The view that contradictions cannot be true has been part of accepted philosophical theory since at least the time of Aristotle. In this regard, it is almost unique in the history of philosophy. Only in the last forty years has the view been systematically challenged with the advent of dialetheism. Since Graham Priest introduced dialetheism as a solution to certain self-referential paradoxes, the possibility of true contradictions has been a live issue in the philosophy of logic. Yet, despite the arguments (...) advanced by dialetheists, many logicians and philosophers still hold the opinion that contradictions cannot be true. -/- Rather than advocating the truth of certain contradictions, this thesis offers a different challenge to the classical logician. By showing that it can be philosophically coherent to propose that true contradictions are metaphysically possible, the thesis suggests that the classical logician must do more than she currently has to justify her confidence in the impossibility of true contradictions. Simply fighting off the dialetheist’s putative examples of true contradictions at the actual world isn’t enough to justify the classical logician’s conclusion that true contradictions are impossible. -/- To aid the thesis dialectically, we introduce a new position, absolutism, which hypothesises that it’s metaphysically possible for at least one contradiction to be true, contrasting with the dialetheic hypothesis that some contradictions are true in the actual world. We demonstrate that absolutism can be given a philosophically coherent interpretation, an appropriate logic, and that certain criticisms are completely toothless against absolutism. The challenge put to the classical logician is then: On what logical or philosophical grounds can we rule out the metaphysical possibility of true contradictions? (shrink)

In his influential work on critical argumentation, Douglas Walton explains how to judge whether an argumentum ad verecundiam is fallacious or legitimate. He provides six critical questions and a number of ancillary sub-questions to guide the identification of reasonable appeals to authority. While it is common for informal logicians to acknowledge the role of bias in sampling procedures and hypothesis confirmation , there is a conspicuous lack of discourse on the effect of identity prejudice on judgments of authority, even though (...) this is a well-documented factor in attributing credibility, expertise, trustworthiness, and professional competence to oppressed groups. This could result in faulty judgments of ad verecundiam fallacy. Focusing on gender bias, I review recent works in feminist epistemology—particularly those of Miranda Fricker and Helen Longino —to develop three gender-based critical questions to supplement Walton’s original list of six. This addition will help us to identify erroneous dismissals of appeals to authority based on epistemic injustice and epistemic irresponsibility on the part of the speaker or knowledge community. This project promotes the overlapping aims of feminist epistemology and informal logic. (shrink)

Informal logic has expanded the concept of an 'argument' beyond that presented traditionally by formal logicians-to include arguments as encountered in 'real-life'. Existent definitions of argument structure are argued to be inadequate by failing to fully recognise that, ultimately, arguments have a human source. Accordingly, a new definition is proposed which appeals to relevant cognitive and behavioural factors. The definition retains some traditional concepts, but introduces the term 'supportive' as a modification to 'premiss'. The concept of a 'persuader' is also (...) developed. The definition is argued to capture more fully the intricacies, subtleties and rich diversity of informal arguments. (shrink)

The aim of this paper is to adapt Miranda Fricker’s concept of testimonial injustice to cases of what I call “argumentative injustice”: those cases where an arguer’s social identity brings listeners to place too much or little credibility in an argument. My recommendation is to adopt a stance of “metadistrust”—we ought to distrust our inclinations to trust or distrust members of stereotyped groups.

Argumentation logicians have recognized a specter of relativism to haunt their philosophy of argument. However, their attempts to dispel pernicious relativism by invoking notions of a universal audience or a community of model interlocutors have not been entirely successful. In fact, their various discussions of a universal audience invoke the context-eschewing formalism of Kant’s categorical imperative. Moreover, they embrace the Kantian method for resolving the antinomies that continually vacillates between opposing extremes – here between a transcendent universal audience and a (...) context-embedded particular audience. This tack ironically restores the very external mediation they thought to obviate in their aim to ‘dethrone’ the absolutism and totalitarianism of formal logic with a democratic turn to audience adherence, the acceptability of premises and inferential links, and a contextual, or participant-relative, notion of cogency. (shrink)

In this overview article, we first explain what we take informal logic to be, discussing misconceptions and distinguishing our conception of it from competing ones; second, we briefly catalogue recent informal logic research, under 14 headings; third, we suggest four broad areas of problems and questions for future research; fourth, we describe current scholarly resources for informal logic; fifth, we discuss three implications of informal logic for philosophy in particular, and take note ofpractical consequences of a more general sort.

