This article offers a novel reconstruction of Foucault’s methodology that emphasises his respect for the natural sciences. Foucault’s work has long been suspected of reducing knowledge to power, and thus collapsing into unconstrained relativism and methodological incoherence. These concerns are predicated on a misunderstanding of Foucault’s overall approach, which takes the form of a historico-critical project rather than a normative epistemology. However, Foucault does sometimes make normative epistemological judgements, especially about the human sciences. Furthermore, there are outstanding questions about what (...) secures the descriptive rigour of the genealogical method. To address these issues, I develop two claims that will significantly enrich our understanding of Foucault’s methodology. The first is that Foucault’s respect for the natural sciences is crucial in making sense of his normative epistemological judgements. The second is that the descriptive rigour of his genealogical method derives from the fact it is modelled on empirical inquiry. (shrink)