This book identifies 25 argumentation schemes for presumptive reasoning and matches a set of critical questions to each.

Coalescent argumentation is a normative ideal that involves the joining together of two disparate claims through recognition and exploration of opposing positions. By uncovering the crucial connection between a claim and the attitudes, beliefs, feelings, values and needs to which it is connected dispute partners are able to identify points of agreement and disagreement. These points can then be utilized to effect coalescence, a joining or merging of divergent positions, by forming the basis for a mutual investigation of non-conflictual (...) options that might otherwise have remained unconsidered. The essay proceeds by defining and discussing ‘argument’, ‘position’ and ‘understanding’. These notions are then brought together to outline the concept of coalescent reasoning. (shrink)

A leading expert in informal logic, Douglas Walton turns his attention in this new book to how reasoning operates in trials and other legal contexts, with special emphasis on the law of evidence. The new model he develops, drawing on methods of argumentation theory that are gaining wide acceptance in computing fields like artificial intelligence, can be used to identify, analyze, and evaluate specific types of legal argument. In contrast with approaches that rely on deductive and inductive logic and (...) rule out many common types of argument as fallacious, Walton’s aim is to provide a more expansive view of what can be considered "reasonable" in legal argument when it is construed as a dynamic, rule-governed, and goal-directed conversation. This dialogical model gives new meaning to the key notions of relevance and probative weight, with the latter analyzed in terms of pragmatic criteria for what constitutes plausible evidence rather than truth. (shrink)

Use of argumentation methods applied to legal reasoning is a relatively new field of study. The book provides a survey of the leading problems, and outlines how future research using argumentation-based methods show great promise of leading to useful solutions. The problems studied include not only these of argument evaluation and argument invention, but also analysis of specific kinds of evidence commonly used in law, like witness testimony, circumstantial evidence, forensic evidence and character evidence. New tools for analyzing (...) these kinds of evidence are introduced. (shrink)

Argumentation involves offering and/or exchanging reasons – either reasons for adopting various attitudes towards specific propositional contents or else reasons for acting in various ways. This paper develops the idea that the force of reasons is through and through a normative force because what good reasons accomplish is precisely to give one a certain sort of entitlement to do what they are reasons for. The paper attempts to shed light on what it is to have a reason, how the (...) sort of entitlement arising from reasons differs from other species of entitlement and how the norms by which such entitlement is assessed obtain their status as norms. (shrink)

Relevant to, and drawing from, a range of disciplines, the chapters in this collection show the diversity, and applicability, of research in Bayesian argumentation.

In this paper we describe the impact that Walton’s conception of argumentation schemes had on AI and Law research. We will discuss developments in argumentation in AI and Law before Walton’s schemes became known in that community, and the issues that were current in that work. We will then show how Walton’s schemes provided a means of addressing all of those issues, and so supplied a unifying perspective from which to view argumentation in AI and Law.

A broad assumption in argumentation theory is that argumentation primarily regards resolving, confronting, or managing disagreement. This assumption is so fundamental that even when there does not appear to be any real disagreement, the disagreement is suggested to be present at some other level. Some have questioned this assumption (most prominently, Perelman and Olbrechts-Tyteca, and Doury), but most are reluctant to give up on the key idea that persuasion, the core of argumentation theory, can only regard disagreements. (...) We argue here that this assumption is false. Argument may be as much about strengthening or maintaining agreement as it is about disagreement. Once we see how argument is possible and manifestly enacted under conditions of agreement, then we have tools to explain otherwise curious fallacies and argumentative phenomena. (shrink)

A paramount, yet unresolved issue in personalised medicine is that of automated reasoning with clinical guidelines in multimorbidity settings. This entails enabling machines to use computerised generic clinical guideline recommendations and patient-specific information to yield patient-tailored recommendations where interactions arising due to multimorbidities are resolved. This problem is further complicated by patient management desiderata, in particular the need to account for patient-centric goals as well as preferences of various parties involved. We propose to solve this problem of automated reasoning with (...) interacting guideline recommendations in the context of a given patient by means of computational argumentation. In particular, we advance a structured argumentation formalism ABA+G (short for Assumption-Based Argumentation with Preferences (ABA+) and Goals) for integrating and reasoning with information about recommendations, interactions, patient’s state, preferences and prioritised goals. ABA+G combines assumption-based reasoning with preferences and goal-driven selection among reasoning outcomes. Specifically, we assume defeasible applicability of guideline recommendations with the general goal of patient well-being, resolve interactions (conflicts and otherwise undesirable situations) among recommendations based on the state and preferences of the patient, and employ patient-centered goals to suggest interaction-resolving, goal-importance maximising and preference-adhering recommendations. We use a well-established Transition-based Medical Recommendation model for representing guideline recommendations and identifying interactions thereof, and map the components in question, together with the given patient’s state, prioritised goals, and preferences over actions, to ABA+G for automated reasoning. In this, we follow principles of patient management and establish corresponding theoretical properties as well as illustrate our approach in realistic personalised clinical reasoning scenaria. (shrink)