Informal logic began in the 1970s as a critique of then-current theoretical assumptions in the teaching of argument analysis and evaluation in philosophy departments in the U.S. and Canada. The last 35 years have seen significant developments in informal logic and critical thinking theory. The paper is a pilot study of the influence of these advances in theory on what is taught in courses on argument analysis and critical thinking in U.S. and Canadian philosophy departments. Its finding, provisional and much-qualified, (...) is that the theoretical developments and refinements have had limited impact on instruction in leading philosophy departments. (shrink)

I will situate the fallacies approach to reasoning with the aim of making it more relevant to contemporary life and thus intellectually significant and valuable as a method for teaching reasoning. This entails a revision that will relegate some of the traditional fallacies to the realm of history and introduce more recently recognized problems in reasoning. Some newly recognized problems that demand attention are revealed by contemporary science studies, which reveal at least two tenacious problems in reasoning that I will (...) explore in this paper. One of these problems is androcentrism, a ubiquitous problem with reasoning that feminists exposed in the twentieth century but that continues to pervade people’s reasoning. The other is biological reductionism in at least two specific forms: genetic determinism and adaptationism. (shrink)

Philosophy and Literature is an internationally renowned refereed journal founded by Denis Dutton at the University of Canterbury, Christchurch. It is now published by the Johns Hopkins University Press. Since its inception in 1976, Philosophy and Literature has been concerned with the relation between literary and philosophical studies, publishing articles on the philosophical interpretation of literature as well as the literary treatment of philosophy. Philosophy and Literature has sometimes been regarded as iconoclastic, in the sense that it repudiates academic pretensions, (...) insidious jargon and institutional vogue. Dutton, who remains the editor, still writes a regular column. A distinctive feature of Philosophy and Literature was the annual Bad Writing Contest, held from 1995–98, which sought to identify (and publish) the ‘most stylistically lamentable passages’ of academic prose, often to great amusement. (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)

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 tribute to the breadth and influence of Trudy Govier’s philosophical work begins with her early scholarship in argumentation theory, paying special attention to its pedagogical expression. Most people first encounter Trudy Govier’s work and many people only encounter it through her textbooks, especially A Practical Study of Argument, published in many editions. In addition to the work on argumentation that has continued throughout her career, much of Govier’s later work addresses social philosophy and the problems of trust and response (...) to moral wrongs. The introduction by Catherine Hundleby situates Govier’s research along the path of her unusual academic life. While following the timeline of Govier’s research publication, in this collection the authors build on her work and suggest certain new connections between her argumentation theory and social philosophy. A Practical Study of Argument, first published in 1985, situates Govier among a distinct segment of informal logicians whose concerns about teaching reasoning to post-secondary students orient their research, Takuzo Konishi argues. Moira Kloster evaluates Govier’s progress in the challenge of providing critical thinking education to diverse and changing social contexts. Shifting gears to social philosophy but still addressing education, Laura Elizabeth Pinto explores the significance of Govier’s work on trust for explaining the problem of “audit culture” for teaching. At the centre of this volume, social philosophy receives an abstract meta-ethical defense from Linda Radzik. Moving solidly into the domain of normative social philosophy, Alice MacLachlan reconsiders Govier’s condemnation of revenge by viewing it as a form of moral address, but she notes how revenge as an act of communication contrasts with argumentation in lacking the respect that Govier maintains is intrinsic to argumentation. MacLachlan ultimately agrees that revenge is morally indefensible. The practical challenges of addressing others in the aftermath of wrongdoing, especially in public contexts, can make it difficult to distinguish between victims and combatants or wrongdoers, Alistair Little and Wilhelm Verwoerd explain, and Kathryn Norlock argues that forgiveness is psychologically vexed too. People may recognize transformation to be in principle possible for all people, Norlock argues, and yet we may find the evidence regarding some particular evildoer sufficient to count that person as an exception. Finally Govier responds to the various papers. (shrink)

