This classic remains one of Karl Popper's most wide-ranging and popular works, notable not only for its acute insight into the way scientific knowledge grows, but also for applying those insights to politics and to history.

Short abstract (98 words). Reasoning is generally seen as a means to improve knowledge and make better decisions. However, much evidence shows that reasoning often leads to epistemic distortions and poor decisions. This suggests that the function of reasoning should be rethought. Our hypothesis is that the function of reasoning is argumentative. It is to devise and evaluate arguments intended to persuade. Reasoning so conceived is adaptive given humans’ exceptional dependence on communication and vulnerability to misinformation. A wide range of (...) evidence in the psychology of reasoning and decision making can be reinterpreted and better explained in the light of this hypothesis. (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.

Now in its Eighth Edition, UNDERSTANDING ARGUMENTS: AN INTRODUCTION TO INFORMAL LOGIC, 8th Edition. has proven itself to be an exceptional guide to understanding and constructing arguments in the context of students' academic studies as well as their subsequent professional careers. Its tried and true strengths include multiple approaches to the analysis of arguments; a thorough grounding on the uses of language in everyday discourse; and chapters in the latter half of the book that apply abstract concepts to concrete legal, (...) moral, and scientific issues. Important Notice: Media content referenced within the product description or the product text may not be available in the ebook version. (shrink)

A comprehensive introduction to formal logic, Logic and Philosophy: A Modern Introduction is a rigorous yet accessible text, appropriate for students encountering the subject for the first time. Abundant, carefully crafted exercise sets accompanied by a clear, engaging exposition build to an exploration of sentential logic, first-order predicate logic, the theory of descriptions, identity, relations, set theory, modal logic, and Aristotelian logic. And as its title suggests, Logic and Philosophy is devoted not only to logic but also to the philosophical (...) debates that led to the development of the field. Much new material has been added for the 13th edition. An introduction to set theory and its relationship to logic and mathematics, including philosophical issues, is now part of Chapter 13. Chapter 15 is an introduction to modal logic and Kripke semantics, concluding with a discussion of philosophical problems with any logical accommodation of modalities. Instructors who do not wish to present proof methods will find chapters on truth trees for both sentential and first-order logic, and a presentation of trees for modal logic. Special features of this text include presentations of the history of logic, alternatives to traditional methods of conditional and indirect proof, and a discussion of semantic problems with universal and existential instantiations. Throughout, the authors are sensitive to philosophical issues that arise from the relationship between ordinary language, symbolic logic, and justifications for the syntax and semantics of the various symbolic languages. Discussions range from the justification of the truth table for the sentential rendering of if... then statements to semantic and syntactic paradoxes, including some troubling paradoxes that arise in ordinary language (e.g., the so-called hangman or surprise quiz paradox). Logic and Philosophy includes ample material for a one-semester or two-semester course and provides a thorough preparation for more advanced logic courses. (shrink)

Ostensibly a discussion about love, the debate in the Phaedrus also encompasses the art of rhetoric and how it should be practised. This new edition contains an introductory essay outlining the argument of the dialogue as a whole and Plato's arguments about rhetoric and eros in particular. The Introduction also considers Plato's style and offers an account of the reception of the dialogue from its composition to the twentieth century. A new Greek text of the dialogue is accompanied by a (...) select textual apparatus. The greater part of the book consists of a Commentary, which elucidates the text and makes clear how Plato achieves his philosophical and literary objectives. Primarily intended for advanced undergraduates and graduate students of ancient Greek literature and philosophy, it will also benefit scholars who want an up-to-date account of how to understand the text, argument, style and background of the work. (shrink)

_Conjectures and Refutations_ is one of Karl Popper's most wide-ranging and popular works, notable not only for its acute insight into the way scientific knowledge grows, but also for applying those insights to politics and to history. It provides one of the clearest and most accessible statements of the fundamental idea that guided his work: not only our knowledge, but our aims and our standards, grow through an unending process of trial and error.

An introduction to informal logic, critical thinking and rhetoric utilizing actual public discourse .

The authors contend that most contemporary logic textbooks fail the average student because they emphasize the evaluation of arguments over their clarification, assuming that the student already understands what motivations underlie logic.

