Douglas Walton

Second edition of the introductory guidebook to the basic principles of constructing sound arguments and criticising bad ones. Non-technical in approach, it is based on 186 examples, which Douglas Walton, a leading authority in the field of informal logic, 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. This edition takes into account many 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 work on argumentation schemes. Ideally suited for use in courses in informal logic and introduction to philosophy, this book will also be valuable to students of pragmatics, rhetoric, and speech communication.

Second edition of the introductory guidebook to the basic principles of constructing sound arguments and criticising bad ones. Non-technical in approach, it is based on 186 examples, which Douglas Walton, a leading authority in the field of informal logic, 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. This edition takes into account many 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 work on argumentation schemes. Ideally suited for use in courses in informal logic and introduction to philosophy, this book will also be valuable to students of pragmatics, rhetoric, and speech communication.

Recent work in artificial intelligence has increasingly turned to argumentation as a rich, interdisciplinary area of research that can provide new methods related to evidence and reasoning in the area of law. Douglas Walton provides an introduction to basic concepts, tools and methods in argumentation theory and artificial intelligence as applied to the analysis and evaluation of witness testimony. He shows how witness testimony is by its nature inherently fallible and sometimes subject to disastrous failures. At the same time such testimony can provide evidence that is not only necessary but inherently reasonable for logically guiding legal experts to accept or reject a claim. Walton shows how to overcome the traditional disdain for witness testimony as a type of evidence shown by logical positivists, and the views of trial sceptics who doubt that trial rules deal with witness testimony in a way that yields a rational decision-making process.

Recent work in artificial intelligence has increasingly turned to argumentation as a rich, interdisciplinary area of research that can provide new methods related to evidence and reasoning in the area of law. Douglas Walton provides an introduction to basic concepts, tools and methods in argumentation theory and artificial intelligence as applied to the analysis and evaluation of witness testimony. He shows how witness testimony is by its nature inherently fallible and sometimes subject to disastrous failures. At the same time such testimony can provide evidence that is not only necessary but inherently reasonable for logically guiding legal experts to accept or reject a claim. Walton shows how to overcome the traditional disdain for witness testimony as a type of evidence shown by logical positivists, and the views of trial sceptics who doubt that trial rules deal with witness testimony in a way that yields a rational decision-making process.

Media argumentation is a powerful force in our lives. From political speeches to television commercials to war propaganda, it can effectively mobilize political action, influence the public, and market products. This book presents a new and systematic way of thinking about the influence of mass media in our lives, showing the intersection of media sources with argumentation theory, informal logic, computational theory, and theories of persuasion. Using a variety of case studies that represent arguments that typically occur in the mass media, Douglas Walton demonstrates how tools recently developed in argumentation theory can be usefully applied to the identification, analysis, and evaluation of media arguments. He draws upon the most recent developments in artificial intelligence, including dialogical theories of argument, which he developed, as well as speech act theory. Each chapter presents solutions to problems central to understanding, analyzing, and criticizing media argumentation.

Media argumentation is a powerful force in our lives. From political speeches to television commercials to war propaganda, it can effectively mobilize political action, influence the public, and market products. This book presents a new and systematic way of thinking about the influence of mass media in our lives, showing the intersection of media sources with argumentation theory, informal logic, computational theory, and theories of persuasion. Using a variety of case studies that represent arguments that typically occur in the mass media, Douglas Walton demonstrates how tools recently developed in argumentation theory can be usefully applied to the identification, analysis, and evaluation of media arguments. He draws upon the most recent developments in artificial intelligence, including dialogical theories of argument, which he developed, as well as speech act theory. Each chapter presents solutions to problems central to understanding, analyzing, and criticizing media argumentation.