Arguing that our attachment to Aristotelian modes of discourse makes a revision of their conceptual foundations long overdue, the author proposes the consideration of unacknowledged factors that play a central role in argument itself. These are in particular the subjective imprint and the dynamics of argumentation. Their inclusion in a four-dimensional framework and the focus on thesis validity allow for a more realistic view of our discourse practice. Exhaustive analyses of fascinating historical and contemporary arguments are provided. These range from (...) Columbus’s advocacy of the Western Passage to India, over the trial of King Louis XVI during the French Revolution, to today’s highly charged controversies surrounding euthanasia and embryo research. Excavating foundational issues such as the purpose of argument itself and the contested role of argument as a generator of knowledge, the book culminates in a discussion of the relationship between rationality and reasonableness and criticizes the restrictions of ‘rational’ argument relying on fixed logical, economic or cultural criteria that in reality are mutable. Here, a true, open argument requires the infusion of Paul Lorenzen’s principle of ‘transsubjectivity’, which recognizes but transcends the partiality of the individual and which can be seen in the pragmatic and expanding consensus that humanity can control itself to safeguard the future of a fragile, damaged world. (shrink)

Jednym z najważniejszych celów kursów krytycznego myślenia powinno być dostarczenie słuchaczom narzędzi pomocnych w podejmowaniu trafnych decyzji w codziennym życiu. Podczas takich kursów wiele uwagi poświęca się zazwyczaj wyrabianiu u studentów umiejętności oceny argumentów. W niniejszym artykule próbuję odpowiedzieć na pytanie – jaka metoda oceny argumentów najlepiej nadaje się do zastosowania podczas kursów krytycznego myślenia? Jak sądzę, metoda taka powinna być możliwie najbardziej intuicyjna, „przyjazna użytkownikowi” – prosta zarówno do opanowania, jak i późniejszego stosowania. Są to warunki konieczne do tego, (...) aby osoby, które ukończyły kurs, faktycznie wykorzystywały ją w codzienny sytuacjach. W artykule opisuję metodę oceny argumentów, która, jak mi się wydaje, spełnia te warunki. Metoda ta opiera się przede wszystkim na koncepcjach S.N. Thomasa i M. Tokarza. Jej szczegóły, a także sposób prezentowania jej studentom, wypracowałem podczas prowadzonych przeze mnie kursów z zakresu logiki nieformalnej i krytycznego myślenia. (shrink)

Recent theorizing and research concerning the pragmatics of analogy in persuasion posits that it serves two communicative functions. Specifically, rebuttal analogy instrumentally functions as argument and also as a social attack device used to demean the competence or character of opponents. The study reported here empirically investigated message receivers' perceptions of rebuttal analogy users. Participants were exposed to one of four messages employing rebuttal analogy or to one of the same four messages with a nonanalogy version of the rebuttal argument. (...) As anticipated, the findings revealed that participants perceived the communicator employing rebuttal analogy as less ethical and less competent than communicators using nonanalogy counterparts. These results are discussed and future research is proposed. (shrink)

Five errors that fit under the category of jumping to a conclusion are identified: (1) arguing from premises that are insufficient as evidence to prove a conclusion (2) fallacious argument from ignorance, (3) arguing to a wrong conclusion, (4) using defeasible reasoning without being open to exceptions, and (5) overlooking/suppressing evidence. It is shown that jumping to a conclusion is best seen not as a fallacy itself, but as a more general category of faulty argumentation pattern underlying these errors and (...) some related fallacies. (shrink)

