In September 1994, Professor Ronald Dworkin presented a new paper at the NYU Colloquium in Legal, Political, and Social Philosophy. Earlier that year, the second edition of Professor H.L.A. Hart’s The Concept of Law had appeared, which now included as a postscript an edited version of an unfinished manuscript that Hart had left at his death.1 Hart’s Postscript (as it came to be known) was Hart’s response to Dworkin’s work. In part, the Postscript addressed Dworkin’s arguments from the late 1960s and early 1970s that had directly discussed Hart’s claims in the book.2 But it also addressed Dworkin’s own theory of law, developed in the 1970s and early 1980s and, most fully and systematically, in Law’s Empire, which appeared in 1986.3 The paper that Dworkin presented at the Colloquium, entitled Hart’s Posthumous Reply,4 was a rebuttal of Hart’s claims in the Postscript. This was an exciting development: Dworkin’s manuscript circulated rapidly and widely, in spite of the fact that, back then, dissemination of manuscripts relied on photocopier and postal service, or even fax.
I. Dworkin and His Critics
To understand why this was exciting requires some background. The publication in 1967 of Dworkin’s The Model of Rules had set off a fierce debate between Dworkin and a large number of critics. Dworkin’s target in that paper was legal positivism, which he defined as a family of theories that purport to explain obligation in law by appeal to the existence of a set of special standards that meet a social test of pedigree: for example, that they have been endorsed by some institution.5 Dworkin contended that such theories cannot adequately account for the role that certain unenacted moral principles play in grounding legal rights and obligations.6 This failure, he argued, led the theories to conflate the use of moral judgment in judicial reasoning (a core judicial duty, given the role of principles) with judicial creation of new legal rights and duties to which litigants are retroactively held (which would be a gross violation of that duty).7 In part, Dworkin framed the discussion as an attack on Hart’s theory, which he considered the strongest version of positivism then available.8 Dworkin’s critics from that period sought to defend positivism. They, too, often focused on Hart, framing their arguments as a defence of Hart’s (or a Hartian) theory, either by developing responses that they claimed to be available to Hart or by suggesting modifications to Hart’s theory that they claimed to be capable of preserving the general positivist outlook that Hart championed and of making the modified theory immune to Dworkin’s criticism.9 Because of its framing, the relevant scholarship came to be known as the “Hart-Dworkin debate,” though of course it was in fact a debate between Dworkin and his numerous critics, since Hart did not reply to Dworkin at that time.
Following the early pair of articles that sparked the debate, Dworkin embarked on the development of a novel conception of law, which came to be known as interpretivism. Dworkin’s new work attracted enormous interest, with each new publication met by a flurry of fresh commentary and criticism. However, the tenor of the debate had now shifted. Dworkin’s new work made scant reference to Hart,10 and the same is true of the responses it elicited.11 Instead, the discussion was now dominated by distinctively Dworkinian themes: the idea of interpretation and the conception of law modeled on it, the value of principled consistency, Dworkin’s various novel analytical devices including the pre- and post-interpretive stages of the process of identifying legal rights and duties, the dimensions of fit and justification of the test that a successful interpretation must meet, his model judge Hercules and the determinacy of law, and so on.12 Critics sought to undermine the new theory directly, with the usual philosophical tools: raising issues about the conception’s initial plausibility, its explanatory power, its internal consistency, or the tenability of its implications.13 The debate was no longer about a newcomer’s challenge to Hart’s established view or even to other variants of legal positivism.14 For the most part, it had now evolved into a contest about the merits of Dworkinian interpretivism in its own right.
It is nonetheless widely thought that the work produced in this longer phase extends and continues the earlier debate between Dworkin and his critics, in which Hart’s work was an object of contention. Indeed, the standard view is that the two phases are continuous, parts of one long-running “Hart-Dworkin debate” that went on to dominate legal theory for decades, and which may well do so to this day.15
In view of Hart’s continued silence, the lack of engagement with Hart’s theory in Dworkin’s work from the 1970s onward, and the content of the critical reactions to that work, we shouldn’t take the suggestion of a continuous “Hart-Dworkin debate” literally. A variety of factors, however, may contribute to a sense of continuity. It might be natural for Hart’s followers to read Dworkin’s new work, which kept appearing as his thought developed, through the prism of its implications for Hart’s work. On this approach, Dworkin’s new theory raised new challenges for Hart’s project, which in turn meant that a retooling of the defences developed in the past was required.16
This approach to the “Hart-Dworkin debate” does not suppose that the named principals did, or even meant to, engage with one another, but only that their theories do so engage. It uses the idea of a debate as a philosophical fiction, a mere device contrived for the purpose of organizing theoretical claims around some question perceived to be interesting or fundamental, regardless of whether those who endorse the claims are aware of the question or consider it relevant. So understood, a debate between two theorists exists when they each defend views that imply competing answers to the key question.