The theory in the book is based on the latest research in argumentation theory, and especially on new applications of artificial intelligence (AI) to legal argumentation. The methodology of the book derives from recent work in argumentation theory and AI in which forms of reasoning other than deductive and inductive have been the focus of much investigation. The aim is not just to show how character judgments are made, but to show how they should properly be made based on sound reasoning, in order to avoid certain fallacies, errors and superficial judgments of a kind that are common. The book is about character judgments, but centrally about the kind of logical reasoning and evidence that should properly be used to support or question such judgments. According to the new theory put forward in this book, such evidence is based on a kind of multi-agent simulative reasoning in which one agent is able to explain the actions of another by understanding the situation confronted by the other,and recreating the plan adopted by the other. According to the theory, one agent can reach reasoned conclusions about the presumed character properties of another, using plan recognition and ar- mentation schemes representing stereotypical forms of reasoning. We use character evidence every day in reasoning, as in the inference, “He has a certain character trait, so that is evidence he is the one who carried out this particular action”.

Fundamentals of Critical Argumentation presents the basic tools for the identification, analysis, and evaluation of common arguments for beginners. The book teaches by using examples of arguments in dialogues, both in the text itself and in the exercises. Examples of controversial legal, political, and ethical arguments are analyzed. Illustrating the most common kinds of arguments, the book also explains how to evaluate each kind by critical questioning. Douglas Walton shows how arguments can be reasonable under the right dialogue conditions by using critical questions to evaluate them. The book teaches by example, both in the text itself and in exercises, but it is based on methods that have been developed through the author's thirty years of research in argumentation studies.

During a recent visit to China to give an invited lecture on legal argumentation I was asked a question about conventional opinion in western countries. If legal r- soning is thought to be important by those both inside and outside the legal prof- sion, why does there appear to be so little attention given to the study of legal logic? This was a hard question to answer. I had to admit there were no large or well-established centers of legal logic in North America that I could recommend as places to study. Going through customs in Vancouver, the customs officer asked what I had been doing in China. I told him I had been a speaker at a conf- ence. He asked what the conference was on. I told him legal logic. He asked 1 whether there was such a thing. He was trying to be funny, but I thought he had a good point. People will question whether there is such a thing as “legal logic”, and some recent very prominent trials give the question some backing in the common opinion. But having thought over the question of why so little attention appears to be given to legal logic as a mainstream subject in western countries, I think I now have an answer. The answer is that we have been looking in the wrong place.

In Relevance in Argumentation, author Douglas Walton presents a new method for critically evaluating arguments for relevance. This method enables a critic to judge whether a move can be said to be relevant or irrelevant, and is based on case studies of argumentation in which an argument, or part of an argument, has been criticized as irrelevant. Walton's method is based on a new theory of relevance that incorporates techniques of argumentation theory, logic, and artificial intelligence. The work uses a case-study approach with numerous examples of controversial arguments, strategies of attack in argumentation, and fallacies. Walton reviews ordinary cases of irrelevance in argumentation, and uses them as a basis to advance and develop his new theory of irrelevance and relevance. The volume also presents a clear account of the technical problems in the previous attempts to define relevance, including an analysis of formal systems of relevance logic and an explanation of the Grecian notion of conversational relevance. This volume is intended for graduate and advanced undergraduate courses in those fields using argumentation theory--especially philosophy, linguistics, cognitive science and communication studies, in addition to argumentation. The work also has practical use, as it applies theory directly to familiar examples of argumentation in daily and professional life. With a clear and comprehensive method for determining relevance and irrelevance, it can be convincingly applied to highly significant practical problems about relevance, including those in legal and political argumentation.

In Relevance in Argumentation, author Douglas Walton presents a new method for critically evaluating arguments for relevance. This method enables a critic to judge whether a move can be said to be relevant or irrelevant, and is based on case studies of argumentation in which an argument, or part of an argument, has been criticized as irrelevant. Walton's method is based on a new theory of relevance that incorporates techniques of argumentation theory, logic, and artificial intelligence. The work uses a case-study approach with numerous examples of controversial arguments, strategies of attack in argumentation, and fallacies. Walton reviews ordinary cases of irrelevance in argumentation, and uses them as a basis to advance and develop his new theory of irrelevance and relevance. The volume also presents a clear account of the technical problems in the previous attempts to define relevance, including an analysis of formal systems of relevance logic and an explanation of the Grecian notion of conversational relevance. This volume is intended for graduate and advanced undergraduate courses in those fields using argumentation theory--especially philosophy, linguistics, cognitive science and communication studies, in addition to argumentation. The work also has practical use, as it applies theory directly to familiar examples of argumentation in daily and professional life. With a clear and comprehensive method for determining relevance and irrelevance, it can be convincingly applied to highly significant practical problems about relevance, including those in legal and political argumentation.

