This is the first publication of these ideas in book form. 'It is a rare treat--important, original philosophy that is also a pleasure to read.

In this article I argue for rule-based, non-monotonic theories of common law judicial reasoning and improve upon one such theory offered by Horty and Bench-Capon. The improvements reveal some of the interconnections between formal theories of judicial reasoning and traditional issues within jurisprudence regarding the notions of the ratio decidendi and obiter dicta. Though I do not purport to resolve the long-standing jurisprudential issues here, it is beneficial for theorists both of legal philosophy and formalizing legal reasoning to see where (...) the two projects interact. (shrink)

This paper gives an account of dimensions in the reason model found in Horty : 1–33, 2011), Horty and Bench-Capon and Rigoni :133–160, 2015. doi: 10.1007/s10506-015-9166-x). The account is constructed with the purpose of rectifying problems with the approach to incorporating dimensions in Horty, namely, the problems arising from the collapse of the distinction between the reason model and the result model on that approach. Examination of the newly constructed theory revealed that the importance of dimensions in the reason model (...) lies in their ability to establish weighings between reasons/factors of the same polarity. This permits past cases to constrain future cases in ways they could not on the reason model with just factors. The paper then discusses how dimensions might be established from a case base and how dimensions that are incomplete in various aspects might be dealt with in the theory. It closes with comparisons to other work in the literature on AI and Law and suggestions for further improvement of the reason model. (shrink)

This new edition of a standard reference of jurisprudence has been fully revised. Many recent developments which touch on the relationship of laws to morals--homosexuality, obscenity, suicide, and abortion--are discussed, together with controversial economic aspects of modern legislation on such as topics as restrictive trade practices and trade unions.

The Concept of Law is one of the most influential texts in English-language jurisprudence. 50 years after its first publication its relevance has not diminished and in this third edition, Leslie Green adds an introduction that places the book in a contemporary context, highlighting key questions about Hart's arguments and outlining the main debates it has prompted in the field. The complete text of the second edition is replicated here, including Hart's Postscript, with fully updated notes to include modern references (...) and further reading. (shrink)

The Concept of Law is the most important and original work of legal philosophy written this century. First published in 1961, it is considered the masterpiece of H.L.A. Hart's enormous contribution to the study of jurisprudence and legal philosophy. Its elegant language and balanced arguments have sparked wide debate and unprecedented growth in the quantity and quality of scholarship in this area--much of it devoted to attacking or defending Hart's theories. Principal among Hart's critics is renowned lawyer and political philosopher (...) Ronald Dworkin who in the 1970s and 80s mounted a series of challenges to Hart's Concept of Law. It seemed that Hart let these challenges go unanswered until, after his death in 1992, his answer to Dworkin's criticism was discovered among his papers. In this valuable and long-awaited new edition Hart presents an Epilogue in which he answers Dworkin and some of his other most influential critics including Fuller and Finnis. Written with the same clarity and candor for which the first edition is famous, the Epilogue offers a sharper interpretation of Hart's own views, rebuffs the arguments of critics like Dworkin, and powerfully asserts that they have based their criticisms on a faulty understanding of Hart's work. Hart demonstrates that Dworkin's views are in fact strikingly similar to his own. In a final analysis, Hart's response leaves Dworkin's criticisms considerably weakened and his positions largely in question. Containing Hart's final and powerful response to Dworkin in addition to the revised text of the original Concept of Law, this thought-provoking and persuasively argued volume is essential reading for lawyers and philosophers throughout the world. (shrink)

Practical Reason and Norms focuses on three problems: In what way are rules normative, and how do they differ from ordinary reasons? What makes normative systems systematic? What distinguishes legal systems, and in what consists their normativity? All three questions are answered by taking reasons as the basic normative concept, and showing the distinctive role reasons have in every case, thus paving the way to a unified account of normativity. Rules are a structure of reasons to perform the required act (...) and an exclusionary reason not to follow some competing reasons. Exclusionary reasons are explained, and used to unlock the secrets of orders, promises, and decisions as well as rules. Games are used to exemplify normative systems. Inevitably, the analysis extends to some aspects of normative discourse, which is truth-apt, but with a diminished assertoric force. (shrink)

Legitimate authority -- The claims of law -- Legal positivism and the sources of law -- Legal reasons, sources, and gaps -- The identity of legal systems -- The institutional nature of law -- Kelsen's theory of the basic norm -- Legal validity -- The functions of law -- Law and value in adjudication -- The rule of law and its virtue -- The obligation to obey the law -- Respect for law -- A right to dissent? : civil disobedience (...) -- A right to dissent? : conscientious objection --The purity of the pure theory -- The argument from justice, or how not to reply to legal positivism. (shrink)

What does it mean to assert or deny the existence of a legal system? How can one determine whether a given law belongs to a certain legal system? What kind of structure do these systems have, that is--what necessary relations obtain between their laws? The examination of these problems in this volume leads to a new approach to traditional jurisprudential question, though the conclusions are based on a critical appraisal, particularly those of Bentham, Austin, Kelsen, and Hart.

