Develops a logical analysis of dialogue in which two or more parties attempt to advance their own interests. It includes a classification of the major types of dialogues and a discussion of several important informal fallacies.

Appeals to emotion—pity, fear, popular sentiment, and _ad hominem_ attacks—are commonly used in argumentation. Instead of dismissing these appeals as fallacious wherever they occur, as many do, Walton urges that each use be judged on its merits. He distinguished three main categories of evaluation. First, is it reasonable, even if not conclusive, as an argument? Second, is it weak and therefore open to critical questioning for argument? And third, is it fallacious? The third category is a strong charge that (...) incurs a critical burden to back it up by citing evidence from the given text and context of dialogue. Walton uses fifty-six case studies to demonstrate that the problem of emotional fallacies is much subtler than has been previously believed. Ranging over commercial advertisements, political debates, union-management negotiations, and ethical disputes, the case studies reveal that these four types of appeals, while based on presumptive reasoning that are tentative and subject to default, are not always or necessarily fallacious types of argumentation. (shrink)

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. (shrink)

Although fallacies have been common since Aristotle, until recently little attention has been devoted to identifying and defining them. Furthermore, the concept of fallacy itself has lacked a sufficiently clear meaning to make it a useful tool for evaluating arguments. Douglas Walton takes a new analytical look at the concept of fallacy and presents an up-to-date analysis of its usefulness for argumentation studies. Walton uses case studies illustrating familiar arguments and tricky deceptions in everyday conversation where the charge (...) of fallaciousness is at issue. The numerous case studies show in concrete terms many practical aspects of how to use textual evidence to identify and analyze fallacies and to evaluate arguments as fallacious. Walton looks at how an argument is used in the context of conversation. He defines a fallacy as a conversational move, or sequence of moves, that is supposed to be an argument that contributes to the purpose of the conversation but in reality interferes with it. The view is a pragmatic one, based on the assumption that when people argue, they do so in a context of dialogue, a conventionalized normative framework that is goal-directed. Such a contextual framework is shown to be crucial in determining whether an argument has been used correctly. Walton also shows how examples of fallacies given in the logic textbooks characteristically turn out to be variants of reasonable, even if defeasible or questionable arguments, based on presumptive reasoning. This is the essence of the evaluation problem. A key thesis of the book, which must not be taken for granted as previous textbooks have so often done, is that you can spot a fallacy from how it was used in a context of dialogue. This is an innovative and even, as Walton notes, "a radical and controversial" theory of fallacy. (shrink)

A Bibliography of Douglas Walton’s Published Works, 1971-20.

Mimesis as Make-Believe is important reading for everyone interested in the workings of representational art.

This book provides a systematic analysis of many common argumentation schemes and a compendium of 96 schemes. The study of these schemes, or forms of argument that capture stereotypical patterns of human reasoning, is at the core of argumentation research. Surveying all aspects of argumentation schemes from the ground up, the book takes the reader from the elementary exposition in the first chapter to the latest state of the art in the research efforts to formalize and classify the schemes, outlined (...) in the last chapter. It provides a systematic and comprehensive account, with notation suitable for computational applications that increasingly make use of argumentation schemes. (shrink)

Synthese: An International Journal for Epistemology, Logic and Philosophy of Science, 157, 2007, 197-240. Published version available at: http://www.springerlink.com/content/q9402gv46t415504/fulltext.pdf.