Bridging the gap between applied ethics and ethical theory, Ethical Argumentation draws on recent research in argumentation theory to develop a more realistic model of how ethical justification actually works. Douglas Walton presents a new model of ethical argumentation in which ethical justification is analyzed as a defeasible form of argumentation considered in a balanced dialogue. Walton's new model employs techniques such as: asking the appropriate critical questions, probing accepted values, finding nonexplicit assumptions in an ethical argument, and deconstructing emotive terms and persuasive definitions. This book will be of significant interest to scholars and advanced students in applied ethics and theory.

A leading expert in informal logic, Douglas Walton turns his attention in this new book to how reasoning operates in trials and other legal contexts, with special emphasis on the law of evidence. The new model he develops, drawing on methods of argumentation theory that are gaining wide acceptance in computing fields like artificial intelligence, can be used to identify, analyze, and evaluate specific types of legal argument. In contrast with approaches that rely on deductive and inductive logic and rule out many common types of argument as fallacious, Walton’s aim is to provide a more expansive view of what can be considered "reasonable" in legal argument when it is construed as a dynamic, rule-governed, and goal-directed conversation. This dialogical model gives new meaning to the key notions of relevance and probative weight, with the latter analyzed in terms of pragmatic criteria for what constitutes plausible evidence rather than truth.

Scare Tactics, the first book on the subject, provides a theory of the structure of reasoning used in fear and threat appeal argumentation. Such arguments come under the heading of the argumentum ad baculum, the `argument to the stick/club', traditionally treated as a fallacy in the logic textbooks. The new dialectical theory is based on case studies of many interesting examples of the use of these arguments in advertising, public relations, politics, international negotiations, and everyday argumentation on all kinds of subjects. Many of these arguments are amusing, once you see the clever tactic used; others are scary. Some of the arguments appear to be quite reasonable, while others are highly suspicious, or even outrageously fraudulent. In addition to the examples taken from logic textbooks, other cases treated come from a variety of sources, including political debates, legal arguments, and arguments from media sources, like magazine articles and television ads. The purpose of this book is to explain how such arguments work as devices of persuasion, and to develop a method for analyzing and evaluating their reasonable and fallacious uses in particular cases. The book shows how such arguments share a common structure, revealing several distinctive forms of argument nested within each other. Based on its account of this cognitive structure, the new dialectical theory presents methods for identifying, analyzing, and evaluating these arguments, as they are used in specific cases. The book is a scholarly contribution to argumentation theory. It is written in an accessible style, and uses many colorful and provocative examples of fear and threat appeal arguments that are suitable for classroom discussions. The matters treated will be of interest to professionals and students in law, critical thinking, advertising, speech communication, informal logic, cognitive science, rhetoric, and media studies.

Arguments from popular opinion have long been regarded with suspicion, and in most logic textbooks the ad populum argument is classified as a fallacy. Douglas Walton now asks whether this negative evaluation is always justified, particularly in a democratic system where decisions are based on majority opinion. In this insightful book, Walton maintains that there is a genuine type of argumentation based on commonly accepted opinions and presumptions that should represent a standard of rational decision-making on important issues, especially those of a personal and political nature. He shows how to judge arguments based on appeals to popular opinion in a more balanced way, identifying eleven subtypes of the ad populum argument and providing a pragmatic method to evaluate each of these types. Walton has examined dozens of logic texts and drawn on a wide range of literature to reveal the many uses and misuses of popular opinion. He contrasts the traditional discussion of ad populum in Greek rhetoric with recent textbook treatment, then contrasts these contemporary views with his own dialectical perspective in order to clarify often confused appeals to prejudice and appeals to common knowledge. Although appeal to popular opinion has long been a powerful argumentative tactic, this is the first book to systematically describe and evaluate it as a well-defined type of argument with its own special characteristics. It enables us to deal with these often deceptive arguments in a critically balanced way and makes an original contribution to an important strand of rhetoric.

