The paper calls for argumentation theory to learn from moral and political philosophy. Several thinkers in these fields help understand the occurrence of what we may call legitimate dissensus: enduring disagreement even between reasonable people arguing reasonably. It inevitably occurs over practical issues, e.g., issues of action rather than truth, because there will normally be legitimate arguments on both sides, and these will be incommensurable, i.e., they cannot be objectively weighed against each other. Accordingly, ‘inference,’ ‘validity,’ and ‘sufficiency’ are inapplicable (...) notions. Further distinctive features of pro and con arguments in practical argumentation are explored, and some corollaries are drawn regarding evaluative norms of legitimate dissensus. Examples from immigrationrelated public debates in Denmark are given. (shrink)

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 relationship between teaching and argumentation is becoming a crucial issue in the field of education and, in particular, science education. Teaching has been analyzed as a dialogue aimed at persuading the interlocutors, introducing a conceptual change that needs to be grounded on the audience’s background knowledge. This paper addresses this issue from a perspective of argumentation studies. Our claim is that argumentation schemes, namely abstract patterns of argument, can be an instrument for reconstructing the tacit premises in students’ argumentative (...) reasoning and retrieving the background beliefs that are the basis of their arguments. On this perspective, the process of premise reconstruction is followed by a heuristic reasoning process aimed at discovering the students’ previous intuitions that can explain the premises and concepts that are left unexpressed in their arguments. The theoretical insights advanced in this paper are illustrated through selected examples taken from activities concerning predictive claims on scientific issues. (shrink)

Formal dialectic has its roots in ancient dialectic. We can trace this influence in Charles Hamblin’s book on fallacies, in which he introduced his first formal dialectical systems. Earlier, Paul Lorenzen proposed systems of dialogical logic, which were in fact formal dialectical systems avant la lettre, with roles similar to those of the Greek Questioner and Answerer. In order to make a comparison between ancient dialectic and contemporary formal dialectic, I shall formalize part of the Aristotelian procedure for Academic debates. (...) The resulting system will be compared (1) with Van Eemeren and Grootendorst’s system of rules of Critical Discussion (the pragma-dialectical discussion procedure), which must, however, first itself be reconstructed as a formal dialectical system, and (2) with a Hamblin-type system, and (3) a Lorenzen-type system. When drawing comparisons, it will become clear that there is a line to be drawn from Aristotle to formal dialectic and pragma-dialectics, extending to contemporary computational models of argument. (shrink)

Society is becoming increasingly reliant upon the dependability of computerbased systems. Achieving and demonstrating the dependability of systems requires the construction and review of valid and coherent arguments. This paper discusses the need for a variety of classes of arguments in dependable systems and reviews existing approaches to the representation of arguments in each of these classes. The issues surrounding the certification of safety critical systems demonstrate the current need for richer representations of dependability arguments which support tools for their (...) construction and review. The paper discusses how a meta-logical framework, informed by aspects of both formal and informal logic, offers a rich and unified means of representing dependability arguments and of thus addressing this need. (shrink)

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 reports research concerning a suitable dialogue model for human computer debate. In particular, we consider the adoption of Moore's (1993) utilization of Mackenzie's (1979) game DC, means of using computational agents as the test-bed to facilitate evaluation of the proposed model, and means of using the evaluation results as motivation to further develop a dialogue model, which can prevent fallacious argument and common errors. It is anticipated that this work will contribute toward the development of human computer dialogue, (...) and help to illuminate research issues in the field of dialectics itself. (shrink)

This article outlines criteria for the evaluation of the argumentum ad hominem (argument against the person, or personal attack in argument) that is traditionally a part of the curriculum in informal logic. The argument is shown to be a kind of criticism which works by shifting the burden of proof in dialogue through citing a pragmatic inconsistency in an arguer's position. Several specific cases of ad hominem argumentation which pose interesting problems in analyzing this type of criticism are studied.

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.

