The dissertation presents a novel interpretation of Nietzsche's Beyond Good and Evil as an argument for the philosophical life, centered on a close reading of the first 29 aphorisms as an interconnected sequence. I argue that Nietzsche’s aim is to recover the ancient idea of philosophy as a way of life, while grounding his conception of first philosophy as psychology, which he calls “the queen of the sciences.” This psychology is a reflexive inquiry into embodied subjectivity, with important analogies to German Idealism. Like Kant and Hegel, Nietzsche steers a middle course between skepticism and dogmatism, and opposes both traditional conceptions of first philosophy (metaphysics as cosmology, theology or general ontology) and empiricist or materialist rejections of first philosophy. Much as for Kant and Hegel, Nietzsche’s first philosophy is based on the resolute rejection of intellectual intuition (Platonic-Aristotelian noesis or scholastic intellectus) in favor of a wholly discursive or productive conception of human intellection. However, while Kant and Hegel want to “save the appearances,” Nietzsche embraces what he regards as the radical consequences of this rejection. The basic categories we use to understand the world are conventional or “fictional.” Particular traditions and conventions rest on what Nietzsche calls the “fundamental errors” of the human species, such as the belief in self-identical “things” and the faith in unconditional “values.” Nietzsche grounds this radical perspective in a reflexive insight into the origin of all determinacy in experience in the interpretive activity of the intellect, a theoretical gambit analogous to Hegel’s “absolute act of self-elevation” in the Science of Logic. Nietzsche attempts to show, in an unavoidably figurative, indirect and rhetorical fashion, how the lifelong “incorporation” (Einverleibung) of this insight results in an elevated way of life and being-in-the-world: “It is not the intensity, but the duration, of exalted sensation which makes for exalted human beings.” Nietzsche presents religion as philosophy's great spiritual and political rival. His deepest aim is to show that the life devoted to critical reflection on “the strange simplification and falsification" in which we live is more “life-enhancing” than a religious life in any of the various possible meanings of "religious" – a conclusion he repeatedly emphasizes the philosopher has no right to take for granted.