The British social philosopher Gillian Rose (1947–1995) developed, in Dialectic of Nihilism, a way of posing the problem of ideology by showing the dependence of philosophical and social thought on historical legal concepts. She termed it ‘jurisprudential wisdom’ and through it aimed to expose unexamined presuppositions within philosophical consciousness and thereby to perform ideology critique on such consciousness. This article examines Rose’s version of ideology critique, first by setting out its context within post-Kantian thought and Rose’s own intellectual project. It (...) then tackles in detail Rose’s view that Roman law significantly shapes Kant’s form of rationality as a whole. It concludes that her argument is suggestive and highlights important features of Kant’s thought, but that it ultimately fails as an ideology critique. It does not follow that Rose’s form of ideology critique via jurisprudence fails as a whole; on the contrary, it retains plausibility. Rose’s misfire against Kant is a salutary lesson in the dangers of ideology critique and Kant’s survival of Rose’s attack is important for the assessment of his philosophy. (shrink)