MOELLIN, JACOB BEN MOSES (1360?–1427), usually referred to as Maharil (Morenu ha-Rav Jacob ha-Levi) and also as Mahari Segal and Mahari Molin), the foremost talmudist of his generation and head of the Jewish communities of Germany, Austria, and Bohemia. Born in Mainz, Jacob was taught by his father, one of its leading rabbis, and then proceeded to Austria, where he studied under Meir ha-Levi and Shalom b. Isaac, who ordained him rabbi with the title morenu. Summoned to Mainz while still young to succeed his father who had died in 1387, Jacob founded a yeshivah there to which many students streamed. The students lived in his house and were supported by "the means provided for him by the leaders of the country" (Sefer Maharil). From this yeshivah came the greatest rabbis of Germany and Austria of the next generation, among them Jacob *Weil.
Moellin became famous throughout Europe. While he was still young, halakhic problems were addressed to him "since from your mouth Torah goes forth to all Israel" (Maharil, resp. no. 148). He was also regarded as the leader of the people in that troubled period. During the Hussite wars and the strengthening of Catholic reaction various communities turned to him for help. On this occasion he decreed a three-day fast upon the whole community, "even upon sucklings," and also took the matter up with the government, with successful results. His rulings, together with those of Israel *Isserlein, serve as the foundation of all the traditions which were kept in German Jewry. In his decisions Moellin took prevailing conditions into consideration, and when a matter which affected the economic position of the community came before him, he assembled the scholars and "investigated the matter until he found a favorable solution." When he felt he had been too strict, he excused himself saying, "I have been very strict with you because you are without a rabbi" (resp. no. 26). He attacked rabbis who "bought" rabbinical positions which they were unqualified to fill (Jacob Weil, Dinim ve-Halakhot, no. 68, Kapust ed. (1834), 59b), and protested against the neglect of Torah study and against the widespread practice of giving decisions based on abridged halakhic works. In his sermons he placed particular emphasis upon the mitzvah of charity, and he was keenly solicitous of the honor of the poor.
Moellin also occupied himself with astronomy and applied himself to the solution of astronomical problems with the aid of instruments, and the study of the astronomical work Shesh Kenafayim of Immanuel b. Jacob *Bonfils. Jacob was well-versed in the different German dialects and composed Hebrew rhymed verse (in Ms.) and piyyutim (Joseph b. Moses, Leket Yosher, ed. by J. Freimann, 1 (1903), 50). Though, like all the rabbis of Germany, he shunned philosophy, he acted with a degree of tolerance toward those who, attracted by it, had strayed in matters of belief. He declared valid the sheḥitah of one who "accepted resurrection only as a traditional belief, but denied that there was a biblical basis for it," even declaring that "though his sin is too great to be tolerated, he is not under suspicion of deliberately transgressing the Torah" (resp. no. 194, p. 64a–b).
Moellin was renowned as a ḥazzan and his activities left a lasting influence on the Ashkenazi tradition. His opinion that traditional tunes should not be changed was a constantly stabilizing factor. The so-called "Niggunei Maharil," attributed to him (or at least thought to have been sanctioned by him) were in use in the Mainz community until modern times (see Idelsohn, Music, 170, 177, 206, 456, and see *Mi-Sinai melodies).
His known works are (1) Minhagei Maharil (Sefer Maharil, first published in Sabionetta, 1556), compiled by his pupil Zalman of St. Goar who for many years noted down his halakhic statements, customs and, in particular, the explanations he heard from him. Through the efforts of various copyists, the work enjoyed wide circulation. Most of the customs noted in it were included by Moses Isserles in his glosses to the Shulḥan Arukh; (2) Responsa, some copied and arranged by Eleazar b. Jacob and published for the first time in Venice in 1549. A far more complete collection has been preserved in manuscript (Margoliouth, Cat. No. 575). The printed editions of the Maharil are full of errors, apparently having been published froma corrupt copy. Moellin died in Worms.
G. Steiman, Custom and Survival – A Study of the Life and Work of R. Jacob Molin (1963); G. Polak, Halikhot Kedem (1846), 79–86; Guedemann, Gesch Erz, 3 (1888), 17–20; D. Kaufmann, in: MGWJ, 42 (1898), 223–9; Weiss, Dor, 5 (19044), 81f., 239–42; Joseph b. Moses, Leket Yosher, ed. by J. Freimann, 2 (1904), XXXV, 132; Finkelstein,