Legal Argumentation

Researchers face perennial difficulties in studying live jury deliberation. As a result, the academic community struggles to reach a consensus on key matters of legal reform concerning jury trials. The hurdles faced by empirical jury researchers are often legal or institutional. This note argues that the legal and institutional barriers preventing live deliberation research should be removed and discusses two forms that live deliberation research could take.

Courts use inferences to the best explanation in many contexts and for a variety of purposes. Yet our understanding of lawyers’ uses of this inferential form is insufficient. In this article, after briefly introducing this inferential form, I set out to: (i) explain the structure of such arguments by reference to an argument scheme; (ii) clarify the types of claims courts support by deploying such inferences while attempting to justify acting in accordance with explanatory principles (inferences to the best explanation—principles, (...) or IBE-Ps); (iii) offer an account of the ‘explanatory’ relationship on which IBE-P is predicated; (iv) explain what precisely can count as part of the explanandum in an IBE-P; and (v) discuss criteria that might be used to adjudicate which is the best among rival explanations. (shrink)

This chapter discusses slippery slope arguments that are used in the context of common-law precedent. The slippery slope argument is often treated as a fallacy. Nonetheless, using or answering slippery slope worries in legal decision-making is conspicuously common. And not only that: several authors have remarked that slippery slope arguments can often be valid, even strong, in the context of legal precedent. In this chapter, I investigate why this should be so. It is argued that there is a special type (...) of slippery slope argument, the precedent slippery slope. Understanding its mechanism reveals why slippery slopes are so strong in the context of precedent. (shrink)

dialectical frameworks have been introduced as a formalism for modeling argumentation allowing general logical satisfaction conditions and the relevant argument evaluation. Different criteria used to settle the acceptance of arguments are called semantics. Semantics of ADFs have so far mainly been defined based on the concept of admissibility. However, the notion of strongly admissible semantics studied for abstract argumentation frameworks has not yet been introduced for ADFs. In the current work we present the concept of strong admissibility of interpretations for (...) ADFs. Further, we show that strongly admissible interpretations of ADFs form a lattice with the grounded interpretation as the maximal element. We also present algorithms to answer the following decision problems: whether a given interpretation is a strongly admissible interpretation of a given ADF, and whether a given argument is strongly acceptable/deniable in a given interpretation of a given ADF. In addition, we show that the strongly admissible semantics of ADFs forms a proper generalization of the strongly admissible semantics of AFs. (shrink)

The First World Congress on Evidential Legal Reasoning, organised by the Legal Culture Chair of the University of Girona, was held between June 6 and 8, 2018. The Congress was attended by 350 participants and featured 18 speakers from four continents. The three days of formal and informal presentations and discussions yielded excellent results, strengthening the interrelation between the legal communities and specialists of different traditions. The 18 papers from the Congress, reviewed by their authors based on the discussions and (...) the suggestions made at the Congress, have been compiled in this book. (shrink)

In questo contributo, propongo una breve riflessione su un punto centrale, ma a mio parere problematico, dell’approccio inferenzialista al ragionamento giuridico proposto da Canale e sviluppato nel volume “En busca de lo implícito” (Externado, 2020). In particolare, mi concentrerò sul modo in cui, all’interno del modello di ragionamento giuridico proposto, è (ri)costruito il contesto istituzionale giudiziale per quanto riguarda l’autorità giudiziaria (§2), i partecipanti (§3), e l’ambito del modello stesso (§4).

The purpose of this essay is to defend a claim that a certain consideration, which I call unworkability, is universally and necessarily relevant to legal reasoning. By that I mean that it is a consideration that must carry legal weight in the justification of some judicial decisions in every legal system in which (1) all disputed matters of law can be adjudicated, and (2) all judicial decisions are to be legally justified. Unworkability's necessary relevance has important implications for a theory (...) of relevance presented by Rolf Sartorius. On this theory, nearly all considerations that are relevant to a judicial decision are supplied by legal principles embedded in the legal rules and decisions, or by extralegal principles dependent, in some way, on the legal principles. (The exceptions to the embedding thesis that Sartorius would, no doubt, recognize are elaborated in the text but can be set aside here.) But there are possible legal systems which do not contain an embedded legal principle concerning unworkability; and nonetheless, unworkability is relevant to judicial reasoning in those systems. Hence, a theory of relevance that relies on principles embedded in the content of rules is too simplistic. Some substantive considerations are relevant for other reasons. (shrink)

Critical review of "The Philosophy of Legal Change," edited by Maciej Chmieliński and Michał Rupniewski, the first volume on its subject matter, with some general remarks on the philosophical methodology of conceptualising legal change.

