•  24
    International Commentary on Evidence, 2006 Vol. 4, Issue 2, 1-47 . [link to online version posted].
  • The straw man fallacy
    In Johan van Benthem (ed.), Logic and argumentation, North-holland. pp. 115--128. 1996.
    In this paper, an analysis is given of the straw man fallacy as a misrepresentation of someone's commitments in order to refute that person's argument. With this analysis a distinction can be made between straw man and other closely related fallacies such as ad hominem, secundum quid and ad verecundiam. When alleged cases of the straw man fallacy are evaluated, the speaker's commitment should be conceived normatively in relation to the type of conversation the speaker was supposed to be engaged …Read more
  •  130
    Dialectical Relevance in Persuasion Dialogue
    Informal Logic 19 (2). 1999.
    How to model relevance in argumentation is an important problem for informal logic. Dialectical relcvance is determined by the use of an argument for some purpose in different types of dialogue, according to the ncw dialectic. A central type of dialogue is persuasion dialogue in which one participant uses rational argumentation to try to get the other participant to accept a designated proposition. In this paper, a method for judging relevance in persuasion dialogue is presented. The method is b…Read more
  •  17
    In the writings of Henry W. Johnstone, Jr. there can be found an evolving and gradually more sophisticated discussion of the relationship between rhetorical and dialectical argument. Johnstone's view on these matters was highly original, and at odds with the prevailing logical empiricism of the time, much like Toulmin's views on argumentation in The Uses of Argument (1958). In view of the rising importance of the issue of the relationship between rhetoric and informal logic, Johnstone's analysis…Read more
  •  23
    A Dialectical Analysis of the Ad Baculum Fallacy
    Informal Logic 34 (3): 276-310. 2014.
    This paper applies dialectical argumentation structures to the problem of analyzing the ad baculum fallacy. It is shown how it is necessary in order to evaluate a suspected instance of the this fallacy to proceed through three levels of analysis: an inferential level, represented by an argument diagram, a speech act level, where conditions for specific types of speech acts are defined and applied, and a dialectical level where the first two levels are linked together and fitted into formal dialo…Read more
  •  28
    with Thomas F. Gordon and Henry Prakken. Artificial Intelligence, forthcoming. [Preprint posted.].
  • Classification of Fallacies of Relevance
    Informal Logic 23 (1). 2003.
    Fallacies of relevance, a major category of informal fallacies, include two that could be called pure fallacies of relevance-the wrong conclusion fallacy and the red herring digression, diversion) fallacy. The problem is how to classify examples of these fallacies so that they clearly fall into the one category or the other, on some rational system of classification. In this paper, the argument diagramming software system, Araucaria. is used to analyze the argumentation in some selected textbook…Read more
  •  46
    In his book on fallacies, Hamblin built a very simple system for argumentation in dialogue he called the Why Because System with Questions. In his discussion of this system, he replaced the concept of burden of proof with a simpler concept of initiative, which could be described as something like getting the upper hand as the argumentation moves back and forth in the dialogue between the one party and the other. No doubt he realized that the concept of burden of proof was too complex a matter to…Read more
  •  66
    Computational Dialectic and Rhetorical Invention
    AI and Society 26 (1): 2011. 2011.
    This paper has three dimensions, historical, theoretical and social. The historical dimension is to show how the Ciceronian system of dialectical argumentation served as a precursor to computational models of argumentation schemes such as Araucaria and Carneades. The theoretical dimension is to show concretely how these argumentation schemes reveal the interdependency of rhetoric and logic, and so the interdependency of the normative with the empirical. It does this by identifying points of disa…Read more
  •  22
    Introduction to ‘Philosophy and Argumentum ad Hominem’
    Inquiry: Critical Thinking Across the Disciplines 12 (3-4): 24-24. 1993.
  •  487
    Dichotomies and oppositions in legal argumentation
    Ratio Juris 23 (2): 229-257. 2010.
    In this paper we use a series of examples to show how oppositions and dichotomies are fundamental in legal argumentation, and vitally important to be aware of, because of their twofold nature. On the one hand, they are argument structures underlying various kinds of rational argumentation commonly used in law as a means of getting to the truth in a conflict of opinion under critical discussion by two opposing sides before a tryer of fact. On the other hand, they are argument structures underling…Read more
  •  377
    Reasoning from Classifications and Definitions
    Argumentation 23 (1): 81-107. 2009.
    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 b…Read more
  •  1
    A Theory Of Argument (review)
    Bulletin of Symbolic Logic 13 (2): 245-245. 2007.
  •  7
    Book reviews (review)
    with Charles Arthur Willard, Erik C. W. Krabbe, Trudy Govier, Lita Lundquist, and Peter Jan Schellens
    Argumentation 6 (4): 473-493. 1993.
  •  11
    How can logic best be applied to arguments?
    Logic Journal of the IGPL 5 (4): 603-614. 1997.
    This talk surveys a number of methods currently being developed that assist in applying logic to the evaluation of arguments used in particular cases. A case is seen as specified by a given text and context of discourse. The methods used are pragmatic, and are based on the Gricean Cooperative Principle , as implemented in several types of goal-directed conversational exchanges
  •  96
    A Pragmatic Theory of Fallacy
    University Alabama Press. 2003.
