In this paper, we use concepts, structure and tools from argumentation theory to show how conversational implicatures are triggered by conflicts of presumptions. Presumptive implicatures are shown to be based on defeasible forms of inference used in conditions of lack of knowledge, including analogical reasoning, inference to the best explanation, practical reasoning, appeal to pity, and argument from cause. Such inferences are modelled as communicative strategies to knowledge gaps that shift the burden of providing the missing contrary evidence to the (...) other party in a dialogue. Through a series of illustrative examples, we show how such principles of inference are based on common knowledge about the ordinary course of events shared by participants in a structured dialogue setting in which they take turns putting forward and responding to speech acts. (shrink)

In Fallacies and Judgments of Reasonableness, Frans H. van Eemeren, Bart Garssen and Bert Meuffels report on their systematic empirical research of the conventional validity of the pragma-dialectical discussion rules. The experimental studies they carried out during more than ten years start from the pragma-dialectical theory of argumentation developed at the University of Amsterdam, their home university. In these studies they test methodically the intersubjective acceptability of the rules for critical discussion proposed in this theory by confronting ordinary arguers who (...) have not received any special education in argumentation and fallacies with discussion fragments containing both fallacious and non-fallacious argumentative moves. The research covers a wide range of informal fallacies. In this way, the authors create a basis for comparing the theoretical reasonableness conception of pragma-dialectics with the norms for judging argumentative moves prevailing in argumentative practice. Fallacies and Judgments of Reasonableness provides a unique insight into the relationship between theoretical and practical conceptions of reasonableness, supported by extensive empirical material gained by means of sophisticated experimental research. (shrink)

Disputational models of argumentation have been criticized as introducing adversariality into argumentation by mistakenly conceiving of it as minimally adversarial, and, in doing so, structurally incentivizing ancillary adversariality. As an alternative, non-adversarial models of argumentation like inquiry have been recommended. In this article I defend disputational, minimally adversarial models of disagreement-based argumentation. First, I argue that the normative kernel of minimal adversariality is properly located in the normative fabric of disagreement, not our practices of disputation. Thus, argumentation’s minimal adversariality is (...) a hereditary, rather than an acquired, trait. Second, I show how attempts to model disagreement-based argumentation non-adversarially, as co-inquiry, misrepresent the normative commitments of disagreers. Indeed, such attempts backfire in their efforts to make argumentation less adversarial, by removing the normative, discursive mechanisms by which we may hold each other to rational account for our commitments. Finally, I show how regulative models of disputation, like the Pragma-Dialectical critical discussion, are designed to minimize ancillary adversariality thereby preventing its escalation. (shrink)

Douglas Walton’s multitudinous contributions to the study of argumentation seldom, if ever, directly engage with argumentation in mathematics. Nonetheless, several of the innovations with which he is most closely associated lend themselves to improving our understanding of mathematical arguments. I concentrate on two such innovations: dialogue types (§1) and argumentation schemes (§2). I argue that both devices are much more applicable to mathematical reasoning than may be commonly supposed.

Not every speech act can be a lie. A good definition of lying should be able to draw the right distinctions between speech acts that can be lies and speech acts that under no circumstances are lies. This paper shows that no extant account of lying is able to draw the required distinctions. It argues that a definition of lying based on the notion of ‘assertoric commitment’ can succeed where other accounts have failed. Assertoric commitment is analysed in terms of (...) two normative components: ‘accountability’ and ‘discursive responsibility’. The resulting definition of lying draws all the desired distinctions, providing an intensionally adequate analysis of the concept of lying. (shrink)

The study of presumptions has intensified in argumentation theory over the last years. Although scholars put forward different accounts, they mostly agree that presumptions can be studied in deliberative and epistemic contexts, have distinct contextual functions, and promote different kinds of goals. Accordingly, there are “practical” and “cognitive” presumptions. In this paper, I show that the differences between practical and cognitive presumptions go far beyond contextual considerations. The central aim is to explore Nicholas Rescher’s contention that both types of presumptions (...) have a closely analogous pragmatic function, i.e., that practical and cognitive presumptions are made to avoid greater harm in circumstances of epistemic uncertainty. By comparing schemes of practical and cognitive reasoning, I show that Rescher’s contention requires qualifications. Moreover, not only do practical and cognitive presumptions have distinct pragmatic functions, but they also perform different dialogical functions and, in some circumstances, cannot be defeated by the same kinds of evidence. Hence, I conclude that the two classes of presumptions merit distinct treatment in argumentation theory. (shrink)

The article develops and justifies, on the basis of the epistemological argumentation theory, two central pieces of the theory of evaluative argumentation interpretation: 1. criteria for recognizing argument types and 2. rules for adding reasons to create ideal arguments. Ad 1: The criteria for identifying argument types are a selection of essential elements from the definitions of the respective argument types. Ad 2: After presenting the general principles for adding reasons (benevolence, authenticity, immanence, optimization), heuristics are proposed for finding missing (...) reasons, for deductive arguments, e.g., semantic tableaux are suggested. (shrink)

This is the introduction to the Routledge Companion to Thought Experiments.