In lieu of an abstract, here is a brief excerpt of the content:Philosophy and Rhetoric 33.2 (2000) 101-115 [Access article in PDF] Case Study of the Use of a Circumstantial Ad Hominem in Political Argumentation Douglas Walton In the 1860s, Northern newspapers attacked Lincoln's policies by attacking his character, using the terms drunk, baboon, too slow, foolish, and dishonest. Steadily on the increase in political argumentation since then, the argumentum ad hominem has been carefully refined as an instrument of (...) "oppo tactics" and "going negative" by the public relations experts who now craft political campaigns at the national level. It has been so prominently used in the major political campaigns, debates, and advertisements of the past few years that there has even been a reaction against it--a feeling that we have gone too far in this direction and that some kind of restraint is needed. 1 But there has been no evidence of such restraint in the argumentation used in recent campaigns. Perhaps what might be helpful is a better understanding on the part of voters and campaigners of how to evaluate ad hominem arguments critically.How does the ad hominem argument really work as a way of molding public opinion, why is it so often so effective, and how can it be defended against? How can it be evaluated as a clearly identifiable type of argument, by some kind of objective standards, in a way that can be applied to particular cases? These appear to be tough questions, but recent research has made some not inconsiderable progress toward answering them.The purpose of this article is to present a new case study of a type of argument commonly used in political discourse, a case study that makes use of the dialectical normative framework for identifying and evaluating personal attack (ad hominem) arguments that is developed in a series of works by Henry W. Johnstone Jr. (1952); Alan Brinton (1985, 1995); Frans H. van Eemeren and Rob Grootendorst (1984, 1995); Erik C. W. Krabbe and Douglas N. Walton (1993), Walton (1989, chap. 6; 1998); and van Eemeren, Grootendorst, Francisca Snoeck Henkemans et al. (1996). This particular case, although typical of so many ad hominem arguments currently [End Page 101] in use in political discourse, has some special features that turn out to be quite interesting not only in showing how the dialectical framework applies to cases, but also in advancing our knowledge of how the ad hominem type of argument works in political argumentation in a democratic system for which the media reportage of events is a big factor in influencing voting. 1. Framework for analysis and evaluation Although the argumentum ad hominem, or personal attack argument, has been traditionally treated as a fallacy in logic, recent research in argumentation (as cited above) shows that, in many cases,--including cases in political argumentation--ad hominem arguments, as used in conversational arguments, are not fallacious. Research has shown that, while some personal attack arguments can definitely be judged fallacious, many others are quite reasonable (when evaluated in the appropriate context), while still others should be evaluated as weak (insufficiently supported) but not fallacious. As shown in this case study, the real function of an ad hominem argument (when properly used) is to attack an arguer's credibility in order to criticize the argument she advocates.Before going any further, it is necessary to define some terminology brought to use in the research cited above. An ad hominem argument is the use of personal attack in a dialogue exchange between two parties, where the one party attacks the character of the other party as bad, in some respect, and then uses this attack as a basis for criticizing the other party's argument. An argument is fallacious if it is a special baptizable (Johnson 1987) type of argument that is used by one party in a dialogue exchange in such a way that it blocks or interferes with the collaborative realization of the goal of the type of dialogue in which the two participants are supposed to be engaged (Walton 1995). Thus, there is a difference between a weak... (shrink)

This book identifies 25 argumentation schemes for presumptive reasoning and matches a set of critical questions to each.

That photography is a supremely realistic medium may be the commonsense view, but—as Edward Steichen reminds us—it is by no means universal. Dissenters note how unlike reality a photograph is and how unlikely we are to confuse the one with the other. They point to “distortions” engendered by the photographic process and to the control which the photographer exercises over the finished product, the opportunities he enjoys for interpretation and falsification. Many emphasize the expressive nature of the medium, observing that (...) photographs are inevitably colored by the photographer’s personal interests, attitudes, and prejudices.1 Whether any of these various considerations really does collide with photography’s claim of extraordinary realism depends, of course, on how that claim is to be understood.Those who find photographs especially realistic sometimes think of photography as a further advance in a direction which many picture makers have taken during the last several centuries, as a continuation or culmination of the post-Renaissance quest for realism.2 There is some truth in this. Such earlier advances toward realism include the development of perspective and modeling techniques, the portrayal of ordinary and incidental details, attention to the effects of light, and so on. From its very beginning, photography mastered perspective. Subtleties of shading, gradations of brightness nearly impossible to achieve with the brush, became commonplace. Photographs include as a matter of course the most mundane details of the scenes they portray—stray chickens, facial warts, clutters of dirty dishes. Photographic images easily can seem to be what painters striving for realism have always been after. 2. See André Bazin, “The Ontology of the Photographic Image,” What is Cinema?, trans. Hugh Gray, vol. 1, p. 12; all further references to this work, abbreviated “OPI,” will be included in the text. See also Rudolf Arnheim, “Melancholy Unshaped,” Toward a Psychology of Art: Collected Essays, p. 186. Kendall L. Walton is professor of Philosophy at the University of Michigan. He is currently completing a book on representation in the arts. (shrink)

