Abstract Naturalized metaphysics remains a default presupposition of much contemporary philosophy of physics. As metaphysics is supposed to be about the general structure of reality, so a naturalized metaphysics draws upon our best physical theories: Assuming the truth of such a theory, it attempts to answer the “foundational question par excellence”, “how could the world possibly be the way this theory says it is?” It is argued that attention to historical detail in the development and formulation of physical theories serves as an ever-relevant hygienic corrective to the “sentiment of rationality” underlying the naturalistic impulse to read ontology off of physics.