At the California State Polytechnic University in San Luis Obispo, where I teach, the subjects traditionally defined as “science”—physics, chemistry, biology—make their institutional home in the College of Science and Mathematics. The history department, on the other hand, is housed in the College of Liberal Arts, alongside philosophy, English, psychology, and the umbrella “social sciences” of sociology, anthropology, and religious studies, to name a few. Why, one might ask, have these fields been organized this way? What exactly distinguishes science from the liberal arts? Meanwhile, within the College of Science and Mathematics, highly credentialed professors offer courses in astronomy and chemistry, but not astrology and alchemy. Why not? My students might respond that the answers are obvious: alchemy is not real science, of course, and whereas science is objective and empirical, the liberal arts are subjective and interpretive. But where did these distinctions originate? Who determines and maintains them? What, if anything, can the history of these categories tell us about the waxing and waning of scientific authority in the twentieth century?