In this overview article, we first explain what we take informallogic to be, discussing misconceptions and distinguishing our conception of it from competing ones; second, we briefly catalogue recent informallogic research, under 14 headings; third, we suggest four broad areas of problems and questions for future research; fourth, we describe current scholarly resources for informallogic; fifth, we discuss three implications of informallogic for philosophy in particular, and take note (...) ofpractical consequences of a more general sort. (shrink)
Informallogic 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 informallogic 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)
Informallogic is a new sub-discipline of philosophy, roughly definable as the philosophy of argument. Contributors have challenged the traditional concept of an argument as a premiss-conclusion complex, in favour of speech-act, functional and dialogical conceptions; they have identified as additional components warrants, modal qualifiers, rebuttals, and a dialectical tier. They have objected that "soundness" is neither necessary nor sufficient for a good argument. Alternative proposals include acceptability, relevance and sufficiency of the premisses; conformity to a valid argument (...) schema; conformity to rules for discussion aimed at rational resolution of a dispute. Informallogic is a significant part of philosophy. (shrink)
This paper is an exercise in intellectual history, an attempt to understand how a specific term—”informallogic”— came to be interpreted in so many different ways. I trace the emergence and development of “informallogic” 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). (shrink)
I take 'informallogic' 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 informallogic 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)
In a posthumous paper, Perelman discusses his decision to bring his theory of argumentation together with rhetoric rather than calling it an informallogic. This is due in part because of the centrality he gives to audience, and in part because of the negative attitude that informal logicians have to rhetoric. In this paper, I explore both of these concerns by way of considering what benefits Perelman’s work can have for informallogic, and what insights (...) the work of informal logicians might bring to the project of Perelman and Olbrechts-Tyteca. (shrink)
Consider the proposition, "Informallogic is a subdiscipline of philosophy". The best chance of showing this to be true is showing that informallogic is part of logic, which in turn is a part of philosophy. Part 1 is given over to the task of sorting out these connections. If successful, informallogic can indeed be seen as part of philosophy; but there is no question of an exclusive relationship. Part 2 is a (...) critical appraisal of the suggestion that informallogic is applied epistemology. Part 3 examines the claim that informallogic has failed to penetrate into mainstream philosophy, and suggestions for amelioration are considered. (shrink)
What is informallogic, is it ``logic" at all? Main contemporary approaches are briefly presented and critically commented. If the notion of consequence is at the heart of logic, does it make sense to speak about ``informal" consequence? A valid inference is truth preserving, if the premises are true, so is the conclusion. According to Prawitz two further conditions must also be satisfied in the case of classical logical consequence: (i) it is because of the (...) logical form of the sentences involved and not because of their specific content that the inference is truth preserving; (ii) it is necessary that if the premises are true, then so is the conclusion. According to the prevalent criteria of informallogic an argument is cogent if and only if (i) its premises are rationally Acceptable, (ii) its premises are Relevant to its conclusion and (iii) its premises constitute Grounds adequate for accepting the conclusion (the ``ARG" conditions according to Govier). The ARG criteria characterize a certain broad kind of consequence relation. We do not (in general) have truth preservence in cogent arguments but if the premises are acceptable and other criteria are met, then so is the conclusion. We can speak about form in a loose sense and finally, there is rational necessity of the grounding or support relation. So a certain broad notion of logical consequence emerges from this comparison. The norms of ARG are norms of elementary scientific methodology in which argument is seen as embodying reasoning within a process of inquiry or of belief formation in subject areas accessible to every informed intellectual. (shrink)
The issue of the relationship between formal and informallogic depends strongly on how one understands these two designations. While there is very little disagreement about the nature of formal logic, the same is not true regarding informallogic, which is understood in various (often incompatible) ways by various thinkers. After reviewing some of the more prominent conceptions of informallogic, I will present my own, defend it and then show how informal (...)logic, so understood, is complementary to formal logic. (shrink)
This article challenges the common view that improvements in critical thinking are best pursued by investigations in informallogic. From the perspective of research in psychology and neuroscience, hu-man inference is a process that is multimodal, parallel, and often emo-tional, which makes it unlike the linguistic, serial, and narrowly cog-nitive structure of arguments. At-tempts to improve inferential prac-tice need to consider psychological error tendencies, which are patterns of thinking that are natural for peo-ple but frequently lead to mistakes (...) in judgment. This article discusses two important but neglected error ten-dencies: motivated inference and fear-driven inference. (shrink)
In an attempt to explore the role of argumentation in scientific inquiry, I explore the conception of argument that appears fruitful in the light of the recent trends in the philosophy of science, away from logical empiricism, and toward a greater emphasis on change, disagreement, and history. I begin by contrasting typical instances philosopers’ theories of both empiricism and apriorism, with typical instances of scientists’ uses of these two attitudes, suggesting that such practice shows a judiciousness lacking in epistemological theory. (...) Then I examine at some length three important version of scientific judgement, namely Einstein's opportunism, Boltzmann's pluralism, and Huygens's eclecticism. I go on to discuss some recent work in the philosophy of science, exploring connections between the notion of judgment and Feyerabend's anarchism, Harold Brown's view of rationality, and Dudley Shapere's analysis of scientific change. All of this suggests a notion of argument in the sense of informallogic, and I examine some aspects of Galileo's work in its terms. (shrink)
In this paper I review a number of Govier’s criticisms of the standard view of logic at the time she was developing her views about the nature of logic as it applies to the critique of arguments in natural language and the development of ways to teach skills in such critique. I argue that the concept of informallogic has emerged at least in part from those criticisms and Govier’s positive alternatives.