Harry Collins' central argument about experimental practice revolves around the thesis that facts can only be generated by good instruments but good instruments can only be recognized as such if they produce facts. This is what Collins calls the experimenters' regress. For Collins, scientific controversies cannot be closed by the ‘facts’ themselves because there are no formal criteria independent of the outcome of the experiment that scientists can apply to decide whether an experimental apparatus works properly or not.No one seems (...) to have noticed that the debate is in fact a rehearsal of the ancient philosophical debate about skepticism. The present article suggests that the way out of radical skepticism offered by the so-called mitigated skeptics is a solution to the problem of consensus formation in science.Keywords: Argumentation; Skepticism; Sociology of science; Philosophy of science; Scientific controversies. (shrink)

Although in some contexts the notions of an ordinary argument’s presumption, assumption, and presupposition appear to merge into the one concept of an implicit premise, there are important differences between these three notions. It is argued that assumption and presupposition, but not presumption, are basic logical notions. A presupposition of an argument is best understood as pertaining to a propositional element (a premise or the conclusion) e of the argument, such that the presupposition is a necessary condition for the truth (...) of e or for a term in e to have a referent. In contrast, an assumption of an argument pertains to the argument as a whole in that it is integral to the reasoning or inferential structure of the argument. A logical assumption of an argument is essentially a proposition that must be true in order for the argument aside from that proposition to be fully cogent. Nothing that is both comparable and distinguishing can be said about presumptions of arguments. Rather, presumptions of arguments are distinctively conventional; they are introduced through conventional rules (e.g., those that concern how to treat promises). So not all assumptions and not all presuppositions of arguments are presumptions of those arguments, although all presumptions of arguments are either assumptions or presuppositions of those arguments. This account avoids making the (monological) notion of presumption vacuous and dissolving the distinction between assumption and presumption, which is a vulnerability of alternative views such as Hansen’s and Bermejo-Luque’s, as is shown. (shrink)

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)

In this essay, Weinstein wants to address the issue of argument strength, of how strongly the premises of an argument support a conclusion. Using the framework of the Toulmin model, arguments have warrants which indicate some general connection between the premises and the conclusion of the argument. We may ask for the backing of the warrant, evidence for it. If the connection is an empirical generalization, the backing includes data supporting the generalization. But the backing may include theoretical generalizations, which (...) may explain the warrant. Furthermore, theories may be reduced by more comprehensive theories. A warrant then may ultimately be backed by some deep and very comprehensive theoretical explanation.Weinstein seeks to explicate the relation between the depth of backing for the warrant and the strength of the connection between premises and conclusion which the warrant indicates through the Model of Emerging Truth . Data relevant to confirming the theory have empir .. (shrink)

Metaphorical meaning can be analyzed as triggered by an apparent communicative breach, an incongruity that leads to a default of the presumptive interpretation of a vehicle. This breach can be solved through contextual renegotiations of meaning guided by the communicative intention, or rather the presumed purpose of the metaphorical utterance. This paper addresses the problem of analyzing the complex process of reasoning underlying the reconstruction of metaphorical meaning. This process will be described as a type of abductive argument, aimed at (...) explaining how the vehicle can best contribute to the purpose of the utterance. This type of reasoning involves the analysis of the possible predicates that can be and usually are attributed to the vehicle, and the selection of the one that can support the implicit conclusion constituting the communicative goal of the metaphorical utterance. Metaphorical meaning, in this perspective, becomes the outcome of a complex process of meaning reconstruction aimed at providing the best explanation of the function of the vehicle within a discourse move. (shrink)

semantic minimalism and moderte contextualism.

In this overview article, we first explain what we take informal logic to be, discussing misconceptions and distinguishing our conception of it from competing ones; second, we briefly catalogue recent informal logic research, under 14 headings; third, we suggest four broad areas of problems and questions for future research; fourth, we describe current scholarly resources for informal logic; fifth, we discuss three implications of informal logic for philosophy in particular, and take note ofpractical consequences of a more general sort.

