(Judah ben Samuel ben Kalonymus he-Ḥasid, "the Pious"; c. 1150-1217). The most important thinker in the principal school of ḤASIDÉ ASHKENAZ, that of the Kalonymus family, which was headed in the middle of the 12th century by Judah's father, R. Samuel. Judah lived for many years in the Rhineland, probably in Speyer, but the later part of his life was spent in Regensburg.
Judah insisted that a writer should never acknowledge the authorship of his works, so as to prevent him and his descendants from taking pride in them. All his works, therefore, do not bear his name, a fact which poses difficult bibliographical problems. Apparently he was the author of a collection of mystical treatises (preserved at Oxford, Mss. 1566 and 1567), and wrote another lost theological work called Sefer ha-Kavod ("The Book of [Divine] Glory"). He composed an extensive commentary on the prayers, which was intended as a polemic against any change in the traditional version of the prayers, but only some quotations have survived. After his death, his son, R. Moses, wrote a summary of their discussions about the weekly portions of the Pentateuch. His magnus opus, however, is the Sefer Ḥasidim ("The Book of the Pious"). R. Judah probably wrote this work during the course of his life, in sections that were combined into a book by his disciples after his death. His son testified that during the week he died he wrote two folios of Sefer Ḥasidim. This work, which deals with all aspect of human life, reflects Judah's wish, probably never realized, to create a pietistic movement of Jews completely dedicated to the religious and ethical commandments, who would segregate themselves from the non-Ḥasidic communities and create an elite led by the Wise (he-Ḥakham). Judah's disciples, especially R. Eleazar of Worms, did not continue in the same direction, and tended to stress the individual rather than the social aspects of religious perfection.
