The article investigates and vindicates the surprising claim Foucault makes in his lecture series The Birth of Biopolitics that the philosophical roots of post-war German neoliberalism lie in Husserl's phenomenology. I study the similarities between Husserl's phenomenology and Walter Eucken's economic theory and examine the way that Husserl's idea of the historical a priori assumes a determinate role in Eucken's economic thinking. I also return to Foucault's lectures in order to show how a version of the historical a priori continues to operate in his history of governmentality, and how it functions as a counterpoint to the universalizing approach to the history of science, such as Husserl and Eucken's. I conclude by rephrasing my initial question on the philosophical connections between Husserl's phenomenology and German neoliberalism as a broader philosophical question on the political effects of our philosophical understanding of the history of science.