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.

We argue that common knowledge, of the kind used in reasoning in law and computing is best analyzed using a dialogue model of argumentation (Walton & Krabbe 1995). In this model, implicit premises resting on common knowledge are analyzed as endoxa or widely accepted opinions and generalizations (Tardini 2005). We argue that, in this sense, common knowledge is not really knowledge of the kind represent by belief and/or knowledge of the epistemic kind studied in current epistemology. This paper takes a (...) different approach, defining it in relation to a common commitment store of two participants in a rule-governed dialogue in which two parties engage in rational argumentation (Jackson & Jacobs 1980; van Eemeren & Grootendorst 2004). A theme of the paper is how arguments containing common knowledge premises can be studied with the help of argumentation schemes for arguments from generally accepted opinion and expert opinion. It is argued that common knowledge is a species of provi- sional acceptance of a premise that is not in dispute at a given point in a dia- logue, but may later be defeated as the discussion proceeds . (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)

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)

The recent redefinition of 'planet' that excludes Pluto as a planet led to controversy that provides a case study of how competing scientific definitions can be supported by characteristic types of evidence. An argumentation scheme from Hastings is used to analyze argument from verbal classification as a form of inference used in rational argumentation. The Toulmin-style format is compared to more recently developed ways of modeling such cases that stem from advances in argumentation technology in artificial intelligence. Using these tools, (...) it is shown how argumentation schemes, in particular argument from verbal classification and argument from definition to verbal classification, apply to cases of scientific argumentation. (shrink)

Stasis-theory seeks to classify rhetorical problems acccording to the underlying structure of the dispute that each involves. Such a classification is of interest to the practising rhetor, since it may help him identify an appropriate argumentative strategy; for example, patterns of argument appropriate to a question of fact may be irrelevant in an evaluative dispute.

À quelles conditions peut-on, dans un discours réel, utiliser un énoncé comme argument en faveur d’un autre? La réponse semble aller de soi, au moins si l’on assimile l’argumentation à une espèce de raisonnement - peut-être lâche et flou, mais analogue en son fond à la démonstration étudiée par les logiciens. Dans ce cas, l’enchaînement des énoncés se fonde sur les informations qu’ils véhiculent, sur ce qu’ils disent de la réalité. C’est justement l’inverse que veut montrer la théorie des échelles (...) argumentatives. Selon elle, la structure des énoncés, au sens le plus étroitement grammatical du terme, contient, indépendamment des informations qu’ils donnent, des indications sur le type de conclusions qu’ils peuvent servir. Le sens même de nos paroles doit alors être vu comme étant, de façon intrinsèque, un moyen pour orienter le discours de l’autre, l’intention de dire ne se distinguant pas de l’intention de faire dire. Ce qui fait triompher le structuralisme là où on l’attend le moins, en sémantique - la valeur sémantique d’un énoncé est constituée par allusion à la possibilité d’un autre énoncé - l’énoncé de l’autre. (shrink)