The implicit dimension of enthymemes is investigated from a pragmatic perspective to show why a premise can be left unexpressed, and how it can be used strategically. The relationship between the implicit act of taking for granted and the pattern of presumptive reasoning is shown to be the cornerstone of kairos and the fallacy of straw man. By taking a proposition for granted, the speaker shifts the burden of proving its un-acceptability onto the hearer. The resemblance of the tacit premise (...) with what is commonly acceptable or has been actually stated can be used as a rhetorical strategy. (shrink)

When we use a word, we face a crucial epistemic gap: we ground our move on the fact that our interlocutor knows the meaning of the word we used, and therefore he can interpret our dialogical intention. However, how is it possible to know the other’s mind? Hamblin explained this dialogical problem advancing the idea of dialectical meaning: on his view, the use of a word is based on a set of presumptions. Building on this approach, the use of a (...) word in a dialogue can be analyzed in terms of presumptive reasoning, while the manipulative strategies based on slanted or loaded terms or redefinitions can be conceived as forms of conflicts of presumptions. A presumptive approach to meaning can also ground different dialectical strategies to solve misunderstanding or definitional disagreements, or tactics to undermine the interlocutor’s arguments by advancing charges of equivocation. (shrink)

The applicability of Bayesian conditionalization in setting one’s posterior probability for a proposition, α, is limited to cases where the value of a corresponding prior probability, PPRI(α|∧E), is available, where ∧E represents one’s complete body of evidence. In order to extend probability updating to cases where the prior probabilities needed for Bayesian conditionalization are unavailable, I introduce an inference schema, defeasible conditionalization, which allows one to update one’s personal probability in a proposition by conditioning on a proposition that represents a (...) proper subset of one’s complete body of evidence. While defeasible conditionalization has wider applicability than standard Bayesian conditionalization (since it may be used when the value of a relevant prior probability, PPRI(α|∧E), is unavailable), there are circumstances under which some instances of defeasible conditionalization are unreasonable. To address this difficulty, I outline the conditions under which instances of defeasible conditionalization are defeated. To conclude the article, I suggest that the prescriptions of direct inference and statistical induction can be encoded within the proposed system of probability updating, by the selection of intuitively reasonable prior probabilities. (shrink)

A concept of critical thinking is developed based on the Socratic method and called accordingly a Socratic model. First the features of critical thinking stressed in this model are stated and illustrated. The Socratic method is presented and interpreted, then taken to yield a model of critical thinking. The process of internalization by which the Socratic model helps us to become critical thinkers is described. Argument analysis is considered as a widely used instructional strategy adaptable for teaching critical thinking on (...) the Socratic model. This Socratic model is advanced as one helpful way of organizing our ideas about critical thinking, helpful in unifying disparate factors and anchoring them in the humanist tradition. (shrink)

Needed for such dialogue games as dialectic are appropriate standards of fairness and rationality. The rules of procedure of dialectic must describe a game playable by actual human participants. The present paper centers on certain idealizations of the dialectician that are not allowable.

How is the burden of proof to be distributed among individuals who are involved in resolving a particular issue? Under what conditions should the burden of proof be distributed unevenly? We distinguish attitudinal from dialectical burdens and argue that these questions should be answered differently, depending on which is in play. One has an attitudinal burden with respect to some proposition when one is required to possess sufficient evidence for it. One has a dialectical burden with respect to some proposition (...) when one is required to provide supporting arguments for it as part of a deliberative process. We show that the attitudinal burden with respect to certain propositions is unevenly distributed in some deliberative contexts, but in all of these contexts, establishing the degree of support for the proposition is merely a means to some other deliberative end, such as action guidance, or persuasion. By contrast, uneven distributions of the dialectical burden regularly further the aims of deliberation, even in contexts where the quest for truth is the sole deliberative aim, rather than merely a means to some different deliberative end. We argue that our distinction between these two burdens resolves puzzles about unevenness that have been raised in the literature. (shrink)

Some critical reactions hardly give clues to the arguer as to how to respond to them convincingly. Other critical reactions convey some or even all of the considerations that make the critic critical of the arguer’s position and direct the arguer to defuse or to at least contend with them. First, an explication of the notion of a critical reaction will be provided, zooming in on the degree of “directiveness” that a critical reaction displays. Second, it will be examined whether (...) there are normative requirements that enhance the directiveness of criticism. Does the opponent have in circumstances a dialectical obligation to provide clarifications, explanations, or even arguments? In this paper, it is hypothesized that the competitiveness inherent in critical discussion must be mitigated by making the opponent responsible for providing her counterconsiderations, if available, thus assisting the proponent in developing an argumentative strategy that defuses them. (shrink)

