This paper argues that not only does history matter to legal epistemology, but also that understanding legal epistemology can yield a certain understanding of the past. The paper focuses on the common law practice of precedent and argues that there is no set of rules, principles, reasons or material facts that constitute the fixed or foundational content of past decisions, but rather that what is taken by a judge resolving a particular dispute to be the content of past decisions depends (...) on the active and creative construal of relevance engaged in by that judge. Precedents are better thought of as `thick resources with dynamic content'. Such content is constrained by a variety of stabilising practices, but never so constrained as to determine how it can be construed to be relevant. This image of law's past may offer a general view of the past as something with which we can actively and creatively relate in the course of coping with the present. (shrink)

Computational models of legal precedent-based reasoning developed in AI and Law are typically based on the simplifying assumption that the background set of precedent cases is consistent. Besides being unrealistic in the legal domain, this assumption is problematic for recent promising applications of these models to the development of explainable AI methods. In this paper I explore a model of legal precedent-based reasoning that, unlike existing models, does not rely on the assumption that the background set of precedent cases is (...) consistent. The model is a generalization of the reason model of precedential constraint. I first show that the model supports an interesting deontic logic, where consistent obligations can be derived from inconsistent case bases. I then provide an explanation of this surprising result by proposing a reformulation of the model in terms of cases that support a new potential decision and cases that conflict with it. Finally, I show that the reformulation of the model allows us to verify that inconsistent case bases do not make verification that a decision is permissible substantially more complex than consistent case bases and to introduce intuitive criteria to compare different permissible decisions. (shrink)

Courts in common law systems decide cases as they decided like cases in the past—even if they believe they decided those past cases wrongly. What, if anything, justifies this practice? I defend two main claims. The first is that fairness favors treating like cases alike if that means treating them correctly. The second is that, in general, a court is as likely to decide an instant case correctly as it was to decide a previous and like case correctly. Together, these (...) claims tell us that departing from and following precedent are equally likely to yield a correct decision, whereas following precedent may also yield a fair decision. Adhering to precedent is the dominant alternative, as a result. Fairness therefore justifies the practice of precedent. While this conclusion is not original, my argument for it is. (shrink)

In this article I defend what I call a ‘particularist approach to arguments by analogy.’ Particularism is opposed to generalism, which is the thesis that arguments by analogy require a universal principle that covers cases compared and guarantees the conclusion. Particularism rejects this claim and holds that arguments by analogy operate on particular cases. I elaborate on two ideas that support this position. On the one hand, I contend that an analogy can be seen as a parallelism of argumentative relationships, (...) drawing on the distinction between similarity and analogy (Gentner 1983) and on the meta-argumentative account of arguments by analogy (Woods and Hudak 1989). On the other hand, I argue that universal principles are not necessary neither for the analysis nor the evaluation of arguments by analogy (Govier 1989) and that, rather than being a requirement, they can be seen as by-products of good analogies. (shrink)

A general practice of precedent is one that can plausibly apply to any well-functioning legal system. This practice, which can be grounded in the Rule of Law, needs to make it the case that courts always have a legal reason for following relevant precedent – even if the precedent is morally suboptimal, so long as it is not evil. Without this reason, a precedent may be treated as having no legal influence for the later court (‘the Null Model’), and this (...) runs counter to the Rule of Law. On top of this reason, courts may have a general legal obligation to follow precedent – stare decisis – but this risks entrenching morally bad decisions in the law. We need, therefore, a type of reason that lies in between the Null Model and stare decisis as a necessary step for any future justification of stare decisis. But how can courts have a legal reason for following morally suboptimal precedent? They can have that reason, I argue, in virtue of a specific judicial duty, positively laid down in a legal source, which aims to advance the Rule of Law in an institutionalised way. In this article, I aim to explain and justify that judicial duty. (shrink)

The first issue of _Artificial Intelligence and Law_ journal was published in 1992. This paper provides commentaries on landmark papers from the first decade of that journal. The topics discussed include reasoning with cases, argumentation, normative reasoning, dialogue, representing legal knowledge and neural networks.

