This volume contains 12 papers addressed to researchers and advanced students in informal logic and related fields, such as argumentation, formal logic, and communications. Among the issues discussed are attempts to rethink the nature of argument and of inference, the role of dialectical context, and the standards for evaluating inferences, and to shed light on the interfaces between informal logic and argumentation theory, rhetoric, formal logic and cognitive psychology.

J. Anthony Blair is a prominent international figure in argumentation studies. He is among the originators of informal logic, an author of textbooks on the informal logic approach to argument analysis and evaluation and on critical thinking, and a founder and editor of the journal Informal Logic. Blair is widely recognized among the leaders in the field for contributing formative ideas to the argumentation literature of the last few decades. This selection of key works provides insights into the history of (...) the field of argumentation theory and various related disciplines. It illuminates the central debates and presents core ideas in four main areas: Critical Thinking, Informal Logic, Argument Theory and Logic, Dialectic and Rhetoric. (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)

Much psychological research on argumentation focuses on persuasion and pragmatics. However, one strand investigates how average people understand the nature of knowledge and knowing, and how these epistemological orientations underlie skilled argumentation. The research reviewed addresses the question whether the normative emphasis of the philosophical epistemological approach to argumentation matches psychological findings. The empirical research reviewed concerns the relationship between personal episte- mological understanding and three aspects of argument: argument construction, identification of informal reasoning fallacies, and orientation toward explanation or (...) evidence. Findings suggest that people develop an epistemological approach toward argumentation in which beliefs about knowledge justification requirements are related with skilled argumentation. (shrink)

Since at least the 1938 publication of Hans Reichenbach’s Experience and Predication , there has been widespread agreement that, when discussing the beliefs that people have, it is important to distinguish contexts of discovery and contexts of justification. Traditionally, when one conflates the two contexts, the result is a “genetic fallacy”. This paper examines genealogical critiques and addresses the question of whether such critiques are fallacious and, if so, whether this vitiates their usefulness. The paper concludes that while there may (...) be one or more senses in which genealogical critiques are fallacious, this does not vitiate their value. (shrink)

The relationship between knowledge, belief, and ethics is an inaugural theme in philosophy; more recently, under the title “ethics of belief” philosophers have worked to develop the appropriate methodology for studying the nexus of epistemology, ethics, and psychology. The title “ethics of belief” comes from a 19th-century paper written by British philosopher and mathematician W.K. Clifford. Clifford argues that we are morally responsible for our beliefs because each belief that we form creates the cognitive circumstances for related beliefs to follow, (...) and we inevitably influence each other through those beliefs. This study argues that recent cognitive research supports Cliffordian insights regarding patterns of belief formation and social influence. From the confirmation offered by such research, it follows that informational accuracy holds serious ethical significance in public discourse. Although scientific and epistemological matters are not always thought to be linked to normative morality, this study builds on Clifford's initial insights to show their linkage is fundamental to inquiry itself. In turn, Clifford's ethical and epistemic outline can inform a framework grounded in “public reason” under which seemingly opposed science communication strategies are philosophically united. With public discourse on climate change as the key example, empirically informed and grounded strategies for science communication in the public sphere are considered. (shrink)

The study describes a method created for the analysis of persuasive strategies, called rhetorical heuristics, which can be applied in speeches where the argument focuses primarily on questions of fact. First, the author explains how the concept emerged from the study of classical oratory. Then the theoretical background of rhetorical heuristics is outlined through briefly discussing relevant aspects of the psychology of decision-making. Finally, an exposition of how one could find these persuasive strategies introduces rhetorical heuristics in more detail.

The commonalities of Douglas Walton's Slippery Slope Arguments and James Davies's Ways of Thinking are obvious: both are written by Canadian philosophers; both lie within the broad field of informal logic; and both make appeals in support of dialogical reasoning. But there the similarities end. The former is the work of a prolific author writing a treatise focussing narrowly on one topic within informal logic; the latter is the product of a newcomer to book-writing, and his is a textbook intended (...) for beginning students. (shrink)

It is obvious that teaching and research in informal logic is a growth industry, indeed one of burgeoning proportions. Judging by skyrocketing enrolments and the avalanche of books, journals, computer aids, conferences, and workshops during the last decade, it would seem to be no passing fad but the overdue recognition of a societal need.

