ROZIN (Rosen), JOSEPH (1858–1936), Polish talmudic genius, called "the Rogachover" after his birthplace (Rogachov). His erudition and profundity were phenomenal. It is said that when he was eight years old, the local scholars felt incompetent to teach him, for he knew the whole of the talmudic order of Nezikin with its commentaries. When he was 13, his father took him to Slutsk where J.B. *Soloveichik taught him together with his own son Ḥayyim. From there he went to Shklov, where he frequented the court of the ḥasidic rabbi of Kapost, of the Chabad sect. He spent the next eight years studying in Warsaw. In 1889 he was appointed rabbi of the ḥasidic community of Dvinsk. During World War I, as the German army drew near, he fled to St. Petersburg [later Leningrad], where he remained as rabbi of the ḥasidic community for ten years, thereafter returning to Dvinsk.
A man of penetrating intelligence, Rozin possessed a phenomenal encyclopedic knowledge and great powers of industry. He knew the Babylonian and the Jerusalem Talmuds, all the known tannaitic and amoraic literature, and most early books without needing to consult them. He visited Rogachov each year on the anniversary of his father's death, on one occasion remarking that he had studied half of the Talmud during his journey there and would finish it on the return journey. He saw a subject as a whole and in its detail, analyzing it carefully and getting to the core of the halakhah. He would show by comparison with other passages which basic concepts were involved, give relevant rules and definitions, and make the subject clear. He frequently explained the Talmud in a way fundamentally different from that of the standard commentators. This is especially noticeable in his treatment of the Jerusalem Talmud which has no early commentary: Rozin's work contains thousands of new explanations. In speaking he was fluent and lucid; his writing, however, is obscure. He refers to his sources by a mere "vide so and so," making tens of references but neither quoting the passage nor explaining its relevance. Despite his difficult style, he was a prolific correspondent who enjoyed writing, and he encouraged correspondents to send him their problems. He answered without any effort all who wrote to him on any topic, and thousands of his letters are to be found throughout the world. His ability to find sources in the Talmud was extraordinary. He often quoted a passage from a subject apparently completely unrelated to the matter under discussion, and inferred from it a persuasive proposition which answered the question. For Rozin, the Talmud was decisive. When he found a source for a custom in the Talmud he practiced it, but not otherwise. He traced to the Talmud the philosophical ideas of Maimonides and the latest discoveries of science. Because of this, great scientists enjoyed conversing with him. His remarkable knowledge of philosophy and science is revealed in his commentary on the Pentateuch. He possessed a keen critical sense and when what purported to be the lost text of the Jerusalem Talmud on Kodashim appeared, his insight recognized it for the forgery it proved to be.
Rozin's imposing and majestic appearance made a deep impression on all who saw him. Though one of the greatest scholars of any age, he was essentially a humble man. He was courteous, striving to see things from the other man's point of view. He bore the physical pain of his closing years stoically, though grudging the time it took him from learning, and continued to answer all who consulted him, whether in writing or in person.
During his lifetime, Rozin published a commentary on Maimonides' Mishneh Torah in five volumes (1903–08) and two volumes of responsa. Four further volumes of responsa were published in 1935–38. During World War II, one of his students, I.A. Sufran-Fuchs, photographed all the manuscripts he could collect and sent the films to a relative in the U.S. There they remained in a box until they were shown to R. Menaḥem *Kasher in the 1950s. He appreciated their true value, and they have subsequently been in the process of publication. All his works appear under the title Ẓafenat Pa'ne'aḥ. A number of volumes of the novellae and the commentary on the Pentateuch have appeared (5 vols., 1960–65). Rozin died in Vienna and his remains were buried in Dvinsk.
O. Feuchtwanger, Righteous Lives (1965), 75–78; M. Grossberg, Ẓefunot ha-Rogachovi (1958); M.S. Kasher, Ha-Ga'on ha-Rogachovi ve-Talmudo (1958); A. Shurin, Keshet Gibborim (1964), 249–53; S.J. Zevin, Ishim ve-Shittot (19663), 87–153.