_ Convention_ was immediately recognized as a major contribution to the subject and its significance has remained undiminished since its first publication in 1969. Lewis analyzes social conventions as regularities in the resolution of recurring coordination problems-situations characterized by interdependent decision processes in which common interests are at stake. Conventions are contrasted with other kinds of regularity, and conventions governing systems of communication are given special attention.

This chapter contains section titled: Introduction Legal Indeterminacy The Core Claim of American Legal Realism Two Branches of Realism Naturalized Jurisprudence? How Should Judges Decide Cases? Legacy of Legal Realism I: Legal Education and Scholarship in the United States Legacy of Legal Realism II: Legal Theory References Further Reading.

This article argues that legal precedents do not create rules, but rather create a special type of reason in favour of a decision in later cases. Precedents are often argued to be analogous to statutes in their law-creating function, but the common law practice of distinguishing is difficult to reconcile with orthodox accounts of the function of rules. Instead, a precedent amounts to a decision on the balance of reasons in the case before the precedent court, and later courts are (...) required to decide cases on the basis that the earlier decision was correctly decided. (shrink)

The result model of precedent holds that a legal precedent controls a fortiori cases—those cases, that is, that are at least as strong for the winning side of the precedent as the precedent case itself. This paper defends the result model against some objections by Larry Alexander, drawing on ideas from the field of Artificial Intelligence and Law in order to define an appropriate strength ordering for cases.

This paper shows how two models of precedential constraint can be broadened to include legal information represented through dimensions. I begin by describing a standard representation of legal cases based on boolean factors alone, and then reviewing two models of constraint developed within this standard setting. The first is the “result model”, supporting only a fortiori reasoning. The second is the “reason model”, supporting a richer notion of constraint, since it allows the reasons behind a court’s decisions to be taken (...) into account. I then show how the initial representation can be modified to incorporate dimensional information and how the result and reason models can be adapted to this new dimensional setting. As it turns out, these two models of constraint, which are distinct in the standard setting, coincide once they are transposed to the new dimensional setting, yielding exactly the same patterns of constraint. I therefore explore two ways of refining the reason model of constraint so that, even in the dimensional setting, it can still be separated from the result model. (shrink)

This paper describes one way in which a precise reason model of precedent could be developed, based on the general idea that courts are constrained to reach a decision that is consistent with the assessment of the balance of reasons made in relevant earlier decisions. The account provided here has the additional advantage of showing how this reason model can be reconciled with the traditional idea that precedential constraint involves rules, as long as these rules are taken to be defeasible. (...) The account presented is firmly based on a body of work that has emerged in AI and Law. This work is discussed, and there is a particular discussion of approaches based on theory construction, and how that work relates to the model described in this paper. (shrink)

This paper proposes a model ofratio decidendi as a justification structure consisting of a series of reasoning steps, some of which relate abstract predicates to other abstract predicates and some of which relate abstract predicates to specific facts. This model satisfies an important set of characteristics ofratio decidendi identified from the jurisprudential literature. In particular, the model shows how the theory under which a case is decided controls its precedential effect. By contrast, a purely exemplar-based model ofratio decidendi fails to (...) account for the dependency of precedential effect on the theory of decision. (shrink)

This paper is an introduction to a virtual special issue of AI and Law exploring the legacy of the influential HYPO system of Rissland and Ashley. The papers included are: Arguments and cases: An inevitable intertwining, BankXX: Supporting legal arguments through heuristic retrieval, Modelling reasoning with precedents in a formal dialogue Game, A note on dimensions and factors, An empirical investigation of reasoning with legal cases through theory construction and application, Automatically classifying case texts and predicting outcomes, A factor-based definition (...) of precedential constraint and An improved factor based approach to precedential constraint. After describing HYPO, in this introduction to the special issue I look at various aspects of its influence on AI and Law: the developments led by Rissland at Amherst; the developments led by Ashley in Pittsburgh; the expression of these ideas in terms of rule based systems, and their subsequent formalisation; value based theories, which were inspired by a critique of HYPO; and contemporary approaches which revive the idea of dimensions. (shrink)