The Handbook of Formal Argumentation is a community effort aimed at providing a comprehensive and up-to-date view of the state of the art and current trends in the lively research field of formal argumentation. The first volume of the Handbook is organised into five parts, containing nineteen chapters in all, each written by leading experts in the field. The first part provides a general and historical perspective on the field. The second part gives a comprehensive coverage of the (...) argumentation formalisms available in the literature at various levels of abstraction. The third part is devoted to cover some of the many dialogical aspects of argumentation, while the fourth one deals with algorithmic, computational and implementation issues. Finally, the fifth part provides some deeper analyses on the previously introduced topics. The Handbook of Formal Argumentation is an open-ended initiative of which the present volume is the first outcome. Further volumes are planned to cover topics not included in the present one and the initiative is conceived to grow by the support and feeding it receives from the community members. (shrink)

In this contribution, I will develop a comprehensive tool for the reconstruction and evaluation of argumentation from expert opinion. This is done by analyzing and then combining two dialectical accounts of this type of argumentation. Walton’s account of the ‘appeal to expert opinion’ provides a number of useful, but fairly unsystematic suggestions for critical questions pertaining to argumentation from expert opinion. The pragma-dialectical account of ‘argumentation from authority’ offers a clear and systematic, but fairly general framework (...) for the reconstruction and evaluation of this type of argumentation. The tool is developed by incorporating Walton’s critical questions into a pragma-dialectical framework. (shrink)

In this paper, I explore the relationship of virtue, argumentation, and philosophical conduct by considering the role of the specific virtue of intellectual humility in the practice of philosophical argumentation. I have three aims: first, to sketch an account of this virtue; second, to argue that it can be cultivated by engaging in argumentation with others; and third, to problematize this claim by drawing upon recent data from social psychology. My claim is that philosophical argumentation can (...) be conducive to the cultivation of virtues, including humility, but only if it is conceived and practiced in appropriately ‘edifying’ ways. (shrink)

Formal logic has often been seen as uniquely placed to analyze mathematical argumentation. While formal logic is certainly necessary for a complete understanding of mathematical practice, it is not sufficient. Important aspects of mathematical reasoning closely resemble patterns of reasoning in nonmathematical domains. Hence the tools developed to understand informal reasoning, collectively known as argumentation theory, are also applicable to much mathematical argumentation. This chapter investigates some of the details of that application. Consideration is given to the (...) many contrasting meanings of the word “argument”; to some of the specific argumentation-theoretic tools that have been applied to mathematics, notably Toulmin layouts and argumentation schemes; to some of the different ways that argumentation is implicated in mathematical practices; and to the social aspects of mathematical argumentation. (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)

Virtue theories have lately enjoyed a modest vogue in the study of argumentation, echoing the success of more far-reaching programmes in ethics and epistemology. Virtue theories of argumentation (VTA) comprise several conceptually distinct projects, including the provision of normative foundations for argument evaluation and a renewed focus on the character of good arguers. Perhaps the boldest of these is the pursuit of the fully satisfying argument, the argument that contributes to human flourishing. This project has an independently developed (...) epistemic analogue: eudaimonistic virtue epistemology. Both projects stress the importance of widening the range of cognitive goals beyond, respectively, cogency and knowledge; both projects emphasize social factors, the right sort of community being indispensable for the cultivation of the intellectual virtues necessary to each project. This paper proposes a unification of the two projects by arguing that the intellectual good life sought by eudaimonistic virtue epistemologists is best realized through the articulation of an account of argumentation that contributes to human flourishing. (shrink)

