. While courts depend on expert opinions in reaching sound judgments, the role of the expert witness in legal proceedings is associated with a litany of problems. Perhaps most prevalent is the question of under what circumstances should testimony be admitted as expert opinion. We review the changing policies adopted by American courts in an attempt to ensure the reliability and usefulness of the scientific and technical information admitted as evidence. We argue that these admissibility criteria are best seen in (...) a dialectical context as a set of critical questions of the kind commonly used in models of argumentation. (shrink)

In this book Bruno Latour brings together these different approaches to provide a lively and challenging analysis of science, demonstrating how social context..

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)

This monograph poses a series of key problems of evidential reasoning and argumentation. It then offers solutions achieved by applying recently developed computational models of argumentation made available in artificial intelligence. Each problem is posed in such a way that the solution is easily understood. The book progresses from confronting these problems and offering solutions to them, building a useful general method for evaluating arguments along the way. It provides a hands-on survey explaining to the reader how to use current (...) argumentation methods and concepts that are increasingly being implemented in more precise ways for the application of software tools in computational argumentation systems. It shows how the use of these tools and methods requires a new approach to the concepts of knowledge and explanation suitable for diverse settings, such as issues of public safety and health, debate, legal argumentation, forensic evidence, science education, and the use of expert opinion evidence in personal and public deliberations. (shrink)

This volume explores evidentialism, a major theory of epistemic justification. It contains more than 20 papers that examine its nuances, its challenges, as well as its future directions. Written by leading and up-and-coming epistemologists, the papers cover a wide array of topics related to evidentialism. The contributors present both sides of the theory: some are advocates of evidentialism, while others are critics. This provides readers with a comprehensive, and cutting-edge, understanding of this epistemic theory. Overall, the book is organized into (...) six parts: The Nature of Evidence, Understanding Evidentialism, Problems for Evidentialism, Evidentialism and Social Epistemology, New Directions for Evidentialism, and Explanationist Evidentialism. Readers will find insightful discussion on such issues as the ontology of evidence, phenomenal dogmatism, how experiences yield evidence, the new evil demon problem, probability, norms of credibility, intellectual virtues, wisdom, epistemic justification, and more. This title provides authoritative coverage of evidentialism, from the latest developments to the most recent philosophical criticisms. It will appeal to researchers and graduate students searching for more information on this prominent epistemological theory. (shrink)

This book brings together in one place David Hitchcock’s most significant published articles on reasoning and argument. In seven new chapters he updates his thinking in the light of subsequent scholarship. Collectively, the papers articulate a distinctive position in the philosophy of argumentation. Among other things, the author:• develops an account of “material consequence” that permits evaluation of inferences without problematic postulation of unstated premises.• updates his recursive definition of argument that accommodates chaining and embedding of arguments and allows any (...) type of illocutionary act to be a conclusion. • advances a general theory of relevance.• provides comprehensive frameworks for evaluating inferences in reasoning by analogy, means-end reasoning, and appeals to considerations or criteria.• argues that none of the forms of arguing ad hominem is a fallacy.• describes proven methods of teaching critical thinking effectively. (shrink)

This is an introductory guidebook to the basic principles of how to construct good arguments and how to criticeze bad ones. It is non-technical in its approach and is based on 150 key examples, each discussed and evaluated in clear, illustrative detail. Professor Walton, a leading authority in the field of informal logic, 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, relevance, appeals to emotion, personal attack, uses and abuses of expert opinion, problems in deploying statistics, loading terms, equivocation, arguments from analogy, and techniques of posing, replying to, and criticizing questions. The book will be ideally suited to courses in informal logic and in the introduction to philosophy. It will also prove valuable to studetns of pragmatics, rhetoric, and speech communication. (shrink)

This book shows how research in linguistic pragmatics, philosophy of language, and rhetoric can be connected through argumentation to analyze a recognizably common strategy used in political and everyday conversation, namely the distortion of another’s words in an argumentative exchange. Straw man argumentation refers to the modification of a position by misquoting, misreporting or wrenching the original speaker’s statements from their context in order to attack them more easily or more effectively. Through 63 examples taken from different contexts (including political (...) and forensic discourses and dialogs) and 20 legal cases, the book analyzes the explicit and implicit types of straw man, shows how to assess the correctness of a quote or a report, and illustrates the arguments that can be used for supporting an interpretation and defending against a distortion. The tools of argumentation theory, a discipline aimed at investigating the uses of arguments by combining insights from pragmatics, logic, and communication, are applied to provide an original account of interpretation and reporting, and to describe and illustrate tactics and procedures that can be used and implemented for practical purposes.. This book will appeal to scholars in the fields of political communication, communication in general, argumentation theory, rhetoric and pragmatics, as well as to people working in public speech, speech writing, and discourse analysis. (shrink)

In redefining logic, philosophers need to go back to the Aristotelian roots of the subject, to expand the boundaries of the subject to include informal logic and to give up false oppositions between informal and formal logic.