Reasoning with cases has been a primary focus of those working in AI and law who have attempted to model legal reasoning. In this paper we put forward a formal model of reasoning with cases which captures many of the insights from that previous work. We begin by stating our view of reasoning with cases as a process of constructing, evaluating and applying a theory. Central to our model is a view of the relationship between cases, rules based on cases, (...) and the social values which justify those rules. Having given our view of these relationships, we present our formal model of them, and explain how theories can be constructed, compared and evaluated. We then show how previous work can be described in terms of our model, and discuss extensions to the basic model to accommodate particular features of previous work. We conclude by identifying some directions for future work. (shrink)

The third of Berman and Hafner’s early nineties papers on reasoning with legal cases concerned temporal context, in particular the evolution of case law doctrine over time in response to new cases and against a changing background of social values and purposes. In this paper we consider the ways in which changes in case law doctrine can be accommodated in a recently proposed methodology for encapsulating case law theories, and relate these changes the sources of change identified by Berman and (...) Hafner. (shrink)

What does it mean to assert or deny the existence of a legal system? How can one determine whether a given law belongs to a certain legal system? What kind of structure do these systems have, that is--what necessary relations obtain between their laws? The examination of these problems in this volume leads to a new approach to traditional jurisprudential question, though the conclusions are based on a critical appraisal, particularly those of Bentham, Austin, Kelsen, and Hart.

Although the study of reasons plays an important role in both epistemology and moral philosophy, little attention has been devoted to the question of how, exactly, reasons interact to support the actions or conclusions they do. In this book, John F. Horty attempts to answer this question by providing a precise, concrete account of reasons and their interaction, based on the logic of default reasoning. The book begins with an intuitive, accessible introduction to default logic itself, and then argues that (...) this logic can be adapted to serve as a foundation for a concrete theory of reasons. Horty then shows that the resulting theory helps to explain how the interplay among reasons can determine what we ought to do by developing two different deontic logics, capturing two different intuitions about moral conflicts.In the central part of the book, Horty elaborates the basic theory to account for reasoning about the strength of our own reasons, and also about the related concepts of undercutting defeaters and exclusionary reasons. The theory is illustrated with an application to particularist arguments concerning the role of principles in moral theory. The book concludes by introducing a pair of issues new to the philosophical literature: the problem of determining the epistemic status of conclusions supported by separate but conflicting reasons, and the problem of drawing conclusions from sets of reasons that can vary arbitrarily in strength, or importance. (shrink)

This fourth edition of Precedent in English Law presents a basic guide to the current doctrine of precedent in England, set in the wider context of the jurisprudential problems which any treatment of this topic involves. Such problems include the nature of _ratio_ _decidendi_ of a precedentand of its binding force, the significance of precedents alongside other sources of law, their role in legal reasoning, and the account which must be taken of them by any general theory of law. Considerable (...) re-writing has been undertaken to update case-law and take account of the possibleimplications for the doctrine of precedent of the impact of European Community law, making it an indispensable work of reference for readers interested in the past history, present state, and future developments of English rules of precedent. (shrink)

Demystifying Legal Reasoning defends the proposition that there are no special forms of reasoning peculiar to law. Legal decision makers engage in the same modes of reasoning that all actors use in deciding what to do: open-ended moral reasoning, empirical reasoning, and deduction from authoritative rules. This book addresses common law reasoning when prior judicial decisions determine the law, and interpretation of texts. In both areas, the popular view that legal decision makers practise special forms of reasoning is false.

In his introduction to these closely linked essays Professor Hart offers both an exposition and a critical assessment of some central issues in jurisprudence and political theory. Some of the essays touch on themes to which little attention has been paid, such as Bentham's identification of the forms of mysitification protecting the law from criticism; his relation to Beccaria; and his conversion to democratic radicalism and a passionate admiration for the United States.

What is law (and why should we care)? -- Crazy little thing called "law" -- Austin's sanction theory -- Hart and the rule of recognition -- How to do things with plans -- The making of a legal system -- What law is -- Legal reasoning and judicial decision making -- Hard cases -- Theoretical disagreements -- Dworkin and distrust -- The economy of trust -- The interpretation of plans -- The value of legality.

This book frames the development of Llewellyn’s thinking and describes the difference between what rules literally prescribe and what is actually done, with ...

