Successful accounts of analogy in law have two burdens to discharge. First, they must reflect the fact that the conclusion of an argument by analogy is a normative claim about how to decide a certain case. Second, they must not fail to accord relevance to the fact that the source case was authoritatively decided in a certain way. We argue in the first half of this paper that the common view of the structure of analogical arguments in law cannot overcome (...) these hurdles. In the second half we develop an original account that aims to succeed where others failed. (shrink)

In recent years several proposals to view reasoning with legal cases as theory construction have been advanced. The most detailed of these is that of Bench-Capon and Sartor, which uses facts, rules, values and preferences to build a theory designed to explain the decisions in a set of cases. In this paper we describe CATE (CAse Theory Editor), a tool intended to support the construction of theories as described by Bench-Capon and Sartor, and which produces executable code corresponding to a (...) theory. CATE has been used in a series of experiments intended to explore a number of issues relating to such theories, including how the theories should be constructed, how sets of values should be compared, and the representation of cases using structured values as opposed to factors. (shrink)

The A Simili Argument draws the conclusion that a target case has a normative property Q since it shares a relevant property P with a source case. It can be seen as a complex inference constituted by three inferential steps: An abduction of the relevant property P , an induction of the class having that property, and a deduction of the target's having property Q . A major problem of this argument is the characterization of the property relevance. The standard (...) answer refers to the notion of ratio: It is the ratio that fixes what is relevant for what. But the determination of the ratio is often a difficult and controversial task. This issue is considered here from an inferentialist point of view, claiming that the ratio and relevance are determined by the normative statuses reciprocally attributed by the speakers in the context of legal argumentation. (shrink)

Selon une thèse largement partagée, le droit et une pratique sociale et les contributions des participants sont complémentaires les unes des autres. Dans ces conditions, le raisonnement juridique consiste d’abord en une interprétation de ces pratiques et présuppose un point de vue interne de la part de celui qui souhaite en rendre compte. Le raisonnement juridique est ainsi conçu comme une argumentation pratique, subordonnée aux exigences de la rationalité car ceux qui participent à la pratique juridique sont contraints de donner (...) des raisons à leur action et ces raisons tissent un réseau de contraintes. Très séduisante, cette thèse qui doit beaucoup à la critique des réalistes par Hart, n’en demeure pas moins justiciable de quelque critique. (shrink)

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 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)

Modelling reasoning with legal cases has been a central concern of AI and Law since the 1980s. The approach which represents cases as factors and dimensions has been a central part of that work. In this paper I consider how several varieties of the approach can be applied to the interesting case of Popov v Hayashi. After briefly reviewing some of the key landmarks of the approach, the case is represented in terms of factors and dimensions, and further explored using (...) theory construction and argumentation schemes approaches. (shrink)

We provide a retrospective of 25 years of the International Conference on AI and Law, which was first held in 1987. Fifty papers have been selected from the thirteen conferences and each of them is described in a short subsection individually written by one of the 24 authors. These subsections attempt to place the paper discussed in the context of the development of AI and Law, while often offering some personal reactions and reflections. As a whole, the subsections build into (...) a history of the last quarter century of the field, and provide some insights into where it has come from, where it is now, and where it might go. (shrink)

The research described here explores the idea of using Supreme Court oral arguments as pedagogical examples in first year classes to help students learn the role of hypothetical reasoning in law. The article presents examples of patterns of reasoning with hypotheticals in appellate legal argument and in the legal classroom and a process model of hypothetical reasoning that relates them to work in cognitive science and Artificial Intelligence. The process model describes the relationships between an advocate’s proposed test for deciding (...) a case or issue, the facts of the hypothetical and of the case to be decided, and the often conflicting legal principles and policies underlying the issue. The process model of hypothetical reasoning has been partially implemented in a computerized teaching environment, LARGO (“Legal ARgument Graph Observer”) that helps students identify, analyze, and reflect on episodes of hypothetical reasoning in oral argument transcripts. Using LARGO, students reconstruct examples of hypothetical reasoning in the oral arguments by representing them in simple diagrams that focus students on the proposed test, the hypothetical challenge to the test, and the responses to the challenge. The program analyzes the diagrams and provides feedback to help students complete the diagrams and reflect on the significance of the hypothetical reasoning in the argument. The article reports the results of experiments evaluating instruction of first year law students at the University of Pittsburgh using the LARGO program as applied to Supreme Court personal jurisdiction cases. The learning results so far have been mixed. Instruction with LARGO has been shown to help law student volunteers with lower LSAT scores learn skills and knowledge regarding hypothetical reasoning better than a text-based approach, but not when the students were required to participate. On the other hand, the diagrams students produce with LARGO have been shown to have some diagnostic value, distinguishing among law students on the basis of LSAT scores, posttest performance, and years in law school. This lends support to the underlying model of hypothetical argument and suggests using LARGO as a pedagogically diagnostic tool. (shrink)