Over the past 60 years there have been tremendous advances made in Argumentation Theory. One crucial advance has been the move from the investigation of static arguments to a concern with dialogic interactions in concrete contexts. This focus has entailed a slow shift toward involving both non-logical and non-discursive elements in the analysis of an argument. I argue that the traditional attitude InformalLogic has displayed toward emotion can be and ought be moderated. In particular, I examine the (...) role of emotion in everyday argumentation, and how InformalLogic can encompass it alongside the more traditional logical mode of communication. (shrink)
We argue that informallogic is epistemological. Two central questions concern premise acceptability and connection adequacy. Both may be explicated in tenns of justification, a central epistemological concept. That some premises are basic parallels a foundationalist account of basic beliefs and epistemic support. Some epistemological accounts of these concepts may advance the analysis of premise acceptability and connection adequacy. Infonnallogic has implications for other aspects of philosophy. If causal interpretations are acceptable premises and thus justified, does the world (...) have a causal structure? If evaluative premises are acceptable, i.e., justified, is value an objective feature of the world? (shrink)
What rational foundation underlies argument-critical judgements? What are the canons of argument criticism and how are they to be "justified"? This paper explores an analogy between art- and argument-criticism and argues that the analogy promises not only to illuminate the nature of argument criticism and capture the central goals of instruction in informallogic, but also to resolve fundamental problems at the foundations of normative theory of argument concerning the "justification" of standards of reasoning.
Classical logic yields counterintuitive results for numerous propositional argument forms. The usual alternatives (modal logic, relevance logic, etc.) generate counterintuitive results of their own. The counterintuitive results create problems—especially pedagogical problems—for informal logicians who wish to use formal logic to analyze ordinary argumentation. This paper presents a system, PL– (propositional logic minus the funny business), based on the idea that paradigmatic valid argument forms arise from justificatory or explanatory discourse. PL– avoids the pedagogical difficulties (...) without sacrificing insight into argument. (shrink)
The argument diagramming method developed by Monroe C. Beardsley in his (1950) book Practical Logic, which has since become the gold standard for diagramming arguments in informallogic, makes it possible to map the relation between premises and conclusions of a chain of reasoning in relatively complex ways. The method has since been adapted and developed in a number of directions by many contemporary informal logicians and argumentation theorists. It has proved useful in practical applications and (...) especially pedagogically in teaching basic logic and critical reasoning skills at all levels of scientific education. I propose in this essay to build on Beardsley diagramming techniques to refine and supplement their structural tools for visualizing logical relationships in a number of categories not originally accommodated by Beardsley diagramming, including circular reasoning, reductio ad absurdum arguments, and efforts to dispute and contradict arguments, with applications and analysis. (shrink)
When, if ever, is one justified in accepting the premises of an argument? What is the proper criterion of premise acceptability? Providing a comprehensive theory of premise acceptability, this book answers these questions from an epistemological approach that the author calls "common sense foundationalism". His work will be of interest to specialists in informallogic, critical thinking and argumentation theory as well as to a broader range of philosophers and those teaching rhetoric.
InformalLogic is an introductory guidebook to the basic principles of constructing sound arguments and criticizing bad ones. Non-technical in approach, it is based on 186 examples, which Douglas Walton, a leading authority in the field of informallogic, discusses and evaluates in clear, illustrative detail. Walton explains how errors, fallacies, and other key failures of argument occur. He shows how correct uses of argument are based on sound strategies for reasoned persuasion and critical responses. Among (...) the many subjects covered are: forms of valid argument, defeasible arguments, relevance, appeals to emotion, personal attack, straw man argument, jumping to a conclusion, uses and abuses of expert opinion, problems in drawing conclusions from polls and statistics, loaded terms, equivocation, arguments from analogy, and techniques of posing, replying to, and criticizing questions. This new edition takes into account many new developments in the field of argumentation study that have occurred since 1989, many created by the author. Drawing on these developments, Walton includes and analyzes 36 new topical examples and also brings in recent work on argumentation schemes. Ideally suited for use in courses in informallogic and introduction to philosophy, this book will also be valuable to students of pragmatics, rhetoric, and speech communication. (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.
