Douglas Walton

(? - 2020)

This paper is a report of a pilot study of how candidates argue when they are running for political office. The election studied was the provincial election in Ontario, Canada, in the fall of 2011. Having collected about 250 arguments given during the election from newspaper media, we sought answers to the following questions, among others: which argumentation schemes have the greatest currency in political elections? Is a list of the best known argumentation schemes sufficient to classify the arguments given in elections? What schemes should be added to the familiar list to make it more adequate for studying elections? Is it useful to classify arguments as being used for positive, policy-critical, person-critical and defensive purposes? Can political parties be usefully characterized by noting their preferred kinds of arguments and their most frequent uses of arguments? What lessons can be learned from this study to better design future studies of the same kind?

This paper builds a dialectical system of explanation with speech act rules that define the kinds of moves allowed, like requesting and offering an explanation. Pre and post-condition rules for the speech acts determine when a particular speech act can be put forward as a move in the dialogue, and what type of move or moves must follow it. A successful explanation has been achieved when there has been a transfer of understanding from the party giving the explanation to the party asking for it. The dialogue has an opening stage, an explanation stage and a closing stage. Whether a transfer of understanding has taken place is tested by a dialectical shift to an examination dialogue

This paper argues that some traditional fallacies should be considered as reasonable arguments when used as part of a properly conducted dialog. It is shown that argumentation schemes, formal dialog models, and profiles of dialog are useful tools for studying properties of defeasible reasoning and fallacies. It is explained how defeasible reasoning of the most common sort can deteriorate into fallacious argumentation in some instances. Conditions are formulated that can be used as normative tools to judge whether a given defeasible argument is fallacious or not. It is shown that three leading violations of proper dialog standards for defeasible reasoning necessary to see how fallacies work are: (a) improper failure to retract a commitment, (b) failure of openness to defeat, and (c) illicit reversal of burden of proof

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

In this paper, a solution to the problem of analyzing burden of proof in argumentation is developed by building on the pioneering work of Erik C. W. Krabbe on metadialogues. Three classic cases of burden of proof disputes are analyzed, showing how metadialogue theory can solve the problems they pose. The solution is based on five dialectical requirements: (1) global burden of proof needs to be set at the confrontation stage of a dialogue, (2) there need to be special mechanisms for resolving disputes about burden of proof at all four stages of the dialogue, (3) they are especially significant during the argumentation stage, where burden of proof often shifts back and forth at each move, (4) such local shifts need to be partly regulated by the global burden of proof already set, and (5) the connection between burden of proof and the speech act of making a presumption in a dialogue needs to be clarified

Douglas N. Walton considers the question of whether the conventions of informal conversation can be articulated more precisely than they are at present. Specifically, he addresses the problem of the fallacy of ad hominem argumentation as it occurs in natural settings. Can rules be formulated to determine if criticisms of apparent hypocrisy in an argument are defensible or refutable? Walton suggests that they can, and ultimately defends the thesis that ad hominem reasoning is not fallacious per se. He carries his analysis to the core of action--theoretic reasoning--by examining a number of specimen arguments. As suggested by the title, the conclusion of ad hominem argument is demonstrated to be relative to the arguer's position. In the appendixes of the book, articles by Gerald McAuliffe and Gordon R. Lowe illustrate vivid and powerful cases in which Walton's contentions are put to the test.

We present a formal, mathematical model of argument structure and evaluation, taking seriously the procedural and dialogical aspects of argumentation. The model applies proof standards to determine the acceptability of statements on an issue-by-issue basis. The model uses different types of premises (ordinary premises, assumptions and exceptions) and information about the dialectical status of statements (stated, questioned, accepted or rejected) to allow the burden of proof to be allocated to the proponent or the respondent, as appropriate, for each premise separately. Our approach allows the burden of proof for a premise to be assigned to a different party than the one who has the burden of proving the conclusion of the argument, and also to change the burden of proof or applicable proof standard as the dialogue progresses from stage to stage. Useful for modeling legal dialogues, the burden of production and burden of persuasion can be handled separately, with a different responsible party and applicable proof standard for each. Carneades enables critical questions of argumentation schemes to be modeled as additional premises, using premise types to capture the varying effect on the burden of proof of different kinds of questions.