This paper proposes an argumentation-based procedure for legal interpretation, by reinterpreting the traditional canons of textual interpretation in terms of argumentation schemes, which are then classified, formalized, and represented through argument visualization and evaluation tools. The problem of statutory interpretation is framed as one of weighing contested interpretations as pro and con arguments. The paper builds an interpretation procedure by formulating a set of argumentation schemes that can be used to comparatively evaluate the types of arguments used in cases of (...) contested statutory interpretation in law. A simplified version of the Carneades Argumentation System is applied in a case analysis showing how the procedure works. A logical model for statutory interpretation is finally presented, covering pro-tanto and all-things-considered interpretive conclusions. -/- . (shrink)

Das hier zu besprechende Buch 'Rhetorik für Plädoyer und forensischen Streit' von T. Lübbig kündigt einen Beitrag im Bereich ‚Rhetorik und Recht‘ an, und dabei insbesondere eine Untersuchung zur Rhetorik in der juristischen Praxis.

The article describes the potential of abductive legal reasoning as a means of systematically exploring the role of inferences within legal reasoning. Starting out from the structures of abduction as originally presented by Peirce in his four‐horsemen example, the author points to the fact that Peirce actually employed a hypothesis that targeted an institutional fact. Hence the abductive inference has a great potential for categorising new phenomena under norms, yet it is undertheorised within the field of law as compared to (...) other fields of science. The article presents the idea of comparison in the frame of “double abduction” as an important feature of legal reasoning. (shrink)

Statutory interpretation involves the reconstruction of the meaning of a legal statement when it cannot be considered as accepted or granted. This phenomenon needs to be considered not only from the legal and linguistic perspective, but also from the argumentative one - which focuses on the strategies for defending a controversial or doubtful viewpoint. This book draws upon linguistics, legal theory, computing, and dialectics to present an argumentation-based approach to statutory interpretation. By translating and summarizing the existing legal interpretative canons (...) into eleven patterns of natural arguments - called argumentation schemes - the authors offer a system of argumentation strategies for developing, defending, assessing, and attacking an interpretation. Illustrated through major cases from both common and civil law, this methodology is summarized in diagrams and maps for application to computer sciences. These visuals help make the structures, strategies, and vulnerabilities of legal reasoning accessible to both legal professionals and laypeople. (shrink)

The primary aim of this chapter is to explain the nature of evidential reasoning, the characteristic difficulties encountered, and the tools to address these difficulties. Our focus is on evidential reasoning in criminal cases. There is an extensive scholarly literature on these topics, and it is a secondary aim of the chapter to provide readers the means to find their way in historical and ongoing debates.

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.

This paper traces the evolution of the concept of presumption from a subordinate part of the Roman law to a central feature of legal disputations in medieval law. Special attention will be given to the second edition of the Libellus Pylei Disputato rius by Pilius of Medicina, and to the anonymous Tractatus de Praesumptionibus. My analysis will emphasize elements of these developments useful in the renewed discussion about the role of presumptions in argumentation stimulate d particularly by Richard Gaskins' Burdens (...) of Proof in Modern Discourse, highlighting the paradigmatic significance of rhetorical manipulations of burdens of proof in legal reasoning. (shrink)

The Logic of Legal Requirements. Essays on Defeasibility, edited by Jordi Ferrer Beltrán and Giovanni Battista Ratti, and published by Oxford University Press in 2012, is a very much welcome contribution to one of the most discussed topics in the contemporary legal theory and philosophy. Defeasibility is connected to many essential issues such as the nature of legal reasoning, the structure of legal norms and legal system, the concept of legal validity, as well as the mechanisms and limits of..

