Two main areas of medieval Jewish thought are explored in this collection of previously published and new essays. A section on Sefer Ḥasidim brings together over half a century of Soloveitchik’s writings on German Pietism, many of which were published in out-of-the-way places, and adds two new essays. The first is a methodological study on how to read Sefer Ḥasidim, a baffling potpourri of pietistic sayings, religious practices, and stories, and on what constitutes (and does not constitute) a valid historical inference. The second new essay, ‘Sefer Ḥasidim and the Social Sciences’, is a guide to the soundness of a number of sociological and anthropological inferences that have been drawn from that work in contemporary historiography.A section on R. Avraham ben David of Posquières updates Soloveitchik’s ‘Ravad of Posquières: A Programmatic Essay’, a highly influential essay which argued that, throughout the Middle Ages, Ravad was known and his influence determined by his role as talmudic commentator, not by his now-famous critiques of Mishneh Torah, which were largely unknown in that period. He has added a new essay on the acrimonious relationship between Ravad and R. Zerahyah ha-Levi of Lunel and the tensions that existed between the stormy, low-born genius of Posquières and the Jewish aristocracy of Languedoc, particularly of Lunel.