This article outlines criteria for the evaluation of the argumentum ad hominem (argument against the person, or personal attack in argument) that is traditionally a part of the curriculum in informal logic. The argument is shown to be a kind of criticism which works by shifting the burden of proof in dialogue through citing a pragmatic inconsistency in an arguer's position. Several specific cases of ad hominem argumentation which pose interesting problems in analyzing this type of criticism are studied

This paper looks around among the major traditional fallacies — centering mainly around the so-called “gang of eighteen” — to discuss which of them should properly be classified as fallacies of relevance. The paper argues that four of these fallacies are fallacies primarily because they are failures of relevance in argumentation, while others are fallacies in a way that is more peripherally related to failures of relevance. Still others have an even more tangential relation to failures of relevance. This paper is part of a larger research project on dialecical relevance in argumentative discourse, currently underway in collaboration with Frans van Eemeren and Rob Grootendorst

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

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. 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.

Walton's book is a study of several fallacies in informal logic. Focusing on question-answer dialogues, and committed to a pragmatic rather than a semantic approach, he attempts to generate criteria for evaluating good and bad questions and answers. The book contains a discussion of such well-recognized fallacies as many questions, black-or-white questions, loaded questions, circular arguments, question-begging assertions and epithets, ad hominem and tu quoque arguments, ignoratio elenchi, and replying to a question with a question. In addition, Walton develops several artificial dialogue games and has an excellent discussion of burden of proof in nonlegal contexts. The discussion is for the most part nontechnical and does not presuppose any training in formal logic. It is illustrated with many (sometimes overlong) examples of fallacies drawn from real life--mostly debates in the Canadian House of Commons. . . . Walton's book breaks new ground on a number of issues. Choice This first full-length study of logical fallacies, errors, faults, illicit attacks, blunders, and other critical deficiencies in interrogation and reply has been written in the tradition of informal fallacies in logic. It is especially valuable, readable, and interesting because of the 139 case studies it presents, many of these case studies come from political debates and some from interviews, legal cross-examinations, and other sources. Walton uses these challenging examples of tricky, aggressive, argumentative, or fallacious questions to develop coherent and pragmatic guidelines for criticizing questionable questions (and in some cases their replies) on logical grounds. Among the types of problematic questions analyzed are: the traditional so-called fallacy of many questions, illustrated by the famous Have you stopped beating your wife?; black and white questions; terminologically loaded questions; and questions containing personal attacks. These and other types of problematic questions as well as evasive replies and replying to a question with a question are studied. Critical errors of reasoning are identified and analyzed by developing context-based, normative models of reasonable dialogue in which a questioner must have freedom to ask informative and probing questions, and the respondent must be constrained to give reasonably direct, not overly evasive answers. In this era of negative and evasive political campaigning, with candidates employing skillful tactics of manipulating public opinion to assure election rather than taking clear stands and seriously debating issues in an informed and sincere manner, Question-Reply Argumentation is especially relevant reading for those who take democracy seriously. The methods used reflect a significant shift from earlier semantically based theories to current pragmatic, dialogue-based models, and will be of interest to logicians and linguists. The volume's conclusions should challenge some current preconceptions. Recommended reading for courses in logic, speech communications, linguistics, philosophy of language, areas of political science relating to political discourse and debate, courses on questioning in cognitive psychology, and courses on critical thinking in education.

The basic question of this monograph is: how should we go about judging arguments to be reasonable or unreasonable? Our concern will be with argument in a broad sense, with realistic arguments in natural language. The basic object will be to engage in a normative study of determining what factors, standards, or procedures should be adopted or appealed to in evaluating an argument as "good," "not-so-good," "open to criticism," "fallacious," and so forth. Hence our primary concern will be with the problems of how to criticize an argument, and when a criticism is reasonably justified.

Reasoning from negative evidence takes place where an expected outcome is tested for, and when it is not found, a conclusion is drawn based on the significance of the failure to find it. By using Gricean maxims and implicatures, we show how a set of alternatives, which we call a paradigm, provides the deep inferential structure on which reasoning from lack of evidence is based. We show that the strength of reasoning from negative evidence depends on how the arguer defines his conclusion and what he considers to be in the paradigm of negated alternatives. If we negate only two of the several possible alternatives, even if they are the most probable, the conclusion will be weak. However, if we deny all possible alternatives, the reasoning will be strong, and even in some cases deductively valid.

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.