In this paper a theoretical definition that helps to explain how the logical structure of legal presumptions is constructed by applying the Carneades model of argumentation developed in artificial intelligence. Using this model, it is shown how presumptions work as devices used in evidentiary reasoning in law in the event of a lack of evidence to assist a chain of reasoning to move forward to prove or disprove a claim. It is shown how presumptions work as practical devices that may (...) be useful in cases in which there is insufficient evidence to prove the claim to an appropriate standard of proof. (shrink)

In “The Gettier Problem and Legal Proof,” I argue that epistemic conditions that undermine knowledge in Gettier-type cases also potentially undermine legal verdicts. For this reason, I argue, there is a deeper connection between knowledge and legal proof than is typically presupposed or argued for in the scholarly legal literature. To support these claims, I present several examples illustrating how conditions that render epistemically justified beliefs merely accidentally true (and thus disqualify them as cases of genuine knowledge) may also render (...) evidentially well-supported verdicts merely accidentally true for similar reasons. Such “Gettierized” verdicts, I contend, fail to realize the epistemic goal or aim of legal proof. Thus I conclude there, legal proof includes something like a knowledge requirement—in the sense that legal verdicts aim not only at truth and sufficient evidential support but also, as with knowledge, at an appropriate connection between their truth and justifying evidential support. (shrink)

Defeasible rules are said to allow for the following two-staged sequence, viz., that p → q and yet p & r → not-q. This is puzzling because in the logic of conditionals the sufficiency of p for q cannot normally be undermined if one adds to the antecedent a further proposition r. Critics argue that the better approach to comprehending defeasibility is explicitly to represent the limiting factor r in a single-stage articulation of the rule, viz., as p & not-r (...) → q. This is a more complete statement of the rule; where the old rule announced, confidently and without qualification, that in circumstances or class of cases p consequence q follows, the new rule admits from the outset that q only follows if we add the qualifier that limits the antecedent circumstances to the smaller class of cases p & not-r. This is not only more complete, the critics argue, it is also a more accurate or truthful statement of the rule. The rule p → q, articulated at the first stage of the defeasible process, is only a pretender encountered along the way to this more complete truth. In this paper I show how, and why, contrary to the critics, the process of private law adjudication supports the multi-staged structure and representation of defeasible legal rules. What matters when one party makes a claim against another party is not so much that the claim is true (or even that it is advanced as a legitimate claim under the rule that is most likely to be true), but rather that the claim is of the sort that the party can justifiably say is true. The latter, at least, is what carries the plaintiff past the initial burden of proof, and what calls for the defendant to reply if the plaintiff is not to carry the day. I illustrate the argument by way of the court’s reluctance in a tort case to entertain a purely statistical basis for a plaintiff’s claim that the defendant has caused her injury. Rather, the court will insist on direct evidence that appears to arise out of the particular circumstances of the case as the plaintiff alleges them to be, and even if, as a purely statistical matter, the latter sort of claim is less likely to be true than the claim grounded in pure statistical likelihood. I relate this argument for defeasible rules (and against rules that are more truthful) to some important arguments offered by the philosopher Stephen Darwall in his recent book The Second Person Viewpoint. Private law’s defeasible rules, I argue, capture the special respect (and interpersonal accountability) that attaches only to rights arising out of “second personal” claiming (and counterclaiming) and which are not realizable merely as a matter of “third personal” (moral) truth. (shrink)

In this paper we will analyse the issue of defeasibility in the law, taking into account research carried out in philosophy, artificial intelligence and legal theory. We will adopt a very general idea of legal defeasibility, in which we will include all different ways in which certain legal conclusions may need to be abandoned, though no mistake was made in deriving them. We will argue that defeasibility in the law involves three different aspects, which we will call inference‐based defeasibility, process‐based (...) defeasibility, and theory‐based defeasibility. Only the integration of these three perspectives allows us to provide a satisfactory account of the role of defeasibility in legal reasoning. (shrink)

