Why is there so much distortion in ordinary, political, social, and ethical argument? Since we have a pervasive interest in reasoning well and corresponding abilities, the extent of distortion invites explanation. The leading candidates are the need to economize, widespread, fallacious heuristics or assumptions, and self-defensive biases. I argue that these are not sufficient. An additional force is the intellectual pressure generated by acceptance of norms of conversation and argument, which exclude ‘middles’ of, prominently, neither accept nor reject. I conjecture (...) that the distortion we find is due to intellectual and normative pressures generated by our commitment to these excluded-middle norms and if, or when, their force is lessened, there is likely to be less distortion. (shrink)

This paper argues for the importance of the distinction between internal and external negation over expressions for belief. The common fallacy is to confuse statement like (1) and (2): (1) John believes that the school is not closed on Tuesday; (2) John does not believe that the school is closed on Tuesday. The fallacy has ramifications in teaching, reasoning, and argumentation. Analysis of the fallacy and suggestions for teaching are offered.

The world’s scientific community must be in a state of constant readiness to address the threat posed by newly emerging infectious diseases. Whether the disease in question is SARS in humans or BSE in animals, scientists must be able to put into action various disease containment measures when everything from the causative pathogen to route(s) of transmission is essentially uncertain. A robust epistemic framework, which will inform decision-making, is required under such conditions of uncertainty. I will argue that this framework (...) should have reasoning at its center and, specifically, that forms of reasoning beyond deduction and induction should be countenanced by scientists who are confronted with emerging infectious diseases. In previous articles, I have presented a case for treating certain so-called traditional informal fallacies as rationally acceptable forms of argument that can facilitate scientific inquiry when little is known about an emerging disease. In this article, I want to extend that analysis by highlighting the unique features of these arguments that makes them specially adapted to cope with conditions of uncertainty. Of course, such a view of the informal fallacies must at least be consistent with the reasoning practices of scientists, and particularly those scientists (viz. epidemiologists) whose task it is to track and respond to newly emerging infectious diseases. To this end, I draw upon examples of scientific reasoning from the UK’s BSE crisis, a crisis that posed a significant threat to both human and animal health. (shrink)

Why is there so much misrepresentation of arguments in public forums? Standard explanations, such as self-interested biases, are insufficient. An additional part of the explanation is our commitment to, or belief in, norms that disallow responses that amount to no firm judgment, as contrasted with definite agreement or disagreement. In disallowing no-firm-judgment responses, these norms deny not only degrees of support or dissent and a variety of ways of suspending judgment, but also indifference. Since these norms leave us with only (...) constricted options that are very intellectually demanding, in accepting these norms we impose on ourselves a pressure to justify our judgment that lends itself to relief through misrepresentation or distortion. (shrink)

This paper presents an analysis of the concept of burden of proof in argument. Relationship of burden of proof to three traditional informal fallacies is considered: (i) argumentum ad hominem, (ii) petitio principii, and (iii) argumentum ad ignorantiam. Other topics discussed include persuasive dialoque, pragmatic reasoning, legal burden of proof, plausible reasoning in regulated disputes, rules of dialogue, and the value of reasoned dialogue.

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.

In spite of significant research efforts, argument technologies do not seem poised to scale up as much as most commentators would hope or even predict. In this paper, I discuss what obstacles bar the way to more widespread success of argument technologies and venture some suggestions on how to circumvent such difficulties: doing so will require a significant shift in how this research area is typically understood and practiced. I begin by exploring a much broader yet closely related question: To (...) what extent are people natively good at arguing? This issue has always been central to philosophical reflection and it has become even more urgent nowadays, with the explosion of persuasive technologies and unprecedented opportunities for large-scale social influence. The answer hinges on what aspect of argumentation is taken under consideration: evidence suggests that people are relatively bad at analyzing the structure of arguments, especially when these are presented out of context and in abstract terms; in contrast, data show that even laymen tend to excel in the interactive practice of argumentation, in particular when motivation is high and something significant is at stake. Unfortunately, current argument technologies are more closely tailored to the former type of activity than to the latter, which is the main reason behind their relative lack of success with the general public. Changing this state of affair will require a commitment to ecological argument technologies: that is, technologies designed to support real-time, engaging and meaningful argumentative interactions performed by laypeople in their ordinary life, instead of catering to the highly specific needs of a minority of niche users. (shrink)

lt is now commonplace in fallacy inquiry for many of the traditional informal fallacies to be viewed as reasonable or nonfallacious modes of argument. Central to this evaluative shift has been the attempt to examine traditional fallacies within their wider contexts of use. However, this pragmatic turn in fallacy evaluation is still in its infancy. The true potential of a contextual approach in the evaluation of the fallacies is yet to be explored. I examine how, in the context of scientific (...) inquiry, certain traditional fallacies function by conferring epistemic gains upon inquiry. Specifically, I argue that these fallacies facilitate the progression of inquiry, particularly in the initial stages ofinquiry when the epistemic context is one of uncertainty. The conception of these fallacies that emerges is that of heuristics of reasoning in contexts of epistemic uncertainty. (shrink)