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. (shrink)

That photography is a supremely realistic medium may be the commonsense view, but—as Edward Steichen reminds us—it is by no means universal. Dissenters note how unlike reality a photograph is and how unlikely we are to confuse the one with the other. They point to “distortions” engendered by the photographic process and to the control which the photographer exercises over the finished product, the opportunities he enjoys for interpretation and falsification. Many emphasize the expressive nature of the medium, observing that (...) photographs are inevitably colored by the photographer’s personal interests, attitudes, and prejudices.1 Whether any of these various considerations really does collide with photography’s claim of extraordinary realism depends, of course, on how that claim is to be understood.Those who find photographs especially realistic sometimes think of photography as a further advance in a direction which many picture makers have taken during the last several centuries, as a continuation or culmination of the post-Renaissance quest for realism.2 There is some truth in this. Such earlier advances toward realism include the development of perspective and modeling techniques, the portrayal of ordinary and incidental details, attention to the effects of light, and so on. From its very beginning, photography mastered perspective . Subtleties of shading, gradations of brightness nearly impossible to achieve with the brush, became commonplace. Photographs include as a matter of course the most mundane details of the scenes they portray—stray chickens, facial warts, clutters of dirty dishes. Photographic images easily can seem to be what painters striving for realism have always been after. 2. See André Bazin, “The Ontology of the Photographic Image,” What is Cinema?, trans. Hugh Gray, vol. 1 , p. 12; all further references to this work, abbreviated “OPI,” will be included in the text. See also Rudolf Arnheim, “Melancholy Unshaped,” Toward a Psychology of Art: Collected Essays , p. 186. Kendall L. Walton is professor of Philosophy at the University of Michigan. He is currently completing a book on representation in the arts. (shrink)

This paper explains the importance of classifying argumentation schemes, and outlines how schemes are being used in current research in artificial intelligence and computational linguistics on argument mining. It provides a survey of the literature on scheme classification. What are so far generally taken to represent a set of the most widely useful defeasible argumentation schemes are surveyed and explained systematically, including some that are difficult to classify. A new classification system covering these centrally important schemes is built.

A "slippery slope argument" is a type of argument in which a first step is taken and a series of inextricable consequences follow, ultimately leading to a disastrous outcome. Many textbooks on informal logic and critical thinking treat the slippery slope argument as a fallacy. Walton argues that used correctly in some cases, they can be a reasonable type of argument to shift a burden of proof in a critical discussion, while in other cases they are used incorrectly. (...) class='Hi'>Walton identifies and analyzes four types of slippery slope argument. Walton presents guidelines that show how each type of slippery slope argument can be used correctly or incorrectly, using over fifty case studies of argumentation on controversial issues. These include abortion, medical research on human embryos, euthanasia, the decriminalization of marijuana, pornography, and censorship, and banning of American flag burning. (shrink)

This is an introductory guide to the basic principles of constructing good arguments and criticizing bad ones. It is nontechnical in its approach, and is based on 150 key examples, each discussed and evaluated in clear, illustrative detail. The author explains how errors, fallacies, and other key failures of argument occur. He shows how correct uses of argument are based on sound argument strategies for reasoned persuasion and critical questions for responding. Among the many subjects covered are: techniques of posing, (...) replying to, and criticizing questions, forms of valid argument, relevance, appeals to emotion, personal attack, uses and abuses of expert opinion, problems in deploying statistics, loaded terms, equivocation, and arguments from analogy. (shrink)