This book provides a systematic analysis of many common argumentation schemes and a compendium of 96 schemes. The study of these schemes, or forms of argument that capture stereotypical patterns of human reasoning, is at the core of argumentation research. Surveying all aspects of argumentation schemes from the ground up, the book takes the reader from the elementary exposition in the first chapter to the latest state of the art in the research efforts to formalize and classify the schemes, outlined (...) in the last chapter. It provides a systematic and comprehensive account, with notation suitable for computational applications that increasingly make use of argumentation schemes. (shrink)

In this article we discuss the so-called cantilever argument, used by Joseph Carens to establish a human right to global freedom of movement. First of all, we criticise Carens’s classification of the argument as both an “analogy” and a “logical extension”. Comparing the cantilever argument with Carens’s popular feudalism analogy suggests understanding it solely as an extension, but certainly not as a “logical” one. Finally, we sketch out whether, by means of the cantilever, he succeeds in shifting the burden of (...) proof to the opponents of such a human right. (shrink)

The purpose of this paper is to analyze the structure and the defeasibility conditions of argument from analogy, addressing the issues of determining the nature of the comparison underlying the analogy and the types of inferences justifying the conclusion. In the dialectical tradition, different forms of similarity were distinguished and related to the possible inferences that can be drawn from them. The kinds of similarity can be divided into four categories, depending on whether they represent fundamental semantic features of the (...) terms of the comparison or non-semantic ones, indicating possible characteristics of the referents. Such distinct types of similarity characterize different kinds of analogical arguments, all based on a similar general structure, in which a common genus is abstracted. Depending on the nature of the abstracted common feature, different rules of inference will apply, guaranteeing the attribution of the analogical predicate to the genus and to the primary subject. This analysis of similarity and the relationship thereof with the rules of inference allows a deeper investigation of the defeasibility conditions. (shrink)

Legal Reason describes and explains the process of analogical reasoning, which is the distinctive feature of legal argument. It challenges the prevailing view, urged by Edward Levi, Cass Sunstein, Richard Posner and others, which regards analogical reasoning as logically flawed or as a defective form of deductive reasoning. It shows that analogical reasoning in the law is the same as the reasoning used by all of us routinely in everyday life and that it is a valid form of reasoning derived (...) from the innate human capacity to recognize the general in the particular, on which thought itself depends. The use of analogical reasoning is dictated by the nature of law, which requires the application of rules to particular facts. Written for scholars as well as students and persons generally who are interested in law, Legal Reason is written in clear, accessible prose, with many examples drawn from the law and from everyday experience. (shrink)

This thesis addresses two enduring issues in legal theory-- rationality and its association with rule of law values--by offering detailed models of two patterns of legal reasoning. One is reasoning by analogy. The other is the inference process that legal reasoners use when they defer epistemically to scientific experts in the course of reaching legal decisions. Discussions in both chapters reveal that the inference pattern known as "abduction" is a deeply important element of many legal inferences, including analogy and epistemic (...) deference to experts--something that has been largely unrecognized in legal theory. After presenting a detailed model of analogy, Chapter 1 argues that legal reasoning by analogy, like analogical argument in logic, mathematics, and the natural sciences, possesses a great deal of rational force when properly executed. Chapter 2 investigates the reasoning process by which non-expert legal reasoners defer epistemically to the judgments of scientists. It presents five main conclusions or explanations. Every practical syllogism actually consists of two distinct chains of inference, and what is usually considered in writings on practical reasoning to be the minor premise of a practical syllogism is actually the conclusion of a separate chain of argument. When a practical reasoner defers epistemically to a theoretical expert, this separate chain of argument has a special structure, which is modeled in Chapter 2. The non-expert legal reasoner must always make a prescriptive practical judgment about the standard of epistemic appraisal and level of epistemic confidence that the reasoner requires of scientific evidence before it may be relied upon in reaching a legal decision. Legal systems should be committed to an emergent rule of law ideal identified and referred to as "intellectual due process" which condemns epistemically arbitrary reasoning processes insofar as they play a role in legal decisionmaking. Since non-arbitrariness is a necessary condition of both epistemic and legal legitimacy, we have compelling reason to doubt that the non-arbitrariness condition can be met when non-experts defer epistemically to scientific experts. (shrink)