The obvious candidate in this case would be the question about the role of morality in the explanation of law.17 For Dworkin, the law is, in its nature, a moral phenomenon. In Hard Cases, which launched his distinctive program, he said that legal rights are a subset of political rights.18 Political rights are moral rights that obtain in civil society and are profoundly related to political institutions.19 Political rights so understood include legal rights, whose content depends on the practice of institutions and which are enforceable on demand by the courts.20 Their institutional dependence implies that, while legal rights are genuine moral rights, they differ from nonpolitical moral rights because they are subject to moral constraints appropriate to enforcement.21 They also differ from the rights that we would have if institutional history were different, so it is always appropriate to distinguish between the question what such rights exist, given the actual history of institutions, and what rights should exist; that is, what rights would exist in some ideal alternative world where institutional history has taken a different, better course.22
Legal rights so understood obtain ultimately in virtue of certain principles of political morality that make institutional practice morally significant.23 In Dworkin’s conception, institutional practice matters because of the moral urgency of constraining the use of the collective coercive power of government. In civil society, we are all vulnerable to demands that others place upon us, and it is vital that the collective power to enforce such demands be limited in a way that respects the fundamental equal dignity of all.24 Dworkin’s hypothesis is that this moral requirement can be met only when coercive force is used in a way consistent in principle with government’s other actions. It follows, Dworkin contends, that legal rights are those rights that bear such a relation to institutional practice as to make it the case that their enforcement would meet the requirement of principled consistency.25 In Dworkin’s interpretivist vocabulary, interpretation identifies the relation that particular legal rights bear to institutional practice that satisfies this condition.26
Dworkin’s conception is thus fundamentally antithetical to any view that purports to explain the grounds of legal rights or obligations (that is, to say in virtue of what more basic facts legal rights or duties obtain and to explain how they do so) without appeal to moral factors.27 Hart’s theory is one such view. Accordingly, in attacking Dworkin’s theory, Dworkin’s various critics may be understood implicitly to support Hart.
II. Dworkin’s Theory
of Law’s Grounding
Hart’s followers have long resisted Dworkin’s assertion that morality plays a fundamental role in the explanation of legal rights and obligations. Hart himself joined them, even if only posthumously. It is, however, doubtful that the role of morality that Hart’s side has been denying is the one that Dworkin asserted. To see this disparity, we need to consider more closely how exactly Dworkin understands moral principles as grounding legal rights and obligations. Early in Law’s Empire, Dworkin poses the question of grounds thus:
Everyone thinks that propositions of law are true or false (or neither) in virtue of other, more familiar kinds of propositions on which these propositions of law are (as we might put it) parasitic. These more familiar propositions furnish what I shall call the “grounds” of law. The proposition that no one may drive over 55 miles an hour in California is true, most people think, because a majority of that state’s legislators said “aye” or raised their hands when a text to that effect lay on their desks. It could not be true if nothing of that sort had ever happened; it could not then be true just in virtue of what some ghostly figure had said or what was found on transcendental tablets in the sky.28
Dworkin’s question of grounds invites us to think about the relations between legal facts and more basic, nonlegal facts in virtue of which the former obtain. As Dworkin points out, it seems obvious that the law is related in such a profound way to certain institutional facts. After all, the fact, if it’s a fact, that no one may drive over 55 miles an hour in California couldn’t obtain if no statute was enacted or no other fact “of that sort” had ever obtained.