Since a clear account of the fallacy of false disjunctive syllogism is missing in the literature, the fallacy is defined and its three types are differentiated after some preliminaries. Section 4 further elaborates the differentia specifica for each of the three types by analyzing relevant argument criticism of each, as well as the related profiles of dialogue. After defining false disjunctive syllogisms, it becomes possible to distinguish between a false dilemma and a false disjunctive syllogism: section 5 analyzes their similarities (...) and section 6 explains their differences. (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 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)

In one of his papers, Moti Mizrahi argues that arguments from an expert opinion are weak arguments. His thesis may seem controversial due to the consensus on this topic in the field of informal logic. I argue that its controversy is framework-dependent, and if translated into a different framework, it appears to be a correct, however trivial, claim. I will use a framework based on Douglas Walton’s argumentation scheme theory and his conception of examination dialogue to demonstrate that it is (...) so. It appears that Mizrahi’s idiosyncratic framework provides an excessively restrictive conception of an argument from expert opinion than Walton’s scheme does. There is no quarrel between both frameworks, as they yield analogous, almost identical, outcomes of argument evaluation. The actual and crucial disagreement is on the topic of argument classification. Mizrahi’s conception of arguments from an expert opinion imposes exact conditions that such argument must fulfil: an expert’s opinion o truth-value must be unknown; o must be unsupported by any evidence; an expert’s peers neither accept o nor reject it. These exclude, by definition, every possible strong, in Walton’s terms, variant of such an argument. Therefore, if rephrased with the notions of the examination dialogue framework, Mizrahi’s thesis sounds as follows: weak arguments from expert opinion are weak arguments. (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.

This paper is an exercise in intellectual history, an attempt to understand how a specific term—”informal logic”— came to be interpreted in so many different ways. I trace the emergence and development of “informal logic” to help explain the many different meanings, how they emerged and how they are related. This paper is also, to some degree, an account of a movement that developed outside the mainstream of philosophy, whose origins lie in a desire to make logic useful (echoing Dewey).

In this paper, I propose that the inquiry known as a/the theory of argument is the “invention” of Trudy Govier, using that term in its rhetorical sense, viz., the process of choosing ideas appropriate to the subject. In her paper, “Is a Theory of Argument Possible?” Govier used the idea of theory of argument to focus her discussion on problems in argument analysis and evaluation that came to light in the 1970s and 1980s. The idea of a theory of argument (...) was already there but Govier “discovered” it in the sense that she made its potential clear. (shrink)

Since the 80s, educators have supported instruction in critical thinking as “an Educational Ideal.” This should not be a surprise given some of the more common conceptions, e.g., Ennis’s “reasonable reflective thinking on what to believe or do,” or Siegel’s “being appropriately moved by reasons,” as opposed to bias, emotion or wishful thinking. Who would want a doctor, lawyer, or mechanic who could not skillfully evaluate arguments, causes, and cures? So, educators endorsed the dream that, through proper CT instruction, students’ (...) critical skills and “rational passions” could be greatly improved. In spite of the dream’s appeal, the reality is, after 30+ years, there is little reason to think the dream resembles reality. After describing what I take to be an adequate definition of CT, such a depressing conclusion will be supported by CT assessment scores from across academe, the continued widespread disagreement among experts in nearly all fields, including CT, and the abundant psychological research on rationality and decision making. And finally, while the ideal extols the value of objectivity, I shall argue that bias may be unavoidable because personal values play a vital role in the evaluation of many arguments. (shrink)

: In “What is a ‘Real’ Argument?” Geoff Goddu (2009) suggests and rejects four candidates for what a real argument is, concluding that argumentation theorists should abandon the idea that there is a theoretically significant sub-class of arguments that should be called real. In this paper, I argue against Goddu’s conclusion, finding that real arguments are arguments that are used or that have prospective use in the practice of thinking about matters that call for reasonable and reflective judgment concerning what (...) to believe or do. What makes these arguments theoretically distinct from arguments in general is that they are used or that they may be used in the pragmatic endeavor of attempting to establish good reasons for beliefs and actions. Real arguments are therefore the arguments that should be treated in a course that aims to improve the skills of argumentation that students might use outside of the classroom in real-life. (shrink)

