In the following dissertation I argue that Spinoza’s concept of the intellectual love of God (ILG) is a – if not the – cardinal concept and value in all of his thought and works. I begin with a discussion of the obstacles to understanding the concept as such, a review of the literature evidencing the various though consistent shortcomings in the scholarly engagements, and a typology of the problems facing a coherent understanding of the concept. I ground the dissertation’s systematic examination of ILG throughout Spinoza’s corpus in a comparative excursus on the concept of ILG in three key works by three key representatives of the medieval Jewish philosophical tradition – a tradition I argue is essential for an adequate understanding of ILG in Spinoza, a tradition I argue he is very much a part of. Upon demonstrating the ubiquity of ILG as well as its rather consistent role and function throughout Spinoza’s corpus, and thus throughout his life and thought, I conclude with a discussion of the fundamentality of ILG for an adequate understanding of his ethical, political, and religious thought, and thus indeed his philosophy as a whole, illustrating the explanatory strength of the concept, and thus, once again, its cardinality for Spinoza.