Doug Walton, who died in January 2020, was a prolific author whose work in informal logic and argumentation had a profound influence on Artificial Intelligence, including Artificial Intelligence and Law. He was also very interested in interdisciplinary work, and a frequent and generous collaborator. In this paper seven leading researchers in AI and Law, all past programme chairs of the International Conference on AI and Law who have worked with him, describe his influence on their work.

Over the last five decades, philosophers of language have looked into the mechanisms for doing things with words. The same attention has not been devoted to how to undo those things, once they have been done. This paper identifies and examines three strategies to make one’s speech acts undone—namely, Annulment, Retraction, and Amendment. In annulling an act, a speaker brings to light its fatal flaws. Annulment amounts to recognizing an act as null, whereas retraction and amendment amount to making it (...) null. Speakers employ retraction to cancel the deontic updates engendered by a given act. They instead use amendment to adjust its degree of strength. I will argue that annulling, retracting, and amending are second-order speech acts, whose felicity conditions vary with the type of illocution they operate on. Undoing is therefore conceived of as a form of doing. Furthermore, I claim that, in calling off our acts, we undo the conventional or illocutionary effects of our words while leaving intact their past causal or perlocutionary outcomes. (shrink)

In the domain of medical science, factual evidence is usually considered as the criterion on which to base decisions and construct hypotheses. Evidence-based medicine is the translation of this approach into the field of patient care, and it means providing only the type of care that is based on evidence that proves its effectiveness and appropriateness. However, while the literature has focused on the types and force of evidence used to establish the recommendation and treatment guidelines, the problem of how (...) evidence is used in doctor–patient interactions to motivate, or refuse, treatment or habit change has been almost completely neglected. In this specific context, characterized by the epistemic unbalance between the interlocutors and a specific conversational goal, the scientific categories of evidence are often irrelevant. The goal of this paper is to address this challenge by analyzing the role evidence plays in doctor–patient interactions in diabetes care. After introducing an analytical distinction between the epistemic and the pragmatic aspect of evidence, we will propose a classification of the types and functions of evidence in chronic care communication, and illustrate its possible uses through its application to our corpus of diabetes-care consultations. From our qualitative analyses, it is possible to observe how in this communicative context a crucial role is played by the conflicts of evidence, in which providers correct patients’ uses of evidence leading them to using less defeasible levels of evidence. (shrink)

Resumen: En este trabajo propongo entender el desacoplamiento argumentativo, esto es, el hecho estructural de la argumentación de presentar algo como dato y luego la misma información como conclusión en otro argumento, como desacoplamiento de representaciones. Para lograr tal aproximación, discuto perspectivas provenientes de teorías cognitivas y evolutivas que describen este fenómeno tanto en comunicación intencional en otras especies como en infantes humanos. Se concluye discutiendo la relación existente entre esta capacidad cognitiva humana y el problema de reflexividad.: In this (...) paper, I propose to understand argumentative decoupling, that is, the structural fact of presenting something as data in one argument and then the same information as a conclusion in another argument, as the decoupling of representations. To achieve this approach, I discuss perspectives from cognitive and evolutionary theories that describe this phenomenon in intentional communication in other species, as well as in human infants. I conclude by discussing the relationship between this human cognitive capacity and the problem of reflexivity. (shrink)

The informal logic movement began as an attempt to develop – and teach – an alternative logic which can account for the real life arguing that surrounds us in our daily lives – in newspapers and the popular media, political and social commentary, advertising, and interpersonal exchange. The movement was rooted in research and discussion in Canada and especially at the University of Windsor, and has become a branch of argumentation theory which intersects with related traditions and approaches (notably formal (...) logic, rhetoric and dialectics in the form of pragma-dialectics). In this volume, some of the best known contributors to the movement discuss their views and the reasoning and argument which is informal logic’s subject matter. Many themes and issues are explored in a way that will fuel the continued evolution of the field. Federico Puppo adds an insightful essay which considers the origins and development of informal logic and whether informal logicians are properly described as a “school” of thought. In considering that proposition, Puppo introduces readers to a diverse range of essays, some of them previously published, others written specifically for this volume. (shrink)