ABSTRACTLegal reasoning is commonly thought of as being based on either rules or analogies. More specifically, there is ongoing debate regarding whether precedential reasoning is best characterized as rule-based or analogical. This article continues that work by comparing recent and representative approaches from each camp, namely, Stevens's analogical model and the “rule-based” model of Horty and Rigoni. In the course of the comparison improvements on each approach are suggested and the improved models serve as the basis for the ultimate evaluation. (...) The evaluation demonstrates that the “best” approach depends on the goals one has in theorizing legal reasoning as well as the jurisprudential assumptions one is willing to make. (shrink)

In this article I defend what Mark Greenberg has labeled the standard picture of law against the attack on it by Greenberg and Scott Hershovitz. I point out that law on the standard picture’s conception of it has moral virtues that Greenberg's own moral impact theory and Hershovitz’s similar theory lack. Moreover, it avoids a vicious circularity that bedevils Greenberg’s theory.

The standard model of precedential constraint holds that a court is equally free to modify a precedent of its own and a precedent of a superior court—overruling aside, it does not differentiate horizontal and vertical precedents. This paper shows that no model can capture the U.S. doctrine of precedent without making that distinction. A precise model is then developed that does just that. This requires situating precedent cases in a formal representation of a hierarchical legal structure, and adjusting the constraint (...) that a precedent imposes based on the relationship of the precedent court and the instant court. The paper closes with suggestions for further improvements of the model. (shrink)

This paper investigates the process of reasoning through which a judge determines whether a precedent-case gives her a binding reason to follow in her present-case. I review the objections that have been raised against the two main accounts of reasoning by precedent: the rule-account and the analogy-account. I argue that both accounts can be made viable by amending them to meet the objections. Nonetheless, I believe that there is an argument for preferring accounts that integrate analogical reasoning: any account of (...) reasoning by precedent that is descriptively minimally adequate will leave some room for judicial discretion. Discretion should be used under consideration of the best legally relevant arguments for and against a decision. Integrating analogical reasoning helps the judge to bring to her own attention the strongest case for following. Analogical reasoning also eases the recognition of possible reasons for distinguishing. Thereby, it facilitates a more balanced decision-making process. (shrink)

Arguers sometimes cite a decision made in an earlier situation as a reason for making the equivalent decision in a later situation. I argue that there are two kinds of “case-to-case arguments”. First, there are arguments by precedent, which cite the mere existence of the past decision as a reason to decide in the same way again now, independent of the past decision’s merits. Second, there are case-to-case arguments from parralel reasoning which presuppose that the past decision was justified and (...) are used to show that an equivalent present decision would also be justified. Both arguments are a type of argument by analogy. They differ in their structures and conditions of cogency, even though they often look the same in presentation. Their similar appearance poses a risk of miss-evaluation and fallacious use. Therefore a clearly theorized distinction is important. (shrink)

Modern belief revision theory is based to a large extent on partial meet contraction that was introduced in the seminal article by Carlos Alchourrón, Peter Gärdenfors, and David Makinson that appeared in 1985. In the same year, Alchourrón and Makinson published a significantly different approach to the same problem, called safe contraction. Since then, safe contraction has received much less attention than partial meet contraction. The present paper summarizes the current state of knowledge on safe contraction, provides some new results (...) and offers a list of unsolved problems that are in need of investigation. (shrink)

Work on analogy has been done from a number of disciplinary perspectives throughout the history of Western thought. This work is a multidisciplinary guide to theorizing about analogy. It contains 1,406 references, primarily to journal articles and monographs, and primarily to English language material. classical through to contemporary sources are included. The work is classified into eight different sections (with a number of subsections). A brief introduction to each section is provided. Keywords and key expressions of importance to research on (...) analogy are discussed in the introductory material. Electronic resources for conducting research on analogy are listed as well. (shrink)