Persuasive definitions – those that convey an attitude in the act of naming – are frequently employed in discourse and are a form of strategic maneuvering. The dynamics of persuasive definition are explored through brief case studies and an extended analysis of the use of the “war” metaphor in responding to terrorism after September 11, 2001. Examining persuasive definitions enables us to notice similarities and differences between strategic maneuvering in dialectical and in rhetorical argument, as well as differences between the (...) role of strategic maneuvering in normatively ideal argument and in actually existing argument. This will avoid the double standard of comparing ideal dialectic with actual rhetoric, or vice versa. The results of the analysis suggest possibilities for a rapprochement between dialectical and rhetorical approaches to argumentation. (shrink)

Although political argumentation is not institutionalized in a formal sense, it does have recurrent patterns and characteristics. Its constraints include the absence of time limits, the lack of a clear terminus, heterogeneous audiences, and the assumption that access is open to all. These constraints make creative strategic maneuvering both possible and necessary. Among the common types of strategic maneuvering are changing the subject, modifying the relevant audience, appealing to liberal and conservative presumptions, reframing the argument, using condensation symbols, employing the (...) locus of the irreparable, and argumentative use of figures and tropes. It is difficult to evaluate strategic maneuvering in political argumentation, however, because the activity types dictate wide latitude for the arguers, so there are few cases of unquestionable derailment. (shrink)

This paper criticizes the pragma-dialectical conception of a fallacy, according to which a fallacy is an argumentative speech act which violates one or more of the rules of 'rational discussion'. That conception is found to be neither a necessary nor a sufficient condition for committing a fallacy. It is also found wanting in several other respects.

This investigation uses the technique of the profile of dialogue as a tool for the evaluation of arguments from ignorance (also called lack-of-evidence arguments, negative evidence, ad ignorantiam arguments and ex silentio arguments). Such arguments have traditionally been classified as fallacies by the logic textbooks, but recent research has shown that in many cases they can be used reasonably. A profile of dialogue is a connected sequence of moves and countermoves in a conversational exchange of a type that is goal-directed (...) and can be represented in a normative model of dialogue. Selected case studies are used to probe special features of using the profile technique as applied to arguments from ignorance of a kind that occur frequently in everyday conversational exchanges. One of these special features is the use of Gricean implicature. Another is the need to use negative profiles of argument. (shrink)

This paper presents an analysis of the concept of burden of proof in argument. Relationship of burden of proof to three traditional informal fallacies is considered: (i) argumentum ad hominem, (ii) petitio principii, and (iii) argumentum ad ignorantiam. Other topics discussed include persuasive dialoque, pragmatic reasoning, legal burden of proof, plausible reasoning in regulated disputes, rules of dialogue, and the value of reasoned dialogue.

In this contribution, I will develop a comprehensive tool for the reconstruction and evaluation of argumentation from expert opinion. This is done by analyzing and then combining two dialectical accounts of this type of argumentation. Walton’s account of the ‘appeal to expert opinion’ provides a number of useful, but fairly unsystematic suggestions for critical questions pertaining to argumentation from expert opinion. The pragma-dialectical account of ‘argumentation from authority’ offers a clear and systematic, but fairly general framework for the reconstruction and (...) evaluation of this type of argumentation. The tool is developed by incorporating Walton’s critical questions into a pragma-dialectical framework. (shrink)

This paper describes an approach to legal logic based on the formal analysis of argumentation schemes. Argumentation schemes a notion borrowed from the .eld of argumentation theory - are a kind of generalized rules of inference, in the sense that they express that given certain premises a particular conclusion can be drawn. However, argumentation schemes need not concern strict, abstract, necessarily valid patterns of reasoning, but can be defeasible, concrete and contingently valid, i.e., valid in certain contexts or under certain (...) circumstances. A method is presented to analyze argumentation schemes and it is shown how argumentation schemes can be embedded in a formal model of dialectical argumentation. (shrink)

The main finding of a comprehensive empirical research project on the intersubjective acceptability of the pragma-dialectical discussion rules (Van Eemeren, Garssen & Meuffels, 2009) is that ordinary language users judge discussion moves that are considered fallacious from an argumentation-theoretical perspective as unreasonable. In light of this finding it is remarkable that in everyday argumentative discourse fallacies occur regularly and seem many times not to be noticed by the participants in the discourse. This also goes for the abusive argumentum ad hominem. (...) While abusive ad hominem attacks are judged to be very unreasonable discussion moves when the unreasonableness of clear cases of this fallacy is rated in experiments, in real life this fallacy remains undetected more often than not. In this paper it is argued that this paradox can be explained by analysing abusive ad hominem attacks as a mode of strategic manoeuvring which takes on a reasonable appearance in real life situations when it mimics, as it often does, legitimate critical reactions to authority argumentation. The hypothesis that abusive fallacies are seen as less unreasonable when they are presented as if they are critical questions pertaining to the argument scheme for authority argumentation than when they are clear cases was tested systematically in two experiments. The results of these experiments confirmed the hypothesis. (shrink)