Donald Trump’s speeches and messages are characterized by terms that are commonly referred to as “thick” or “emotive,” meaning that they are characterized by a tendency to be used to generate emotive reactions. This paper investigates how emotive meaning is related to emotions, and how it is generated or manipulated. Emotive meaning is analyzed as an evaluative conclusion that results from inferences triggered by the use of a term, which can be represented and assessed using argumentation schemes. The evaluative inferences (...) are regarded as part of the connotation of emotive words, which can be modified and stabilized by means of recontextualizations. The manipulative risks underlying the misuse and the redefinition of emotive words are accounted for in terms of presuppositions and implicit modifications of the interlocutors’ commitments. (shrink)

The article develops and justifies, on the basis of the epistemological argumentation theory, two central pieces of the theory of evaluative argumentation interpretation: 1. criteria for recognizing argument types and 2. rules for adding reasons to create ideal arguments. Ad 1: The criteria for identifying argument types are a selection of essential elements from the definitions of the respective argument types. Ad 2: After presenting the general principles for adding reasons (benevolence, authenticity, immanence, optimization), heuristics are proposed for finding missing (...) reasons, for deductive arguments, e.g., semantic tableaux are suggested. (shrink)

The concern for the role of emotion in argumentative encounters has rested upon the concept of emotion as arguments, emotions to obtain the adherence of the audience and reflect the virtues of a good arguer. In this paper, we focus on understanding emotion and argumentation based on cognitive approaches that identify the relationship between the two elements, to propose the use of emotion regulation strategies in deliberative dialogue. Bearing in mind that the intensity of emotional responses may, in some cases, (...) hamper one’s capacity to solve problems during a practical argument, we suggest that the use of emotion regulation strategies may favor deliberative dialogue, leading to more adaptive emotional responses and, in turn, better argumentative encounters, rendering decision-making more efficient. This article conceptualizes argumentation, revealing the historical path of emotion in studies on argumentation. It presents the concepts of emotion and emotion regulation, followed by the function of emotion regulation in argumentative encounters, illustrating this in two different situations. We conclude with the contribution made by the use of strategies for emotion regulation during deliberative dialogue. (shrink)

This paper advances an approach to relevance grounded on patterns of material inference called argumentation schemes, which can account for the reconstruction and the evaluation of relevance relations. In order to account for relevance in different types of dialogical contexts, pursuing also non-cognitive goals, and measuring the scalar strength of relevance, communicative acts are conceived as dialogue moves, whose coherence with the previous ones or the context is represented as the conclusion of steps of material inferences. Such inferences are described (...) using argumentation schemes and are evaluated by considering 1) their defeasibility, and 2) the acceptability of the implicit premises on which they are based. The assessment of both the relevance of an utterance and the strength thereof depends on the evaluation of three interrelated factors: 1) number of inferential steps required; 2) the types of argumentation schemes involved; and 3) the implicit premises required. (shrink)

When should you engage with difficult arguments against your cherished controversial beliefs? The primary conclusion of this book is that your obligations to engage with counterarguments are more limited than is often thought. In some standard situations, you shouldn't engage with difficult counterarguments and, if you do, you shouldn't engage with them open-mindedly. This conclusion runs counter to aspects of the Millian political tradition and political liberalism, as well as what people working in informal logic tend to say about argumentation. (...) -/- Not all misleading arguments wear their flaws on their sleeve. Each step of a misleading argument might seem compelling and you might not be able to figure out what's wrong with it. Still, even if you can't figure out what's wrong with an argument, you can know that it's misleading. One way to know that an argument is misleading is, counterintuitively, to lack expertise in the methods and evidence-types employed by the argument. When you know that a counterargument is misleading, you shouldn't engage with it open-mindedly and sometimes shouldn't engage with it at all. You shouldn't engage open-mindedly because you shouldn't be willing to reduce your confidence in response to arguments you know are misleading. And you sometimes shouldn't engage closed-mindedly, because to do so can be manipulative or ineffective. -/- In making this case, Jeremy Fantl discusses echo chambers and group polarization, the importance in academic writing of a sympathetic case for the opposition, the epistemology of disagreement, the account of open-mindedness, and invitations to problematic academic speakers. (shrink)

