As with many issues in contemporary jurisprudence, a host of recent debates concerning the proper methodology for legal theorists to adopt have been set into motion by H.L.A. Hart's The Concept of Law.H.L.A. HART, THE CONCEPT OF LAW (1st ed., 1961; 2nd ed. with Postscript, Penelope A. Bulloch and Joseph Raz, eds., 1994). All page references to this work are given according to the pagination in the 2nd edition. In the opening pages of the original edition of the book, Hart presents legal scholars in a self-reflective light, claming that they have a distinctive tendency to be drawn into theoretical debates concerning the subject matter of their discipline: “No vast literature is dedicated to answering the questions ‘What is chemistry?’ or ‘What is medicine?,’ as it is to the question ‘What is law?’HART, supra note 1, at 1.

Nearly all philosophers of law agree that nonnormative, nonevaluative, contingent facts—descriptive facts, for short—are among the determinants of the content of the law. In particular, ordinary empirical facts about the behavior and mental states of people such as legislators, judges, other government officials, and voters play a part in determining that content. It is highly controversial, however, whether the relevant descriptive facts, which we can call law-determining practices, or law practices (or simply practices) for short, are the only determinants of legal content, or whether legal content also depends on normative or evaluative facts—value facts, for short. In fact, a central—perhaps the central—debate in the philosophy of law is a debate over whether value facts are among the determinants of the content of the law (though the debate is not usually characterized in this way).

Sometimes there are reasons for us to think or act in certain ways. We pay our taxes, we show up on time for our classes, we refuse to assent to claims that we recognize to be inconsistent, and we refrain from wanton violence, and we do each of these things because—we assume—there are reasons for us to do them. I will express the general point by saying that there are norms that apply to us, and to our thought and action. For a norm to apply to a person is for there to be a reason for that person to think or act in a particular way—the way indicated by the norm. Perhaps this reason is one that the person herself does not in any way recognize or acknowledge. But the reason itself—whether or not it is recognized or acknowledged by the person for whom it purports to be a reason—is what I call a “norm.” For instance, I might not recognize or acknowledge various norms concerning theft. But those norms still exist, and they still apply to me; there is a reason for me not to steal, whether or not I recognize or acknowledge that reason. My failure to recognize or acknowledge such reasons does not make them any less real or any less applicable to me.