Recognizing this kind of fundamental dependence of legal facts on social facts about institutions raises further questions. How do institutions shape the law? How is it that, when California legislators said “aye” when some text was put before them, people’s normative situation changed in some way? What exactly about the actions of legislators matters to the law and why? Why should institutional action, as a kind, bear on the law in the first place? Why should it matter that some institution said or did something in the past, when we face the question of what we ought to do now, or what demands government may currently enforce on people? There are importantly different answers to these questions, and the uncontroversial thesis that the law depends on institutional social facts does not discriminate among them.29
We can put Dworkin’s answer, which appeals to the morality of coercion, this way: while legal facts depend on and vary with institutional social facts, the explanation of how this dependence works is ultimately moral.30 Certain facts of political morality explain how it is that, by taking actions such as passing a statute or deciding a case, political institutions make the law as it is. In this explanation, the moral facts are basic: the question of why the actions of institutions matter takes priority over the question of how they make the law. It is the background moral reasons that favor the actions’ having some specified role as determinants of (enforceable) rights that confer upon the actions the specified role and thereby explain the actions’ having that role.31 Legal interpretations, on this approach, model the operation of this moral mechanism: they are moral explanations that run from institutional and other social facts to legal rights and duties.32
Dworkin’s hypothesis is easy to miss, or to mistake for a very different one. The standard question in legal theory asks: does the law ultimately depend only on institutional social facts or do moral factors also play some fundamental role?
The standard question is almost always understood to raise certain theoretical possibilities that do not include Dworkin’s hypothesis. On one side, moral factors play no role whatsoever. On the other, the possibility that we are to consider is not that moral factors might explain how institutions make the law as it is. Instead, we are to consider whether morality might be a separate, noninstitutional source of law. It might be that, in addition to the rights and duties made by institutions, moral factors separately contribute some further rights and duties or restrict, extend, or otherwise process those produced by institutional action. On this familiar picture, morality might filter out evil laws or fill in gaps in other laws produced by institutions, or otherwise help make laws so produced better cohere with each other.
If that is the possible place of moral factors in the fundamental explanation of law, there is no point querying how institutions modify legal rights and duties. We can treat it as common ground among theories on either side of the divide that, whatever the answer to the question of how institutions shape the law, it is nonmoral. Theories that fall on one side say that that is the only kind of explanatory mechanism at work. Those that fall on the other assume that mechanism as basic, but postulate a separate moral mechanism that operates in tandem with the institutional one.
This understanding of the territory therefore encourages suppressing the question of grounds in a way that favors one side. Since everyone agrees that institutional social factors somehow determine at least part of the law, it makes sense to concentrate theoretical attention on the only matter in dispute: whether morality might constitute a further genuine source of law. On this approach, the question becomes one of boundaries: does the law extend only to the content contributed by institutions, or does it also include the content separately contributed by morality?33
There is, however, an obvious and important alternative that suppressing the question of grounds has concealed: that, rather than postulating the existence of noninstitutional law, the claim that moral factors play some role in the fundamental explanation of law is instead a hypothesis about how institutions shape the law. (An example would be Dworkin’s hypothesis that institutional history matters morally, and that the specifics of why it matters explain how its impact on the law obtains.)
Now if this is the postulated role of morality, the possibilities raised by the classic question are very different. The idea that institutions shape the law in ways that can be understood without appeal to moral factors represents only one side of the divide, rather than an unexamined background commitment shared by both. It has now become a controversial hypothesis that needs to be articulated and defended. On the other side, we have the view that moral factors explain how it is that the history of institutions can affect legal rights and duties: on this view, such factors give the history its grounding role.
If we understand moral explanations of law in this way, theories of law on either side of the social/moral divide offer competing grounding explanations that run from institutional history to the law. Both now postulate a single mechanism, by appeal to which they each purport to explain the whole of the law. The alternative understanding of moral explanations therefore allows for genuine disagreement between the two kinds of theory and a clear way forward: we now need to settle how the history of institutions makes the law as it is.
Dworkin’s work, at least from Hard Cases onwards, is best considered from this perspective.34
III. How a Debate that Never Was Came to Be
During his lifetime, Hart took virtually no part in the debate that bears his name, which, by the time the Postscript appeared, had been running for some twenty-seven years. He did not respond to Dworkin’s early pair of papers that discussed his own work. He turned his attention to Dworkin’s later work on the nature of law on only a few occasions, and did so both briefly and cautiously.35 For the entire period from 1967 to 1994, the “Hart-Dworkin debate” existed only in a highly figurative sense: Hart was not a participant, and for the most part the debate did not directly engage his work.
