Some conspicuous characteristics of argumentation as we all know this phenomenon from our shared everyday experiences are in my view vital to its theoretical treatment because they should have methodological consequences for the way in which argumentation research is conducted. To start with, argumentation is in the first place a communicative act complex, which is realized by making functional verbal communicative moves.

This paper compares current ways of modeling the inferential structure of practical reasoning arguments, and proposes a new approach in which it is regarded in a modular way. Practical reasoning is not simply seen as reasoning from a goal and a means to an action using the basic argumentation scheme. Instead, it is conceived as a complex structure of classificatory, evaluative, and practical inferences, which is formalized as a cluster of three types of distinct and interlocked argumentation schemes. Using two (...) real examples, we show how applying the three types of schemes to a cluster of practical argumentation allows an argument analyst to reconstruct the tacit premises presupposed and evaluate the argumentative reasoning steps involved. This approach will be shown to overcome the limitations of the existing models of practical reasoning arguments within the BDI and commitment theoretical frameworks, providing a useful tool for discourse analysis and other disciplines. In particular, applying this method brings to light the crucial role of classification in practical argumentation, showing how the ordering of values and preferences is only one of the possible areas of deep disagreement. (shrink)

How do Dutch people let each other know that they disagree? What do they say when they want to resolve their difference of opinion by way of an argumentative discussion? In what way do they convey that they are convinced by each other’s argumentation? How do they criticize each other’s argumentative moves? Which words and expressions do they use in these endeavors? By answering these questions this short essay provides a brief inventory of the language of argumentation in Dutch.

In the pragma-dialectical approach, fallacies are considered incorrect moves in a discussion for which the goal is successful resolution of a dispute. Ten rules are given for effective conduct at the various stages of such a critical discussion (confrontation, opening, argumentation, concluding). Fallacies are discussed as violations of these rules, taking into account all speech acts which are traditionally recognized as fallacies. Special attention is paid to the role played by implicitness in fallacies in everyday language use. It is stressed (...) that identifying and acknowledging fallacies in ordinary discussions always has a conditional character. Differences between the pragma-dialectical perspective, the Standard Treatment, and the formal logic approach to fallacy analysis are discussed. (shrink)

Pragmatic presupposition is analyzed in this paper as grounded on an implicit reasoning process based on a set of presumptions, which can define cultural differences. The basic condition for making a presupposition can be represented as a reasoning criterion, namely reasonableness. Presuppositions, on this view, need to be reasonable, namely as the conclusion of an underlying presumptive reasoning that does not or may not contain contradictions with other presumptions, including the ordering of the hierarchy of presumptions. Presumptions are in turn (...) analyzed considering their nature and their hierarchy, namely their object and their possible contextual backing, which eliminates some of their possible defaults. This analysis of presupposition brings to light the relationship between communicative infelicities or misunderstandings deriving from presuppositional failures and the underlying system of presumptions and presumptive reasoning. This approach can be applied to the investigation of communicative problems within the medical context, and more precisely the communication in diabetes cases. (shrink)

The study presented here examines how interacting with a more capable interlocutor influences use of argumentation strategies in electronic discourse. To address this question, 54 young adolescents participating in an intervention centered on electronic peer dialogs were randomly assigned to either an experimental or control condition. In both conditions, pairs who held the same position on a social issue engaged in a series of electronic dialogs with pairs who held an opposing position. In the experimental condition, in some dialogs, unbeknownst (...) to them (because dialog took place electronically), the opponent was a more capable (“expert”) adult. Dialogs in the control condition were only with peers. Argumentation strategies of the experimental group who argued with the “expert” showed immediate strategy improvements in their subsequent peer dialogs, improvement absent in the control group (Cohen's d = 1.12). In particular, the experimental group showed greater use of counterargument in general and advanced forms of counterargument (undermining) that challenges the deeper premises or reasoning on which an argument is based. Implications with respect to mechanisms of change in the development of argumentation skills are considered. (shrink)