Legal theorists tend to focus on disagreement over the law, and yet a theory of law should also explain why lawyers and judges agree on the law as often as they do. To that end, this article first pins down a precise sense in which there can be pervasive agreement on the law. It then argues that such agreement obtains in the United States and likely in many other jurisdictions as well. Finally, it contends that Hartian Positivism offers a straightforward (...) explanation of this phenomenon and, indeed, a better explanation than rival theories, like Ronald Dworkin’s Law as Integrity or Scott Shapiro’s Planning Theory. Given the ubiquity of legal agreement, Hartian Positivism’s explanatory superiority in this regard is a strong, albeit still not dispositive, consideration in its favour. The broader lesson is that theories of law should give greater priority to explaining legal agreement than many theories now do. (shrink)

Some authors argue that the rule-of-law ideal gives judges a prima facie duty to provide a determinate formulation of the precedent’s general norm in all their precedent-opinions. I question that claim. I agree that judges have a duty to decide their cases based on reasons and that they should formulate these reasons in their opinions. I also agree that formulations of general norms should be the goal of common-law development and that judges have a duty to contribute to the realization (...) of this goal. However, I argue that judges may sometimes do so better if they do not provide a determinate formulation of a general norm in their opinion. Often, judges may not feel confident that they are able to formulate a good general norm for their precedent decision, even if they believe that their decision is both correct and justifiable through argument. In this case, various reasons speak against providing a determinate formulation of a general norm, including rule-of-law reasons. (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)

The first issue of Artificial Intelligence and Law journal was published in 1992. This paper provides commentaries on nine significant papers drawn from the Journal’s second decade. Four of the papers relate to reasoning with legal cases, introducing contextual considerations, predicting outcomes on the basis of natural language descriptions of the cases, comparing different ways of representing cases, and formalising precedential reasoning. One introduces a method of analysing arguments that was to become very widely used in AI and Law, namely (...) argumentation schemes. Two relate to ontologies for the representation of legal concepts and two take advantage of the increasing availability of legal corpora in this decade, to automate document summarisation and for the mining of arguments. (shrink)

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)

Taking into account one of the meanings of the expression binding precedent and stipulating a definition for that meaning, this article aims to contribute to the concept's structural characterization. By this I mean the effort to identify the legal norms on which the existence and functioning of binding precedents depend and to show that these norms constitute a group of Hohfeldian legal relations between the courts whose precedents must be followed, the courts that must follow them, and the individuals whose (...) legal situations are as a result modified by the observance and the breach of those precedents. (shrink)

Coherentists fail to distinguish between the individual revision of a conviction and the intersubjective revision of a rule. This paper fills this gap. A conviction is a norm that, according to an individual, ought to be ascribed to a provision. By contrast, a rule is a judicially ascribed norm that controls a case and is protected by the formal principles of competence, certainty, and equality. A revision of a rule is the invalidation or modification such a judicially ascribed norm, provided (...) that the judge meets the burden of argumentation of formal principles. Thus, judges can revise their convictions without changing the law. (shrink)

The passage of time influences the content of the law and therefore also the validity of legal arguments. This is true even for charter-arguments, despite the widely held view that constitutional law is made to last. In this paper, I investigate the reason why the sanctity-of life argument against physician assisted suicide lost its validity between the Supreme Court decision in Rodriguez v. British Columbia in 1993 and Carter v. Canada in 2015. I suggest that a rhetorical approach to argument (...) evaluation is the best basis for a satisfying explanation. (shrink)

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)

The article considers two different interpretations of the reason model of precedent pioneered by John Horty. On a plausible interpretation of the reason model, past cases provide reasons to prioritize reasons favouring the same outcome as a past case over reasons favouring the opposing outcome. Here I consider the merits of this approach to the role of precedent in legal reasoning in comparison with a closely related view favoured by some legal theorists, according to which past cases provide reasons for (...) undercutting (or ‘excluding’) reasons favouring the opposing outcome. After embedding both accounts within a general default logic, I note some important differences between the two approaches that emerge as a result of plausible distinctions between rebutting and undercutting defeat in formal models of legal reasoning. These differences stem from the ‘preference independence’ of undercutting defeat. Undercutting reasons succeed in defeating opposing reasons irrespective of their relative strength. As a result, the two accounts differ in their account of the way in which precedents constrain judicial reasoning. I conclude by suggesting that the two approaches can be integrated within a single model, in which the distinction between undercutting and rebutting defeat is used to account for the distinction between strict and persuasive forms of precedential constraint. (shrink)