In this paper, I review and compare major literature on goals in argumentation scholarship, aiming to answer the question of how to take the different goals of arguers into account when analysing and evaluating public political arguments. On the basis of the review, I suggest to differentiate between the different goals along two important distinctions: first, distinguish between goals which are intrinsic to argumentation and goals which are extrinsic to it and second distinguish between goals of the act (...) of arguing and goals of argumentative interactions. Furthermore, I propose to analyse public political arguments as multi-purposive activity types and reconstruct the argumentative exchanges as a series of simultaneous discussions. This enables us to examine public political arguments from a perspective in which the intrinsic goals of argumentation are in principle instrumental for the achievement of the socio-political purposes of argumentation, and consequently, it makes our assessment of the argumentative quality of the argument also indicative of the quality of the socio-political processes to which the arguments contribute. (shrink)

This essay explores the role of informal logicand its application in the context of currentdebates regarding evidence-based medicine. This aim is achieved through a discussion ofthe goals and objectives of evidence-basedmedicine and a review of the criticisms raisedagainst evidence-based medicine. Thecontributions to informal logic by StephenToulmin and Douglas Walton are explicated andtheir relevance for evidence-based medicine isdiscussed in relation to a common clinicalscenario: hypertension management. This essayconcludes with a discussion on the relationshipbetween clinical reasoning, rationality, andevidence. It is argued that (...) informal logic hasthe virtue of bringing explicitness to the roleof evidence in clinical reasoning, and bringssensitivity to understanding the role ofdialogical context in the need for evidence inclinical decision making. (shrink)

An argumentation profile is defined as a methodological instrument for analyzing argumentative discourse considering distinct and interrelated dimensions: the types of argument used, their quality, and the emotions triggered. Walton’s theoretical contributions are developed as a coherent analytical and multifaceted toolbox for capturing these aspects. Argumentation schemes are used to detect and quantify the types of argument. Fallacy analysis and the assessment of the implicit premises retrieved through the schemes allow evaluating arguments. Finally, the frequency of emotive words (...) signals the most common emotions aroused. This method is illustrated through a corpus of argumentative tweets of three politicians. (shrink)

Bridging the gap between applied ethics and ethical theory, Ethical Argumentation draws on recent research in argumentation theory to develop a more realistic model of how ethical justification actually works.

The study presented here examines how interacting with a more capable interlocutor influences use of argumentation strategies in electronic discourse. To address this question, 54 young adolescents participating in an intervention centered on electronic peer dialogs were randomly assigned to either an experimental or control condition. In both conditions, pairs who held the same position on a social issue engaged in a series of electronic dialogs with pairs who held an opposing position. In the experimental condition, in some dialogs, (...) unbeknownst to them (because dialog took place electronically), the opponent was a more capable (“expert”) adult. Dialogs in the control condition were only with peers. Argumentation strategies of the experimental group who argued with the “expert” showed immediate strategy improvements in their subsequent peer dialogs, improvement absent in the control group (Cohen's d = 1.12). In particular, the experimental group showed greater use of counterargument in general and advanced forms of counterargument (undermining) that challenges the deeper premises or reasoning on which an argument is based. Implications with respect to mechanisms of change in the development of argumentation skills are considered. (shrink)

This paper proposes a formal top-level model of explaining the outputs of machine-learning-based decision-making applications and evaluates it experimentally with three data sets. The model draws on AI & law research on argumentation with cases, which models how lawyers draw analogies to past cases and discuss their relevant similarities and differences in terms of relevant factors and dimensions in the problem domain. A case-based approach is natural since the input data of machine-learning applications can be seen as cases. While (...) the approach is motivated by legal decision making, it also applies to other kinds of decision making, such as commercial decisions about loan applications or employee hiring, as long as the outcome is binary and the input conforms to this paper’s factor- or dimension format. The model is top-level in that it can be extended with more refined accounts of similarities and differences between cases. It is shown to overcome several limitations of similar argumentation-based explanation models, which only have binary features and do not represent the tendency of features towards particular outcomes. The results of the experimental evaluation studies indicate that the model may be feasible in practice, but that further development and experimentation is needed to confirm its usefulness as an explanation model. Main challenges here are selecting from a large number of possible explanations, reducing the number of features in the explanations and adding more meaningful information to them. It also remains to be investigated how suitable our approach is for explaining non-linear models. (shrink)