Starting from a concept of reasonableness as well-consideredness, it is discussed in what way science could serve as a model for reasonable argumentation. It turns out that in order to be reasonable two requirements have to be fulfilled. The argumentation should comply with rules which are both problem-valid and intersubjectively valid. Geometrical and anthropological perspectives don't meet these criteria, but a critical perspective does. It is explained that a pragma-dialectical approach to argumentation which agrees with this critical perspective is indeed (...) problem-valid and that strong pragmatic and utilitarian arguments can be given for its intersubjective validity. Thus, conventional validity is promoted for a code of conduct for discussants who want to resolve their disputes reasonably by way of a critical discussion. (shrink)

The paper's thesis is that dialogue is not an adequate model for all types of argument. The position of Walton is taken as the contrary view. The paper provides a set of descriptions of dialogues in which arguments feature in the order of the increasing complexity of the argument presentation at each turn of the dialogue, and argues that when arguments of great complexity are traded, the exchanges between arguers are turns of a dialogue only in an extended or metaphorical (...) sense. It argues that many of the properties of engaged back-and-forth exchanges of paradigmatic argument dialogues are not found in ‘solo’ arguments, and that at least some of the norms appropriate to the former type of argument, such as some of the pragma-dialectical rules of van Eemeren and Grootendorst's model, do not apply to the latter. (shrink)

Argumentation schemes are forms of reasoning that are fallible but correctable within a self-correcting framework. Their use provides a basis for taking rational action or for reasonably accepting a conclusion as a tentative hypothesis, but they are not deductively valid. We argue that teleological reasoning can provide the basis for justifying the use of argument schemes both in monological and dialogical reasoning. We consider how such a teleological justification, besides being inspired by the aim of directing a bounded cognizer to (...) true belief and correct choices, needs to take into account the attitudes of dialogue partners as well as normative models of dialogue and communicative activity types, in particular social and cultural settings. (shrink)

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)

According to van Eemeren, argumentation theory is a hybrid discipline, because it requires a multidisciplinary, if not interdisciplinary approach, combining descriptive and normative insights. He points out that modern argumentation theorists give substance to the discipline by relying either on a dialectical perspective, concentrating on the reasonableness of argumentation, or on a rhetorical perspective, concentrating on its effectiveness. Both the dialectical and the rhetorical perspective are interpreted in ways related to how they were viewed by Aristotle, but in modern argumentation (...) theory the relationship between the two, captured in Aristotle’s term antistrophos, is lost. According to van Eemeren, this relationship, which he considers crucial to a full-fledged argumentation theory, has been recovered in extended pragma-dialectics with the help of the theoretical notion of ‘strategic manoeuvring.’. (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)

ABSTRACT This article focuses on Arne Naess's work in the philosophy of language, which he began in the mid-1930s and continued into the 1960s. This aspect of his work is nowadays relatively neglected, but it deserves to be revisited. Firstly, it is intrinsically interesting to the history of analytic philosophy in the twentieth century, because Naess questioned some of the established philosophical methodologies and assumptions of his day. Secondly, it suggests a compelling but unacknowledged intellectual pedigree for some recent developments (...) in linguistics. Naess's philosophy of language developed from his reaction against logical positivism, in particular against what he saw as its unempirical assumptions about language. He went on to establish ?empirical semantics?, in which the study of language was based on real-life linguistic data, drawn primarily from questionnaires issued to philosophically naïve subjects. He also experimented with methods for ?occurrence analysis?, but concluded that the collection and analysis of sufficiently large bodies of naturally-occurring data was impractical. Empirical semantics was not well received by Naess's philosophical contemporaries. It was also seen as being at odds with contemporary trends in linguistics. However, some present-day branches of linguistics have striking resonances with Naess's work from as much as seventy years ago. In sociolinguistics, questionnaires have become an established means of collecting linguistic data. In corpus linguistics, advances in technology have made Naess's unobtainable ideal of ?occurrence analysis? a viable methodology. Some of the principal conclusions reached as a result of this methodology are strikingly similar to Naess's own findings. (shrink)