This study investigates the processes involved in the shaping of a society's economic ethos. The discussion of ethics and economics has a very long history across multiple disciplines. The founder of modern economics, Adam Smith, likewise had a keen interest in this topic. However, with the development of economic science, scholarly assessment has shifted toward positive analysis while normative analysis has been left mainly to philosophers. By utilizing the newly developed morality of profit-making scale, the authors sought to understand how (...) respondents' economic ethical worldview shifts over time. Specifically, we theorized that the news media's copious negative coverage of the gasoline price crisis of 2006 would significandy impact individuals' MPM worldview. The results show that respondents' explicit attitudes toward MPM were significantly impacted. However, respondents' more deeply held, implicit economic ethical worldview was only slightly impacted. The authors argue that only patient, long-term explanation and argumentation can permanently affect a society's economic ethos. Implications and future research directions for business researchers are oudined. (shrink)

El artículo argumenta que se puede trazar un paralelo entre la elaboración husserliana del imperativo categórico y la caracterización heideggeriana de la indicación formal en los tempranos cursos de Friburgo. Introduce la cuestión con una exposición de la distinción heideggeriana entre los niveles de objetualización teórica, objetivización formal y el “proto-algo”. El artículo se ocupa luego de comparar el sentido de contenido heideggeriano con la primera formulación del imperativo categórico como un motivo conductor para subsiguientes especificaciones. Esto proporciona una base (...) para considerar una ulterior semejanza entre el sentido de referencia y el desarrollo del imperativo con relación a un mundo de objetos, a un horizonte intersubjetivo y al pleno horizonte de la propia vida, en armonía con las nociones heideggerianas de mundo circundante, mundo compartido y mundo del sí-mismo. Además, se argumenta que el sentido de ejecución puede ser tomado como un modelo para el énfasis husserliano en el logro de un cumplimiento del imperativo. Por último, el “proto-algo”, que es indiferente a cualquier tipo particular de objeto, es considerado a la luz de las unidades hyléticas pre-objetivas de Husserl, que pueden ser convertidas en objetos perceptivos, emotivos o volitivos. (shrink)

In fifteen essays-one new, two newly revised and expanded, three with new postscripts-Kendall L. Walton wrestles with philosophical issues concerning music, metaphor, empathy, existence, fiction, and expressiveness in the arts. These subjects are intertwined in striking and surprising ways. By exploring connections among them, appealing sometimes to notions of imagining oneself in shoes different from one's own, Walton creates a wide-ranging mosaic of innovative insights.

This is an introductory guide to the basic principles of constructing good arguments and criticizing bad ones. It is nontechnical in its approach, and is based on 150 key examples, each discussed and evaluated in clear, illustrative detail. The author explains how errors, fallacies, and other key failures of argument occur. He shows how correct uses of argument are based on sound argument strategies for reasoned persuasion and critical questions for responding. Among the many subjects covered are: techniques of posing, (...) replying to, and criticizing questions, forms of valid argument, relevance, appeals to emotion, personal attack, uses and abuses of expert opinion, problems in deploying statistics, loaded terms, equivocation, and arguments from analogy. (shrink)

Statutory interpretation involves the reconstruction of the meaning of a legal statement when it cannot be considered as accepted or granted. This phenomenon needs to be considered not only from the legal and linguistic perspective, but also from the argumentative one - which focuses on the strategies for defending a controversial or doubtful viewpoint. This book draws upon linguistics, legal theory, computing, and dialectics to present an argumentation-based approach to statutory interpretation. By translating and summarizing the existing legal interpretative canons (...) into eleven patterns of natural arguments - called argumentation schemes - the authors offer a system of argumentation strategies for developing, defending, assessing, and attacking an interpretation. Illustrated through major cases from both common and civil law, this methodology is summarized in diagrams and maps for application to computer sciences. These visuals help make the structures, strategies, and vulnerabilities of legal reasoning accessible to both legal professionals and laypeople. (shrink)