The purpose of this paper is to show the pervasive, though often implicit, role of arguments in negotiation dialogue. This holds even for negotiations that start from a difference of interest such as mere bargaining through offers and counteroffers. But it certainly holds for negotiations that try to settle a difference of opinion on policy issues. It will be demonstrated how a series of offers and counteroffers in a negotiation dialogue contains a reconstructible series of implicit persuasion dialogues. The paper (...) is a sequel to van Laar and Krabbe, in which we showed that for some differences of opinion it may be reasonable to shift from persuasion dialogue, aimed at a resolution of the difference on the merits, to negotiation dialogue, aimed at compromise, whereas in the present paper we show that such a shift need not amount to the abandonment of argumentation. Our main aim in this paper as well as in the previous one is to contribute to the theory of argumentation within the context of negotiation and compromise formation. (shrink)

The main goal of this paper is to investigate what explanatory resources Robert Brandom’s distinction between acknowledged and consequential commitments affords in relation to the problem of logical omniscience. With this distinction the importance of the doxastic perspective under consideration for the relationship between logic and norms of reasoning is emphasized, and it becomes possible to handle a number of problematic cases discussed in the literature without thereby incurring a commitment to revisionism about logic. One such case in particular is (...) the preface paradox, which will receive an extensive treatment. As we shall see, the problem of logical omniscience not only arises within theories based on deductive logic; but also within the recent paradigm shift in psychology of reasoning. So dealing with this problem is important not only for philosophical purposes but also from a psychological perspective. (shrink)

Argumentation schemes are forms of argument that capture stereotypical patterns of human reasoning, especially defeasible ones like argument from expert opinion, that have proved troublesome to view deductively or inductively. Much practical work has already been done on argumentation schemes, proving their worth in A1 [19], but more precise investigations are needed to formalize their structures. The problem posed in this paper is what form justification of a given scheme, as having a certain precise structure of inference, should take. It (...) is argued that defeasible argumentation schemes require both a systematic and a pragmatic justification, of a kind that can only be provided by the case study method of collecting key examples of arguments of the types traditionally classified as fallacies, and subjecting them to comparative examination and analysis. By this method, postulated structures for schemes can be formulated as hypotheses to solve three kinds of problems: (1) how to classify such arguments into different types, (2) how to identify their premises and conclusions, and (3) how to formulate the critical questions used to evaluate each type of argument. (shrink)

The paper offers a theoretical investigation regarding the sources of normativity in practical argument from the following perspective: Do we need objectively-minded, unbiased arguers or can we count on “good” argumentative processes in which individual biases cancel each other out? I will address this problem by analysing a detailed structure of practical argument and its varieties. I will argue that given the structure proposed, biased advocacy upholds reasonableness whenever the argumentative activity is adequately designed.

This paper uses argument diagrams, argumentation schemes, and some tools from formal argumentation systems developed in artificial intelligence to build a graph-theoretic model of relevance shown to be applicable as a practical method for helping a third party judge issues of relevance or irrelevance of an argument in real examples. Examples used to illustrate how the method works are drawn from disputes about relevance in natural language discourse, including a criminal trial and a parliamentary debate.

This paper focuses on argumentation in a specific institutional context: debate in the European Parliament. A parliamentary debate is a distinct argumentative activity type. In the pragma-dialectical approach, argumentative activity types are defined as conventionalized argumentative practices in which the possibilities for strategic manoeuvring are predetermined. What are the characteristics of the activity type of a debate in European Parliament that predetermine the possibilities for strategic manoeuvring? What kind of constraints and opportunities for strategic manoeuvring can be distinguished?

