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. (shrink)

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)

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 can be applied to a determination of whether an (...) argument in a specific case is relevant are not in these examples. The approach is based on a linguistic account of dialogue and text from congruity theory, and on the notion of a dialectical shift. Such a shift occurs where an argument starts out as fitting into one type of dialogue, but then it only continues to makes sense as a coherent argument if it is taken to be a part of a different type of dialogue. (shrink)

There are emotively powerful words that can modify our judgment, arouse our emotions and influence our decisions. This paper shows how the use of emotive meaning in argumentation can be explained by showing how their logical dimension, which can be analysed using argumentation schemes, combines with heuristic processes triggered by emotions. Arguing with emotive words is shown to use value-based practical reasoning grounded on hierarchies of values and maxims of experience for evaluative classification.

In this paper we present an analysis of persuasive definition based on argumentation schemes. Using the medieval notion of differentia and the traditional approach to topics, we explain the persuasiveness of emotive terms in persuasive definitions by applying the argumentation schemes for argument from classification and argument from values. Persuasive definitions, we hold, are persuasive because their goal is to modify the emotive meaning denotation of a persuasive term in a way that contains an implicit argument from values. However, our (...) theory is different from Stevenson’s, a positivistic view that sees emotive meaning as subjective, and defines it as a behavioral effect. Our proposal is to treat the persuasiveness produced by the use of emotive words and persuasive definitions as due to implicit arguments that an interlocutor may not be aware of. We use congruence theory to provide the linguistic framework for connecting a term with the function it is supposed to play in a text. Our account allows us to distinguish between conflicts of values and conflicts of classifications. (shrink)

We contend that it is possible to argue reasonably for and against arguments from classifications and definitions, provided they are seen as defeasible (subject to exceptions and critical questioning). Arguments from classification of the most common sorts are shown to be based on defeasible reasoning of various kinds represented by patterns of logical reasoning called defeasible argumentation schemes. We show how such schemes can be identified with heuristics, or short-cut solutions to a problem. We examine a variety of arguments of (...) this sort, including argument from abductive classification, argument from causal classification, argument from analogy-based classification and arguments from classification based on generalizations. (shrink)

This article analyses the fallacy of wrenching from context, using the dialectical notions of commitment and implicature as tools. The data, a set of key examples, is used to sharpen the conceptual borderlines around the related fallacies of straw man, accent, misquotation, and neglect of qualifications. According to the analysis, the main characteristics of wrenching from context are the manipulation of the meaning of the other’s statement through devices such as the use of misquotations, selective quotations, and quoting out of (...) context. The theoretical tools employed in the analysis are pragmatic theories of meaning and a dialectical model of commitment, used to explain how and why a standpoint is distorted. The analysis is based on a conception of fallacies as deceptive strategic moves in a game of dialogue. As a consequence, our focus is not only on misquotations as distortions of meaning, but on how they are used as dialectical tools to attack an opponent or win a dispute. Wrenching from context is described as a fallacy of unfairly attributing a commitment to another party that he never held. Its power as a deceptive argumentation tactic is based on complex mechanisms of implicit commitments and on their misemployment to improperly suggest an attribution of commitment. (shrink)

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)

The aim of the paper is to present a typology of argument schemes. In first place, we found it helpful to define what an argument scheme is. Since many argument schemes found in contemporary theories stem from the ancient tradition, we took in consideration classical and medieval dialectical studies and their relation with argumentation theory. This overview on the main works on topics and schemes provides a summary of the main principles of classification. In the second section, Walton’s theory is (...) briefly explained to introduce the schemes classification and its different levels. At least, the final part shows the main application of the schemes in computing and AI. -/- . (shrink)

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 moves made in strategic advocacy by both sides that function as platforms for different kinds of questionable argumentation tactics and moves that are in some instances tricky and deceptive. (shrink)

A problem for dialogue models of argumentation is to specify a set of conditions under which an opponent’s claims, offered in support of a standpoint under dispute, ought to be challenged. This project is related to the issue of providing a set of acceptability conditions for claims made in a dialogue. In this paper, we consider the conditions of suspicion and trust articulated by Jacobs (Alta, 2003), arguing that neither are acceptable as general conditions for challenge. We propose a third (...) condition that attempts to mark a middle ground between suspicion and trust. (shrink)