In this paper, we will explore two initiatives that focus on the importance of employing logical theories in educating people how to think and reason properly, one in Poland: The Lvov-Warsaw School; the other in North America: The Informal Logic Initiative. These two movements differ in the logical means and skills that they focus on. However, we believe that they share a common purpose: to educate students in logic and reasoning (logical education conceived as a process) so that they may (...) be able to apply their skills to analyze the issues in their society (logical culture as a result of logical education). The aim of the paper is to justify this claim by exploring research objectives and products that are common to both movements. (shrink)

In this paper we compare central elements of Dialogue Logic and Belief Revision theory. Dialogue Logic of the Hamblin/Mackenzie style, or Formal Dialectic, contains three main features. First, there is a rule governed interaction between dialogue participants—the minimal case being two participants. Second, each participant has a commitment store which changes as the dialogue progresses. Third, the changes in the commitment store are governed by rules for additions and withdrawals of material. Withdrawal of material is one major source of difficulty (...) in proposing rules for commitment store change. The classic Belief Revision theory is the AGM theory. AGM theory is a theory about ideal rational believers who change their sets of beliefs by either expansion or contraction. Contraction is a major source of difficulty in belief revision theory. We claim that the commitment stores of dialogue logic include, in a sense, the belief sets of belief revision theory. Further, withdrawal and contraction are essentially the same process. We consider various kinds of withdrawal and contraction, and show how approaches to these processes illuminate certain of the formal fallacies. (shrink)

Inconsistent Commitments and Commitment to Inconsistencies.

This paper is aimed at combining the advances in argumentation theory with the models used in the field of education to address the issue of improving students’ argumentative behavior by interacting with an expert. The concept of deeper or more sophisticated argumentative strategy is theoretically defined and used to advance two new coding schemes, based on the advances in the argumentation studies and aimed at capturing the dialectical, or structural, behavior, and the argumentative content of each dialogue unit. These coding (...) schemes are then applied for a qualitative analysis of a study designed to investigate how students’ argumentative behavior can be influenced by the interaction with an expert, who used specific types of attacks to the interlocutors’ positions. The twofold coding shows at which dialogical level expert–peer interactions can directly and more stably affect students’ argumentative behavior, and what effects such more sophisticated strategies can have on the discussion and the analysis of disagreements. In particular, this paper shows how a specific type of deep-level attack, the underminer, can open dialogues of a different level, focused on unveiling and debating background beliefs underlying a specific position. (shrink)

SummaryThis paper studies some classic cases of the fallacy of begging the question based on appeals to testimony containing circular reasoning. For example, suppose agents a, b and c vouch for d’s credentials, and agents b, d, and e vouch for a’s credentials. Such a sequence of reasoning is circular because a is offering testimony for d but d is offering testimony for a. The paper formulates and evaluates restrictions on the use of testimonial evidence that might be used to (...) deal with such problematic arguments. One is called the Non-repeater Rule: in an extended sequence of argumentation based on testimony, once a source x has been appealed to at any given point in the sequence, that same source x must never be appealed to again at any next point in the same sequence. (shrink)

In Fallacies and Judgments of Reasonableness, Frans H. van Eemeren, Bart Garssen and Bert Meuffels report on their systematic empirical research of the conventional validity of the pragma-dialectical discussion rules. The experimental studies they carried out during more than ten years start from the pragma-dialectical theory of argumentation developed at the University of Amsterdam, their home university. In these studies they test methodically the intersubjective acceptability of the rules for critical discussion proposed in this theory by confronting ordinary arguers who (...) have not received any special education in argumentation and fallacies with discussion fragments containing both fallacious and non-fallacious argumentative moves. The research covers a wide range of informal fallacies. In this way, the authors create a basis for comparing the theoretical reasonableness conception of pragma-dialectics with the norms for judging argumentative moves prevailing in argumentative practice. Fallacies and Judgments of Reasonableness provides a unique insight into the relationship between theoretical and practical conceptions of reasonableness, supported by extensive empirical material gained by means of sophisticated experimental research. (shrink)

How do Dutch people let each other know that they disagree? What do they say when they want to resolve their difference of opinion by way of an argumentative discussion? In what way do they convey that they are convinced by each other’s argumentation? How do they criticize each other’s argumentative moves? Which words and expressions do they use in these endeavors? By answering these questions this short essay provides a brief inventory of the language of argumentation in Dutch.

The research discussed in this paper concerns an investigation of logical dialogue games as a vehicle for enhanced human-computer communication. The need for a dialogue capability in computer systems is argued, and a prima facie case made for dialogue games, in particular Mackenzie's "DC", as a suitable dialogue model. Empirical work concerning DC is outlined, and strategies for adoption by the computer are presented. A user interface, software architecture and conceptualised example are discussed. The hope is that the paper will (...) help bring together two groups of workers-philosophers of dialogue and designers of computer systems-to the mutual benefit of each. (shrink)

