Leiter's "Naturalizing Jurisprudence" Reviewed
Brian Leiter is one of the leading proponents of the use and application of so-called "naturalistic developments" in contemporary philosophy to central questions in analytic jurisprudence. He is also arguably the leading philosophical interpreter of legal realism. In Naturalizing Jurisprudence, he collects many of his most important essays on these topics, organized by theme, and presents previously unpublished responses to critics. The result is a work that goes well beyond the individual essays to present a trenchant, multi-faceted and mutually-reinforcing set of challenges to core views and methodologies that are prevalent in the field. In an important sense, the book is also agenda-setting: it clarifies the impact that naturalistic developments in philosophy can have on core questions in analytic jurisprudence, while gesturing towards a larger and partly empirical project aimed at working out the full scope of these consequences for legal epistemology, the nature of law, and the objectivity of legal judgment.
This is thus an important book by one of the most influential legal philosophers of our time. In what follows, I will critically examine the three parts of this book, which address, more specifically: (1) the philosophical legacy of American legal realism, with specific reference to the nature of justification in adjudication; (2) the appropriate philosophical methodology to determine the nature of law (including what conclusions to draw from this methodology); and (3) the bearing that issues in meta-ethics might have on legal objectivity. Although Leiter devotes portions of his book to arguing for various of his naturalistic commitments as well, these are large topics, which have commanded an enormous literature of their own. The commitments themselves are controversial but have a distinguished pedigree and have garnered widespread approval in one form or another. It is therefore clearly important to know what naturalism might mean for jurisprudence if true. Leiter's more distinctive contributions are, in any event, on this narrower topic, and I will therefore focus on those aspects of his work here.