What should a virtue theory of argumentation say about fallacious reasoning? If good arguments are virtuous, then fallacies are vicious. Yet fallacies cannot just be identified with vices, since vices are dispositional properties of agents whereas fallacies are types of argument. Rather, if the normativity of good argumentation is explicable in terms of virtues, we should expect the wrongness of bad argumentation to be explicable in terms of vices. This approach is defended through analysis of several fallacies, with particular emphasis (...) on the ad misericordiam. (shrink)

After C. L. Hamblin's groundbreaking work Fallacies, re-interpreting what used to be known as "mistakes in reasoning" or "bad arguments" since Aristotle, the study of fallacies started to bloom, coming up with ever new perspectives and conceptualizations of what should count as a mistake in reasoning and argumentation, and why a certain kind of reasoning should at all be considered a mistake. This paper will be concerned with two questions. First, an epistemological one: do we commit fallacies, or do we (...) use them? Secondly, a methodological one: when we detect a fallacy, on what conceptual grounds do we differentiate between committed and used fallacies? Aren't we forced to commit "fallacies" whenever we talk about other people, their views, or their work? Examples from Critical Discourse Analysis will be used to extensively illustrate this point. (shrink)

This paper scrutinizes some peculiarities of the culture of Internet argumentation: it is a qualitative pragma-dialectical study of different strategies arguers employ to question or attack argumentation of their opponents in online political discussion forums. The basic assumption of the paper is that this particular context of argumentation—or: argumentative activity type—creates special opportunities and constraints for critical reactions regarding propositional content and relevance of argumentation. These opportunities and constraints, it is argued, may lead online discussions to being endless, yet not (...) necessarily fruitless from an argumentative perspective. (shrink)

People argue to reconcile differences of opinion, but reconciliation may fail to happen. In these cases, most theorists assume arguers are left with the same disagreement from which they started. This is too optimistic, since disagreement might instead escalate, and this may happen because of the argumentative practice, not in spite of it. These dangers depend on epistemological, pragmatic, and cultural factors, and show why arguers should be careful in picking their dialogical fights.

Design deliberation refers to the process of thoughtfully weighing options, before making a design decision. This process is strongly related to argumentation, not only because of the well-known relation between argumentation and deliberation, but also due to characteristics of the design process. However, no structural model of team design deliberation exists to guide designers’ practice. This paper checks the hypothesis of inter-dependence between argument structures and group decision-making struc-ture as expressed through prescribed deliberation stages.

This paper presents the results of a quantitative study in which self-report scales were developed to measure four of the six dialogue types proposed by Walton : persuasion, negotiation, information-seeking, and eristic dialogues. The paper details the research design, presents the measurement instruments developed, and describes the analyses conducted to assess the dimensionality and reliability of the proposed scales.

The paper aims to bring together and unify two traditions in studying dialogue as a game: dialogical logic introduced by Lorenzen ; and persuasion dialogue systems as specified by Prakken. We propose a system which allows the elimination of both informal and formal fallacies. To this end, we reconstruct dialogical logic in terms of speech acts as suggested in.

This paper uses the language of formal dialectics to explore how argumentation schemes and their critical questions can be characterized as an extension to traditional dialectical systems. The aim is to construct a dialectical system in which the set of locutions is extended to include scheme-based moves the set of structural rules describes the roles that critical questioning can play; and the set of commitment rules distinguishes between exceptions and assumptions.

