Last week we began our discussion of lo sisgodidu, the injunction against allowing divergent halachic practices within a unified constituency. We noted that according to Rashi the intention of the prohibition is to prevent the appearance that there are two legal systems, whereas according to Rambam it is meant to limit disputes. Rambam, whose position we accept, invoked lo sisgodidu in the context of minhagim. While the Talmudic application of lo sisgodidu is confined to two courts in the same city issuing differing rulings, it may apply to divergent liturgical practices in a single synagogue as well.

Changes in Nusach
Poskim discuss whether an individual who prays in nusach Ashkenaz and finds himself in a synagogue that conducts itself in nusach Sefard (or vice-versa) may retain his personal nusach. The Pe’as Hashulchan (3:31) rules that to allow him to do so would constitute a violation of lo sisgodidu. The consensus of halachic literature, however, concludes otherwise. Netziv (Meishiv Davar 17) contends that praying quietly in a different nusach should be permissible both according to Rashi and according to Rambam. Although praying in a different nusach may be construed as two “Torah”s, Rashi, the proponent of that position, holds that lo sisgodidu does not apply to minhagim. On the other hand, the concern about fomenting disputes does not exist with regard to silent divergences, as in privately using a different nusach.

R’ Moshe Feinstein (Igros Moshe Orach Chayim II 23) and R’Ovadia Yosef (Yabia Omer VI Orach Chayim 10, 4) in this context assume that lo sisgodidu will not apply to prayers recited silently. Netziv does claim, however, that one may not use a different nusach for kedusha, since kedusha is recited in unison, and doing so may lead to disputes. R’ Ovadia Yosef permits even this, as he claims that the lines over which Ashkenazic and Sephardic liturgy differ are not considered a significant component of the kedusha. Rabbi Hershel Schachter (Beis Yitzchok Vol. 25 p. 4) notes that Rav Soloveitchik as well was lenient in this regard.

R’ Aaron Yafen (annotation to Ritva, Yevamos 13b, Mossad HaRav Kook edition, footnote 951) suggests that a comment of the Magen Avrohom may be relevant to this discussion. Magen Avraham (Orach Chayim 493:6) writes that lo sisgodidu does not apply where one constituency realizes that a different practice is correct for the other constituency. For example, the small villages that read megilla on an earlier date than the cities realized that the cities were supposed to read megilla on the correct date. Magen Avraham rules that if a group of Polish Jews, who observed the fast on 20 Sivan in commemoration of the Chmielnizki massacres found themselves in a different community on that date, it would not be improper for them to fast. In this case, the Polish Jews’ tradition to fast for a specific reason does not apply to members of the other community, and both communities would acknowledge this. Similarly, if one who prays in nusach Ashkenaz believes that others who pray in nusach Sefard have a legitimate basis for doing so, lo sisgodidu would not apply.

Tefillin on Chol Hamoed
Perhaps the most famous discussion of lo sisgodidu relates to wearing tefillin on Chol Hamoed. Rishonim dispute whether one must wear tefillin on Chol Hamoed. (See Tos. Menachos 36b s.v. yatzu; Moed Katan 19a s.v. R’ Yosi; Eiruvin 96a s.v. Yamim, Shut Rashba I 690; Or Zarua 589; Kesef Mishna Yom Tov 7:13.) The traditional practice of Ashkenazic Jewry was to wear tefillin and the traditional practice of Sephardic Jewry was not to. In the eighteenth century, two significant sectors of Ashkenzic Jewry, Chassidim and followers of the Vilna Gaon, adopted the practice of not wearing tefillin. Chassidim were influenced by the Zohar, which speaks in very harsh terms of those who wear tefillin on Chol Hamoed, and the Vilna Gaon (O.C. 30:4) felt that there was no real source for wearing tefillin.

In pre-war Europe, most communities had long-standing customs regarding wearing tefillin on Chol Hamoed. German Jewry, for example, uniformly wore tefillin, and Chassidic communities uniformly did not. In modern day Israel the universally accepted practice, dating back to the early nineteenth century immigration of the Vilna Gaon’s students, is to refrain from wearing tefillin. Contemporary American Jewry, comprised of Jews from all types of backgrounds, has no universal custom, and often members of a given community or synagogue will adhere to different practices.

The Mishna Brurah writes that because of lo sisgodidu it is “not proper” to have a single synagogue in which some members wear tefilin and others do not. Igros Moshe (Orach Chayim V 24:6) notes that the Mishna Brurah does not claim that this is absolutely prohibited, only that it is “not proper.” He suggests that when everyone knows that there are two accepted positions, so long as a given city has not uniformly adopted one practice, lo sisgodidu does not pose a problem. This applies to tefillin on Chol Hamoed, since everyone is aware of two longstanding traditions, and both practices exist in every American city. Yet, Igros Moshe concludes that if an Ashkenzi Jew finds himself in a synagogue where the prevalent practice is to wear tefillin, he should do so, as this is the authentic original practice of Ashkenazic Jewry.

R’ Ovadia Yosef (Yabia Omer. ibid. 10, 6) cites two additional limitations relevant to both the nusach and the tefillin issues. The Maharshag (II 12) claims that lo sisgodidu only applies where one attempts to convince others of his position. Where different practices coexist without an effort of one party to influence the other, no prohibition is in place. The Parshas Mordechai (Orach Chayim 4) writes that lo sisgodidu is only relevant at the onset of a dispute. However, regarding a longstanding disagreement, as with different nuschaos or wearing tefillin on Chol HaMoed, since the followers of each practice are already set in their ways, they may freely practice their positions.

Conclusion
Even if lo sisgodidu is limited in practical application, its underlying message remains significant. R’ Moshe Shmuel Galazner, great-grandson of the Chasam Sofer, notes in his Dor Revi’i (Chulin 111b s.v. v’da) that for Judaism to survive in the Diaspora, certain uniform standards must exist. The Talmud suggests, for example, that while Beis Shammai held a more stringent position regarding certain types of forbidden relationships, they nevertheless adopted the more lenient position of Beis Hillel so that they could retain uniform marriage standards. While any nation in the world bases its unity on a common land and language, all that unites the Jewish people in the Diaspora is the Torah. To hold different standards that limit our interactions with other Jews, to figuratively create two Torahs, is to break that last unifying bond.