This article presents Hermann Cohen's Ethical Monotheism as an epistemological rejoinder to the theologico-political predicament of liberalism in Wilhelmine Germany (1871-1918). Beginning with an intellectual historical portrait of liberal Protestantism as a diffuse cultural context rather than a defined ideology, the article then proceeds to explicate Cohen's “liberal” Jewish conception of an epistemological “God-idea” as a defense against the antisemitic and essentializing thought of Paul de Lagarde. The article then concludes by suggesting that Cohen's interpretation of the Noahide presents a Jewish minority account of “God” as a basis for “secular” public morality in a hyper-contested public sphere.