Wellman’s “conduction” and Govier’s “conductive arguments” are best described as appeals to considerations. The considerations cited are features of a subject of interest, and the conclusion is the attribution to it of a supervenient status like a classification, an evaluation, a prescription or an interpretation. The conclusion may follow either conclusively or non-conclusively or not at all. Weighing the pros and cons is only one way of judging whether the conclusion follows. Further, the move from in-formation about the subject’s cited (...) features to the attribution of a supervenient status is often but one moment in a more complex process. (shrink)

Wellman identified three types of conductive arguments, the third of which contains both pro and counter-considerations in the same piece of reasoning. This paper provides a pragma-dialectical analysis of this type of argumentation, with special focus on argumentation reconstruction. It argues that the account of pro/con argumentation in the framework of argument-as-product has problems solvable by a pragma-dialectical approach. The paper asserts that pro/con argumentation should be analyzed as a dialectical strategy of a protagonist, where acknowledgement of counter-considerations shows that (...) the antagonist’s reasons have been taken into consideration, although the pro-considerations override them. Thus, the pro-considerations of pro/con argumentation should be interpreted as the protagonist’s overriding defeaters of the antagonist’s counter-arguments, the protagonist incorporating the latter as counter-considerations. The paper further argues that the pragma-dialectical framework needs an additional conceptual tool to properly reconstruct complex forms of pro/con argumentation. Finally, the pragma-dialectical approach to reconstruct pro/con argumentation has several advantages, especially to a more logical-structural approach to complex pro/con argumentation. (shrink)

This paper is aimed at combining the advances in argumentation theory with the models used in the field of education to address the issue of improving students’ argumentative behavior by interacting with an expert. The concept of deeper or more sophisticated argumentative strategy is theoretically defined and used to advance two new coding schemes, based on the advances in the argumentation studies and aimed at capturing the dialectical, or structural, behavior, and the argumentative content of each dialogue unit. These coding (...) schemes are then applied for a qualitative analysis of a study designed to investigate how students’ argumentative behavior can be influenced by the interaction with an expert, who used specific types of attacks to the interlocutors’ positions. The twofold coding shows at which dialogical level expert–peer interactions can directly and more stably affect students’ argumentative behavior, and what effects such more sophisticated strategies can have on the discussion and the analysis of disagreements. In particular, this paper shows how a specific type of deep-level attack, the underminer, can open dialogues of a different level, focused on unveiling and debating background beliefs underlying a specific position. (shrink)

When the original Dutch version of this book was presented in 1971 to the University of Leiden as a thesis for the Doctorate in philosophy, I was prevented by the academic mores of that university from expressing my sincere thanks to three members of the Philosophical Faculty for their support of and interest in my pursuits. I take the liberty of doing so now, two and a half years later. First and foremost I want to thank Professor G. Nuchelmans warmly (...) for his expert guidance of my research. A number of my most im portant sources were brought to my attention by him. During the whole process of composing this book his criticism and encouragement were carried out in a truly academic spirit. He thereby provided working conditions that are a sine qua non for every author who is attempting to approach controversial matters in a scientific manner, conditions which, however, were not easily available at that time. In a later phase I also came into contact with Professors L. M. de Rijk and J. B. Ubbink, with both of whom I had highly stimulating discussions and exchanges of ideas. The present edition contains some entirely new sections, viz. 1-9, IV-29, V-9, V-20, VII-14 (iii), (iv), VII-17 (i), VIII-22, IX-17, IX-19, X-9 and XI-8. Section X-9 was inspired by a remark made by Professor A. (shrink)