This study examines how evidence is used differently in argumentative discourse compared to individual arguments. Applying a 1×2 crossover study design, 37 secondary school students were asked either to discuss a social issue with their partner before individually writing an essay outlining their opinion or, vice versa, first to discuss and then to write. As background information, they were provided with pieces of evidence with different levels of quality. Dialogs and essays were analyzed regarding (a) the type of evidence and (...) (b) the way evidence was used. Results showed that in their essays students referred more often to the pieces of evidence provided to them (shared evidence). In contrast, they used evidence more often to address the opposing viewpoint in dialogs by incorporating it in a more elaborated (clearer) line of reasoning. Findings suggest that dialogues are a more effective tool than individual writing production, and the study provides first hints regarding how to design curricula that will encourage students to use evidence in a more sophisticated way in their argumentation. (shrink)

How should we evaluate an argument in which two witnesses independently testify to some claim? In fact what would happen is that the testimony of the second witness would be taken to corroborate that of the first to some extent, thereby boosting up the plausibility of the first argument from testimony. But does that commit the fallacy of double counting, because the second testimony is already taken as independent evidence supporting the claim? Perhaps the corroboration effect should be considered illogical, (...) since each premise should be seen as representing a separate reason in a convergent argument for accepting the claim as plausible. In this paper, we tackle the problem using argumentation schemes and argument diagramming. We examine a number of examples, and come up with two hypotheses that offer methods of analyzing and evaluating this kind of evidence. (shrink)

While courts depend on expert opinions in reaching sound judgments, the role of the expert witness in legal proceedings is associated with a litany of problems. Perhaps most prevalent is the question of under what circumstances should testimony be admitted as expert opinion. We review the changing policies adopted by American courts in an attempt to ensure the reliability and usefulness of the scientific and technical information admitted as evidence. We argue that these admissibility criteria are best seen in a (...) dialectical context as a set of critical questions of the kind commonly used in models of argumentation. (shrink)

The Toulmin diagram layout is very familiar and widely used, particularly in the teaching of critical thinking skills. The conventional box-and-arrow diagram is equally familiar and widespread. Translation between the two throws up a number of interesting challenges. Some of these challenges (such as the relationship between Toulmin warrants and their counterparts in traditional diagrams) represent slightly different ways of looking at old and deep theoretical questions. Others (such as how to allow Toulmin diagrams to be recursive) are diagrammatic versions (...) of questions that have already been addressed in artificial intelligence models of argument. But there are further questions (such as the relationships between refutations, rebuttals and undercutters, and the roles of multiple warrants) that are posed as a specific result of examining the diagram inter-translation problem. These three classes of problems are discussed. To the first class are addressed solutions based on engineering pragmatism; to the second class, are addressed solutions drawn from the appropriate literature; and to the third class, fuller exploration is offered justifying the approaches taken in developing solutions that offer both pragmatic utility and theoretical interest. Finally, these solutions are explored briefly in the context of the Araucaria system, showing the ways in which analysts can tackle arguments either using one diagrammatic style or another, or even a combination of the two. (shrink)

Some solo verbal reasoning serves the function of arriving at a correct answer to a question from information at the reasoner’s disposal. Such reasoning is good if and only if its grounds are justified and adequate, its warrant is justified, and the reasoner is justified in assuming that no defeaters apply. I distinguish seven sources of justified grounds and state the conditions under which each source is trustworthy. Adequate grounds include all good relevant information practically obtainable by the reasoner. The (...) claim must follow from the grounds in accordance with a justified general warrant. If this warrant is not universal, the reasoner must be justified in assuming that no exception-making circumstances hold in the particular case to which it is applied. (shrink)

Relevance of premises to conclusion can be explicated through Toulmin’s notion of warrant, understood as an inference rule, albeit not necessarily formal. A normative notion of relevance requires the warrant to be reliable. To determine reliability, we propose a fourfold classification of warrants into a priori, empirical, institutional, and evaluative, with further subdivisions possible. This classification has its ancestry in classical rhetoric and recent epistemology. Distinctive to each type of warrant is the mode by which such connections are intuitively discovered (...) and the grounds on which we ultimately justify them. The classification of warrants is thus epistemic. We illustrate the difference by contrasting empirical physical with institutional intuition, and argue for the advantages of this approach over Toulmin’s conception of field dependence. (shrink)

This book analyzes the uses of emotive language and redefinitions from pragmatic, dialectical, epistemic and rhetorical perspectives, investigating the relationship between emotions, persuasion and meaning, and focusing on the implicit dimension of the use of a word and its dialectical effects. It offers a method for evaluating the persuasive and manipulative uses of emotive language in ordinary and political discourse. Through the analysis of political speeches and legal arguments, the book offers a systematic study of emotive language in argumentation, rhetoric, (...) communication, political science and public speaking. (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)

Pragmatic presupposition is analyzed in this paper as grounded on an implicit reasoning process based on a set of presumptions, which can define cultural differences. The basic condition for making a presupposition can be represented as a reasoning criterion, namely reasonableness. Presuppositions, on this view, need to be reasonable, namely as the conclusion of an underlying presumptive reasoning that does not or may not contain contradictions with other presumptions, including the ordering of the hierarchy of presumptions. Presumptions are in turn (...) analyzed considering their nature and their hierarchy, namely their object and their possible contextual backing, which eliminates some of their possible defaults. This analysis of presupposition brings to light the relationship between communicative infelicities or misunderstandings deriving from presuppositional failures and the underlying system of presumptions and presumptive reasoning. This approach can be applied to the investigation of communicative problems within the medical context, and more precisely the communication in diabetes cases. (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)

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.

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)

The study presented here examines how interacting with a more capable interlocutor influences use of argumentation strategies in electronic discourse. To address this question, 54 young adolescents participating in an intervention centered on electronic peer dialogs were randomly assigned to either an experimental or control condition. In both conditions, pairs who held the same position on a social issue engaged in a series of electronic dialogs with pairs who held an opposing position. In the experimental condition, in some dialogs, unbeknownst (...) to them (because dialog took place electronically), the opponent was a more capable (“expert”) adult. Dialogs in the control condition were only with peers. Argumentation strategies of the experimental group who argued with the “expert” showed immediate strategy improvements in their subsequent peer dialogs, improvement absent in the control group (Cohen's d = 1.12). In particular, the experimental group showed greater use of counterargument in general and advanced forms of counterargument (undermining) that challenges the deeper premises or reasoning on which an argument is based. Implications with respect to mechanisms of change in the development of argumentation skills are considered. (shrink)