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

Reasoning in medicine requires the critical use of a clinical methodology whose validity must be evaluated as well as its limits. In the last decade, an increasing amount of evidence has shown severe limitations and flaws in the conduct of prognostic studies. The main reason behind this fact is that prognostic judgments are at high risk of error. In this paper we investigate the pragmatic and illocutionary aspects of different forms of linguistic acts and judgments involved in clinical practice. More (...) specifically, we analyze the role of uncertainty with regard to ‘particular’ clinical judgments and its relation with ‘general’ evidence. Focusing on how prognostic judgments are formulated and justified, our main purpose is to highlight the explication, the structure and the limits of prognosis from a linguistic and epistemological perspective. (shrink)

The Covid-19 pandemic presents argumentation theorists with an opportunity to reflect on the ways in which people, agencies and governments respond to the emergence of a new virus. Reponses have revealed a range of judgements and decisions, not all of which are rationally warranted. This article will examine errors in reasoning, several of which have reduced the public’s compliance with important health measures. This article will also analyse rationally warranted reasoning about Covid-19 employed by public health agencies. In examining instances (...) of good and bad reasoning during the Covid-19 pandemic, we can begin to construct a taxonomy of arguments that facilitated and hindered individual and collective responses during this public health emergency. (shrink)

The purpose of this paper is twofold: to give a good account of the argument from ignorance, with a presumptive argumentation scheme, and to raise issues on the work of Walton, the nature of abduction and the concept of epistemic closure. First, I offer a brief disambiguation of how the terms 'argument from ignorance' and 'argumentum ad ignorantiam' are used. Second, I show how attempts to embellish this form of reasoning by Douglas Walton and A.J. Kreider have been unnecessary and (...) unhelpful. Lastly, I offer a full and effective account of the argument from ignorance and discuss the lessons of the analysis.Le but de cet article est double: donner un bon compte rendu de l'argument par l'ignorance, avec un schème d'argumentation présomptif, et soulever des questions sur certains aspects de l’œuvre de Walton, la nature des raisonnements abductifs et le concept de fermeture épistémique. Premièrement, j'offre une brève désambiguïsation de la façon dont les termes «argument par l'ignorance» et «argumentum ad ignorantiam» sont utilisés. Deuxièmement, je montre comment les tentatives de Douglas Walton et de A.J. Kreider d'embellir cette forme de raisonnement ont été ni nécessaires et ni utiles. Enfin, j'offre un compte-rendu complet et utile de l'argument par l'ignorance et je discute des leçons de l'analyse. (shrink)

By explaining the argument from ignorance in terms of the presumption of innocence, many textbooks in argumentation theory suggest that some arguments from ignorance might share essential features with some types of presumptive reasoning. The stronger version of this view, suggesting that arguments from ignorance and presumptive reasoning are almost indistinguishable, is occasionally proposed by Douglas Walton. This paper explores the nature and limits of the stronger proposal and argues that initial presumptions and arguments from ignorance are not closely connected. (...) There are three main reasons. First, the argument from ignorance, unlike typical presumptive reasoning, is a negative kind of inference. Second, the typical initial presumption is sensitive to a broader set of defeaters and thus assumes a higher standard of acceptability. Third, in dialectical terms, initial presumption and argument from ignorance bring different attacking rights and obligations. I conclude that Waltonian intuition is unsupported or, at best, is limited only to practical presumptions and practical arguments from ignorance. (shrink)

Arguments from ignorance should be schematized: It has not been proven false that p. So it is possible that p. So, it is reasonable to believe p. Also, in opposition to standard views they should be distinguished from burden of proof and absence of evidence arguments. Much of the persuasiveness of such arguments can be located in the slippery uses of "possible." Besides equivocations on "possible" the argument is a fallacy for two reasons. First, the possibility implied by the first (...) premise does not yield the serious possibility that is needed for establishing the conclusion. Second, ignorance is never sufficient reason for belief, only adequate evidence. (shrink)