A meticulous examination of the logical and axiological principles of analogical inference in legal reasoning. The first part presents an elementary but useful survey of traditional and modern logical analyses of analogy and analogical inference. In the second part, these concepts are examined in their juridical applications. Much is made of the conclusion that analogical inference cannot be rendered "binding" by logical considerations alone; to make up for this in legal reasoning, axiological principles must be employed.--L. K. B.

Lloyd Weinreb’s Legal Reason: The Use of Analogy in Legal Argument is the latest contribution to a familiar debate. Since the Second World War, a recurrent theme of Anglo–American jurisprudence has been the desire to explain and justify the process of courtroom adjudication, especially at appellate level. Such explanation and justification has proved extraordinarily elusive. According to the doctrine of separation of powers, the functions of the judiciary must differ from those of the legislature and executive. We therefore need to (...) know the scope of power of each branch of government. Yet, at the same time, judges must be able to declare any inappropriate acts or decisions of either the executive or legislature to be unlawful, illegal and/or unconstitutional. Such explanation and justification is thus tasked with showing how, in a representative democracy, an unelected judiciary stands as a bulwark against tyranny — even if, as in the early years of German fascism, it is a tyranny of the majority — without at the same time causing it to usurp the legitimate functions of the elected representatives of the people. In other words, a theory of judicial adjudication is required which both denies the judiciary any power to trespass on the legitimate territory of the other branches of government, while still permitting — nay, requiring — judges to hold the legislature and executive to account where the political process is unable to do so. This is, in short, the conundrum of the “rule of law.”. (shrink)

This paper applies recent work on scripts and stories developed as tools of evidential reasoning in artificial intelligence to model the use of argument from analogy as a rhetorical device of persuasion. The example studied is Gerry Spence’s closing argument in the case of Silkwood v. Kerr-McGee Corporation, said to be the most persuasive closing argument ever used in an American trial. It is shown using this example how argument from analogy is based on a similarity premise where similarity between (...) two cases is modeled using the device of a story scheme from the hybrid theory of legal evidential reasoning (Bex in Arguments, stories and criminal evidence: a formal hybrid theory. Springer, Dordrecht 2011). It is shown how the rhetorical strategy of Spence’s argumentation in the closing argument interweaves argument from analogy with explanation through three levels. (shrink)

Legal reasoning is not the same as the reasoning in mathematics or the physical sciences. It is like them. Specifying the likeness in more detail, and deciding whether there is more likeness than unlikeness, are the kinds of tasks that legal reasoning is better adapted to do than mathematical or scientific reasoning.

Argument from analogy is a common and formidable form of reasoning in law and in everyday conversation. Although there is substantial literature on the subject, according to a recent survey ( Juthe 2005) there is little fundamental agreement on what form the argument should take, or on how it should be evaluated. Th e lack of conformity, no doubt, stems from the complexity and multiplicity of forms taken by arguments that fall under the umbrella of analogical reasoning in argumentation, dialectical (...) studies, and law. Modeling arguments with argumentation schemes has proven useful in attempts to refine the analyst’s understanding of not only the logical structures that shape the backbone of the argument itself, but also the logical underpinning of strategies for evaluating it, strategies based on the semantic categories of genus and relevance. By clarifying the distinction between argument from example and argument from analogy, it is possible to advance a useful proposal for the treatment of argument from analogy in law. (shrink)

This paper identifies a type of multi-source (case-based) reasoning and differentiates it from other types of analogical reasoning. Work in cognitive science on mental space mapping or conceptual blending is used to better understand this type of reasoning. The type of argument featured herein will be shown to be a kind of source-blended argument. While it possesses some similarities to traditionally conceived analogical arguments, there are important differences as well. The triple contract (a key development in the usury debates of (...) the fifteenth and sixteenth centuries) will be shown to make use of source-blended arguments. (shrink)