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.

The aim of the paper is to propose a unified formal account of dialogical cognitive processes so that it allows the analysis of similarities and differences between those processes. Formal dialogue systems constitute two basic categories or paradigms of modelling communication depending on what cognitive process is described by a given system. The first paradigm consists of designing a set of dialogue rules in a similar manner to Lorenzen’s dialogue logic, and according to which players jointly aim to prove the (...) validity of a formula. In such cases we will say that the system describes formal dialogues and the formal cognitive process of proving the validity of a formula. The second paradigm focuses on building a system similar to Hamblin’s formal dialectics, which “simulates” the real-life communication practice. In the type of dialogues described by those systems, players perform “good” argumentation, i.e. argumentation which fulfils certain requirements of rationality such as e.g. the requirement of not committing a fallacy of circular reasoning. In such a case we will be speaking of a natural dialogue and a natural cognitive process of argumentation. (shrink)

This essay addresses the collapse/incoherence problem for normative frameworks that contain both fundamental values and rules for promoting those values. The problem is that in some cases, we would bring about more of the fundamental value by violating the framework’s rules than by following them. In such cases, if the framework requires us to follow the rules anyway, then it appears to be incoherent; but if it allows us to make exceptions to the rules, then the framework “collapses” into one (...) that doesn’t make use of rules in the first place. The chapter begins with an examination of happiness and truth as fundamental values in Mill’s work, which lead into parallel versions of the collapse/incoherence problem in ethics and epistemology. It then sets out the collapse problem for rule-consequentialist approaches in ethics, truth-directed accounts of justification in epistemology, and epistemological approaches to argument cogency. The chapter closes with discussion of two potential solutions to the problem. (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)

This paper examines Andrei Sakharov's dissident protests against the Soviet regime as arguments to a non-cooperating interlocutor. Approaching the 1970s-1980s Soviet dissident public sphere as a Toulminian ‘field’ of argumentation, I infer a field-dependent function of Sakharov's argument from an analysis of its structure and implicit assessment criteria. Besides justification, the function of Sakharov’s argument is performative: he argues for political action by demonstrating a model of practical reasoning that raises private consciousness to the level of public agency. By exposing (...) his own political rationality as a ‘live’ mode of proof for the speculative ‘truth’ of his conviction, Sakharov suggests a connection between theoretical thinking and action. (shrink)

From a decision theoretic perspective, arguments stem from decisions made by arguers. Despite some promising results, this approach remains underdeveloped in argumentation theories, mostly because it is assumed to be merely descriptive. This assumption is mistaken: considering arguments as the product of decisions brings into play various normative models of rational choice. The challenge is rather to reconcile strategic rationality with other normative constraints relevant for argumentation, such as inferential validity and dialectical appropriateness.

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)

In argumentation, as elsewhere, speakers strategically engage favourable presumptions by manifestly making themselves accountable for their communicative efforts. Such strategies provide the addressee with reasons to regard the speaker as accountable in specific ways and, via that regard for the speaker, with situation-specific rationales for responding positively to what the speaker says. This paper identifies some resources available to arguers for strengthening, elaborating, and focusing such special presumptions. The paper offers an analysis of Barbara Jordan’s “Statement on the Articles of (...) Impeachment” as illustrative of these resources for strengthening a speaker’s ethos. (shrink)

Informal logic is a method of argument analysis which is complementary to that of formal logic, providing for the pragmatic treatment of features of argumentation which cannot be reduced to logical form. The central claim of this paper is that a more nuanced understanding of mathematical proof and discovery may be achieved by paying attention to the aspects of mathematical argumentation which can be captured by informal, rather than formal, logic. Two accounts of argumentation are considered: the pioneering work of (...) Stephen Toulmin [The uses of argument, Cambridge University Press, 1958] and the more recent studies of Douglas Walton, [e.g. The new dialectic: Conversational contexts of argument, University of Toronto Press, 1998]. The focus of both of these approaches has largely been restricted to natural language argumentation. However, Walton’s method in particular provides a fruitful analysis of mathematical proof. He offers a contextual account of argumentational strategies, distinguishing a variety of different types of dialogue in which arguments may occur. This analysis represents many different fallacious or otherwise illicit arguments as the deployment of strategies which are sometimes admissible in contexts in which they are inadmissible. I argue that mathematical proofs are deployed in a greater variety of types of dialogue than has commonly been assumed. I proceed to show that many of the important philosophical and pedagogical problems of mathematical proof arise from a failure to make explicit the type of dialogue in which the proof is introduced. (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)

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.

The paper analyses the role played by the concept of ‘common ground’ in argumentation theories. If a common agreement on all the rules of a discursive exchange is required, either at the beginning or at the end of an argumentative practice, then no violation of the rules is possible. The paper suggests an alternative understanding of ‘common ground’ as something that can change during the development of the argumentative practice, and in particular something that can change without the practice being (...) stopped, just as one sometimes violates the rule of a game without stopping playing. The analysis of some historical examples shows that the violation of rules sometimes leads to a consensual change of a set of beliefs and values. The argumentative rationality thus needs to be reconsidered in the light of the analysis of the conditions under which it would be legitimate to change the rules of an argumentative practice: ‘common ground’ and the right to disagreement, even radical or violent, could then be defended as essential components of argumentative rationality. (shrink)