Argumentation, which can be abstractly defined as the interaction of different arguments for and against some conclusion, is an important skill to learn for everyday life, law, science, politics and business. The best way to learn it is to try it out on real instances of arguments found in everyday conversational exchanges and legal argumentation. The introductory chapter of this book gives a clear general idea of what the methods of argumentation are and how they work as (...) tools that can be used to analyze arguments. Each subsequent chapter then applies these methods to a leading problem of argumentation. Today the field of computing has embraced argumentation as a paradigm for research in artificial intelligence and multi-agent systems. Another purpose of this book is to present and refine tools and techniques from computing as components of the methods that can be handily used by scholars in other fields. (shrink)

Philosophy’s adversarial argumentation style is often noted as a factor contributing to the low numbers of women in philosophy. I argue that there is a level of adversariality peculiar to philosophy that merits specific feminist examination, yet doesn’t assume controversial gender differences claims. The dominance of the argument-as-war metaphor is not warranted, since this metaphor misconstrues the epistemic role of good argument as a tool of rational persuasion. This metaphor is entangled with the persisting narrative of embattled reason, which, (...) in turn, is linked to the sexism-informed narrative of the “man of reason” continually warding off or battling “feminine” unreason. (shrink)

John Woods and Brent Hudak’s theory on arguments by analogy (1989), although correct in its meta-argumentative approach, gives rise to problems when we consider the possibility of weighing reasons. I contend that this is an outcome of construing the relationship between the premises and the conclusion of arguments compared in argumentation by analogy as inferences. An interpretation in terms of reasons is proposed here. The reasons-based approach solves these problems and allows the theory to be extended to account for (...) a particular variant of argumentation by analogy in which the subjects of comparison are not arguments, but weighings of reasons. (shrink)

A pervasive aspect of human communication and sociality is argumentation: the practice of making and criticizing reasons in the context of doubt and disagreement. Argumentation underpins and shapes the decision-making, problem-solving, and conflict management which are fundamental to human relationships. However, argumentation is predominantly conceptualized as two parties arguing pro and con positions with each other in one place. This dyadic bias undermines the capacity to engage argumentation in complex communication in contemporary, digital society. This book (...) offers an ambitious alternative course of inquiry for the analysis, evaluation, and design of argumentation as polylogue: various actors arguing over many positions across multiple places. Taking up key aspects of the twentieth-century revival of argumentation as a communicative, situated practice, the polylogue framework engages a wider range of discourses, messages, interactions, technologies, and institutions necessary for adequately engaging the contemporary entanglement of argumentation and complex communication in human activities. (shrink)

Some authors have begun to appeal directly to studies of argumentation in their analyses of mathematical practice. These include researchers from an impressively diverse range of disciplines: not only philosophy of mathematics and argumentation theory, but also psychology, education, and computer science. This introduction provides some background to their work.

The detection of hate speech and fake news in political discourse is at the same time a crucial necessity for democratic societies and a challenge for several areas of study. However, most of the studies have focused on what is explicitly stated: false article information, language that expresses hatred, derogatory expressions. This paper argues that the explicit dimension of manipulation is only one – and the least problematic – of the risks of political discourse. The language of the unsaid is (...) much more dangerous and incomparably more difficult to detect, hidden in different types of fallacies and inappropriate uses of emotive language. Through a threefold coding scheme based on the instruments of argumentation theory and pragmatics, a corpus of argumentative tweets published by 4 politicians (Matteo Salvini, Donald Trump, Jair Bolsonaro, and Joseph Biden) within 6 months from their taking office (corresponding to the official end of their election campaign) is analyzed, detecting the types of argument, the fallacies, and the uses and misuses of “emotive words.” This coding results in the argumentation profiles of the speakers, which are compared statistically to show their different implicit strategies and deceptive tactics. (shrink)

The book offers a compact but comprehensive introductory overview of the crucial components of argumentation theory. In presenting this overview, argumentation is consistently approached from a pragma-dialectical perspective by viewing it pragmatically as a goal-directed communicative activity and dialectically as part of a regulated critical exchange aimed at resolving a difference of opinion. As a result, the book also systematically explains how the constitutive parts of the pragma-dialectical theory of argumentation, which are discussed in a number of (...) separate publications, hang together. The following crucial topics are discussed: argumentation theory as a discipline; the meta-theoretical principles of pragma-dialectics; the model of a critical discussion aimed at resolving a difference of opinion; fallacies as violations of a code of conduct for reasonable argumentative discourse; descriptive research of argumentative reality; analysis as theoretically-motivated reconstruction; strategic manoeuvring aimed at combining achieving effectiveness with maintaining reasonableness; the conventionalization of argumentative practices; prototypical argumentative patterns; pragma-dialectics amidst other approaches. Argumentation Theory: A Pragma-Dialectical Perspective is clearly written and makes argumentation theory understandable to all scholars and advanced students interested in argumentation research. (shrink)

Douglas Walton’s multitudinous contributions to the study of argumentation seldom, if ever, directly engage with argumentation in mathematics. Nonetheless, several of the innovations with which he is most closely associated lend themselves to improving our understanding of mathematical arguments. I concentrate on two such innovations: dialogue types (§1) and argumentation schemes (§2). I argue that both devices are much more applicable to mathematical reasoning than may be commonly supposed.

