ר׳ מרדכי יוסף ליינר

ר׳ מרדכי יוסף ליינר (c. 1800–1854), known as the Ishbitzer Rebbe and בעל מי השילוח, was a major Polish Hasidic thinker and founder of the Izbica–Radzyn dynasty. Born in Tomaszów Lubelski to ר׳ יעקב ליינר, he lost his father as a young child. He entered the Peshischa school under ר׳ שמחה בונים מפשיסחה and subsequently became a leading disciple and organizer for ר׳ מנחם מנדל מקוצק. In 1839 or 1840 he broke dramatically with Kotzk; accounts disagree over both timing and cause, and later partisan traditions should be treated cautiously. He first gathered followers in Tomaszów and then settled in Izbica, where he established an independent court emphasizing inward discernment, divine providence and the difficult process of clarifying one’s true religious duty. His teachings could appear radically deterministic, but modern scholarship cautions against reducing them to simple antinomianism. His leading disciples included ר׳ יהודה לייב איגר and ר׳ צדוק הכהן מלובלין; his son ר׳ יעקב ליינר succeeded him. He died in Izbica in 1854 and was buried there. He left no finished authored book. His grandson ר׳ גרשון חנוך הניך ליינר edited oral teachings as מי השילוח, volume I appearing posthumously in 1860 and volume II in 1922. The work became one of Hasidism’s most original theological texts.