Frederick Schauer has posted A Critical Guide to Vehicles in the Park on SSRN. Here is the abstract:
The 1958 debate in the pages of the Harvard Law Review between Lon Fuller and H.L.A. Hart is one of the landmarks of modern jurisprudence. And although much of the debate was about the relative merits of Hart’s version of legal positivism and Fuller’s brand of natural law theory, the debate also contained the memorable controversy about the fictional rule prohibiting vehicles from the park. By examining this debate, and by largely removing it from the surrounding controversy over positivism and natural law, we can still gain valuable insights about legal rules, legal interpretation, and the nature of legal language.