Informallogic 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)
Informallogic is the attempt to develop a logic to assess, analyse and improve ordinary language (or "everyday") reasoning. It intersects with attempts to understand such reasoning from the point of view of philosophy, formal logic, cognitive psychology, and a range of other disciplines. Most of the work in informallogic focuses on the reasoning and argument (in the premise-conclusion sense) one finds in personal exchange, advertising, political debate, legal argument, and the social commentary (...) that characterizes newspapers, television, the World Wide Web and other forms of mass media. (shrink)
Much work in MKM depends on the application of formal logic to mathematics. However, much mathematical knowledge is informal. Luckily, formal logic only represents one tradition in logic, specifically the modeling of inference in terms of logical form. Many inferences cannot be captured in this manner. The study of such inferences is still within the domain of logic, and is sometimes called informallogic. This paper explores some of the benefits informal (...) class='Hi'>logic may have for the management of informal mathematical knowledge. (shrink)
In this reflection piece, Ralph Johnson provides an account of the development of informallogic and how it intersected with the Critical Thinking Movement. Section I is an account of the origins of what Johnson calls the “InformalLogic Initiative.” Section II discusses how the InformalLogic Initiative connected with the Critical Thinking Movement at the Sonoma State University Conferences starting in 1981. Section III discusses the relationship between logic and critical thinking. Section (...) IV describes “The Network Problem,” which emerged for Johnson in the mid-1980s – largely as a result of his experiences at critical thinking conferences, especially the Sonoma State conference. Section V expresses some concerns about the current status of critical thinking as an educational idea and about the Critical Thinking Movement. (shrink)
Informallogic offers a radical new perspective on the evaluation of arguments. But little work has been done on how deep concepts in the logical foundations of argument need to be modified in light of such efforts. This paper offers an indication of what might be done by sketching a new approach to the theory of entailment, truth and relevance.
I examine a Canadian Supreme Court decision concerning the constitutionality of Canada's 1982 rape-shield legislation, and suggest how material from the decision might profitably be used in an informal-logic class in connection with the topics of relevance and conductive argument. I also consider theoretical matters related to the decision: first I develop two analyses of what I call an argument from 'unchasteness' and connect them to George Bowles's theory of propositional relevance; then I present Trudy Govier with a (...) problem in response to which she might revise her account of a conductive argument in a way I describe. (shrink)
Domain constraint, the requirement that analogues be selected from "the same category," inheres in the popular saying "you can't compare apples and oranges" and the textbook principle "the greater the number of shared properties, the stronger the argument from analogy." I identify roles of domains in biological, linguistic, and legal analogy, supporting the account of law with a computer word search of judicial decisions. I argue that the category treatments within these disciplines cannot be exported to general informal (...) class='Hi'>logic, where the relevance of properties, not their number, must be the logically prior criterion for evaluating analogical arguments. (shrink)
Informallogic 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)
This is a critical examination of Johnstone's thesis that all valid philosophical arguments are ad hominem. I clarify his notions of valid, philosophical, and ad hominem. I illustrate the thesis with his refutation ofthe claim that only ordinary language is correct. r discuss his three supporting arguments (historical, theoretical, and intermediate). And r criticize the thesis with the objections that if an ad hominem argument is valid, it is really ad rem; that it's unclear how his own theoretical argument can (...) be ad hominem; that if an ad hominem argument is really valid, it would have to be based on the proponent's own assumptions; and that the thesis is not true of philosophical arguments that are constructive rather than critical. (shrink)
Natural normativity describes the means whereby social and cultural controls are placed on argumentative behaviour. The three main components of this are Goals, Context, and Ethos, which combine to form a dynamic and situational framework. Natural normativity is explained in light of Pragma-dialectics, InformalLogic, and Rhetoric. Finally, the theory is applied to the Biro-Siegel challenge.
An argumentative passage that might appear to be an instance of denying the antecedent will generally admit of an alternative interpretation, one on which the conditional contained by the passage is a preface to the argument rather than a premise of it. On this interpretation. which generally is a more charitable one, the conditional plays a certain dialectical role and, in some cases, a rhetorical role as welL Assuming only a very weak principle of exigetical charity, I consider what it (...) would take in a given case to justify accepting the less charitable interpretation. I then present evidence that those conditions are seldom met. Indeed, I was unable to find a single published argument that can justifiably be charged with denying the antecedent. (shrink)
Three misrepresentations of informal and formal logic by two feminist writers are discussed. Andrea Nye's criticism that the semantics for formal logic abstracts from context is a misrepresentation of formal logic because Nye ignores the development of intensional logics. Second, Nye's criticism that informaIlogicians ignore the origins of arguments is a misrepresentation of fallacy theory. Prominent writers in the field specifiy numerous cases where the origins of an argument are relevant to its evaluation. Third, Valerie Plumwood's (...) criticism that negation in classical logic rests on an exclusivistic dualism that encourages the exclusion of women is shown to be false. (shrink)