In this article I respond to Brian Leiter’s and Peter Kail’s critiques of my book, Nietzsche’s Naturalism: Philosophy and the Life Sciences in the Nineteenth Century. While Leiter’s and Kail’s analytic reconstructions of Nietzsche’s naturalism prioritize a psychological reading, I argue for a philosophically oriented historical contextualization of Nietzsche’s position. The latter situates his naturalism in the context of the nineteenth-century life sciences and early neo- Kantianism. While Leiter views normativity as based on irreducible mental states, and while Kail denies outright that Nietzsche is even concerned with normativity, I suggest that Nietzsche’s understanding of the emergence of norms and values is best understood along biological lines. As such, his naturalism holds that what we regard as normative—as belonging to the world of knowledge and morality but also to the world of affect—is already constitutive of our existence and agency as natural beings.