Ivan G. Marcus is the Frederick P. Rose Professor of Jewish History at Yale University. He is author of several books, including Piety and Society: The Jewish Pietists of Medieval Germany.
Marcus's groundbreaking and inspiring book about Sefer Hasidim is highly recommended for every scholar or student who is interested in this specific text and also in the more general concept of an 'open book' not only in Ashkenazic literature. -European Journal of Jewish Studies Ivan G. Marcus lays out in a new way how Sefer Hasidim develops and functions as an Ashkenazic book. The summary, assessment, and synthesis of prior research he presents is enlightening and helpful. -Ephraim Kanarfogel, Yeshiva University