Against the Metaphysical Turn in Recent American Jurisprudence

Abstract I argue against the recent fad in American general jurisprudence of characterizing debates about the nature of law as debates about how “legal facts” (the content of law) are determined by “social facts” and “moral facts.” The reframing is due to Mark Greenberg in a 2004 article, but was popularized by Scott Shapiro in a 2011 book. In Part I, I argue that (1) Greenberg’s reframing distorts the historical debates in jurisprudence (which were about validity, not content); (2) Greenberg’s own view of legal content cannot explain how law guides conduct outside the courts and, in any case, is unmotivated by any realistic considerations; and (3) Greenberg demands that legal philosophers answer a metaphysical question about determination that neither Kripke (in philosophy of language) nor Goodman (in philosophy of science) could answer on the terms Greenberg proposes and which are, in any case, irrelevant to important jurisprudential questions. In Part II, I argue that (1) Shapiro’s adoption of the Greenberg framing of the core questions of general jurisprudence erases the major natural law positions in the field (e.g., those of Finnis and Murphy), and results in a version of “positivism” that major legal positivists (e.g., Hart) do not accept; (2) Shapiro’s explanation of how answers to questions about the nature of law matter for how judges should decide cases is confused; and (3) Shapiro is incorrect that Hart commits a “category mistake.” At various places, I note the ways in which Shapiro, nominally a legal positivist, in fact commits to views characteristic of antipositivists, like Dworkin and Greenberg.