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.

I take 'informal logic' to be the (descriptive and normative) study of 'real arguments'-arguments which are or have been used with the aim of convincing others of a point of view. I argue that the informal logic tradition thus conceived (i) lends strong support to something like Quine's view that our beliefs really support one another like the filaments in a spider's web--and thus that the traditional view that implication is an asymmetric relation is false; (ii) suggests that the classic (...) division of arguments into deductive and inductive has distorted our thinking about the evaluation of real arguments; and (iii) implies that naturalised epistemology is on the right track. (shrink)

It is argued in this study that (i) progress in the philosophy of mathematical practice requires a general positive account of informal proof; (ii) the best candidate is to think of informal proofs as arguments that depend on their matter as well as their logical form; (iii) articulating the dependency of informal inferences on their content requires a redefinition of logic as the general study of inferential actions; (iv) it is a decisive advantage of this conception of logic that it (...) accommodates the many mathematical proofs that include actions on objects other than propositions; (v) this conception of logic permits the articulation of project-sized tasks for the philosophy of mathematical practice, thereby supplying a partial characterisation of normal research in the field. (shrink)

This paper explores why respondents to a telephone public-opinion survey often give reasons for answering as they do, even though reason-giving is neither required nor encouraged and it is difficult to see the reasons as attempts to deal with disagreement. We find that respondents give reasons for the policy claims they make in their answers three times as frequently as they give reasons for value or factual claims, that their reasons tend to involve appeals to personal experience, and that they (...) often talk about their thought processes, especially when the evidentiary stakes are high. We then explore several ways of explaining these findings. We suggest that one useful approach is to see the reason-giving in the survey interviews as deliberative, reflexive argumentation of the sort described as `critical thinking. We further suggest that the reason such argumentation is often conducted out loud in the interviews, rather than internally, is that it functions in the service of rhetorical ethos, in particular the need to display the fact that one is human, with human autonomy and agency. Doing this may be particularly important in contexts such as anonymous survey interviews in which people are at risk of being treated like machines. (shrink)

I first support Alec Fisher's thesis that premises and conclusions in arguments can be unasserted first by arguing in its favor that only it preserves our intuition that it is at least possible that two arguments share the same premises and the same conclusion although not everything that is asserted in the one is also asserted in the other and second by answering two objections that might be raised against it. I then draw from Professor Fisher's thesis the consequence that (...) in suppositional arguments the falsity (or unacceptability) of a supposition does not tell unfavorably in the evaluation of the argument, because the falsity (or unacceptability) of a (nonredundant) premise counts against an argument if and only if that premise is asserted. Finally, I observe that, despite the fact that they are neither expressed nor even alluded to, implicit assumptions in arguments are always asserted, unless the conclusion, but none of the explicit premisses, is unasserted. Hence, apart from an exceptional case of the kind just mentioned, the falsity (or unacceptability) of implicit assumptions always counts against an argument. (shrink)

This is a critical examination of Antoine Arnauld's Logic or the Art of Thinking (1662), commonly known as the Port-Royal Logic. Rather than reading this work from the viewpoint of post-Fregean formal logic or the viewpoint of seventeenth-century intellectual history, I approach it with the aim of exploring its relationship to that contemporary field which may be labeled informal logic and/or argumentation theory. It turns out that the Port-Royal Logic is a precursor of this current field, or conversely, that this (...) field may be said to be in the same tradition. (shrink)

Against Norton's claim that all thought experiments can be reduced to explicit arguments, I defend Brown's position that certain thought experiments yield a priori knowledge. They do this, I argue, not by allowing us to perceive “Platonic universals” (Brown), even though they may contain non-propositional components that are epistemically indispensable, but by helping to identify certain tacit presuppositions or “natural interpretations” (Feyerabend's term) that lead to a contradiction when the phenomenon is described in terms of them, and by suggesting a (...) new natural interpretation in terms of which the phenomenon can be redescribed free of contradiction. (shrink)

