This book examines the influence of the Jewish tradition on the work of the German-Jewish philosopher Walter Benjamin. It was hitherto always assumed that Benjamin's knowledge of Judaism was very limited and that he was interested only in the mystical tradition of the Kabbalah, the study of which was pioneered by his friend Gershom Scholem. However, on the latter's recommendation, Benjamin also read Franz Joseph Molitor's "Philosophie der Geschichte oder uber die Tradition" (1827-1857), a massive four-volume work which presents a comprehensive overview of both mainstream and mystical aspects of the Jewish tradition. Having unearthed the most likely written source of Benjamin's knowledge of Judaism, this study sets out to show that Benjamin's thought was influenced considerably by Jewish concepts of language, experience and history, and that this influence is persistent enough to lend a unity to Benjamin's work that transcends its division into an early, metaphysical and a late, materialist or Marxist stage. Within this context, the book also provides a reassessment of some of Benjamin's key texts, from the early programmatic writings on language, philosophy and literature to the little-known "Protokolle zu Drogenversuchen" and the unfinished "Passagen-Werk.""