Dialogical logic is a game-theoretical approach to logic. Logic is studied with the help of certain games, which can be thought of as idealized argumentations. Two players, the Proponent, who puts forward the initial thesis and tries to defend it, and the Opponent, who tries to attack the Proponent’s thesis, alternately utter argumentative moves according to certain rules. For a long time the dialogical approach had been worked out only for classical and intuitionistic logic. The seven papers of this dissertation (...) show that this narrowness was uncalled for. The initial paper presents an overview and serves as an introduction to the other papers. Those papers are related by one central theme. As each of them presents dialogical formulations of a different non-classical logic, they show that dialogical logic constitutes a powerful and flexible general framework for the development and study of various logical formalisms and combinations thereof. As such it is especially attractive to logical pluralists that reject the idea of “the single correct logic”. The collection contains treatments of free logic, modal logic, relevance logic, connexive logic, linear logic, and multi-valued logic. (shrink)

According to van Eemeren, argumentation theory is a hybrid discipline, because it requires a multidisciplinary, if not interdisciplinary approach, combining descriptive and normative insights. He points out that modern argumentation theorists give substance to the discipline by relying either on a dialectical perspective, concentrating on the reasonableness of argumentation, or on a rhetorical perspective, concentrating on its effectiveness. Both the dialectical and the rhetorical perspective are interpreted in ways related to how they were viewed by Aristotle, but in modern argumentation (...) theory the relationship between the two, captured in Aristotle’s term antistrophos, is lost. According to van Eemeren, this relationship, which he considers crucial to a full-fledged argumentation theory, has been recovered in extended pragma-dialectics with the help of the theoretical notion of ‘strategic manoeuvring.’. (shrink)

Presuppositions are at the same time a crucial and almost neglected dimension of arguments and fallacies. Arguments involve different types of presuppositions, which can be used for manipulative purposes in distinct ways. However, what are presuppositions? What is their dialectical function? Why and how can they be dangerous? This paper intends to address these questions by developing the pragmatic approaches to presupposition from a dialectical perspective. The use of presuppositions will be analyzed in terms of presumptive conclusions concerning the interlocutor’s (...) acceptance of a proposition, which can be assessed as reasonable or unacceptable. Their dialectical function is described in terms of dark side commitments attributed to a collective "voice" representing what is commonly shared. For this reason, they count as attempts to include the presupposed contents into the hearer’s commitment store, which in some circumstances can reverse the burden of proof. The different manipulative strategies grounded on controversial presuppositions will be examined by showing the distinct roles that the latter play and the relationship between the degrees of presuppositional implicitness and the speaker’s burden of retraction. (shrink)

How do Dutch people let each other know that they disagree? What do they say when they want to resolve their difference of opinion by way of an argumentative discussion? In what way do they convey that they are convinced by each other’s argumentation? How do they criticize each other’s argumentative moves? Which words and expressions do they use in these endeavors? By answering these questions this short essay provides a brief inventory of the language of argumentation in Dutch.

Written by experts in the field, this volume presents a comprehensive investigation into the relationship between argumentation theory and the philosophy of mathematical practice. Argumentation theory studies reasoning and argument, and especially those aspects not addressed, or not addressed well, by formal deduction. The philosophy of mathematical practice diverges from mainstream philosophy of mathematics in the emphasis it places on what the majority of working mathematicians actually do, rather than on mathematical foundations. -/- The book begins by first challenging the (...) assumption that there is no role for informal logic in mathematics. Next, it details the usefulness of argumentation theory in the understanding of mathematical practice, offering an impressively diverse set of examples, covering the history of mathematics, mathematics education and, perhaps surprisingly, formal proof verification. From there, the book demonstrates that mathematics also offers a valuable testbed for argumentation theory. Coverage concludes by defending attention to mathematical argumentation as the basis for new perspectives on the philosophy of mathematics. ​. (shrink)

