The chapter discusses the impact of philosophy on the development of Judaism in modernity and claims that German Wissenschaft des Judentums – movement was not only an enterprise of historicism and philology, as is commonly assumed, but was also the attempt to formulate a new theology, at times even a whole philosophy for Judaism. The goal of this movement is re-formulated in the chapter – it was not gaining civic emancipation but to give the religious reform project a stable intellectual foundation – for which the use of Maimonides' philosophical treatise for contemporary theological purposes is a clear indication. With Maimonidean support, reforming Judaism seemed to be not anymore a daring and heretofore unknown theological undertaking that the liberal rabbis had to answer for, but rather a long overdue development, only impeded by the darkness and persecution of the late Middle Ages.In addition, the chapter introduces the state of the field of modern reception history of Maimonides' Guide and outlines structure, methods and intellectual approaches of the entire book.