In their analyses of controversy, many researchers begin with the assumption that it is a juvenile or failed dialectical exchange. In conceptualizing controversy this way, they get caught in an is-ought dilemma, often shaping controversy into a two-sided affair involving an open issue with arguments marshalled but then simultaneously pointing out its shortcomings against these same criteria. As Dascal has pointed out, thinking of controversy as a juvenile dialectical exchange seems to be a therapeutic gesture that may present it as (...) a better-behaved object of study than experience would support. In this paper, I approach controversy first and foremost as a textual object, rather than as a dialectical or argumentative one. While I am ultimately interested in the reasoning of participants, I begin by asking how media texts represent controversies. I start here because media texts are the dominant channel by which we learn about public controversies. Their presentation will have a powerful effect on the ways that the events, arguments, participants, and so on are memorialized. In addition, media texts are part of the variegated institutional, historical, social, and textual environment in which controversies emerge. In this paper, I analyze the reasoning of participants in the Brooklyn Museum controversy as it is presented by in a corpus of media texts reporting on the event. I ask the following question: How much and what kinds of reasoning by controversy participants do media texts present in this case? In discussing my results I reflect on the role of media texts as source material for argument and debate reconstruction. (shrink)

A crucial challenge in terms of research methods in philosophy of education is that of combining philosophical ways of analyzing and arguing, with the dialogical and pluralist way of thinking needed in educational research. In this article I describe how I dealt with this challenge in my research project focusing on educational implications of the positions defended in the debate on constructivism and realism between Israel Scheffler and Nelson Goodman. The key to my methodological approach is an emphasis on the (...) role of a thoroughgoing process of analysis and synthesis. I see this process as the prerequisite for profound philosophical dialogue on education. (shrink)

Most studies of reason-giving have focussed on formal, planned situations rather than on how reason-giving functions in relatively unplanned discourse. This study looks at reason-giving by respondents to an anonymous telephone public-opinion survey, e xploring the relationship between fact, policy, and value claims and the types of reasons used to support those claims. The results resonate with two important areas in argumentation theory: argument fields and critical thinking. Further, I suggest that reason-giving can serve as a method for individuals to (...) present themselves as human and thoughtfully reasonable. (shrink)

In this paper, a survey is presented of the main approaches to the structure of argumentation. The paper starts with a historical overview of the distinctions between various types of argument structure. Next, the main definitions given in the various approaches are discussed as well as the methods that are proposed to deal with doubtful cases.

This presentation seeks to understand informal logic as a set of methods for the logical evaluation of natural language arguments. Some of the methods identified are the fallacies method, deductivism, warrantism and argument schemes. A framework for comparing the adequacy of the methods is outlined consisting of the following categories: learner- and user-efficiency, subjective and objective reliability, and scope. Within this framework, it is also possible to compare informal and formal logic.

I characterize the deductivist ideal of justification and, following to a great extent Toulmin’s work The Uses of Argument, I try to explain why this ideal is erroneous. Then I offer an alternative model of justification capable of making our claims to knowledge about substantial matters sound and reasonable. This model of justification will be based on a conception of justification as the result of good argumentation, and on a model of argumentation which is a pragmatic linguistic reconstruction of Toulmin’s (...) model of argument. (shrink)

Normal 0 21 false false false ES X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabla normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} If the open society is a society that ‘sets free the critical powers of man’ (Popper, 1945, Introduction), then the subject of critical thinking, now widely taught in universities in North America and at the level of (...) further education in the UK, might seem to be a welcome innovation. Caution is advised. By mistakenly supposing that thinking intelligently is identical with thinking logically, critical thinking textbooks almost invariably regard the purpose of argument to be a combination of justification and persuasion, authoritarian goals that critical rationalists, and other supporters of the open society, must shun. If students do not learn the proper place of reason, and its limitations, they will be disappointed when it fails, and like many irrationalists in the past, may be induced to reason their way out of reason altogether. (shrink)

Woods and Walton deserve credit for including a discussion of “economic reasoning” and its susceptibility to the “fallacy of composition.” Unfortunately, they did not sufficiently pursue the topic, and argumentation scholars have apparently ignored their pioneering effort. Yet, obviously, economic argumentation is extremely important, and economists constantly harp on this fallacy. This paper calls attention to this problem, elaborating my own approach, which is empirical, historical, and meta-argumentational.