How should we evaluate an argument in which two witnesses independently testify to some claim? In fact what would happen is that the testimony of the second witness would be taken to corroborate that of the first to some extent, thereby boosting up the plausibility of the first argument from testimony. But does that commit the fallacy of double counting, because the second testimony is already taken as independent evidence supporting the claim? Perhaps the corroboration effect should be considered illogical, (...) since each premise should be seen as representing a separate reason in a convergent argument for accepting the claim as plausible. In this paper, we tackle the problem using argumentation schemes and argument diagramming. We examine a number of examples, and come up with two hypotheses that offer methods of analyzing and evaluating this kind of evidence. (shrink)

This short work presents a popular fringe theory as a source of case studies for use in teaching informal logic in an introductory course. It puts forward ancient astronaut theory as the candidate source, together with a characterization of why it fits the bill. The televised material associated with that theory is well suited to being used as case studies given that they are easy to follow, contain a surprising number of arguments and fallacies, and keep students reliably engaged. The (...) paper includes an overview of the forms of argumentation and fallacies that these cases may be used to teach, along with a sketch of how to best implement them in the classroom. (shrink)

“Reasonable hostility” is a norm of communicative conduct initially developed by studying public exchanges in education governance meetings in local U.S. communities. In this paper I consider the norm’s usefulness for and applicability to a U.S. state-level public hearing about a bill to legalize civil unions. Following an explication of reasonable hostility and grounded practical theory, the approach to inquiry that guides my work, I describe Hawaii’s 2009, 18-hour public hearing and analyze selected seg-ments of it. I show that this (...) particular public hearing raised demands for testifiers on the anti-civil union side of the argument that reasonable hostility does not do a good job of addressing. Development of a norm of communication conduct for this practice, as well as others, must engage with the culture and time-specific beliefs that a society holds, beliefs that will shape not only how to argue but what may be argued and what must be assumed about particular categories of persons. (shrink)

In this paper, we closely examine the various ways in which a multi-party argumentative discussion—argumentative polylogue—can be analyzed in a dialectical framework. Our chief concern is that while multi-party and multi-position discussions are characteristic of a large class of argumentative activities, dialectical approaches would analyze and evaluate them in terms of dyadic exchanges between two parties: pro and con. Using as an example an academic committee arguing about the researcher of the year as well as other cases from argumentation literature, (...) we scrutinize the advantages and pitfalls of applying a dialectical framework to polylogue analysis and evaluation. We recognize two basic dialectical methods: interpreting polylogues as exchanges between two main camps and splitting polylogues into a multitude of dual encounters. On the basis of this critical inquiry, we lay out an argument expressing the need for an improved polylogical model and propose its basic elements. (shrink)

In some recent cases in Anglo-American law juries ruled contrary to an expert's testimony even though that testimony was never challenged, contradicted or questioned in the trial. These cases are shown to raise some theoretical questions about formal dialogue systems in computational dialectical systems for legal argumentation of the kind recently surveyed by Bench-Capon (1997) and Hage (2000) in this journal. In such systems, there is a burden of proof, meaning that if the respondent questions an argument, the proponent is (...) obliged to offer some support for it give it up. But what should happen in a formal system of dialogue if the proponent puts forward an argument and the respondent fails to critically question it, and simply moves on to another issue? Is this some kind of fault that should have implications? Should it be taken to imply that, by default, the respondent has conceded the argument? What, if anything, should be the outcome of such a failure to question in a formal dialogue system of argumentation? These questions are considered by examining some legal cases of expert opinion testimony in relation rules for formal dialectical argumentation systems. (shrink)

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.

Different approaches analyze the strength of a natural language argument in different ways. This paper contrasts the dialectical, structural, probabilistic (or Bayesian), computational, and empirical approaches by exemplarily applying them to a single argumentative text (Epicureans on Squandering Life; Aikin & Talisse, 2019). Rather than pitching these approaches against one another, our main goal is to show the room for fruitful interaction. Our focus is on a dialectical analysis of the squandering argument as an argumentative response that voids an interlocutor’s (...) right to assertion. This analysis addresses the pragmatic dimensions of arguing and implies an argument structure that is consistent with empirical evidence of perceived argument strength. Results show that the squandering argument can be evaluated as a (non-fallacious) ad hominem argument, which however is not necessarily stronger than possible arguments attacking it. (shrink)