With the appearance of the Postscript and Dworkin’s prompt response, we finally got a genuine debate between the named principals of the “Hart-Dworkin debate”: a direct, sustained, and forceful response to Dworkin’s work by Hart, followed by a systematic and equally forceful rejoinder by Dworkin.
Soon after the Colloquium at which Dworkin presented his paper, most of us with an interest in legal philosophy had a copy.36 It was discussed in seminars and placed on reserve in libraries for the use of students. It was taken into account in the avalanche of commentary on the Postscript then being written and in other work.37 Dworkin was an author who went quickly to press, and this was a paper on the hottest subject in the field in a long time. In the usual course of events, the paper would have appeared in print within a few months.
This time was different. Soon, Dworkin had second thoughts. From the outset, he had doubts about the quality of the manuscript that had become the Postscript and he wondered whether Hart had been satisfied with it. He hints at these concerns in his response to the Postscript and in other work.38 He was more direct in conversation. His worry was that the material in the Postscript fell short of the familiar, exceptionally high standard of Hart’s previous work. Although the text was polished and the exposition as lucid as one could expect, in substance the work was weak. Dworkin was worried by what he felt was an inadequate response to the challenge posed by the question about the grounds of law introduced early in Law’s Empire and the place of morality in the interpretive conception of law that constitutes Dworkin’s answer to this question.39
He was also troubled by Hart’s late embrace of inclusive positivism as a way of making sense of moral argument in adjudication. This is the thesis that moral factors may, but need not, play a role in the explanation of legal rights and obligations: if they do, it is in virtue of some fundamental social fact about what people did or said or thought, such as a social practice that constitutes a Hartian rule of recognition, which assigns them that role. If so, social facts retain explanatory priority over moral ones, which, on this view, is the core commitment of all forms of legal positivism.40 On this view, equality, freedom, and fairness bear on the content of legal rights and duties in the United States, in virtue of the fact that their relevance is recognized in the settled practice of U.S. officials. Dworkin considered that view almost transparently indefensible, as he explains in his response, and he thought it mysterious that Hart could have come to endorse it.41 He also had other concerns about Hart’s grasp of the issues about the nature of law that divided them, including Hart’s claim that his thesis that social practice is the ultimate foundation of law would stand even if it turned out that most lawyers in fact accepted Dworkin’s interpretivist theory of law.42
Dworkin thought that Hart’s manuscript should not have been published and gradually leaned toward the view that, now that it had been, publishing a point by point rebuttal would have been unkind to Hart, who would have no opportunity to respond.
Dworkin dithered for a long time but publication remained on the cards. A few years later he confirmed that he intended to publish “a substantial response” to the Postscript in the near future.43 To my knowledge he never made a firm decision either way and eventually lost the draft. He was unable to provide a copy when, many years later, I couldn’t locate mine and discovered that everyone else seemed also to have lost theirs: he said that his original electronic file was lost when his hard disk failed. (I am grateful to Dr. Luís Duarte d’Almeida, who sent me a scan of the manuscript that had somehow come into his possession.)
It is ironic that, just like Hart’s response to him, Dworkin’s rejoinder should end up being published posthumously.44 Publication now has a very different character than it would have had in Dworkin’s lifetime. Dworkin’s reservations about the quality of the Postscript are now moot. Notwithstanding any weaknesses, the Postscript has acquired a prominent place in the canon of jurisprudential scholarship as representing Hart’s final view. Some of its responses to Dworkin’s views are widely considered successful and have been further explored by other writers.45 There is no doubt that the Postscript will continue to attract scholarly attention, and rightly so. The challenges posed by Dworkin’s work and questions about the success of Hart’s responses, therefore, still matter: even if Dworkin is right that Hart’s theory, however revised or reconstructed, ultimately fails, it remains important to see why it does. With the publication of the rejoinder, a new generation of legal philosophers will finally have a complete picture of the single genuine cycle in the “Hart-Dworkin debate” since that debate’s inception some fifty years ago.
* Associate Professor of Legal Theory, University of Oxford. I am grateful to Mark Greenberg, Scott Hershovitz, and George Letsas for comments and suggestions on an earlier draft. Special thanks to Michael Zuckerman and Ahson Azmat, as well as to Robert Batista, Jenya Godina, and other editors of the Harvard Law Review, for their helpful suggestions. Harrison Tait provided valuable research assistance.