In this paper the authors give a brief overview of the theoretical background of their research project “Linguistic indicators of argumentative moves.” Starting from the pragma-dialectical ideal model of a critical discussion, they design dialectical profiles for capturing the moves that may or must be made at a particular stage or sub-stage of such a discussion. They explain how these dialectical profiles can be methodically exploited for systematically identifying the verbal expressions that can be indicative of any of these moves (...) in argumentative practice. (shrink)

La oposición a una estricta separación entre las dimensiones dialéctica y retórica de la actividad argumentativa es una de las aportaciones más destacadas y peculiares de la denominada escuela holandesa sobre argumentación. Frans H. van Eemeren y Peter Houtlosser reaccionaron contra una separación estricta entre dialéctica y retórica en varios trabajos, pero uno de los más inspiradores es sin duda su artículo “William the Silent’s argumentative discourse” (1998) presentado en la ciudad de Ámsterdam con ocasión de la cuarta conferencia organizada (...) por la International Society for the Study of Argumentation (ISSA). Sobre este tema siguieron investigando para presentar un análisis de la perspectiva dialéctica inherente al caso de Guillermo I de Orange en un congreso de la Japan Debate Association en Tokio (van Eemeren y Houtlosser, 2000). (shrink)

The problem of establishing the best interpretation of a speech act is of fundamental importance in argumentation and communication in general. A party in a dialogue can interpret another’s or his own speech acts in the most convenient ways to achieve his dialogical goals. In defamation law this phenomenon becomes particularly important, as the dialogical effects of a communicative move may result in legal consequences. The purpose of this paper is to combine the instruments provided by argumentation theory with the (...) advances in pragmatics in order to propose an argumentative approach to meaning reconstruction. This theoretical proposal will be applied to and tested against defamation cases at common law. Interpretation is represented as based on a hierarchy of interpretative presumptions. On this view, the development of the logical form of an utterance is regarded as the result of an abductive pattern of reasoning in which various types of presumptions are confronted and the weakest ones are excluded. Conflicts of interpretations and equivocation become essentially interwoven with the dialectical problem of fulfilling the burden of defeating a presumption. The interpreter has a burden of explaining why a given presumption is subject to default, assuming that the speaker is reasonable and acting based on a set of shared expectations. (shrink)

Using tools like argument diagrams and profiles of dialogue, this paper studies a number of examples of everyday conversational argumentation where determination of relevance and irrelevance can be assisted by means of adopting a new dialectical approach. According to the new dialectical theory, dialogue types are normative frameworks with specific goals and rules that can be applied to conversational argumentation. In this paper is shown how such dialectical models of reasonable argumentation can be applied to a determination of whether an (...) argument in a specific case is relevant are not in these examples. The approach is based on a linguistic account of dialogue and text from congruity theory, and on the notion of a dialectical shift. Such a shift occurs where an argument starts out as fitting into one type of dialogue, but then it only continues to makes sense as a coherent argument if it is taken to be a part of a different type of dialogue. (shrink)

Trust is a natural mechanism by which an autonomous party, an agent, can deal with the inherent uncertainty regarding the behaviours of other parties and the uncertainty in the information it shares with those parties. Trust is thus crucial in any decentralised system. This paper builds on recent efforts to use argumentation to reason about trust. Specifically, a set of schemes is provided, and abstract patterns of reasoning that apply in multiple situations geared towards trust. Schemes are described in which (...) one agent, A, can establish arguments for trusting another agent, B, directly, as well as schemes that A can use to construct arguments for trusting C, where C is trusted by B. For both sets of schemes, a set of critical questions is offered that identify the situations in which these schemes can fail. (shrink)

During a dialogue, agents exchange information with each other and need thus to deal with incoming information. For that purpose, they should be able to reason effectively about trustworthiness of information sources. This paper proposes an argument-based system that allows an agent to reason about its own beliefs and information received from other sources. An agent's beliefs are of two kinds: beliefs about the environment and beliefs about trusting sources . Six basic forms of trust are discussed in the paper (...) including the most common one on sincerity. Starting with a base which contains such information, the system builds two types of arguments: arguments in favour of trusting a given source of information and arguments in favour of believing statements which may be received from other agents. We discuss how the different arguments interact and how an agent may decide to trust another source and thus to accept information coming from that source... (shrink)