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. (shrink)

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. (shrink)

I propose a way of understanding empathy on which it does not necessarily involve any-thing like thinking oneself into another’s shoes, or any imagining at all. Briefly, the empa-thizer uses an aspect of her own mental state as a sample, expressed by means of a phenomenal concept, to understand the other person. This account does a better job of explaining the connection between empathetic experiences and the objects of empathy than most traditional ones do. And it helps to clarify the (...) relations among different varieties of empathy and empathy-like experiences, including empathy with fictional characters. -/- . (shrink)

This book examines three areas in which abductive reasoning is especially important: medicine, science, and law. The reader is introduced to abduction and shown how it has evolved historically into the framework of conventional wisdom in logic. Discussions draw upon recent techniques used in artificial intelligence, particularly in the areas of multi-agent systems and plan recognition, to develop a dialogue model of explanation. Cases of causal explanations in law are analyzed using abductive reasoning, and all the components are finally brought (...) together to build a new account of abductive reasoning. By clarifying the notion of abduction as a common and significant type of reasoning in everyday argumentation, _Abductive Reasoning_ will be useful to scholars and students in many fields, including argumentation, computing and artificial intelligence, psychology and cognitive science, law, philosophy, linguistics, and speech communication and rhetoric. (shrink)

Understanding everyday behavior relies heavily upon understanding our ability to improvise, how we are able to continuously anticipate and adapt in order to coordinate with our environment and others. Here we consider the ability of musicians to improvise, where they must spontaneously coordinate their actions with co-performers in order to produce novel musical expressions. Investigations of this behavior have traditionally focused on describing the organization of cognitive structures. The focus, here, however, is on the ability of the time-evolving patterns of (...) inter-musician movement coordination as revealed by the mathematical tools of complex dynamical systems to provide a new understanding of what potentiates the novelty of spontaneous musical action. We demonstrate this approach through the application of cross wavelet spectral analysis, which isolates the strength and patterning of the behavioral coordination that occurs between improvising musicians across a range of nested time-scales. Revealing the sophistication of the previously unexplored dynamics of movement coordination between improvising musicians is an important step towards understanding how creative musical expressions emerge from the spontaneous coordination of multiple musical bodies. (shrink)

This article analyses the fallacy of wrenching from context, using the dialectical notions of commitment and implicature as tools. The data, a set of key examples, is used to sharpen the conceptual borderlines around the related fallacies of straw man, accent, misquotation, and neglect of qualifications. According to the analysis, the main characteristics of wrenching from context are the manipulation of the meaning of the other’s statement through devices such as the use of misquotations, selective quotations, and quoting out of (...) context. The theoretical tools employed in the analysis are pragmatic theories of meaning and a dialectical model of commitment, used to explain how and why a standpoint is distorted. The analysis is based on a conception of fallacies as deceptive strategic moves in a game of dialogue. As a consequence, our focus is not only on misquotations as distortions of meaning, but on how they are used as dialectical tools to attack an opponent or win a dispute. Wrenching from context is described as a fallacy of unfairly attributing a commitment to another party that he never held. Its power as a deceptive argumentation tactic is based on complex mechanisms of implicit commitments and on their misemployment to improperly suggest an attribution of commitment. (shrink)

This book provides a practical and accessible way of evaluating good and bad arguments used in everyday conversations by applying normative models of dialectical (interactive) argumentation, where two parties reason together in an orderly and cooperative way. Using case studies, the author analyzes correct and incorrect uses of argumentation on controversial issues that engage the reader's interest while illustrating points in a practical way. Walton gives clear explanations of the most common errors and tricky deceptions -- traditionally called "fallacies" (...) -- that can trip up an unwary arguer. (shrink)

INTRODUCTION BY THE EDITORS Gilbert Ryle, in his Concept of Mind (1949), attacked volitional theories of human actions; JL Austin, in his "If and Cans" ...