In her recent Counter-Reply to my views, Evelyn Pluhar defends her use of literature on nutrition and restates her argument for moral vegetarianism. In his Vegan Ideal article, Gary Varner claims that the nutrition literature does not show sufficient differences among women, men, and children to warrant concern about discrimination. In this response I show how Professor Pluhar continues to draw fallacious inferences: she begs the question on equality, avoids the main issue in my ethical arguments, argues from irrelevancies, misquotes (...) her sources, equivocates on context, confuses safety with morality, appeals to fear, confuses correlation with cause, fails to evaluate scientific studies, draws hasty conclusions from insufficient data, ignores a large amount of data which would call her views into question, does not follow good scientific or moral argumentation, objectionably exceeds the limits of her expertise, and resorts to scapegoating. I also argue that Professor Varner fails to make his case because he offers virtually no evidence from scientific studies on nutrition, relies on outdated and fallacious sources, makes unsupported claims, ignores evidence that would contravene his claims, draws hasty conclusions based on weakly supported hypotheses rather than facts, employs a double standard, appeals to ignorance, does not evaluate arguments from his sources, and makes anad hominem attack on a respected nutritionist when his focus should be on evaluating the evidence and arguments from the scientific studies themselves. Neither Varner nor Pluhar have responded sufficiently to the real issue in my arguments, that of discrimination and bias in the vegan ideal. (shrink)

This volume presents a selection of papers reflecting key theoretical issues in argumentation theory. Its six sections are devoted to specific themes, including the analysis and evaluation of argumentation, argument schemes and the contextual embedding of argumentation. The section on general perspectives on argumentation discusses the trends of empiricalization, contextualization and formalization, offers descriptions of the analytical and evaluative tools of informal logic, and highlights selected principles that argumentation theorists do and do not agree upon. In turn, the section on (...) linguistic approaches to argumentation focuses on the problem of distinguishing between explanation and argument, while also elaborating on the role of verbal indicators of argument schemes. All essays included in this volume point out notable recent developments in the study of argumentation. (shrink)

We are pleased to release this edition of Ralph Johnson’s The Rise of Informal Logic as Volume 2 in the series Windsor Studies in Argumentation. This edition is a reprint of the previous Vale Press edition with some typographical errors and other minor mistakes corrected. The prime motive for gathering Ralph H. Johnson’s essays under one cover is their clear articulation of the goals, concerns and problems of the discipline of informal logic. To my knowledge all of the published articles, (...) even of the 1980s, are still in print. But some are obtainable only by special request of a journal back issue. Their availability, even their existence, is not nearly widely enough known, and this volume is dedicated to remedying that disservice to those currently working in the field of informal logic, critical thinking, argumentation, and practical reasoning. Three of these sixteen pieces appear here in print for the first time. The previously published pieces have appeared from 1980 to 1992 as chapters in collective works or as articles in journals, and these in turn published in Canada, USA, The Netherlands and Belgium. It is hoped that gathering this hitherto scattered material under one cover will contribute to a greater understanding of what informal logic is, and to an enhanced sense of the impact of Johnson’s ideas. A discipline of informal logic might exist today without the writings of Johnson and his frequent co-author, J. Anthony Blair. But it would almost certainly be quite different from what it actually is. (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.

Over the last few years, there have been five best sellers critical of religion and religious belief. It seems that there is great interest in questions about religious belief. Ironically, critical thinking texts seldom examine the topic. This paper will evaluate eight arguments to exempt religious belief from rational critique. I conclude that the topic of religious belief should not be exempt from critical thinking classes.

This paper examines whether philosophers of argument, in spite of their disavowing ‘timeless principles’, nevertheless embrace a set of principles, or axioms, to underlie argumentation theory. First, it reviews the thinking of some prominent philosophers of argument; second, it extracts some principles common to their philosophies; and third, it draws out possible consequences for argumentation theory and asks whether such theory has an underlying political posture.