    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 i…Read more
  •  57
    Evaluating Corroborative Evidence
    with Chris Reed
    Argumentation 22 (4): 531-553. 2008.
    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 consider…Read more
  •  770
    Argument from Analogy in Law, the Classical Tradition, and Recent Theories
    with Fabrizio Macagno and Douglas Walton
    Philosophy and Rhetoric 42 (2): 154-182. 2009.
    Argument from analogy is a common and formidable form of reasoning in law and in everyday conversation. Although there is substantial literature on the subject, according to a recent survey ( Juthe 2005) there is little fundamental agreement on what form the argument should take, or on how it should be evaluated. Th e lack of conformity, no doubt, stems from the complexity and multiplicity of forms taken by arguments that fall under the umbrella of analogical reasoning in argumentation, dialecti…Read more
  •  59
    New Dialectical Rules For Ambiguity
    Informal Logic 20 (3). 2000.
    A set often rules is proposed for dealing with problems of ambiguity when interpreting a text of argumentative discourse. The rules are based on Grice's pragmatic rules for a collaborative conversation and on principles and maxims used to deal with ambiguity in interpreting legal and religious writings. The rules are meant to be applied to a given argument used in a given case, and to resolve (or at least deal with) an ambiguity in the argument (or affecting the argument) by using evidence deriv…Read more
  •  57
    Argument from analogy in legal rhetoric
    Artificial Intelligence and Law 21 (3): 279-302. 2013.
    This paper applies recent work on scripts and stories developed as tools of evidential reasoning in artificial intelligence to model the use of argument from analogy as a rhetorical device of persuasion. The example studied is Gerry Spence’s closing argument in the case of Silkwood v. Kerr-McGee Corporation, said to be the most persuasive closing argument ever used in an American trial. It is shown using this example how argument from analogy is based on a similarity premise where similarity bet…Read more
  •  973
    Types of Dialogue, Dialectical Relevance and Textual Congruity
    Anthropology and Philosophy 8 (1-2): 101-120. 2007.
    Using tools like argument diagrams and profiles of dialogue, this paper studies a number of examples of everyday conversational argumentation where determination of relevance and irrelevance can be assisted by means of adopting a new dialectical approach. According to the new dialectical theory, dialogue types are normative frameworks with specific goals and rules that can be applied to conversational argumentation. In this paper is shown how such dialectical models of reasonable argumentation c…Read more
  •  69
    Commitment, Types of Dialogue, and Fallacies
    Informal Logic 14 (2): 93-103. 1992.
    This paper, based on research in a forthcoming monograph, Commitment in Dialogue, undertaken jointly with Erik Krabbe, explains several informal fallacies as shifts from one type of dialogue to another. The normative framework is that of a dialogue where two parties reason together, incurring and retracting commitments to various propositions as the dialogue continues. The fallacies studied include the ad hominem, the slippery slope, and many questions
  •  32
    . A heuristic search procedure for inventing legal arguments is built on two tools already widely in use in argumentation. Argumentation schemes are forms of argument representing premise‐conclusion and inference structures of common types of arguments. Schemes especially useful in law represent defeasible arguments, like argument from expert opinion. Argument diagramming is a visualization tool used to display a chain of connected arguments linked together. One such tool, Araucaria, available f…Read more
  •  58
    The Argument of the Beard
    Informal Logic 18 (2). 1996.
    The essence of the argument of the beard (so-called by some logic textbooks) is the tactic used by a respondent to reply to a proponent, "The criterion you used to define a key term in your argument is vague, therefore your use of this term in your argument is illegitimate, and your argument is refuted." This familiar kind of argument tactic is similar to the much more famous heap (sorites) argument of Eubulides, closely associated with the slippery slope argument. This article provides a system…Read more
  •  75
    Classification of Fallacies of Relevance
    Informal Logic 24 (1): 71-103. 2004.
    Fallacies of relevance, a major category of informal fallacies, include two that could be called pure fallacies of relevance-the wrong conclusion (ignoratio elenchi, wrong conclusion, missing the point) fallacy and the red herring digression, diversion) fallacy. The problem is how to classify examples of these fallacies so that they clearly fall into the one category or the other, on some rational system of classification. In this paper, the argument diagramming software system, Araucaria. is us…Read more
  •  4
    Judging How Heavily a Question is Loaded
    Inquiry: Critical Thinking Across the Disciplines 17 (2): 53-71. 1997.
  •  424
    Presumptions in Legal Argumentation
    Ratio Juris 25 (3): 271-300. 2012.
    In this paper a theoretical definition that helps to explain how the logical structure of legal presumptions is constructed by applying the Carneades model of argumentation developed in artificial intelligence. Using this model, it is shown how presumptions work as devices used in evidentiary reasoning in law in the event of a lack of evidence to assist a chain of reasoning to move forward to prove or disprove a claim. It is shown how presumptions work as practical devices that may be useful in …Read more