Reasoners compare problems to prior cases to draw conclusions about a problem and guide decision making. All Case-Based Reasoning (CBR) employs some methods for generalizing from cases to support indexing and relevance assessment and evidences two basic inference methods: constraining search by tracing a solution from a past case or evaluating a case by comparing it to past cases. Across domains and tasks, however, humans reason with cases in subtly different ways evidencing different mixes of and mechanisms for these components.In (...) recent CBR research in Artificial Intelligence (AI), five paradigmatic approaches have emerged: statistically-oriented, model-based, planning/design-oriented, exemplar-based, and adversarial or precedent-based. The paradigms differ in the assumptions they make about domain models, the extent to which they support symbolic case comparison, and the kinds of inferences for which they employ cases. (shrink)

This article describes recent jurisprudential accountsof analogical legal reasoning andcompares them in detail to the computational modelof case-based legal argument inCATO. The jurisprudential models provide a theoryof relevance based on low-levellegal principles generated in a process ofcase-comparing reflective adjustment. Thejurisprudential critique focuses on the problemsof assigning weights to competingprinciples and dealing with erroneously decidedprecedents. CATO, a computerizedinstructional environment, employs ArtificialIntelligence techniques to teach lawstudents how to make basic legal argumentswith cases. The computational modelhelps students test legal hypotheses againsta database of (...) legal cases, draws analogiesto problem scenarios from the database, andcomposes arguments by analogy with a setof argument moves. The CATO model accountsfor a number of the important featuresof the jurisprudential accounts, includingimplementing a kind of reflective adjustment.It also avoids some of the problems identifiedin the critique; for instance, it deals withweights in a non-numeric, context-sensitivemanner. The article concludes by describingthe contributions AI research can make tojurisprudential investigations of complexcognitive phenomena of legal reasoning. Forinstance, unlike the jurisprudential models,CATO provides a detailed account of how togenerate multiple interpretations of a citedcase, downplaying or emphasizing the legalsignificance of distinctions in terms of thepurposes of the law as the argument contextdemands. (shrink)

This paper presents criticisms of the method for moral and political philosophy known as ?reflective equilibrium? (RE), or in its fuller form ?wide reflective equilibrium? (WRE). This negative purpose has an ulterior positive aim: to set off, by favourable contrast, an alternative approach based on analogical argument as an instrument of an evolving (liberal) tradition. WRE derives from John Rawls but has been broadly endorsed. Though a meta?theory, it involves a certain way of construing liberalism. This essay's target is in (...) key part that construal. It seeks an approach to moral?political philosophy, and to liberalism in particular, that is at once rationally grounded and contextually oriented, and provides for explanation as well as justification. WRE fails on all counts, plus others. Section I presents WRE and suggests the alternative. Section II presents the critique of WRE, partly drawing on established criticisms and partly presenting new ones. Section III opposes the application suggested for WRE by (surprisingly) a critic of Rawls, M. Sandel. The preferability of the analogical alternative is demonstrated throughout. (shrink)

This paper presents a methodology to design and implement programs intended to decide cases, described as sets of factors, according to a theory of a particular domain based on a set of precedent cases relating to that domain. We useDialectical Frameworks, a recent development in AI knowledge representation, as the central feature of our design method. ADFs will play a role akin to that played by Entity–Relationship models in the design of database systems. First, we explain how the factor hierarchy (...) of the well-known legal reasoning system CATO can be used to instantiate an ADF for the domain of US Trade Secrets. This is intended to demonstrate the suitability of ADFs for expressing the design of legal cased based systems. The method is then applied to two other legal domains often used in the literature of AI and Law. In each domain, the design is provided by the domain analyst expressing the cases in terms of factors organised into an ADF from which an executable program can be implemented in a straightforward way by taking advantage of the closeness of the acceptance conditions of the ADF to components of an executable program. We evaluate the ease of implementation, the performance and efficacy of the resulting program, ease of refinement of the program and the transparency of the reasoning. This evaluation suggests ways in which factor based systems, which are limited by taking as their starting point the representation of cases as sets of factors and so abstracting away the particular facts, can be extended to address open issues in AI and Law by incorporating the case facts to improve the decision, and by considering justification and reasoning using portion of precedents. (shrink)