In this paper, I argue that many arguments from expert opinion are strong arguments. Therefore, in many cases it is rational to rely on experts since in many cases the fact that an expert says that p makes it highly likely that p is true. I will defend this claim by providing 5 arguments that illuminate and elaborate on 5 crucial claims about expertise. In this way, I aim to undermine recent attempts to establish a rampant scepticism about arguments from (...) expert opinion. (shrink)

The present study examined how the pre-war debate of the US decision to invade Iraq (in March 2003) was discursively constructed in the US/British mainstream newspaper opinion/editorial (op/ed) argumentation. Drawing on theoretical insights from critical discourse analysis and argumentation theory, I problematised the fallacious discussion used in the pro-war op/eds to build up a ‘moral/legal case’ for war on Iraq based on adversarial (rather than dialogical) argumentation. The proponents of war deployed ‘instrumental rationality’ (ends-justify-means reasoning), ‘ethical necessity’ (Bush’s ‘Preemption Doctrine’) (...) and ‘humanitarian virtue’ (the bombing of Iraq to ‘save’ Iraqis from Saddam’s pestilent tyranny) to justify the pending invasion of Iraq. Their arguments intertextually resonated with Bush administration’s ‘war on terror’ rhetoric in a way that created a form of indexical association through ‘recontextualisation’. The type of arguments marshalled by the pro-war op/ed commentators uncritically bolstered the set of US official ‘truth claims’ and ‘presuppositions’. (shrink)

The current dominant approach on the assessment of critical thinking takes as a starting point a conception of criticality that does not commit to any substantive view or context of meaning concerning what issues are relevant to be critical about in society or in life. Nevertheless, as a detailed examination of the identification of assumptions shows, when going from the theory of critical thinking to the praxis of producing and evaluating arguments, the critical person will inevitably make such commitments from (...) particular perspectives, using particular contexts of meaning. But then she may fail to take notice of relevant ones and may end up using her critical powers in a mercenary way. It is then proposed, in the context of assessment of critical thinking, to choose and use some privileged contexts of meaning, while making them available for critical scrutiny and allowing for the possibility that new ones be brought up by those being assessed. (shrink)

Abstract: The article presents and critically discusses Walton's (and Reed's and Macagno's) argument scheme approach to a theory of good argumentation. In particular, four characteristics of Walton's approach are presented: 1. It presents normative requirements for argumentation in the form of argument schemes, i.e. relatively concrete type descriptions. 2. These schemata are enthymematic, i.e. they omit some of the premises required by other approaches. 3. The actual argument schemes are usually supplemented by critical questions. 4. The method is inductive, bottom-up, (...) gaining the normative schemata by abstraction from empirically collected groups of similar arguments. These characteristics, among others, are then discussed on the basis of four adequacy conditions: AC1: effectiveness in achieving the epistemic goal of obtaining and communicating justified acceptable opinions; AC2: completeness in capturing the good argument types; AC3: efficiency in achieving the goals; AC4: justification of the argument schemes. The discussion then reveals a number of weaknesses in Walton's argument schemes; among other things, they are neither effective (in the defined sense) nor truly justified. Contributing factors to these problems include the schema approach, i.e. not looking at the form of arguments, and the lack of epistemological foundations in the development of good types of arguments. However, the critical analyses reveal a better alternative: an epistemological approach based on epistemological principles. The article concludes with a detailed analysis of the scheme Practical Inference, which confirms the general criticism in detail. (shrink)