§1. Introduction. I dedicate this essay to the two-dozen-odd people whose refutations of Cantor's diagonal argument have come to me either as referee or as editor in the last twenty years or so. Sadly these submissions were all quite unpublishable; I sent them back with what I hope were helpful comments. A few years ago it occurred to me to wonder why so many people devote so much energy to refuting this harmless little argument—what had it done to make them (...) angry with it? So I started to keep notes of these papers, in the hope that some pattern would emerge.These pages report the results. They might be useful for editors faced with similar problem papers, or even for the authors of the papers themselves. But the main message to reach me is that there are several points of basic elementary logic that we usually teach and explain very badly, or not at all.In 1995 an engineer named William Dilworth, who had published a refutation of Cantor's argument in the Transactions of the Wisconsin Academy of Sciences, Arts and Letters, sued for libel a mathematician named Underwood Dudley who had called him a crank. (shrink)

§1. Introduction. I dedicate this essay to the two-dozen-odd people whose refutations of Cantor's diagonal argument have come to me either as referee or as editor in the last twenty years or so. Sadly these submissions were all quite unpublishable; I sent them back with what I hope were helpful comments. A few years ago it occurred to me to wonder why so many people devote so much energy to refuting this harmless little argument—what had it done to make them (...) angry with it? So I started to keep notes of these papers, in the hope that some pattern would emerge.These pages report the results. They might be useful for editors faced with similar problem papers, or even for the authors of the papers themselves. But the main message to reach me is that there are several points of basic elementary logic that we usually teach and explain very badly, or not at all.In 1995 an engineer named William Dilworth, who had published a refutation of Cantor's argument in the Transactions of the Wisconsin Academy of Sciences, Arts and Letters, sued for libel a mathematician named Underwood Dudley who had called him a crank. (shrink)

Qualitative comparative analysis (QCA) opens up two new forms of knowledge: (1) knowing about alternative pathways to one outcome (equifinality) and (2) perceiving nuances of necessary cause and sufficient cause. Several misunderstandings of QCA occur in the article by Lucas and Szatrowski (this volume, p. 1). First, there are minor problems with expressions. Second, there are differences between their philosophy of science (arguments 1, 2, and 3 below) and a realist approach. Third, they misinterpret what was meant by sufficient and (...) necessary cause (arguments 4 and 5 below). The minor problems with expressions arise in sections 2.2 and 3. In section 2.2, the authors define consistency, but here they miss out on two key points. First, they neglect to say that this particular measure of consistency is a measure of sufficiency of cause, not of necessary cause. Second, they ignore the way that the consistency level exists for each possible configuration of characteristics. A configuration can be shown in one row of a truth table, with n1 = 28, n2 = 17 within a larger sample of 155, and so on (see Byrne 2009:262). Using QCA’s definition of “consistency,” we can discern more about the pattern of causality than one might initially expect. This learning is possible whether N overall is 155, or just 39, or thousands of cases. The essential task is to simplify and rank the list of configurations (Ragin 2001, 2006). (shrink)

Numerous informal logi- cians and argumentation theorists restrict their theorizing to what they call “real” arguments. But is there a clear distinction to be made between “real” and “non-real” arguments? Here I explore four possible accounts of the alleged distinction and argue that none can serve the theoretical uses to which the distinction is most often put. Résumé: Plusieurs logiciens construction formels et théoriciens de l’argument- ation limitent leur non de théories à ce qu’ils appellent des arguments « authentiques ». (...) Mais y-a- t’il une distinction claire entre des arguments« authentiques » et « inau- thentiques » ? Ici j’explore quatre descriptions possibles de cette préten- due distinction et je soutiens qu’- aucune ne répond aux besoins théori- ques auxquels elles sont censées ré- pondre. (shrink)

In order to write successfully, students need to understand what it is they are expected to write, why it is written in a particular way and the form that the final text should take. Linguistics research indicates that the ubiquitous essay and report conceal significant disciplinary variation. Educational research reveals variation with regard to assessment and marking of written work within disciplines, between lecturers, across departments, nationally and internationally. We present an interdisciplinary, genre-based model that we have piloted and tested (...) in History at the University of Portsmouth. Our aim is to bring disciplinary, applied linguistic and academic skills expertise to the point where students are taught to write particular assignments. We offer the model for testing in other genres, disciplines and institutions. (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)