The concept of a dialogue is considered in general terms from the standpoint of its referential presuppositions. The semantics of dialogue implies that dialogue participants must generally have a collective intentionality of agreed-upon references that is minimally sufficient for them to be able to disagree about other things, and ideally for outstanding disagreements to become clearer at successive stages of the dialogue. These points are detailed and illustrated in a fictional dialogue, in which precisely these kinds of referential confusions impede (...) progress in shared understanding. It is only through a continuous exchange of question and answer in this dialogue case study that the meanings of key terms and anaphorical references are disambiguated, and a relevantly complete collective intentionality of shared meaning between dialogue participants is achieved. The importance of a minimally shared referential semantics for the terms entering into reasoning and argument in dialogue contexts broadly construed cannot be over-estimated. Where to draw the line between referential agreement and disagreement within any chosen dialogue, as participants work toward better mutual understanding in clearing up referential incongruities, is sometimes among the dialogue’s main points of dispute. (shrink)

Deductivism is not merely a logical technique, but also a theory of normativity: it provides an objective and universal standard of evaluation. Contemporary dialectical logic rejects deductive normativity, replacing its universal standard by an intersubjective standard. It is argued in this paper that dialectical normativity does not improve upon deductive normativity. A dialogico-rhetorical alternative is proposed.

Mathematicians often speak of conjectures, yet unproved, as probable or well-confirmed by evidence. The Riemann Hypothesis, for example, is widely believed to be almost certainly true. There seems no initial reason to distinguish such probability from the same notion in empirical science. Yet it is hard to see how there could be probabilistic relations between the necessary truths of pure mathematics. The existence of such logical relations, short of certainty, is defended using the theory of logical probability (or objective Bayesianism (...) or non-deductive logic), and some detailed examples of its use in mathematics surveyed. Examples of inductive reasoning in experimental mathematics are given and it is argued that the problem of induction is best appreciated in the mathematical case. (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)

This special issue of Informal Logic brings together a num-ber of traditions from the psychology and philosophy of argument. Psycho-logists’ interest in argument typically arises in understanding how indivi-duals form and change their beliefs. Thus, theories of argument can serve as models of the structure of justi-fications for belief, as methods of diagnosing errors in beliefs, and as prototypes for learning. The articles in this issue illustrate all three of these connections.

Manipulation of quotation, shown to be a common tactic of argumentation in this paper, is associated with fallacies like wrenching from context, hasty generalization, equivocation, accent, the straw man fallacy, and ad hominem arguments. Several examples are presented from everyday speech, legislative debates and trials. Analysis using dialog models explains the critical defects of argumentation illustrated in each of the examples. In the formal dialog system CB, a proponent and respondent take turns in making moves in an orderly goal-directed sequence (...) of argumentation in which the proponent tries to persuade the respondent to become committed to a conclusion by asking questions and offering arguments. Analyzing quotation by using the notion of commitment in dialog, it is shown (a) how an arguer’s previous assertions can be brought to light in the course of a dialog to deal with problems arising from misquotation, (b) how the profile of dialog model allows a critic to analyse the fundamental effects misquotation brings about in a dialog, and (c) how the critic can use such an analysis to correct the problem. (shrink)

This paper is an exercise in intellectual history, an attempt to understand how a specific term—”informal logic”— came to be interpreted in so many different ways. I trace the emergence and development of “informal logic” to help explain the many different meanings, how they emerged and how they are related. This paper is also, to some degree, an account of a movement that developed outside the mainstream of philosophy, whose origins lie in a desire to make logic useful (echoing Dewey).

