The paper considers contemporary models of presumption in terms of their ability to contribute to a working theory of presumption for argumentation. Beginning with the Whatelian model, we consider its contemporary developments and alternatives, as proposed by Sidgwick, Kauffeld, Cronkhite, Rescher, Walton, Freeman, Ullmann-Margalit, and Hansen. Based on these accounts, we present a picture of presumptions characterized by their nature, function, foundation and force. On our account, presumption is a modal status that is attached to a claim and has the (...) effect of shifting, in a dialogue, a burden of proof set at a local level. Presumptions can be analysed and evaluated inferentially as components of rule-based structures. Presumptions are defeasible, and the force of a presumption is a function of its normative foundation. This picture seeks to provide a framework to guide the development of specific theories of presumption. (shrink)

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, dialectical (...) studies, and law. Modeling arguments with argumentation schemes has proven useful in attempts to refine the analyst’s understanding of not only the logical structures that shape the backbone of the argument itself, but also the logical underpinning of strategies for evaluating it, strategies based on the semantic categories of genus and relevance. By clarifying the distinction between argument from example and argument from analogy, it is possible to advance a useful proposal for the treatment of argument from analogy in law. (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)

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 paper studies the use of hypothetical and value-based reasoning in US Supreme-Court cases concerning the United States Fourth Amendment. Drawing upon formal AI & Law models of legal argument a semi-formal reconstruction is given of parts of the Carney case, which has been studied previously in AI & law research on case-based reasoning. As part of the reconstruction, a semi-formal proposal is made for extending the formal AI & Law models with forms of metalevel reasoning in several argument schemes. (...) The result is compared with Rissland’s (1989) analysis in terms of dimensions and Ashley’s (2008) analysis in terms of his process model of legal argument with hypotheticals. (shrink)

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. (shrink)

tational background of dialectic: the structure of formal disputation. Formal disputation Perhaps the clearest, and surely historically the most prominent, ...

The notions of burden of proof and presumption are central to law, but as noted in McCormick on Evidence, they are also the slipperiest of any of the family of legal terms employed in legal reasoning. However, recent studies of burden of proof and presumption (Prakken et al. 2005; Prakken and Sartor 2006). Gordon et al. (2007) offer formal models that can render them into precise tools useful for legal reasoning. In this paper, the various theories and formal models are (...) comparatively evaluated with the aim of working out a more comprehensive theory that can integrate the components of the argumentation structure on which they are based. It is shown that the notion of presumption has both a logical component and a dialectical component, and the new theory of presumption developed in the paper, called the dialogical theory, combines these two components. (shrink)

This paper studies the modelling of legal reasoning about evidence within general theories of defeasible reasoning and argumentation. In particular, Wigmore's method for charting evidence and its use by modern legal evidence scholars is studied in order to give a formal underpinning in terms of logics for defeasible argumentation. Two notions turn out to be crucial, viz. argumentation schemes and empirical generalisations.

This paper presents a speech act analysis of presumption, using the framework of a dialogue in which two parties reason together. In the speech act of presumption, as opposed to that of assertion, the burden of proof resides not on the proponent to prove, but on the respondent to rebut. Some connections of this account with nonmonotonic reasoning and informal fallacies in argumentation are explored.

Grennan bases his evaluation of arguments on two criteria: logical adequacy and pragmatic adequacy. He asserts that the common formal logic systems, while logically sound, are not very useful for evaluating everyday inferences, which are almost all deductively invalid as stated. Turning to informal logic, he points out that while more recent informal logic and critical thinking texts are superior in that their authors recognize the need to evaluate everyday arguments inductively, they typically cover only inductive fallacies, ignoring the inductively (...) sound patterns frequently used in successful persuasion. To redress these problems, Grennan introduces a variety of additional inductive patterns. Concluding that informal logic texts do not encourage precision in evaluating arguments, Grennan proposes a new argument evaluation procedure that expresses judgments of inferential strength in terms of probabilities. Based on theories of Stephen Toulmin, Roderick Chisholm, and John Pollock, his proposed system allows for a more precise judgment of the persuasive force of 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)

This paper studies the modelling of legal reasoning about evidence within general theories of defeasible reasoning and argumentation. In particular, Wigmore's method for charting evidence and its use by modern legal evidence scholars is studied in order to give a formal underpinning in terms of logics for defeasible argumentation. Two notions turn out to be crucial, viz. argumentation schemes and empirical generalisations.

Presumption is a remarkably versatile and pervasively useful resource. Firmly grounded in the law of evidence from its origins in classical antiquity, it made its way in the days of medieval scholasticism into the theory and practice of disputation and debate. Subsequently, it extended its reach to play an increasingly significant role in the philosophical theory of knowledge. It has thus come to represent a region where lawyers, debaters, and philosophers can all find some common around. In Presumption and the (...) Practices of Tentative Cognition, Nicholas Rescher endeavors to show that the process of presumption plays a role of virtually indispensable utility in matters of rational inquiry and communication. The origins of presumption may lie in law, but its importance is reinforced by its service to the theory of information management and philosophy. (shrink)

blandior ratio : C, 34). I will first survey how extensive, albeit usually overlooked, is Leibniz’s concern with these “weaker” forms of reasoning, and how crucial they are for many of his practical and theoretical endeavors. I will then trace back this acute need of Leibniz´s brand of rationalism to the peculiar nature of the Principle of Sufficient Reason (PSR), as opposed to the other basic principle of his philosophy, the Principle of Contradiction (PC). I will present here only the (...) bare bones of the argument, in a sort of extended summary, omitting the textual support as well the references to the relevant secondary literature. (shrink)