This paper explores the possibilities for strategic maneuvering of the argumentative technique that Perelman and Olbrechts-Tyteca (The New Rhetoric. A Treatise on Argumentation, University of Notre Dame Press, Notre Dame/London, 1969) called dissociation. After an exploration of the general possibilities that dissociation may have for enhancing critical reasonableness and rhetorical effectiveness, the use of dissociation in the successive stages of a critical discussion is examined. For each stage, first, the dialectical moves that dissociation can be employed in are specified, then, (...) the specific ways in which dissociation contributes to fulfilling the dialectical tasks that are associated with these moves are delineated, and, finally, the rhetorical gain that␣dissociation can bring in the fulfillment of these tasks is discussed. Some general conclusions are drawn for research that aims at understanding the potential of an argumentative technique for strategic maneuvering. (shrink)

According to the pragma-dialectical approach to argumentation, for analysing argumentative discourse, a normative reconstruction is required which encompasses four kinds of transformations. It is explained in this paper how speech act conditions can play a part in carrying out such a reconstruction. It is argued that integrating Searlean insights concerning speech acts with Gricean insights concerning conversational maxims can provide us with the necessary tools. For this, the standard theory of speech acts has to be amended in several respects and (...) the conversational maxims have to be translated into speech act conditions. Making use of the rules for communication thus arrived at, and starting from the distribution of speech acts in a critical discussion as specified in the pragma-dialectical model, it is then demonstrated how indirect speech acts are to be transformed when reconstructing argumentative discourse. (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)

In this article it is pointed out what kind of rules for communication and argumentation are required in order to make it possible to resolve disputes in an orderly way. In section 2, Gricean maxims and Searlean speech act conditions are integrated in such a way that five general rules for communication can be formulated. In section 3, starting from Lewis's definition of convention, it is argued that the interactional effect of accepting is conventionally linked with the complex communicative act (...) complex of argumentation. In section 4, the rules for argumentation are placed in a dialogical perspective. (shrink)

The paper reacts against the strict separation between dialectical and rhetorical approaches to argumentation and argues that argumentative discourse can be analyzed and evaluated more adequately if the two are systematically combined. Such an integrated approach makes it possible to show how the opportunities available in each of the dialectical stages of a critical discussion have been used strategically to further the rhetorical aims of the speaker or writer. The approach is illustrated with the help of an analysis of an (...) `advertorial' published by R. J. Reynolds Tobacco Company. (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)

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. 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)

According to the pragma-dialectical ideal of reasonableness, in case of a difference of opinion the protagonist and the antagonist of a standpoint should attempt to find out by means of a critical discussion whether the protagonist's standpoint is capable of withstanding the antagonist's criticism. In this paper, the authors formulate the latest version of their basic rules for the performance of speech acts in the various stages that can beanalytically distinguished in a critical discussion that can lead to the resolution (...) of a single and non-mixed difference opinion. (shrink)

In Return to Reason, Stephen Toulmin argues that the potential for reason to improve our lives has been hampered by a serious imbalance in our pursuit of ...

This paper discusses some of the ways recent models have brought rhetoric into argumentation theory. In particular, it explores the rationale for and role of rhetoric in the strategic maneuvering project of pragma-dialectics and compares it with the author’s own implementation of rhetorical features. A case is made for considering the active ways audiences influence the strategies of arguers and for seeing the role of rhetoric in argumentation as both fundamental and reasonable on its own terms.

Garssen and van Laar in effect concede our main criticism of the pragma-dialectical approach. The criticism is that the conclusions of arguments can be ‘P-D reasonable’ yet patently unreasonable, epistemically speaking. The concession consists in the claim that the theory “remains restricted to the investigation of standpoints in the light of particular sets of starting points” which are “up to individual disputants to create” and the admission that all the relevant terms of normative appraisal have been redefined. We also discuss (...) their criticisms of the epistemic account of argumentation and argument evaluation and raise some new questions about the approach they defend. (shrink)