This paper reports preliminary work into the exploitation of argumentation schemes within dialogue games. We identify a property of dialogue games that we call “scheme awareness” that captures the relationship between dialogue game systems and argumentation schemes. Scheme awareness is used to examine the ways in which existing dialogue games utilise argumentation schemes and consequently the degree with which a dialogue game can be used to construct argument structures. The aim is to develop a set of guidelines (...) for dialogue game design, which feed into a set of Dialogue Game Description Language (DGDL) extensions in turn enabling dialogue games to better exploit argumentation schemes. (shrink)

The Pyrrhonist’s argumentative practice is characterized by at least four features. First, he makes a therapeutic use of arguments: he employs arguments that differ in their persuasiveness in order to cure his dogmatic patients of the distinct degrees of conceit and rashness that afflict them. Secondly, his arguments are for the most part dialectical: when offering an argument to oppose it to another argument advanced by a given dogmatist, he accepts in propria persona neither the truth of its premises and (...) conclusion nor the validity of its logical form. Thirdly, he avails himself of arguments in his own open-minded inquiry into the truth about a wide range of topics. Fourthly, Pyrrhonian argumentation is oppositional inasmuch as it typically works by producing oppositions among arguments that appear to the Pyrrhonist to be equipollent. In this article, I focus on the first three features with the aim of both shedding some light on them and determining whether they are in tension or coherently relate to each other. (shrink)

Virtue theories of argumentation (VTA) emphasize the roles arguers play in the conduct and evaluation of arguments, and lay particular stress on arguers’ acquired dispositions of character, that is, virtues and vices. The inspiration for VTA lies in virtue epistemology and virtue ethics, the latter being a modern revival of Aristotle’s ethics. Aristotle is also, of course, the father of Western logic and argumentation. This paper asks to what degree Aristotle may thereby be claimed as a forefather by (...) VTA. (shrink)

To create a programming environment for contract dispute resolution, we propose an extension of assumption-based argumentation into modular assumption-based argumentation in which different modules of argumentation representing different knowledge bases for reasoning about beliefs and facts and for representation and reasoning with the legal doctrines could be built and assembled together. A distinct novel feature of modular argumentation in compare with other modular logic-based systems like Prolog is that it allows references to different semantics in the (...) same module at the same time, a feature critically important for application of argumentation in legal domains like contract dispute resolution where the outcomes of court cases often depend on whether credulous or skeptical modes of reasoning were applied by the contract parties. We apply the new framework to model the doctrines of contract breach and mutual mistake. (shrink)

Empirical research in the field of legal interpretation shows that, in many cases, analogy argumentation is complex rather than simple. Traditional analytical approaches to analogy argumentation do not explore that complexity. In most cases analogy argumentation is reconstructed as a simple form of argumentation that consists of two premises and a conclusion. This article focuses on the question of how to analyze and evaluate complex analogy argumentation. It is shown how the pragma-dialectical approach provides clues (...) for analyzing complex analogy argumentation and how the criteria for evaluating analogy argumentation can be used to reconstruct these types of complex analogy argumentation in Dutch case law. The critical questions in the argumentation scheme do not only serve as a tool for analyzing arguments justifying analogy argumentation, but are also helpful in analyzing arguments against a specific analogy argumentation. (shrink)

This paper supports the need for health professionals to be trained in argumentation theory, by illustrating the challenges that they face in interacting with patients and according to the different models of consultation that patients prefer. While there is no ideal model of consultation that can be promoted universally, the ability to construct arguments in support of health professionals’ points of view, as well as the ability to engage in critical discussion with patients, translate in essential skills for reaching (...) patients’ agreement when communication develops through the interpretative model or the informed decision model or, eventually, shared decision-making. Keywords: models of consultation, argumentation skills, medical training, patient-centeredness, informed consent. (shrink)