(1766–1828), Talmudist, kabbalist, and Hasidic master in Staroselye (Starosselje) in the province of Mohilev. In his youth, Aharon ha-Levi became a follower of Shneur Zalman of Liady, founder of Ḥabad (Lubavitch) Hasidism. Horowitz studied under the guidance of Shneur Zalman with Dov Ber, who was Shneur Zalman’s son and successor. The two were close companions until they had a serious quarrel; although this rift was of a personal nature, it was also over matters of Ḥabad philosophy: Dov Ber frowned on all but completely authentic ecstasy in prayer but Aharon was tolerant of even sham ecstasy.
Shneur Zalman died in 1813, and when Dov Ber succeeded his father as the second Ḥabad leader in the town of Lubavitch, Horowitz established a rival Ḥabad court in Starosselje. After Horowitz’s death, some of his followers accepted his son, Ḥayim Refa’el, as their rebbe, but it was not long before the Starosselje dynasty collapsed, as most of its Hasidim switched their allegiance to Lubavitch.
Horowitz was a prolific author. Among his works are the collection ‘Avodat ha-Levi (The Levite’s Worship; 1842 and 1866), Sha‘ar ha-tefilah (Gate of Prayer; 1852), Sha‘are ‘avodah (Gates of Worship; 1821), and Sha‘are ha-yiḥud va-emunah (Gates of Unity and Faith; 1820), a massive work in two volumes.
Despite their hostility, even Lubavitch Hasidim came to accept Horowitz as a leading Ḥabad thinker, since his works are a powerful exposition of the ideas of Shneur Zalman, albeit with nuances that were Horowitz’s own. Horowitz’s central idea is that God is the sole ultimate reality and that the universe has no independent existence at all. Horowitz explores this theme with such subtlety that in the eyes of many he deserves a particularly honored place among Jewish theologians.
Rachel Elior, Torat ha-elohut ba-dor ha-sheni shel ḥasidut Ḥabad (Jerusalem, 1982); Louis Jacobs, Seeker of Unity: The Life and Works of Aaron of Starosselje (New York, 1966).