This book offers an account of a key event in Jewish intellectual history that is also an important chapter in the history of Western philosophy: the dissemination of Maimonides’ chief philosophical work, the Guide of the Perplexed, through Samuel ibn Tibbon at the beginning of the 13th century in Southern France. Whereas Maimonides interpreted Judaism as a philosophical religion, Ibn Tibbon turned this interpretation into the foundation of Jewish philosophy up to Spinoza, making it into a systematic justification for studying Greco-Arabic philosophy and science in a religious setting. If Maimonides’ work was the gate through which philosophy became an important component of Jewish culture, Ibn Tibbon built the hinge without which this gate would have remained shut. The book examines Ibn Tibbon’s relationship to Maimonides in all its facets: how he translated Maimonides’ work from Arabic into Hebrew, explained its technical terminology, and interpreted and taught its doctrines. Due attention is also paid to Ibn Tibbon’s comprehensive criticism of Maimonides. The book includes the edition of what may be called the first commentary on the Guide: about 100 glosses attributed to Ibn Tibbon that were discovered through examining 145 manuscripts of Ibn Tibbon’s Hebrew translation. The glosses illustrate the different aspects of Ibn Tibbon’s relationship to Maimonides and the complex transition of Maimonides’ work from one cultural context to another.