In many contexts a retraction of commitment isfrowned upon. For instance, it is not appreciated,generally, if one withdraws a promise or denies anearlier statement. Critical discussion, too, caneasily be disrupted by retractions, if these occur toofrequently and at critical points. But on the otherhand, the very goal of critical discussion –resolution of a dispute – involves a retraction,either of doubt, or of some expressed point of view.A person who never retracts, not even under pressureof cogent arguments, would hardly qualify as (...) areasonable discussant. Also, inconsistencies in one'sposition, once they have been pointed out, must bedealt with by some kind of retraction. The problem ofretraction is to find a suitable model of dialoguethat allows retractions where they seem reasonable, oreven required, and rules them out (or puts sanctionsupon them) whenever they would become disruptive of awell-organized process of dialogue.The present paper tries to point to a solution basedon the following principles: (1) Retraction rulesdetermine what retractions are permissible, and (2) ifpermissible what the consequences of retraction are.(3) Retraction rules vary according to the type ofdialogue and (4) according to the type of commitmentretracted. For instance, assertions and mereconcessions need to be distinguished, as well aslight-side and dark-side commitments. (5) To accountfor our contradictory intuitions on the issue ofretractions, one may best resort to a complex type ofdialogue in which different retraction rules hold fordifferent parts.The paper explains, summarizes, and expands upon thediscussion of retraction in Commitment inDialogue by Douglas Walton and the present author(cf. Walton and Krabbe 1995). (shrink)

Criticism may degenerate into quibbling or nitpicking. How can discussants keep quibblers under control? In the paper we investigate cases in which a battle about words replaces a discussion of the matters that are actually at issue as well as cases in which a battle about minor objections replaces a discussion of the major issues. We survey some lines of discussion dealing with these situations in profiles of dialogue.

We shall investigate the similarities and dissimilarities between old and new dialectic. For the ‘old dialectic’, we base our survey mainly on Aristotle’s Topics and Sophistical Refutations, whereas for the ‘new dialectic’, we turn to contemporary views on dialogical interaction, such as can, for the greater part, be found in Walton’s The New Dialectic. Three issues are taken up: types of dialogue, fallacies, and strategies. Though one should not belittle the differences in scope and outlook that obtain between the old (...) and the new dialectic, the paper will show that in many respects the old dialectic foreshadows the new dialectic. (shrink)

Bayesian reasoning has been applied formally to statistical inference, machine learning and analysing scientific method. Here I apply it informally to more common forms of inference, namely natural language arguments. I analyse a variety of traditional fallacies, deductive, inductive and causal, and find more merit in them than is generally acknowledged. Bayesian principles provide a framework for understanding ordinary arguments which is well worth developing.

ABSTRACTIn everyday situations, people regularly receive information from large groups of people and from single experts. Although lay opinions and expert opinions have been studied extensively in isolation, the present study examined the relationship between the two by asking how many laypeople are needed to counter an expert opinion. A Bayesian formalisation allowed the prescription of this quantity. Participants were subsequently asked to assess how many laypeople are needed in different situations. The results demonstrate that people are sensitive to the (...) relevant factors identified for determining how many lay opinions are required to counteract a single expert opinion. People's assessments were fairly good in line with Bayesian predictions. (shrink)

During the last forty or so years it has become popular to offer explanations of logical notions in terms of games. There is no doubt that many people find games helpful for understanding various logical phenomena. But we ask whether anything is really 'explained' by these accounts, and we analyse Paul Lorenzen's dialogue foundations for constructive logic as an example. The conclusion is that the value of games lies in their ability to provide helpful metaphors and representations, rather than in (...) any true conceptual analysis. In fact some of the standard explanations of logical notions in terms of competitive games simply don't work. /// [Erik C. W. Krabbe] In an attempt to redeem the Lorenzen-type dialogues from their detractors, it is perhaps best first to provide a survey of the various benefits these dialogues have been supposed to yield. This will be done in Section I. It will not be possible, within the confines of this paper, to scrutinize them all, but in Section II we shall delve deeper into the capacity of this type of dialogue to yield a model for the immanent criticism of philosophical positions. Section III will extend the concept of a dialogue in such a way as to conform better with our intuitive conceptions of what a rational discussion of a position should contain. This will be followed up by a concept of 'winning a dialogue' that takes position midway between the old conception of 'winning one play' and that of the full-fledged presentation of a winning strategy . Concepts of 'rational discussion' are thus shown to be, plausibly, more fundamental than those of proof. In Section IV, I shall discuss the specific problems about dialogical foundations put forward by Wilfrid Hodges. (shrink)