I characterize the deductivist ideal of justification and, following to a great extent Toulmin’s work The Uses of Argument, I try to explain why this ideal is erroneous. Then I offer an alternative model of justification capable of making our claims to knowledge about substantial matters sound and reasonable. This model of justification will be based on a conception of justification as the result of good argumentation, and on a model of argumentation which is a pragmatic linguistic reconstruction of Toulmin’s (...) model of argument. (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)

In attempting to build intelligent litigation support tools, we have moved beyond first generation, production rule legal expert systems. Our work integrates rule based and case based reasoning with intelligent information retrieval.When using the case based reasoning methodology, or in our case the specialisation of case based retrieval, we need to be aware of how to retrieve relevant experience. Our research, in the legal domain, specifies an approach to the retrieval problem which relies heavily on an extended object oriented/rule based (...) system architecture that is supplemented with causal background information. We use a distributed agent architecture to help support the reasoning process of lawyers. (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)

We discuss several aspects of legal arguments, primarily arguments about the meaning of statutes. First, we discuss how the requirements of argument guide the specification and selection of supporting cases and how an existing case base influences argument formation. Second, we present,our evolving taxonomy of patterns of actual legal argument. This taxonomy builds upon our much earlier work on argument moves and also on our more recent analysis of how cases are used to support arguments for the interpretation of legal (...) statutes. Third, we show how the theory of argument used by CABARET, a hybrid case-based/rule-based reasoner, can support many of the argument patterns in our taxonomy. (shrink)

The BankXX system models the process of perusing and gathering information for argument as a heuristic best-first search for relevant cases, theories, and other domain-specific information. As BankXX searches its heterogeneous and highly interconnected network of domain knowledge, information is incrementally analyzed and amalgamated into a dozen desirable ingredients for argument (called argument pieces), such as citations to cases, applications of legal theories, and references to prototypical factual scenarios. At the conclusion of the search, BankXX outputs the set of argument (...) pieces filled with harvested material relevant to the input problem situation.This research explores the appropriateness of the search paradigm as a framework for harvesting and mining information needed to make legal arguments. In this article, we describe how legal research fits the heuristic search framework and detail how this model is used in BankXX. We describe the BankXX program with emphasis on its representation of legal knowledge and legal argument. We describe the heuristic search mechanism and evaluation functions that drive the program. We give an extended example of the processing of BankXX on the facts of an actual legal case in BankXX's application domain — the good faith question of Chapter 13 personal bankruptcy law. We discuss closely related research on legal knowledge representation and retrieval and the use of search for case retrieval or tasks related to argument creation. Finally we review what we believe are the contributions of this research to the understanding of the diverse disciplines it addresses. (shrink)

This article joins a somewhat nascent, but growing, body of scholarship addressing the ethical obligation to pay tax. The analysis is grounded to the ethical duty to obey law generally and highlights two competing orientations to statutory interpretation. The norms of self-interested advocacy suggest that tax planners should assert that interpretation that will generate the most wealth for the client. The norms of professional advising, by contrast, direct the tax planner to interpret tax law with reference to plain meaning, interpretive (...) maxims, court precedents, and legislative purpose. When the two orientations differ, the ethical duty to obey law requires the tax planner to recommend, and for the taxpayer to follow, the latter view. Case studies drawn from a Louisiana sales tax avoidance scheme and from Google’s profit-shifting activities illustrate the ethical issues incumbent in tax interpretation. (shrink)

. This paper offers a survey of the current state of Artificial Intelligence and Law, and makes recommendations for future research. Two main areas of investigation are discussed: the practical work on intelligent legal information systems, and the theoretical work on computational models of legal reasoning. In both areas, the knowledge representation problem is identified as the most important issue facing this field.