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 cases in which there is insufficient evidence to prove the claim to an appropriate standard of proof. (shrink)

This paper shows how reasoning from best explanation combines with linguistic and factual presumptions during the process of retrieving a speaker’s intention. It is shown how differences between presumptions need to be used to pick the best explanation of a pragmatic manifestation of a dialogical intention. It is shown why we cannot simply jump to an interpretative conclusion based on what we presume to be the most common purpose of a speech act, and why, in cases of indirect speech acts, (...) we need to depend on an abductive process of interpretation. (shrink)

This paper attempts to systematically characterize critical reactions in argumentative discourse, such as objections, critical questions, rebuttals, refutations, counterarguments, and fallacy charges, in order to contribute to the dialogical approach to argumentation. We shall make use of four parameters to characterize distinct types of critical reaction. First, a critical reaction has a focus, for example on the standpoint, or on another part of an argument. Second, critical reactions appeal to some kind of norm, argumentative or other. Third, they each have (...) a particular illocutionary force, which may include that of giving strategic advice to the other. Fourth, a critical reaction occurs at a particular level of dialogue (the ground level or some meta-level). The concepts here developed shall be applied to discussions of critical reactions by Aristotle and by some contemporary authors. (shrink)

Koopman’s book revolves around the notion of transition, which he proposes is one of the central ideas of the pragmatist tradition but one which had not previously been fully articulated yet nevertheless shapes the pragmatist attitude in philosophy. Transition, according to Koopman, denotes “those temporal structures and historical shapes in virtue of which we get from here to there”. One of the consequences of transitionalism is the understanding of critique and inquiry as historical pro...

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 disagreement in a dialectical format through using argumentation schemes (...) and critical questions. The social dimension is to show how the Ciceronian dialectical viewpoint integrates with the use of computational tools that can be used to support the principle of reason-based deliberation and facilitate deliberative democracy. (shrink)

Recent proposals for computer-assisted argumentation have drawn on dialectical models of argumentation. When used to assist public policy planning, such systems also raise questions of political legitimacy. Drawing on deliberative democratic theory, we elaborate normative criteria for deliberative legitimacy and illustrate their use for assessing two argumentation systems. Full assessment of such systems requires experiments in which system designers draw on expertise from the social sciences and enter into the policy deliberation itself at the level of participants.

This paper highlights the difference between Lilian Bermejo-Luque’s account of warrants with the quite different accounts of warrants offered by Toulmin, Hitchcock, and myself, and lays out some of the reasons why I think a “Toulminesque” account of warrants captures crucial aspects of arguing more adequately than her account does.

In this work it is argued that legal justification can best be studied from a procedural, dialogical point of view: legal statements are justified if the audience is convinced in an argumentative dialog. The formalized and implemented model DiaLaw guards the procedure in which two players aim at justifying statements. DiaLaw shows the advances and problems linked to procedural models of legal justification. Moreover, an instructive discussion of the different models of procedural justification is provided. It is stressed that in (...) legal justification not only logically compelling arguments should be considered, but also convincing arguments. Therefore DiaLaw also deals with the rhetorical, psychological aspects of argument. This book is relevant for scholars in legal theory, artificial intelligence, and argumentation, and can be used in graduate courses on AI and Law, and legal argumentation. (shrink)

An approach to argument macrostructure -- The dialectical nature of argument -- Toulmin's problematic notion of warrant -- The linked-convergent distinction, a first approximation -- Argument structure and disciplinary perspective : the linked-convergent versus multiple-co-ordinatively compound distinctions -- The linked-convergent distinction, refining the criterion -- Argument structure and enthymemes -- From analysis to evaluation.