Argument is often taken to deal with conflicting opinion or belief, while negotiation deals with conflicting goals or interests. It is widely accepted that argument ought to comply with some principles or norms. On the other hand, negotiation and bargaining involve concession exchange and tactical use of power, which may be contrasted with attempts to convince others through argument. However, there are cases where it is difficult to draw a clear distinction between bargaining and argument: notably cases where negotiators persuade (...) others through `framing' and cases where the aims of negotiation have to do with public assertion and acceptance. Those cases suggest that the distinction between negotiation and argument is not absolute, and this raises the question whether rules about what is acceptable in argument and rules about what is acceptable in negotiation can all be viewed as instances of more general common norms about human interaction. (shrink)

David N. Perkins has studied everyday reasoning by an experimental-critical approach involving taped interviews during which subjects reflect on controversial issues and articulate their reasoning on both sides. The present author has studied scientific reasoning in natural language by an historical-textual approach involving the reconstruction and evaluation of the arguments in Galileo's Two Chief World Systems. They have, independently, reached the strikingly similar substantive conclusion that the most common flaw of informal reasoning is the failure to consider lines of argument (...) supporting conclusions contrary to the one in fact reached. This article describes, compares, and contrasts their respective approaches, results, and theoretical frameworks. (shrink)

More or less explicitly inspired by the Aristotelian classification of arguments, a wide tradition makes a sharp distinction between argument and proof. Ch. Perelman and R. Johnson, among others, share this view based on the principle that the conclusion of an argument is uncertain while the conclusion of a proof is certain. Producing proof is certainly a major part of mathematical activity. Yet, in practice, mathematicians, expert or beginner, argue about mathematical proofs. This happens during the search for a proof, (...) then when the proof is presented and discussed by experts, and finally when it is taught or used in didactical contexts. (shrink)

The distinction between constitutive and regulative rules is applied to rules for critical discussion that have to do with the use of ambiguous expressions. This leads to a distinction between rule violating fallacies, by which one abandons a critical discussion, and norm violating fallacies, which are in a way admissible within a critical discussion. According to the formal model for critical discussion, proposed in this paper, fallacies of the norm violating type arc not prohibited. Instead, it provides discussants with devices (...) to discuss fallacies and fallacy criticisms. (shrink)

It furthers the dialectic when the opponent is clear about what motivates and underlies her critical stance, even if she does not adopt an opposite standpoint, but merely doubts the proponent’s opinion. Thus, there is some kind of burden of criticism. In some situations, there should an obligation for the opponent to offer explanatory counterconsiderations, if requested, whereas in others, there is no real dialectical obligation, but a mere responsibility for the opponent to cooperate by providing her motivations for being (...) critical. In this paper, it will be shown how a set of dialogue rules may encourage an opponent, in this latter type of situation, to provide her counterconsiderations, and to do so at an appropriate level of specificity. Special attention will be paid to the desired level of specificity. For example, the critic may challenge a thesis by saying “Why? Says who?,” without conveying whether she could be convinced by an argument from expert opinion, or from position to know, or from popular opinion. What are fair dialogue rules for dealing with less than fully specific criticism? (shrink)

We argue that there are mutually beneficial connections to be made between ideas in argumentation theory and the philosophy of mathematics, and that these connections can be suggested via the process of producing computational models of theories in these domains. We discuss Lakatos’s work (Proofs and Refutations, 1976) in which he championed the informal nature of mathematics, and our computational representation of his theory. In particular, we outline our representation of Cauchy’s proof of Euler’s conjecture, in which we use work (...) by Haggith on argumentation structures, and identify connections between these structures and Lakatos’s methods. (shrink)

In this article we present a training program based on the empirical research conducted in the project 'argumentational integrity'. After a brief sketch of the problem dimensions concerning unfair argumentation we give an overview of the training concept and the underlying empirical research. Exemplification of the instructional design is given for the second and the fifth training dimension (standards of argumentational integrity and reactions to unfair contributions). Finally we indicate how the training is to be evaluated and present initial results (...) demonstrating that in comparison with an untrained control group participants in the training significantly improve their skills in identifying and naming argumentative rule violations. (shrink)

