In Law's Empire Prof. Ronald Dworkin has advanced a new theory of law, complex and intriguing. He calls it law as integrity. But in some ways the more radical and surprising claim he makes is that not only were previous legal philosophers mistaken about the nature of law, they were also mistaken about the nature of the philosophy of law or jurisprudence. Perhaps it is possible to summarize his main contentions on the nature of jurisprudence in three theses: First, jurisprudence is interpretive: “General theories of law… aim to interpret the main point and structure of legal practice” (LE, 90). Second, legal philosophy cannot be a semantic account of the word “law.” Legal philosophers “cannot produce useful semantic theories of law” (id.). Third, legal philosophy or jurisprudence “is the general part of adjudication, silent prologue to any decision at law” (id.).

Even to disagree, we need to understand each other. If I reject what you say without understanding you, we will only have the illusion of a disagreement. You will be asserting one thing and I will be denying another. Even to disagree, we need some agreement.

It has often and correctly been remarked that the Hart-Fuller debate of 1956–1969 set the agenda for Anglo-American jurisprudence in the last half of the twentieth century. The nature of law, of legal obligation, of legal authority, and of law's relation to morality were the questions that debate made central to jurisprudence as we have since practiced it.

Nowhere has H.L.A. Hart's influence on philosophical jurisprudence in the English-speaking world been greater than in the way its fundamental project and method are conceived by its practitioners. Disagreements abound, of course. Philosophers debate the extent to which jurisprudence can or should proceed without appeal to moral or other values. They disagree about which participant perspective—that of the judge, lawyer, citizen, or “bad man”—is primary and about what taking up the participant perspective commits the theorist to. However, virtually unchallenged is the view that jurisprudence is fundamentally interpretive or “hermeneutic”; that it takes for its subject a certain kind of social practice, constituted by the behavior and understandings of its participants; that its task is to explain this practice and its relations to other important social practices; and that it can properly be explained only by taking full account of participant understandings. It is, perhaps, some measure of the hegemony of Hart's influence that Ronald Dworkin mounts his fundamental challenge to Hart's positivism squarely from within this jurisprudential orthodoxy. Dworkin may have exceeded the limits of the method as Hart conceived it, but, as Stephen Perry has argued, “the seeds of Dworkin's strong version of inter-pretivism were sown by Hart himself.”

Conversions occur in legal theory about as often as they do in religion, which is to say rarely—so rarely that they fascinate as much for the fact that they happen at all as for the reasons they happen. It should not surprise, then, that the Postscript to H.L.A. Hart's famous work on jurisprudence reveals “the outstanding English philosopher of law of the twentieth century” reaffirming, rather than revising in any significant way, the two central tenets that distinguish his theory from that of both classical natural law theorists and modern “new naturalists” like Ronald Dworkin: (1) There is no necessary connection between law and morality; and (2) judges inevitably confront cases where the decision is “not dictated by the law” and the judge “must act as a conscientious legislator would by deciding according to his own beliefs and values” (p. 273).