J. Anthony Blair is a prominent international figure in argumentation studies. He is among the originators of informal logic, an author of textbooks on the informal logic approach to argument analysis and evaluation and on critical thinking, and a founder and editor of the journal Informal Logic. Blair is widely recognized among the leaders in the field for contributing formative ideas to the argumentation literature of the last few decades. This selection of key works provides insights into the history of (...) the field of argumentation theory and various related disciplines. It illuminates the central debates and presents core ideas in four main areas: Critical Thinking, Informal Logic, Argument Theory and Logic, Dialectic and Rhetoric. (shrink)

This paper analyzes legal fact-argumentation in the framework of the argumentation-based litigation game by Xiong :16–19, 2012). Rather than as an ontological one, an ALG treats a legal fact as a fact-qua-claim whose acceptability depends on the reasons supporting it. In constructing their facts-qua-claims, parties to an ALG must interact to maintain a game-theoretic equilibrium. We compare the general interactional constraints that the civil and common law systems assign, and detail what the civil, administrative, and criminal codes of mainland China (...) require of the suitor, the respondent, and the trier to establish their respective S-, R- and T-facts. We also offer an improved version of the legal syllogism. (shrink)

Implicatures are described as particular forms reasoning from best explanation, in which the para-digm of possible explanations consists of the possible semantic interpretations of a sentence or a word. The need for explanation will be shown to be triggered by conflicts between presumptions, namely hearer’s dialogical expectations and the presumptive sentence meaning. What counts as the best explanation can be established on the grounds of hierarchies of presumptions, dependent on dialogue types and interlocutors’ culture.

Argumentation involves offering and/or exchanging reasons – either reasons for adopting various attitudes towards specific propositional contents or else reasons for acting in various ways. This paper develops the idea that the force of reasons is through and through a normative force because what good reasons accomplish is precisely to give one a certain sort of entitlement to do what they are reasons for. The paper attempts to shed light on what it is to have a reason, how the sort (...) of entitlement arising from reasons differs from other species of entitlement and how the norms by which such entitlement is assessed obtain their status as norms. (shrink)

Presupposition has been described in the literature as closely related to the listener’s knowledge and the speaker’s beliefs regarding the other’s mind. However, how is it possible to know or believe our interlocutor’s knowledge? The purpose of this paper is to find an answer to this question by showing the relationship between reasoning, presumption and language. Presupposition is analyzed as twofold reasoning process: on the one hand, the speaker by presupposing a proposition presumes that his interlocutor knows it; on the (...) other hand, the listener reconstructs the propositions taken for granted and assesses them against the shared presumptions. The possibility of reconstructing a presupposition is distinguished from its assessment, where the consistency of the presupposition with the shared or common ground is evaluated, and its reasonableness established. The analysis of presuppositions from an argumentative perspective provides an instrument for evaluating the reasonableness of a presupposition and understanding its dialogical effect. On this view, the dialogical force of a presupposition lies in its presumptive nature, which sets and shifts the burden of proving its unacceptability or unreasonableness. (shrink)

The question of who has the burden of proof is often important in practice. We must frequently make decisions and act on the basis not of conclusive evidence but of what is reasonable to presume true. Consequently, it happens that a given practical question must be solved by referring to principles that explicitly or implicitly determine, at least partly, where the burden of proof should rest. In this essay, I consider the role of the logic of the burden of proof (...) in a debate on global justice. In particular, I ask how the logic of the burden of proof is seen by those who defend conservative positions in a debate and deny our obligations to reduce poverty beyond borders. I argue that defenders of conservative positions tend to shift the burden of proof in an unjustified way. (shrink)

This volume contains 12 papers addressed to researchers and advanced students in informal logic and related fields, such as argumentation, formal logic, and communications. Among the issues discussed are attempts to rethink the nature of argument and of inference, the role of dialectical context, and the standards for evaluating inferences, and to shed light on the interfaces between informal logic and argumentation theory, rhetoric, formal logic and cognitive psychology.

On the standard view, all presumptions share the same deontic function: they asymmetrically allocate the burden of proof. But what, exactly, does this function amount to? Once presumptions are rejected, do they place the burden of arguing, the burden of explanation, or the most general burden of reasoning on their opponents? In this paper, I take into account the differences between cognitive and practical presumptions and argue that the standard accounts of deontic function are at least ambiguous, and likely implausible. (...) As a result, they require qualifications. (shrink)

This volume presents a selection of papers reflecting key theoretical issues in argumentation theory. Its six sections are devoted to specific themes, including the analysis and evaluation of argumentation, argument schemes and the contextual embedding of argumentation. The section on general perspectives on argumentation discusses the trends of empiricalization, contextualization and formalization, offers descriptions of the analytical and evaluative tools of informal logic, and highlights selected principles that argumentation theorists do and do not agree upon. In turn, the section on (...) linguistic approaches to argumentation focuses on the problem of distinguishing between explanation and argument, while also elaborating on the role of verbal indicators of argument schemes. All essays included in this volume point out notable recent developments in the study of argumentation. (shrink)

