The Ineliminability of Hartian Social Rules†

On Shapiro’s view, any viable legal theory must successfully respond to his Possibility Puzzle and Humean Challenge. Moreover, he argues that Hartian legal theory fails in this respect. Here, I take issue with his characterization of these challenges and the Hartian response to them. I argue that he equivocates with respect to a number of the key terms and relations that inform his Possibility Puzzle, and I argue that if we disambiguate its terms consistently and plausibly, we will see that its putative challenge to Hartian legal theory is illusory. I also argue that once we adequately characterize Hartian legal theory, it easily meets the Humean Challenge. If correct, these arguments undermine Shapiro’s larger project of defending his planning theory of law, for a key pillar supporting his theory is that it meets challenges that rival theories cannot. I also consider his planning theory directly, and I argue that it compares unfavourably to the Hartian approach in a crucial respect. It obscures the Hartian insight that customary practice is an ineliminable and fundamental feature of legal systems. Thus, I conclude that though Shapiro’s Legality brings to the fore many of the key issues in contemporary analytic jurisprudence and does so in an insightful and provocative way, it does not succeed in its ultimate ambition of improving upon and supplanting Hartian legal theory.