Introduction: From legal realism to naturalized jurisprudence -- A note on legal indeterminacy -- Part I. American legal realism and its critics -- Rethinking legal realism: toward a naturalized jurisprudence (1997) -- Legal realism and legal positivism reconsidered (2001) -- Is there an "American" jurisprudence? (1997) -- Postscript to Part I: Interpreting legal realism -- Part II. Ways of naturalizing jurisprudence -- Legal realism, hard positivism, and the limits of conceptual analysis (1998, 2001) -- Why Quine is not a postmodernist (...) (1997) -- Beyond the Hart/Dworkin debate: the methodology problem in jurisprudence (2003) -- Part III. Naturalism, morality, and objectivity -- Moral facts and best explanations (2001) -- Objectivity, morality, and adjudication (2001) -- Law and objectivity (2002). (shrink)

In "The Rule of Rules" Larry Alexander and Emily Sherwin examine this dilemma.

Shapiro has recently argued that Dworkin posed a new objection to legal positivism in Law's Empire, to which positivists, he says, have not adequately responded. Positivists, the objection goes, have no satisfactory account of what Dworkin calls “theoretical disagreement” about law, that is, disagreement about “the grounds of law” or what positivists would call the criteria of legal validity. I agree with Shapiro that the critique is new, and disagree that it has not been met. Positivism can not offer an (...) explanation that preserves the “face value” of theoretical disagreements, because the only intelligible dispute about the criteria of legal validity is an empirical or “head count” dispute, i.e., a dispute about what judges are doing, and how many of them are doing it. Positivism, however, has two other explanations for theoretical disagreement, which “explain away” rather than preserve the “face value” disagreement. According to positivists, either theoretical disagreements are disingenuous, in the sense that the parties, consciously or unconsciously, are really trying to change the law, that is, they are trying to say, as Dworkin puts it, “what it should be” not “what the law is”; or they are simply in error, that is, they honestly think there is a fact of the matter about what the grounds of law are, and thus what the law is, in the context of their disagreement, but they are mistaken, because, in truth, there is no fact of the matter about the grounds of law in this instance precisely because there is no convergent practice of behavior among officials constituting a Rule of Recognition on this point. The “Disingenuity” and “Error Theory” accounts of theoretical disagreement are explored, with attention to the theoretical desiderata at stake in choosing between competing explanatory theories. Particular attention is given to the best explanation for Riggs v. Palmer in light of the actual historical context of the decision and other opinions by the Riggs judges in contemporaneous cases. (shrink)

This paper describes one way in which a precise reason model of precedent could be developed, based on Grant Lamond’s general idea that a later court is constrained to reach a decision that is consistent an earlier court’s assessment of the balance of reasons. The account provided here has the additional advantage of showing how this reason model can be reconciled with the traditional idea that precedential constraint involves rules, as long as these rules are taken to be defeasible.

This paper contributes to our formal understanding of the common law — especially the nature of the reasoning involved, but also its point, or justification, in terms of social coordination. I present two apparently distinct models of constraint by precedent in the common law, establish their equivalence, and argue for a perspective according to which courts are best thought of, not as creating and modifying rules, but as generating a social priority ordering on reasons through a procedure that is piecemeal, (...) distributed, and responsive to particular circumstances. (shrink)

The scope of Supreme Court precedent is capacious. Justices of the Court commonly defer to sweeping rationales and elaborate doctrinal frameworks articulated by their predecessors. This practice infuses judicial precedent with the prescriptive power of enacted constitutional and statutory text. The lower federal courts follow suit, regularly abiding by the Supreme Court’s broad pronouncements. These phenomena cannot be explained by—and, indeed, oftentimes subvert—the classic distinction between binding holdings and dispensable dicta. This Article connects the scope of precedent with recurring and (...) foundational debates about the proper ends of judicial interpretation. A precedent’s forward- looking effect should not depend on the superficial categories of holding and dictum. Instead, it should reflect deeper normative commitments that define the nature of adjudication within American legal culture. The account that emerges is one in which the scope of precedent is inextricably linked to interpretive theory and constitutional understandings. Divergent methods of interpretation, from originalism to common law constitutionalism and beyond, carry distinctive implications for describing a precedent’s constraining effect. So, too, do various methods of interpretation in the statutory and common law contexts. Ultimately, what should determine the scope of precedent is the set of premises—regarding the judicial role, the separation of powers, and the relevance of history, morality, and policy—that informs a judge’s methodological choices. (shrink)