A clarification of Naess's ?depth metaphor? is offered. The relationship between Naess's empirical semantics and communication theory and his deep ecology approach to ecophilosophy (DEA) is developed. Naess's efforts to highlight significant conflicts by eliminating misunderstandings and promoting deep problematizing are focused upon. These insights are used to develop the implications of the DEA for environmental policy. Naess's efforts to promote the integration of science, ethics, and politics are related to the National Environmental Policy Act (NEPA). The action?oriented aspect of (...) deep ecology, its focus upon redirecting environmental policy, is also highlighted. The discussion is framed by Brian Norton's contention, in Toward Unity Among Environmentalists, that Naess's deep/ shallow distinction is not consequential. In the final section some of the uniqueness of Naess's contribution is intimated, the ?sturdiness? of deep ecology's foundation is considered, and directions for future theoretical and practical contributions are suggested. As will be observed, Naess has many important insights to offer, but some vexing issues persist. (shrink)

In this paper the conception of argumentation theory as applied epistemology is discussed. The point of departure is the description of four perspectives that are considered as founders of the modern theory of argumentation, in order to observe whether there was a similar concept in those theories or if they provided the patterns to go into that direction. Further on the reasons why contemporary scholars have given this emphasis to the notion of argumentation theory is discussed. En este artículo se (...) discute la visión de la teoría de la argumentación como una forma de epistemología aplicada. El punto de partida es la descripción de cuatro perspectivas que se consideran fundadoras de la teoría moderna de la argumentación, para desde allí observar si en ellas hubo un concepto similar o si se dieron las pautas para tomar esa dirección. Luego, se reflexiona en torno a las razones por las que los teóricos posteriores han dado énfasis a esta visión de la teoría de la argumentación. (shrink)

ABSTRACT It is obvious that Arne Naess had his most important philosophical experience, and quite possibly made his most significant achievement, in confrontation with the variety of philosophical scepticism known as Pyrrhonism. Naess maintained, however, that he did not defend scepticism as a philosophical position, and he was concerned to distinguish Pyrrhonism from the inverse form of dogmatism often associated with the term ?scepticism?. Naess was primarily preoccupied with the practical implications of this radical form of scepticism, in which he (...) thought peace of mind and serious inquisitiveness could be combined. In this article, I introduce some central aspects of Naess's Pyrrhonian scepticism, to illustrate how his philosophy may contribute to a relevant form of anti-dogmatism. (shrink)

What sets Naess's deep ecology apart from most inquiries into environmental philosophy is that it does not seek a radical shift in fundamental values. Naess offered a utopian, life-affirming grand narrative, a new Weltanschauung that shifted the focus of inquiry to coupling values, knowledge, understanding, and wisdom to behavior. The core of Naess's approach is that sustainability hinges on developing more thoroughly reasoned and consistent views, policies, and actions, which are tied back to wide-identifying ultimate norms and a rich, well-informed (...) understanding of the state of the planet. But humans can have multiple ultimate norms and these norms sometimes conflict; our neurobiology may not be well-structured for accommodating consequences that are spatially and temporally separated and uncertain; we are governed by bounded rationality; much of human learning results from the passive modeling of unsustainable activities; and our cultures can be maladaptive, creating hurdles and perverse incentives/disincentives that likely demand more than consistent reasoning from wide-identifying ultimate premises. After keenly demonstrating how problem characterization and formulation shape both solution strategies and outcomes, Naess may conceptualize the process of change too narrowly. In the end, deep ecology helps us to shine a brighter searchlight on the gap between our attitudes and our generally unsustainable actions and policies. In doing so it expands the frontier of the unknown, opening more questions. This is its allure, frustration, and promise. (shrink)

