Maimonides’ Sefer ha-Mitsvot comprises his attempt at identifying the 613 commandments which the Talmud reports Moses received at Sinai. He opens this book with an introduction in which he lays out fourteen principles he used to guide his enumeration of the commandments. This study focuses on that introduction, and particularly on six of these principles: the first five and the eighth. These principles offer opportunities to probe, among other things, Maimonides’ conception of the relationship between divine and rabbinic law, his methods of scriptural exegesis, and his enlistment of Aristotelian logic in mining the text of the Torah for its legislative units. While previous studies have looked at many important features of the introduction, the majority of this study is dedicated to examining an element of Sefer ha-Mitsvot which has not received the attention it merits; namely, the manner in which Maimonides incorporates elements of Islamic legal literature in framing the overall project of the book. We can see the imprint of Maimonides’ Islamic milieu on the way he formats and structures his introductory principles, as well as on the substance of the principles themselves. This dissertation by no means ignores the diachronic perspective which has dominated studies of Sefer ha-Mitsvot for generations, as that perspective proves indispensable in appreciating Maimonides’ work. This study, though, does seek to show the importance of a synchronic, cross-cultural outlook in understanding Maimonides’ goals for this book and the methods he employed to accomplish those goals. He adapts the tools and techniques with which Muslim jurists built Islamic law upon the foundation of its canonical sources to his project of extracting divine commandments from the text of the Torah. This study demonstrates the ways in which that adaptation manifests itself in Sefer ha-Mitsvot. It also includes a new critical edition of the Judeo-Arabic text of the introduction to Sefer ha-Mitsvot and original annotated English translations of the six principles discussed in the dissertation.