This paper is divided in five sections. Section 11.1 sketches the history of the distinction between speech act with negative content and negated speech act, and gives a general dynamic interpretation for negated speech act. “Downdate semantics” for AGM contraction is introduced in Section 11.2. Relying on semantically interpreted contraction, Section 11.3 develops the dynamic semantics for constative and directive speech acts, and their external negations. The expressive completeness for the formal variants of natural language utterances, none of which is (...) a retraction, has been proved in Section 11.4. The last section gives a laconic answer to the question posed in the title of the paper. (shrink)

The aim of the paper is to propose a framework for the structure of persuasive communica-tion based on the Elaboration Likelihood Model by Petty and Cacioppo, the Inference Anchoring Theory by Budzynska and Reed and the Interpersonal Argumentation Model by Budzynska. The ELM suggests that there are two routes to persuasion: central and peripheral. IAT assumes that com-munication acts generate their contents and inferences by means of illocutionary connections. The model of IP-argumentation provides the general representation of arguments in which (...) the proponent refers to com-munication acts of some participant of communication. The paper discusses where exactly means of the central and peripheral routes operate in the structure of persuasive communication and argumentation. (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)

Is it possible to distinguish communities of arguers by tracking the argumentation schemes they employ? There are many ways of relating schemes to communities, but not all are productive. Attention must be paid not only to the admissibility of schemes within a community of argumentational practice, but also to their comparative frequency. Two examples are discussed: informal mathematics, a convenient source of well-documented argumentational practice, and anthropological evidence of nonstandard reasoning.

The history of fallacy theory is long, distinguished and, admittedly, checkered. I offer a bird eye view on it, with the aim of contrasting the standard conception of fallacies as attractive and universal errors that are hard to eradicate with the contemporary preoccupation with “non-fallacious fallacies”, that is, arguments that fit the bill of one of the traditional fallacies but are actually respectable enough to be used in appropriate contexts. Godden and Zenker have recently argued that reinterpreting alleged fallacies as (...) non-fallacious arguments requires supplementing the textual material with something else, e.g. probability distributions, pragmatic considerations, dialogical context. Thus fallacies remain gappy on all accounts, and this is the hallmark of their failure. However, I argue that such gappiness is typically unproblematic, and thus no more flawed than enthymematic argumentation in general. This, in turn, calls into question the usefulness of the very notion of fallacy. (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)

Since the work of Plaza (1989) about acts of public communication, a lot of dynamic epistemic logic systems have emerged. A general state of the art can be found in van Ditmarsch et al. (2007). Such logics model situations in which some announcements can be made and after an announcement, the situations which are incompatible with it are deleted from the model. In this paper we propose a reconstruction of the logic PAC (Public Announcement logic with Common Knowledge, see van (...) Ditmarsch et al. (2007)) through the dialogical framework. The idea of this work is to rediscover announcements as acts: acts of an arguer during an argumentative dialogue about knowledge change of agents instead of "model-modifiers". We name this reconstruction DEMAL for Dialogical Epistemic Multi-Agent Logic. (shrink)

Sperber and Mercier maintain that argumentation is a meta-representational module. In their evolutionary view of argumentation, the function of this module would be to regulate the flow of information between interlocutors through persuasiveness on the side of the communicator and epistemic vigilance on the side of the audience. The aim of this paper is to discuss this definition of argumen-tation by analyzing what they mean by “communicator’s persuasiveness” and “audience epistemic vigilance”.

If dialogue is a necessary condition for argument, argumentation in oratory becomes questionable, since rhetoric is not a dialogically structured activity. If special norms apply to the ‘solo’ performances of rhetoric, the orator’s activity may be more appropriately described as reasoning than as arguing. By analyzing in what respect rhetorical texts can be interpreted as dialogue-based and subject to criteria of Informal Logic, the virtues of rhetorical argumentation in contrast to logic and dialectic emerge.

Although contemporary dialectical logic recognizes an important role for the opponent in argumentation, it remains loyal to the idea that arguments are supportive. In this paper, it is argued that because of this dialectical logic does not take seriously its own dialogical perspective. Without acknowledging a substantial role for rebutting factors in argumentation, the role of the opponent remains secondary. Toulmin’s understanding of the rebuttal suggests a way to incorporate such a substantial role of the opponent.

In this paper, we report results from experiments in which people read conversational arguments and then judge the convincingness of each claim and the individual speakers' burden of proof. The results showed an "anti-primacy" effect: People judge the speaker who makes the first claim as having greater burden of proof. This effect persists even when each speaker's claims are rated equally convincing. We also find that people rate claims less convincing when they appear in the first part of an argument (...) than when they appear in isolation. (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.

In the paper I want to give a new account of notions of reasoning, argumentation, and persuasion. The aim of it is to resolve problems of the traditional accounts. The investigation uses the issue of circular reasoning. These types of arguments are considered a fallacy in informal logic, whereas formal logic holds that they are valid. The new account suggests a possibility of reconciliation of the informal and formal perspective.

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)

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 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.

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)

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)

In this paper, I critically examine the main accounts of goals in argumentative discourse, aiming to formulate an account that is suitable for the examination of public political arguments, where typically multiple legitimate goals are pursued simultaneously. Such arguments are viewed as contributions to what can be dialectically reconstructed as multiple simultaneous discussions, and are analysed as strategic manoeuvres that can under certain conditions be reasonable but may, if such conditions are violated, become fallacious.

The straw man fallacy consists in inappropriately constructing or selecting weak versions of the opposition's arguments. We will survey the three forms of straw men recognized in the literature, the straw, weak, and hollow man. We will then make the case that there are examples of inappropriately reconstructing stronger versions of the opposition's arguments. Such cases we will call iron man fallacies.