This volume reflects the development and theoretical foundation of a new paradigm for critical thinking based on inquiry. The field of critical thinking, as manifested in the Informal Logic movement, developed primarily as a response to the inadequacies of formalism to represent actual argumentative practice and to provide useful argumentative skills to students. Because of this, the primary focus of the field has been on informal arguments rather than formal reasoning. Yet the formalist history of the field is still evident (...) in its emphasis, with respect to both theory and pedagogy, on the structure and evaluation of individual, de-contextualized arguments. It is our view that such a view of critical thinking is excessively narrow and limited, failing to provide an understanding of argumentation as largely a matter of comparative evaluation of a variety of contending positions and arguments with the goal of reaching a reasoned judgment on an issue. As a consequence, traditional critical thinking instruction is problematic in failing to provide the reasoning skills that students need in order to accomplish this goal. Instead, the goal of critical thinking instruction has been seen largely as a defensive one: of learning to not fall prey to invalid, inadequate, or fallacious arguments. (shrink)

This paper introduces a multi-agent dynamic epistemic logic for abstract argumentation. Its main motivation is to build a general framework for modelling the dynamics of a debate, which entails reasoning about goals, beliefs, as well as policies of communication and information update by the participants. After locating our proposal and introducing the relevant tools from abstract argumentation, we proceed to build a three-tiered logical approach. At the first level, we use the language of propositional logic to encode states of a (...) multi-agent debate. This language allows to specify which arguments any agent is aware of, as well as their subjective justification status. We then extend our language and semantics to that of epistemic logic, in order to model individuals’ beliefs about the state of the debate, which includes uncertainty about the information available to others. As a third step, we introduce a framework of dynamic epistemic logic and its semantics, which is essentially based on so-called event models with factual change. We provide completeness results for a number of systems and show how existing formalisms for argumentation dynamics and unquantified uncertainty can be reduced to their semantics. The resulting framework allows reasoning about subtle epistemic and argumentative updates—such as the effects of different levels of trust in a source—and more in general about the epistemic dimensions of strategic communication. (shrink)

In the pragma-dialectical approach, fallacies are considered incorrect moves in a discussion for which the goal is successful resolution of a dispute. Ten rules are given for effective conduct at the various stages of such a critical discussion (confrontation, opening, argumentation, concluding). Fallacies are discussed as violations of these rules, taking into account all speech acts which are traditionally recognized as fallacies. Special attention is paid to the role played by implicitness in fallacies in everyday language use. It is stressed (...) that identifying and acknowledging fallacies in ordinary discussions always has a conditional character. Differences between the pragma-dialectical perspective, the Standard Treatment, and the formal logic approach to fallacy analysis are discussed. (shrink)

A concept of critical thinking is developed based on the Socratic method and called accordingly a Socratic model. First the features of critical thinking stressed in this model are stated and illustrated. The Socratic method is presented and interpreted, then taken to yield a model of critical thinking. The process of internalization by which the Socratic model helps us to become critical thinkers is described. Argument analysis is considered as a widely used instructional strategy adaptable for teaching critical thinking on (...) the Socratic model. This Socratic model is advanced as one helpful way of organizing our ideas about critical thinking, helpful in unifying disparate factors and anchoring them in the humanist tradition. (shrink)

The Argument Web is maturing as both a platform built upon a synthesis of many contemporary theories of argumentation in philosophy and also as an ecosystem in which various applications and application components are contributed by different research groups around the world. It already hosts the largest publicly accessible corpora of argumentation and has the largest number of interoperable and cross compatible tools for the analysis, navigation and evaluation of arguments across a broad range of domains, languages and activity types. (...) Such interoperability is key in allowing innovative combinations of tool and data reuse that can further catalyse the development of the field of computational argumentation. The aim of this paper is to summarise the key foundations, the recent advances and the goals of the Argument Web, with a particular focus on demonstrating the relevance to, and roots in, philosophical argumentation theory. (shrink)

This paper is a critical assessment of argumentum ad baculum, or appeal to force. Its principal contention is that, contrary to common opinion, there is no general fallacy of ad baculum. Most real-life ad baculums are, in fact, fairly strong. A basic logical form for reconstructed ad baculums is proposed, and a number of heterodoxical conclusions are also advanced and argued for. They include that ad baculum is not necessarily a prudential argument, that ad baculum need not involve force, violence, (...) or threats, and that one can argue ad baculum to oneself. The starting point of the paper, however, is a critical evaluation of three ad baculums from the exercise sets of Irving Copi's well-known Introduction to Logic. (shrink)

The purpose of this paper is to discuss some ways in which dialectical models can be put to computational use. In particular, we consider means of facilitating human-computer debate, means of catering for a wider range of dialogue types than purely debate and means of providing dialectical support for group dialogues. We also suggest how the computational use of dialectical theories may help to illuminate research issues in the field of dialectic itself.