The doctrine of precedent, as it has evolved within the common law, has at its heart a form of reasoning—broadly speaking, alogic—according to which the decisions of earlier courts in particular cases somehow generalize to constrain the decisions of later courts facing different cases, while still allowing these later courts a degree of freedom in responding to fresh circumstances. Although the techniques for arguing on the basis of precedent are taught early on in law schools, mastered with relative ease, and (...) applied on a daily basis by legal practitioners, it has proved to be considerably more difficult to arrive at a theoretical understanding of the doctrine itself—a clear articulation of the underlying logic. (shrink)

The volume analyses and develops David Makinson’s efforts to make classical logic useful outside its most obvious application areas. The book contains chapters that analyse, appraise, or reshape Makinson’s work and chapters that develop themes emerging from his contributions. These are grouped into major areas to which Makinsons has made highly influential contributions and the volume in its entirety is divided into four sections, each devoted to a particular area of logic: belief change, uncertain reasoning, normative systems and the resources (...) of classical logic. Among the contributions included in the volume, one chapter focuses on the “inferential preferential method”, i.e. the combined use of classical logic and mechanisms of preference and choice and provides examples from Makinson’s work in non-monotonic and defeasible reasoning and belief revision. One chapter offers a short autobiography by Makinson which details his discovery of modern logic, his travels across continents and reveals his intellectual encounters and inspirations. The chapter also contains an unusually explicit statement on his views on the role of logic in philosophy. (shrink)

Proponents of strict rule-based theories of judicial reasoning in common-law systems have offered a number of criticisms of analogical alternatives. I explain these criticisms and show that at best they apply equally well to rule-based theories. Further, I show how the analogical theories explain a feature of judicial common-law reasoningthat rule-based theories ignore. Finally, I show that reason-based, analogical theories of common-law judicial reasoning, such as those offered by John Horty and Grant Lamond, offer especially strong rejoinders to the rule-theorist (...) objections and persuasive accounts of distinguishing. (shrink)

ABSTRACTAccording to the prioritized reason model of precedent, precedential constraint is explained in terms of the need for decision-makers to reconcile their decisions with a settled priority order extracted from past cases. The prioritized reason model of precedent departs from the view that common law rules comprise protected reasons for action. In this article I show that a model utilizing protected reasons and the prioritized reason model of precedential constraint are, in an important sense, equivalent. I then offer some reflections (...) on the philosophical significance of this result. I argue that the protected reason model is consistent with the phenomenology of precedential constraint. I suggest an account of precedential reasoning that reconciles the prioritized reason and protected reason models. (shrink)

I distinguish between two ways of understanding the effect of a decision as a precedent in the common law, which I refer to as the individual rule approach and the holistic approach. I consider the different versions of the common law that they would be expected to give rise to, which approach is more closely reflected in the practices of the common law, and why the holistic approach is preferable as a method for finding and developing the law in adjudication. (...) I explain why under the holistic approach the common law contains principles as well as rules, and I consider the two approaches in the light of the requirement of the rule of law, and I show how the holistic approach explains a version of the policy/principle distinction. (shrink)

Precedent is a central feature of legal practice, requiring courts to follow decisions reached in earlier cases, thereby transforming the decisions in individual cases into a source of law. This article examines two major questions associated with precedent: (a) how to characterise the way that precedent operates as a source of law; and (b) how to justify the requirement that courts follow earlier decisions regardless of the merits of those decisions. Precedents are often thought to create general legal rules, but (...) it is controversial whether this is the best way to understand their role in legal reasoning. Equally, it is unclear that the most common justifications for precedent unequivocally vindicate the practice. (shrink)

This paper explores the extension of formal accounts of precedential constraint to make use of a factor hierarchy with intermediate factors. A problem arises, however, because constraints expressed in terms of intermediate factors may give different outcomes from those expressed only using base level factors. We argue that constraints that use only base level factors yield the correct outcomes, but that intermediate factors play an important role in the justification and explanation of those outcomes. The discussion is illustrated with a (...) running example. (shrink)