The notions of types of dialogue and dialectical relevance are central themes in Walton’s work and the grounds for a dialectical approach to many fallacies. After outlining the dialogue models constituting the background of Walton’s account, this article presents the concepts of dialectical relevance and dialogue shifts in their application to biased argumentation, fallacious moves, and illicit argumentative strategies. Showing the different dialectical proposals Walton advanced in several studies on argumentation as a development of a dialogical system, it has proved (...) possible to highlight the fundamental aspects of his theory in a comprehensive model of communication and interaction. (shrink)

The purpose of this paper is to inquire into the relationship between persuasive definition and common knowledge (propositions generally accepted and not subject to dispute in a discussion). We interpret the gap between common knowledge and persuasive definition (PD) in terms of potential disagreements: PDs are conceived as implicit arguments to win a potential conflict. Persuasive definitions are analyzed as arguments instantiating two argumentation schemes, argument from classification and argument from values, and presupposing a potential disagreement. The argumentative structure of (...) PDs reveals different levels of disagreement, and different pos-sibilities of resolving the conflict or causing dialogical deadlock. (shrink)

Van Eemeren and Houtlosser observe that Walton’s (and Walton and Krabbe’s) notion of ‘dialogue type’ involves a mixture of an empirical notion on a par with a speech event or activity type and a normative notion such as the model of a critical discussion. Then they discuss Walton’s contextual analysis of fallacies as illegitimate dialectical shifts of dialogue types and offer an alternative in which both the empirical and the normative dimension are given their due.

Eight structural criteria are developed as part of a dialogical method by testing them against seven examples of arguments from negative consequences. The aim is to provide a method for evaluating the arguments in the examples as fallacious or not. It is shown that any method that can be satisfactorily used to evaluate such examples needs to be based on two techniques. The first is careful application of argumentation underlying shifts from one type of dialog to another schemes. The second (...) is consideration of contextual factors concerning. (shrink)

The distinction between constitutive and regulative rules is applied to rules for critical discussion that have to do with the use of ambiguous expressions. This leads to a distinction between rule violating fallacies, by which one abandons a critical discussion, and norm violating fallacies, which are in a way admissible within a critical discussion. According to the formal model for critical discussion, proposed in this paper, fallacies of the norm violating type arc not prohibited. Instead, it provides discussants with devices (...) to discuss fallacies and fallacy criticisms. (shrink)

This article concerns the structure of defeasible arguments like: 'If Bob has red spots, Bob has the measles; Bob has red spots; therefore Bob has the measles.' The issue is whether such arguments have the form of modus ponens or not. Either way there is a problem. If they don't have the form of modus ponens, the common opinion to the contrary taught in leading logic textbooks is wrong. But if they do have the form of modus ponens, doubts are (...) raised about the conventional dogma that all arguments having the form of modus ponens are deductively valid. By carefully examining arguments on both sides of the issue, reasonable doubts are raised about the view that all arguments having a modus ponens form are valid. (shrink)

As an introduction to the special issue on Perspectives on Strategic Maneuvering, this article provides a synthetic recapitulation of the various steps that were taken in developing the pragma-dialectical theory of strategic maneuvering. First, the concept of strategic maneuvering is described as a means to reconcile the simultaneous pursuit of dialectical and rhetorical aims. Second, strategic maneuvering is related to the various kinds of argumentative activity types in which it takes place. Third, the concept of dialectical profiles is discussed and (...) the parameters that are pertinent to distinguishing between different types of strategic maneuvering. Fourth, the fallacies are viewed as derailment of strategic maneuvering. Fifth, as a case in point, strategic maneuvering with inconsistency is examined. (shrink)

In this paper, a solution to the problem of analyzing burden of proof in argumentation is developed by building on the pioneering work of Erik C. W. Krabbe on metadialogues. Three classic cases of burden of proof disputes are analyzed, showing how metadialogue theory can solve the problems they pose. The solution is based on five dialectical requirements: (1) global burden of proof needs to be set at the confrontation stage of a dialogue, (2) there need to be special mechanisms (...) for resolving disputes about burden of proof at all four stages of the dialogue, (3) they are especially significant during the argumentation stage, where burden of proof often shifts back and forth at each move, (4) such local shifts need to be partly regulated by the global burden of proof already set, and (5) the connection between burden of proof and the speech act of making a presumption in a dialogue needs to be clarified. (shrink)

A Bibliography of Douglas Walton’s Published Works, 1971-20.