subsequently comes to live [and erect a competing mill] opposite the opening so that a Gentile cannot enter the alleyway without passing by Shimon’s door, the law is that Reuven may prevent Shimon [from erecting a competing mill] in accordance with Rav Huna’s teaching.” It might appear from this that [according to the Avi’asaf, as cited by the later authority] the law follows Rav Huna…. However, we can [explain this apparent discrepancy] by distinguishing between two types of damage: In the “residents’ alleyway” case, when [as in the case of the dead end alleyway] the second-comer will certainly cause damage to the first, everybody concedes that the law is according to Rav Huna.
Therefore, that is the rule in our case. For, in our case there is also certain damage [to the Gaon] because the second patrician has proclaimed that he will sell each of his books for a gold coin less than those of the Gaon. And who will see this and not come to him [the second patrician] to buy from him. And he is able to sell cheaply because he is one of the wealthiest men in the country. Thus, [like the case of the dead end alley], in our case the law is according to Rav Huna -- and this Child of Noah [the Gentile patrician, Giustiniani] shall be judged according to the laws of Israel, and the judgment is as I have just explained.
And one cannot argue that for the sake of peace with the kingdom or avoiding hatred [i.e., risk of anti-Semitic outbursts], we shall be lenient and forego this line of justice. This cannot be done because … where the issue is one of commerce, there is no rule of [being lenient with Gentiles] to avoid “hatred.” In such cases every Jew can [effectively avoid hatred]: he can apologize [to the Gentile] and remind him that, in matters of commerce, each person is to decide in his own best interest whether to buy or sell. Thus, there is no reason to prevent implementation of this ruling.
[Isserles then proceeds to set out the second and third foundations for his ruling. The second is that Jews must accord preference to rabbinic scholars in their commercial dealings. The third is that Jews must accord preference to fellow Jews in commercial dealings, even if a Gentile sells for a lower price.]
The fourth foundation upon which the structure [i.e., this ruling in favor of the Maharam of Padua] rests is in [the Talmud tractate of] Ketuvot in Chapter 2, page 19b. In that passage we see that it is forbidden to continue to hold in one’s house for more than thirty days a Torah scroll containing scribal errors that have not been corrected. As it is written “If iniquity is in your hand, distance it; And do not allow injustice to dwell in your tents” [Job 11:14]. And according to the Haggahot Ashri [a medieval collection of commentaries on the Talmud] and the Haggahot Maimoniot [a thirteenth-century commentary on the Mishneh Torah], that rule that works containing textual errors must be discarded applies not only to the Torah [i.e, the Pentateuch] but also to the Prophets and the Writings, as well as other holy books, including the Talmud and collections of rulings on Jewish law…. Indeed, the abovementioned law has even more force with regard to the Talmud and the other [rabbinic] authors [setting out and explaining the law], because if the text of such a book is even slightly mistaken, one is liable to make an error in understanding and applying the law, and may thus prohibit that which is permitted, permit that which is prohibited, and purify the impure, etc.
This is also shown in [the Babylonian Talmud] Bava Batra Chapter  Lo Yachpor page 21a, where we learn:
“Rava said: Between two teachers of children, one who teaches a lot but does not ensure that the children learn accurately, and the other which ensures accurate learning but teaches less, it is preferable that a teacher teaches more although he is less accurate, because his mistakes will eventually be revealed [when the child gets older and understands where he was taught wrong].
But Rav Dimi of Nehardea said: it is preferable that a teacher teaches accurately, because a young student that is taught inaccurately will absorb the mistake [in his mind].”
Behold that Rava only disagrees [with Rav Dimi of Nehardea] in the case in which one teacher teaches a lot but does not ensure that the children learn accurately. However, if there is one teacher who ensures both a large quantity and accuracy in learning, and another teacher who ensures only quantity but not accuracy in learning, it is obvious that the teacher who ensures both a large quantity and accuracy in learning is preferable…. In this regard, all of Israel should avoid being smitten with the curse attendant to buying a book that has not been corrected and to thus transgressing against the Biblical injunction “do not allow injustice to dwell in your tents.” [Isserles seems to assume that the Maharam of Padua-Bragadini edition has been corrected, while the Giustiniani edition has not.]
A litigant might claim that everyone knows that these [Christian] printers have taught Torah in Israel [most books of Jewish learning studied in rabbinic academies of the day were published by Christian publishers in Venice] and without them, Heaven forbid, the Torah would have already been forgotten by Israel. Therefore, the litigant might claim, it is fitting to support their mission so that there will be no ruin. But this is no claim at all. For I have already explained that there is no law of preventing hatred [enhancing the risk of anti-Semitic outbursts] in the commerce context, in which we can simply explain that we don’t have need for their books. Moreover, as a matter of common sense, those who engage in the business of publishing publish do so in order to profit, like others who deal in commerce. Thus, even if they lose [sales] on one occasion, they will not refrain from further printing because of this. On the contrary, they will be even more eager to replenish their loss.
In conclusion, the abovementioned Gaon has been successful in his claim and he should be granted the right to sell his books first. Accordingly, no person shall buy a book of Maimonides [i.e., the Mishneh Torah] that has recently been printed unless it has been printed under the auspices of the abovementioned Gaon or his agents. Thus, we consider whether to “trim” and to “chop” with an iron chopper whosoever breaches the Gaon’s right and path. And we agree that anyone who does so shall suffer the punishment of ostracism, excommunication, and anathema. Thus it is a holy writ upon all students [of Torah] and who have a name that burns weakly or brightly to ensure that no person in our land shall buy a book that has been recently printed, unless it has been published under the auspices of the abovementioned Gaon or his agents. And whosoever shall breach [this ban] shall be struck by “the bite of the Rabbis” and whosoever shall possess them [i.e., editions of the Mishneh Torah recently printed by any publisher other than the Maharam of Padua] shall be likewise excommunicated. And all Israelites are obliged to excommunicate those whose souls carry such transgressions, because they will not be atoned until their death, when their burial shall be likened to the burial of a mule [see Jeremiah 22:19: “A donkey‘s burial shall be buried, dragged and tossed past the gates of Jerusalem”], and whosoever shall identify [i.e., correctly impose] the “snake” [a Hebrew acronym for the punishments of ostracism, excommunication, and anathema shall live and receive blessings from the Lord until his lips shall shrivel from saying “enough!”
[This responsa was given] on Sunday, on the fourth day of Elul of the [Jewish calendar] year 5310 [August 16, 1550].
So speaks the simple man who wishes to roll in the dust of Torah scholars and to satiate his thirst with their words, and has not spoken until now unless it was to learn and to accustom himself to their virtues, and to be one of their insignificant servants. These are the words that have been spoken by Moshe the son of Yisrael, may he live a long life, otherwise known as Moshe [Moses] Isserles of Krakow.