Robert H. Holden, in ‘The Public University's Unbearable Defiance of Being’ (2009, Educational Philosophy and Theory, 41:5, pp. 575–591) argues that the public university ought to welcome the infusion of relevant beliefs, including religious ones, in carrying out its research and teaching responsibilities. In this paper, I examine whether he has shown that some opinions are suppressed, whether he has shown that other views are hegemonic, the central argument that lies behind his thinking, and then consider the educational consequences of (...) his position. (shrink)

The question of whether the normative testimony of ethics experts should be admissible under the rules of evidence has been the subject of much debate. Professor Imwinkelried's paper is an effort to get us, for a moment, to change that subject. He seeks to turn our attention, instead, to a means by which bioethics experts’ normative analyses might come before the court without regard to the rules of evidence - a means lying formally outside those rules’ jurisdiction. The court, he (...) argues, may freely consider evidence from expert bioethicists so long as it is performing a legislative rather than an adjudicative function. The rules of evidence apply to the court's efforts to find the facts of a particular case, Imwinkelried argues, but they do not constrain the court's investigations relative to its creative law-making efforts. (shrink)

The question of whether the normative testimony of ethics experts should be admissible under the rules of evidence has been the subject of much debate. Professor Imwinkelried's paper is an effort to get us, for a moment, to change that subject. He seeks to turn our attention, instead, to a means by which bioethics experts’ normative analyses might come before the court without regard to the rules of evidence - a means lying formally outside those rules’ jurisdiction. The court, he (...) argues, may freely consider evidence from expert bioethicists so long as it is performing a legislative rather than an adjudicative function. The rules of evidence apply to the court's efforts to find the facts of a particular case, Imwinkelried argues, but they do not constrain the court's investigations relative to its creative law-making efforts. (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 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)

Critical Legal Studies poses a direct and expressed challenge to the basic tenets of American legal education and scholarship. Critical Legal Studies postulates that law is not a scientific exercise involving the application of objective principles, but rather a creative process involving the selection of conflicting rules which has the effect of reinforcing the existing political order. In an effort to explain the contribution of Critical Legal Studies to argumentation theory, this essay briefly discusses the role of legal reasoning in (...) the American legal system, describes and critiques Legal Positivism, lays the intellectual foundation for Critical Legal Studies, and considers the implications that this conception of jurisprudence has for argumentation theory. (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)

Bruce Waller has defended a deductive reconstruction of the kinds of analogical arguments found in ethics, law, and metaphysics. This paper demonstrates the limits of such a reconstruction and argues for an alternative. non-deductive reconstruction. It will be shown that some analogical arguments do not fit Waller's deductive schema, and that such a schema does not allow for an adequate account of the strengths and weaknesses of an analogical argument. The similarities and differences between the account defended herein and the (...) Trudy Govier's account are discussed as well. (shrink)

Bruce Waller has defended a deductive reconstruction of the kinds of analogical arguments found in ethics, law, and metaphysics. This paper demonstrates the limits of such a reconstruction and argues for an alternative. non-deductive reconstruction. It will be shown that some analogical arguments do not fit Waller's deductive schema, and that such a schema does not allow for an adequate account of the strengths and weaknesses of an analogical argument. The similarities and differences between the account defended herein and the (...) Trudy Govier's account are discussed as well. (shrink)

Informal justice often is castigated as rough justice, procedurally unauthorized and substantively unrationalized and prone to error. Yet those same features are present, to some extent, in formal justice as well: they do not form the basis for any sharp categorical contrast between formal and informal justice. Furthermore, some roughness in justice may be no bad thing. Certain of those elements of roughness in formal justice are inextricably bound up with other features of formal justice that are rightly deemed morally (...) important. And rough informal justice can sometimes be used to change formal justice in more just directions. (shrink)

The principle of bivalence is the assertion that every statement is either true or else false. Its legal analog, however, must be formulated relative to particular legal systems and in terms of validity rather than truth. It asserts that every statement of law that can be formulated in the vocabulary of a given legal system is valid or else invalid in that system. A line of New York cases is traced, beginning with Thomas v. Winchester . This case, which involved (...) a poison mislabeled as a medicine, established an exception to the rule that a manufacturer or supplier is never liable for negligence to a remote purchaser. The court made an exception because a poison is an “imminently dangerous” thing. How far may this exception be applied to other fact‐situations? Some subsequent cases are examined, and it is considered whether there is no correct answer in these instances and, more dramatically, whether more than one correct answer is tenable. In either event the legal analog of bivalence would seem to fail. (shrink)