_Arguments from Ignorance _explores the situations in which the argument from ignorance functions as a respectable form of reasoning and those in which it is indeed fallacious. Douglas Walton draws on everyday conversations on all kinds of practical matters in which the _argumentum ad ignorantiam _is used quite appropriately to infer conclusions. He also discusses the inappropriate use of this kind of argument, referring to various major case studies, including the Salem witchcraft trials, the McCarthy hearings, and the Alger (...) Hiss case. This book makes an original contribution in the areas of argumentation theory and informal logic, contending that, despite its traditional classification as a fallacy, the argument from ignorance is a genuine, very common, and legitimate type of argumentation with an identifiable structure. But the book is also interdisciplinary in scope, explaining many widely interesting and controversial subjects in artificial intelligence, medical education, philosophy of science, and philosophy of law in a clear way that makes it accessible to a broad range of readers. (shrink)

In this paper we analyze the uses and misuses of argumentation schemes from verbal classification, and show how argument from definition supports argumentation based on argument from verbal classification. The inquiry has inevitably included the broader study of the concept of definition. The paper presents the schemes for argument from classification and for argument from definition, and shows how the latter type of argument so typically supports the former. The problem of analyzing arguments based on classification is framed in a (...) structure that reveals the crucial role it plays in the persuasion process. The survey of the literature includes the work of Hastings, Perelman, Kienpointner and Schiappa, but still finds much of value in Aristotle. Lessons drawn from Aristotle’s Topics are shown to be useful for developing new tools for assessing definitions and arguments from definition. (shrink)

We are happy to present to the reader the first book of our Applied Logic Series. Walton's book on the fallacies of ambiguity is firmly at the heart of practical reasoning, an important part of applied logic. There is an increasing interest in artifIcial intelligence, philosophy, psychol ogy, software engineering and linguistics, in the analysis and possible mechanisation of human practical reasoning. Continuing the ancient quest that began with Aristotle, computer scientists, logicians, philosophers and linguists are vigorously seeking to (...) deepen our understanding of human reasoning and argumentation. Significant communities of researchers are actively engaged in developing new approaches to logic and argumentation, which are better suited to the urgent needs of today's applications. The author of this book has, over many years, made significant contributions to the detailed analysis of practical reasoning case studies, thus providing solid foundations for new and more applicable formal logical systems. We welcome Doug Walton's new book to our series. (shrink)

In a recent paper, Cayirlioglu et al. report that the disruption of a specific miRNA, miR‐279, which normally acts to inhibit the transcription factor Nerfin‐1, uncovers a population of hybrid CO2 neurons in the Drosophila maxillary palp.1 Normally, fruit fly CO2 neurons are found only in the antennae, while mosquito CO2 neurons are found only in the maxillary palps. The hybrid neurons in this miRNA mutant may, thus, recapitulate an evolutionary intermediate unseen since the divergence of these two dipteran lineages (...) over 250 million years ago. BioEssays 30:621–623, 2008. © 2008 Wiley Periodicals, Inc. (shrink)

This book provides a systematic analysis of many common argumentation schemes and a compendium of 96 schemes. The study of these schemes, or forms of argument that capture stereotypical patterns of human reasoning, is at the core of argumentation research. Surveying all aspects of argumentation schemes from the ground up, the book takes the reader from the elementary exposition in the first chapter to the latest state of the art in the research efforts to formalize and classify the schemes, outlined (...) in the last chapter. It provides a systematic and comprehensive account, with notation suitable for computational applications that increasingly make use of argumentation schemes. (shrink)