Toward a Shared Metaphoric Meaning in Children's Discourse: The Role of Argumentation The text deals with the phenomenon of understanding and interpreting metaphoric expressions in children. Of the many metaphoric figures, one type was selected: the ‘so-called’ psychological-physical metaphors that illuminate a psychological experience by appealing to an event in the physical domain. The data consist of children's discussions in pairs, in which they make a joint interpretation of metaphors including a dual-function adjective, e.g., a hard person, a sweet person, (...) an empty person. A hundred and forty-four dialogues between peer dyads were recorded from three age groups : 6;6-7;6, 8;6-9;6, and 10;6-11;6. The children's task was to prepare an interpretation of metaphorical expressions for two television quiz shows, one for peers and one for young preschoolers. The research design was balanced for age, gender, and order of metaphoric interpretation in the two experimental variants. Following Quignard's model, we analyzed children's argumentation as a particular case of dialogical problem solving, whereby children had to understand the metaphoric meaning and convey it to the potential addressee. The results show an interesting dynamic in the argumentative orientation of the pro and the contra type, depending on the age of interlocutors. The frequency of metaphoric interpretations in opposition to those presented by the partner decreases with the children's age, but the frequency of compound proposals with the use of the partner's contribution increases. For the younger addressee, children most frequently interpret metaphors as descriptions of magical situations. (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.

Introduction: Clinical practice guidelines (CPGs) are an important source of justification for clinical decisions in modern evidence-based practice. Yet, we have given little attention to how they argue their evidence. In particular, how do CPGs argue for treatment with long-term medications that are increasingly prescribed to older patients? Approach and rationale: I selected six disease-specific guidelines recommending treatment with five of the medication classes most commonly prescribed for seniors in Ontario, Canada. I considered the stated aims of these CPGs and (...) the techniques employed towards those aims. Finally, I reconstructed and logically analysed the arguments supporting recommendations for pharmacotherapy. Analysis: The primary function of CPGs is rhetorical, or persuasive, and their means of persuasion include both a display of their credibility and their argumentation. Arguments supporting pharmacotherapy recommendations for the target population follow a common inductive pattern: statistical generalization from randomized controlled trial (RCT) and meta-analysis evidence. Two of the CPGs also argue their treatment recommendations for older patients in this style, while three fail to justify pharmacotherapy specifically for the older population. Discussion: The arguments analysed lack the auxiliary assumptions that would warrant making a generalization about the clinical effectiveness of medications for the older population. Guidelines reason using simple induction, while ignoring important inferential gaps. Future guidelines should aspire to be well-reasoned rather than simply evidence-based; argue from a plurality of evidence; be wary of hasty inductions; appropriately limit the scope of their recommendations; and avoid making law-like, prescriptive generalizations. (shrink)

The Consequence Argument has elicited various responses, ranging from acceptance as obviously right to rejection as obviously problematic in one way or another. Here we wish to focus on one specific response, according to which the Consequence Argument begs the question. This is a serious accusation that has not yet been adequately rebutted, and we aim to remedy that in what follows. We begin by giving a formulation of the Consequence Argument. We also offer some tentative proposals about the nature (...) of begging the question. Although the charge of begging the question is frequently made in philosophy, it is surprisingly difficult to pin down the precise nature of this dialectical infelicity (or family of such infelicities). Thus we offer some new proposals about the nature of begging the question with an eye to understanding what is going on in central cases in which the charge is legitimately made. We then defend the Consequence Argument against the charge that it begs the question, so construed. We contend that, whatever the other liabilities of the argument may be, it does not beg the question against the compatibilist. (shrink)

Collaborative learning with cases characteristically involves discussing and developing shared explanations. We investigated the argumentation scheme which learners use in constructing shared explanations over evidence. We observed medical students attempting to explain how a judge had arrived at his verdict in a case of medical negligence. The students were learning within a virtual learning environment and their communication was computer mediated. We identify the dialogue type that these learners construct and show that their argumentation conforms with an abductive form of (...) argumentation scheme (‘inference to the best explanation’). We also assessed the students’ learning and propose that it is related to particular features of this argumentation scheme. (shrink)