Arguments from popular opinion have long been regarded with suspicion, and in most logic textbooks the ad populum argument is classified as a fallacy. Douglas Walton now asks whether this negative evaluation is always justified, particularly in a democratic system where decisions are based on majority opinion. In this insightful book, Walton maintains that there is a genuine type of argumentation based on commonly accepted opinions and presumptions that should represent a standard of rational decision-making on important issues, especially those of a personal and political nature. He shows how to judge arguments based on appeals to popular opinion in a more balanced way, identifying eleven subtypes of the ad populum argument and providing a pragmatic method to evaluate each of these types. Walton has examined dozens of logic texts and drawn on a wide range of literature to reveal the many uses and misuses of popular opinion. He contrasts the traditional discussion of ad populum in Greek rhetoric with recent textbook treatment, then contrasts these contemporary views with his own dialectical perspective in order to clarify often confused appeals to prejudice and appeals to common knowledge. Although appeal to popular opinion has long been a powerful argumentative tactic, this is the first book to systematically describe and evaluate it as a well-defined type of argument with its own special characteristics. It enables us to deal with these often deceptive arguments in a critically balanced way and makes an original contribution to an important strand of rhetoric.

Because developments in informal logic have been based, for the most part, on idealized and abstract models, the tools available for argument analysis are not easily adapted to the needs of everyday argumentation. In this book Douglas Walton proposes a new and practical approach to argument analysis based on his theory that different standards for argument must apply in the case of different types of dialogue. By refining and extending the existing formal classifications of dialogue, Walton shows that each dialogue type, be it inquiry, negotiation, or critical discussion, has its own set of goals. He goes on to demonstrate that an argument can best be evaluated in terms of its contribution, positive or negative, to the goals of the particular dialogue it is meant to further. In this way he illustrates how argument can be brought into the service of many types of dialogue, and thus has valuable uses that go well beyond the mere settling of disputes and differences. By reaching back to the Aristotelian roots of logic as an applied, practical discipline and by formulating a new framework of rationality for evaluating arguments, Douglas Walton restores a much-needed balance to argument analysis. This book complements and extends his Argument Structure: A Pragmatic Theory (University of Toronto Press, 1996).

A new pragmatic approach, based on the latest developments in argumentation theory, analyzing appeal to expert opinion as a form of argument. Reliance on authority has always been a common recourse in argumentation, perhaps never more so than today in our highly technological society when knowledge has become so specialized—as manifested, for instance, in the frequent appearance of "expert witnesses" in courtrooms. When is an appeal to the opinion of an expert a reasonable type of argument to make, and when does it become a fallacy? This book provides a method for the evaluation of these appeals in everyday argumentation. Specialized domains of knowledge such as science, medicine, law, and government policy have gradually taken over as the basis on which many of our rational decisions are made daily. Consequently, appeal to expert opinion in these areas has become a powerful type of argument. Challenging an argument based on expert scientific opinion, for example, has become as difficult as it once was to question religious authority. Walton stresses that even in cases where expert opinion is divided, the effect of it can still be so powerful that it overwhelms an individual's ability to make a decision based on personal deliberation of what is right or wrong in a given situation. The book identifies the requirements that make an appeal to expert opinion a reasonable or unreasonable argument. Walton's new pragmatic approach analyzes that appeal as a distinctive form of argument, with an accompanying set of appropriate critical questions matching the form. Throughout the book, a historical survey of the key developments in the evolution of the argument from authority, dating from the time of the ancients, is given, and new light is shed on current problems of "junk science" and battles between experts in legal argumentation.

In just the last twenty years there has arisen a strong interest, especially among teachers of logic at the universities, in teaching techniques of applied logical reasoning and critical thinking. Many universities are now stressing these skills at an introductory level, and to meet the need, informal logic has begun to form and grow as a discipline in its own right. Like all subjects, it helps us to understand it if we can situate it in a context of historical development. This collection of essays provides the readings required to understand the development of a subject whose historical origins have been so far little studied. Many of the chapters are written by scholars in philosophy and speech communication who are themselves leading contributors to the subject, and their contemporary views throw light on how these earlier writers have influenced their thinking. This dimension gives an added interest to the essays, and indicates the way informal logic is currently evolving and seeking out its ancient historical origins.