Brian Leiter

Evolutionary biology – or, more precisely, two (purported) applications of Darwin's theory of evolution by natural selection, namely, evolutionary psychology and what has been called human behavioral biology – is on the cusp of becoming the new rage among legal scholars looking for interdisciplinary insights into the law. We argue that as the actual science stands today, evolutionary biology offers nothing to help with questions about legal regulation of behavior. Only systematic misrepresentations or lack of understanding of the relevant biology, together with far-reaching analytical and philosophical confusions, have led anyone to think otherwise. Evolutionary accounts are etiological accounts of how a trait evolved. We argue that an account of causal etiology could be relevant to law if (1) the account of causal etiology is scientifically well-confirmed, and (2) there is an explanation of how the well-confirmed etiology bears on questions of development (what we call the Environmental Gap Objection). We then show that the accounts of causal etiology that might be relevant are not remotely well-confirmed by scientific standards. We argue, in particular, that (a) evolutionary psychology is not entitled to assume selectionist accounts of human behaviors, (b) the assumptions necessary for the selectionist accounts to be true are not warranted by standard criteria for theory choice, and (c) only confusions about levels of explanation of human behavior create the appearance that understanding the biology of behavior is important. We also note that no response to the Environmental Gap Objection has been proffered. In the concluding section of the article, we turn directly to the work of Owen Jones, a leading proponent of the relevance of evolutionary biology to law, and show that he does not come to terms with any of the fundamental problems identified in this article

This is my contribution to a symposium on my book Why Tolerate Religion?, in which I respond to essays by François Boucher and Cécile Laborde, Frederick Schauer, Corey Brettschneider, and Peter Jones. I clarify and revise my view of the sense in which some religious beliefs are “insulated from reasons and evidence” in response to the criticisms of Boucher and Laborde, but take issue with other aspects of their critique. I defend most of my original argument against utilitarian and egalitarian objections from, respectively, Schauer and Brettschneider. I also discuss and defend the “No Exemptions” approach to conscientious objection to neutral laws of general applicability against a variety of objections, arguing, in particular, that my view is probably not very different from that of Jones.

In teaching jurisprudence, I typically distinguish between two different families of theories of adjudication—theories of how judges do or should decide cases. “Formalist” theories claim that the law is “rationally” determinate, that is, the class of legitimate legal reasons available for a judge to offer in support of his or her decision justifies one and only one outcome either in all cases or in some significant and contested range of cases ; and adjudication is thus “autonomous” from other kinds of reasoning, that is, the judge can reach the required decision without recourse to nonlegal normative considerations of morality or political philosophy. I also note that “formalism” is sometimes associated with the idea that judicial decision-making involves nothing more than mechanical deduction on the model of the syllogism—Beccaria, for example, expresses such a view. I call the latter “Vulgar Formalism” to emphasize that it is not a view to which anyone today cares to subscribe.

The American Legal Realists, as I read them, are tacit legal positivists: they presuppose views about the criteria of legality that have affinities with positivist accounts of law in the sense that they employ primarily pedigree tests of legal validity. Ever since Ronald Dworkin's well-known critique of H.L.A. Hart's positivism a generation ago, however, it has been hotly contested whether there is anything about positivism as a legal theory that requires that tests of legal validity be pedigree tests. So-called Soft or Inclusive versions of positivism are willing to relax the restrictions on the content of a Rule of Recognition to admit non-pedigree criteria of legal validity; Hard or Exclusive versons of positivism deny that such a move is compatible with the central commitments of positivism. Hard Positivism, of which Joseph Raz has been the leading proponent, thus competes with various Soft Positivisms, defended by, among others, Coleman, Lyons, Soper, Waluchow, and now, explicitly, Hart himself in the “Postscript.” If the Realists are positivists, as I claim, then it cannot be the case that Soft Positivism is a genuinely positivistic doctrine. But there is more at stake here than just labels. Realist arguments for the indeterminacy of law—arguments central to the whole Realist enterprise—depend crucially on their tacit Hard Positivism. If, in fact, positivism has a more relaxed view of the criteria of legality than Hard Positivism supposes, then Realist arguments depend on unsound tacit premises about legal validity. What is at stake, then, is not whether Realists should be called “Positivists” or merely “Hard Positivists,” but whether their underlying view of the criteria of legality is sound. It can only be so if the best arguments favor Hard Positivism