This work discusses an empirical study of reasoning as it occurs in conversations. Reasoning in this context has features not usually accounted for in standard methods for describing argumentation (e.g., Toulmin, (1964), Toulmin, Rieke, and Janik (1984)). For example, insufficient attention has been paid to challenges which can be used to shift the ground of an argument and to the development of multiple conversational grounds. Moreover, even though the value of cooperative efforts in building arguments is widely recognized, more needs (...) to be said about analyzing co-constructed arguments. This empirical work was primarily descriptive and concerned with how people construct arguments in conversations, but one goal of the study was to lay groundwork for comparing the quality of reasoning in conversations which differ with respect to whether the arguments they contain are primarily the contributions of individuals or are genuinely co-constructed arguments. (shrink)

This paper makes a case for a refined look at the so- called ‘fallacy of hasty generalization’ by arguing that this expression is an umbrella term for two fallacies already distinguished by Aristotle. One is the fallacy of generalizing in an inappropriate way from a particular instance to a universal generalization containing a ‘for all x’ quantification. The other is the secundum quid (‘in a certain respect’) fallacy of moving to a conclusion that is supposed to be a universal generalization (...) containing a ‘for all x‘ quantification while overlooking qualifications that have to be added to the more limited kind of generalization expressed in the premise. It is shown that these two fallacies relate to two different kinds of generalization. (shrink)

Thesis (Ph. D.)--University of Hawaii at Manoa, 1991.

Although debate is a richly structured and prevalent form of discourse, it has received little scholarly attention. Logicians have focused on the structure of individual arguments—how they divide into premises and conclusions, which in turn divide into various constituents. In contrast, I focus on the structure of sets of arguments, showing how arguments are themselves constituents in high-level dialectical structures. I represent debates and positions by graphs whose vertices correspond to arguments and whose edges correspond to two inter-argument relations: “dispute” (...) and “support,” respectively. On this basis I develop a theory of the structure of debate. (shrink)

We discuss five kinds of representations of rationales and provide a formal account of how they can alter disputation. The formal model of disputation is derived from recent work in argument. The five kinds of rationales are compilation rationales, which can be represented without assuming domain-knowledge (such as utilities) beyond that normally required for argument. The principal thesis is that such rationales can be analyzed in a framework of argument not too different from what AI already has. The result is (...) a formal understanding of rationales, a partial taxonomy, and a foundation for computer programs that represent and reason with rationales.The five kinds of rationales are as follows: (c)ompression and (s)pecialization, which yield rules, and (d)isputation, which yields a decision. These are modeled as potentially changing the focus of the dispute. Then there are (f)it, a rationale for rules, and (r)esolution, a rationale for decisions. These cannot be modeled as simply; they force disputation to a meta-level, at least temporarily. (shrink)

The ArgumentThe purpose of this article is twofold. Firstly, I propose to analyze controversies using a “dialectical” model, in the sense described in Aristotle'sTopics. This approach presupposes that we temporarily disregard, for the sake of clarity, the concreteness of real life controversies in order to focus on their argumentative structure. From this point of view, the main advantage of controversies is that they allow the interlocutorsto testeach other's claims and therefore to arrive at relatively corroborated conclusions. This testing function in (...) a dialectical context is implemented through theassentto commonly accepted premises, and thenecessitywhich characterizes each step of the reasoning.Secondly, I shall apply this dialectical framework to the study of the controversy concerning the motion of the Earth, or rather a small episode of it. I shall examine an exchange of letters, written in 1616 and in 1624 respectively, between Galileo Galilei and Francesco Ingoli, one of his Aristotelian opponents. I shall then compare this exchange with the first day of Galileo'sDialogue Concerning the Two Chief Systems of the World, a fictional debate, where Galileo discusses some of the same arguments. While the first exemplifies what I call “negative” testing, and yields a refutation of the opponent's theses, the second exemplifies “positive” testing and yields a dialectical demonstration of the motion of the Earth. (shrink)

Parmenides as Secret Hero. Gregor Betz’s Theorie Dialektischer Strukturen (Theory of Dialectical Structures) Content Type Journal Article Pages 1-13 DOI 10.1007/s10503-011-9213-z Authors Frank Zenker, Department of Philosophy and Cognitive Science, Lund University, Kungshuset, Lundagård, 222 22 Lund, Sweden Journal Argumentation Online ISSN 1572-8374 Print ISSN 0920-427X.