ABSTRACT Arne Naess once called himself ?a kind of metaphysician?: did or did he not therewith turn his back on his philosophical mentors in the Vienna Circle? To try to determine the meaning of this self-ascription, this paper first considers in detail two works in which his disagreements with the philosophers of the Vienna Circle found their clearest and most detailed expression. Concentrating on Carnap it will be argued that while some of Naess's criticisms cannot be taken as authoritative, he (...) did indicate a clear dividing line between himself and Carnap. Turning then to Naess's valediction to philosophy of science from 1972, Naess's appreciation of the role of metaphysics for science will be discussed and compared with his appreciation for the role of metaphysics for personal and political life as expressed in his still later ecophilosophy. Once allowance is made for the different needs addressed by his writings for the deep ecology movement and a certain 1960s' rhetoric is discounted as no longer appropriate, it can be seen that Naess's theoretical philosophy exhibited a remarkable continuity throughout. (shrink)

To illustrate the development of argumentation theory, the paper traces the journey of the pragma-dialectical theory as it widened its scope, step by step, from an abstract model of critical discussion to the complexities of actual argumentative discourse. It describes how, having contextualized, empiricalized and formalized their approach, pragma-dialecticians are now putting the theory’s analytical instruments to good use in identifying prototypical argumentative patterns in specific communicative activity types in the various communicative domains. This means that they can now start (...) answering the crucial question about the typical characteristics of their discourse asked by interested lawyers, politicians, academics and other practitioners of argumentation. (shrink)

Mathematicians often speak of conjectures, yet unproved, as probable or well-confirmed by evidence. The Riemann Hypothesis, for example, is widely believed to be almost certainly true. There seems no initial reason to distinguish such probability from the same notion in empirical science. Yet it is hard to see how there could be probabilistic relations between the necessary truths of pure mathematics. The existence of such logical relations, short of certainty, is defended using the theory of logical probability (or objective Bayesianism (...) or non-deductive logic), and some detailed examples of its use in mathematics surveyed. Examples of inductive reasoning in experimental mathematics are given and it is argued that the problem of induction is best appreciated in the mathematical case. (shrink)

An argument that makes use of a generalization activates the prototype for the category used in the generalization. We conducted two experiments that investigated how the activation of the prototype affects the persuasiveness of the argument. The results of the experiments suggest that the features of the prototype overshadow and partly overwrite the actual facts of the case. The case is, to some extent, judged as if it had the features of the prototype instead of the features it actually has. (...) This prototype effect increases the persuasiveness of the argument in situations where the audience finds the judgment more warranted for the prototype than for the actual case, but decreases persuasiveness in situations where the audience finds the judgment less warranted for the prototype than for the actual case. (shrink)

In reply to Gullv g (Inquiry , Vol. 18 [1975]) it is conceded that there are limitations to a pluralistic metaphilosophy. The limits are not, however, specifiable. By increasing a philosophical system's comprehensiveness one decreases its refutability, because the system then begins to incorporate its own rules of refutation and other concepts required for assessing validity, but there are no definite limits to comprehensiveness. By increasing a system's comprehensiveness one also diminishes the possibility of comparing that system with others. There (...) is a fairly neutral but vague and imprecise way of expressing oneself metaphilosophically, but such expressions can never attain absolute neutrality. Nevertheless it might be useful to retain as a regulative idea the notion that all comprehensive systems try to embrace the same single reality. (shrink)

According to pragma-dialectical methodology, a party in an argumentative discussion can be assumed to manoeuvre strategically between dialectical and rhetorical objectives. One confrontational form of strategic manoeuvring occurs when a critic charges an arguer with advancing a standpoint that has socially harmful consequences. In special situations this form of manoeuvring can be dialectically sound, for example when the standpoint is advanced in a way that damages the dialectical process. The boundary between fallacious and dialectically sound applications of this form of (...) manoeuvring is examined by looking for the manoeuvring’s soundness conditions. (shrink)

When interlocutors start to talk at cross purposes it becomes less likely that they will be able to resolve their differences of opinion. Still, a critic, in the confrontation stage of a discussion, should be given some room of manoeuvre for rephrasing and even for revising the arguer’s position. I will distinguish between licit and illicit applications of this form of strategic manoeuvring by stating three soundness conditions.