Mordecai Joseph Leiner of Izbica was one of the most original thinkers in the history of Hasidism. His teachings, partially anchored in the Przysucha-Kotsk school, contain elements that are unique in Hasidic history. He was the first Hasidic thinker to adopt the concept of absolute divine providence as a cornerstone of his teachings.

Mordecai Joseph was intimately associated with the Przysucha-Kotsk school of Hasidism for over twenty years (from the time his friend Menahem Mendel introduced him to Simhah Bunem of Przysucha until his departure from Kotsk in 1840) and adopted two of the central tenets of this school: its individualism and its striving for spiritual self-perfection. However, he created a new path to the attainment of these goals by reinterpreting the Lurianic concept of tiqqun, originally intended as a cosmological concept, to apply to the individual.

Morris M. Faierstein studied at the City College of New York, the Hebrew University, Jewish Theological Seminary of America and received his Ph.D. at Temple University. His books include, Rabbi Hayyim Vital’s Sefer Hezyonot (Ben Zvi Institute, 2005); Jewish Mystical Autobiographies (Classics of Western Spirituality, Paulist Press, 1999); The Libes Briv of Isaac Wetzlar (Brown Judaic Series, Scholars Press, 1996); Abraham Joshua Heschel, Prophetic Inspiration after the Prophets: Maimonides and Others (Ktav, 1996); All Is In The Hands Of Heaven: The Teachings of Rabbi Mordecai Joseph Leiner of Izbica (Yeshiva University Press/Ktav, 1989). He has also published more than fifty articles and reviews in a wide variety of scholarly journals. He retired from active duty as a Jewish chaplain in the U.S. Air Force, and has been a visiting professor at a number of universities. He is currently an independent scholar.