A natural language is an organic living thing; and meanings change as words take on new, and shed old, connotations. Recent philosophy of language has paid little attention to the growth of meaning; radical philosophers like Feyerabend and Rorty have suggested that meaning-change undermines the pretensions of science to be a rational enterprise. Thinkers in the classical pragmatist tradition, however -Peirce in philosophy of science and, more implicitly, Holmes in legal theory- both recognized the significance of growth of meaning, and (...) understood how it can contribute to the progress of science and to the adaptation of a legal system to changing circumstances. This paper develops these insights, and illustrates them by reference to the growth of meaning of "DNA" from the identification of "nuclein" to the discovery of mtDNA almost a century later, and the growth of meaning of "the establishment of religion" in the First Amendment to the U.S. Constitution from its ratification in 1791 to the present day. Arguing that the growth of meaning can indeed contribute to rationality, it also shows why narrowly formal models are inadequate both to science and to law. Un lenguaje natural es una cosa viviente orgánica, y los significados cambian a medida que las palabras adoptan nuevas connotaciones y abandonan viejas. La filosofía del lenguaje reciente ha prestado poca atención al desarrollo del significado; filósofos radicales, como Feyerabend y Rorty han sugerido que el cambio de significado socava las pretensiones de la ciencia de ser una empresa racional. Pensadores en la tradición pragmatista clásica, sin embargo -Peirce en la filosofía de la ciencia y, más implícitamente, Holmes en la teoría del Derecho- reconocieron la importancia del desarrollo del significado y comprendieron cómo éste puede contribuir al progreso de la ciencia y a la adaptabilidad de un sistema jurídico a las circunstancias cambiantes. Este trabajo desarrolla estas ideas, y las ilustra por medio de una referencia a el desarrollo del significado de "ADN" desde la identificación de la "nucleína" hasta el descubrimiento del ADN mitocondrial casi un siglo más tarde, y el desarrollo del significado de "el establecimiento de una religión" en la Primera Enmienda de la Constitución de los Estados Unidos desde su ratificación en 1791 hasta la actualidad. Argumentando que el desarrollo del significado puede contribuir mucho a la racionalidad, también muestra por qué los modelos estrechamente formales son inadecuados, tanto para la ciencia como para el Derecho. (shrink)

In this thesis I outline a view of primary legislation from a systems perspective. I suggest that systems theory and, in particular, autopoietic theory, as modified by field theory, is a mechanism for understanding how society operates. The description of primary legislation that I outline differs markedly from any conventional definition in that I argue that primary legislation is not, and indeed cannot be, either a law or any of the euphemisms that are usually accorded to an enactment by a (...) parliament. I cite two reasons for such a conclusion. The primary reason for my conclusion is that I see primary legislation as being an output of a particular subsystem of society, while the law is the output of another subsystem of society. I argue that these outputs are the discrete products of separate subsystems of society. I argue that primary legislation should be viewed as a trinity. The first state of this trinity is that, upon enactment, primary legislation is a brute fact in that it is but a thing and the only property of this thing is that of being a text. The second state of this trinity is that following the act of enactment, the thing enacted will be reproduced and this reproduction is a separate thing that will sit in some repository until used. The third state of this trinity is that, upon use, this thing that is primary legislation will be transformed into an object and the user will attribute such functions and attributes to that object as are appropriate to the context within which the object is used. The thing has therefore become an object and an institutional fact. The second reason for my conclusion that primary legislation is not a law relates to the fact that the thing that is primary legislation is a text and the only function of a text is that it is available to be read. That is to say, of itself, a text is incapable of doing anything: it is the reader who defines the status of the text and attributes functions and attributes. Upon use, primary legislation thus becomes a censored input for future action and one of these actions may be some statement by a court of law. I assert that the view of primary legislation that has been accepted within the body politic is the product of the discourse of a particular subsystem of society that I have designated 'the legal practice', and I outline why and how this has occurred. Outlining a view about primary legislation also necessitates outlining a view as to the nature of the law. I assert that the law is a myth and I see this myth as a product of the discourse of the legal practice. I have asserted that although it is the judges that state the law, such statements flow from the discourse of those who practise the law. (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.