The most important promise of the legacy of legal realism is its robust understanding of law, which is irreducible to one or another more or less familiar jurisprudential school, as a set of institutions distinguished by the difficult accommodation of three constitutive yet irresolvable tensions: between power and reason, science and craft, and tradition and progress. This essay defends that view through a critical analysis of Brian Leiter’s ambitious and provocative account of legal realism, whose legacy he described as naturalized jurisprudence. I argue that Leiter understates the realist indeterminacy critique of pedigreed sources, misses the realist distinction between doctrine (or pedigreed sources) and law, and errs in classifying legal realists as tacit hard positivists. Studying these mistakes and refining his naturalistic claims reveals why Leiter must also be incorrect in reducing legal realism to a descriptive theory of adjudication. Leiter’s account obscures the real legacy of legal realism.