“Deductivism” is a broad label for various theories that emphasize the importance of deductive argument in contexts of rational discussion. This paper makes a case for a very specific form of deductivism. The paper highlights the dialectical importance of advancing deductively valid arguments in natural-language reasoning. Sections 2 and 3 explain the various forms that deductivism has taken. Section 4 makes a case for a particular form of deductivism. Section 5 discusses the value of deductive argument in law. Section 6 (...) concludes and acknowledges critical questions that need to be addressed more fully in future work. (shrink)

This article examines the role of normative hierarchies in constitutional argumentation. A threefold distinction between formal, material, and axiological hierarchy is employed. The correlative concepts of formal validity, material validity, and applicability are also briefly described. Within this framework, four cases are analysed: Decisions 1146/1988 and 10/2010 of the Italian Constitutional Court, and Kadi I and Opinion 2/2013 of the Court of Justice of the European Union. As a result, it is argued that axiological hierarchies are frequently used to reshape (...) certain fundamental legal arrangements, namely, the hierarchy of sources (Decision 1146/1988 and Kadi), competence clauses (Decision 10/2010), and interpretive methodologies (Opinion 2/13). (shrink)

The Toulmin diagram layout is very familiar and widely used, particularly in the teaching of critical thinking skills. The conventional box-and-arrow diagram is equally familiar and widespread. Translation between the two throws up a number of interesting challenges. Some of these challenges (such as the relationship between Toulmin warrants and their counterparts in traditional diagrams) represent slightly different ways of looking at old and deep theoretical questions. Others (such as how to allow Toulmin diagrams to be recursive) are diagrammatic versions (...) of questions that have already been addressed in artificial intelligence models of argument. But there are further questions (such as the relationships between refutations, rebuttals and undercutters, and the roles of multiple warrants) that are posed as a specific result of examining the diagram inter-translation problem. These three classes of problems are discussed. To the first class are addressed solutions based on engineering pragmatism; to the second class, are addressed solutions drawn from the appropriate literature; and to the third class, fuller exploration is offered justifying the approaches taken in developing solutions that offer both pragmatic utility and theoretical interest. Finally, these solutions are explored briefly in the context of the Araucaria system, showing the ways in which analysts can tackle arguments either using one diagrammatic style or another, or even a combination of the two. (shrink)

The Argument Web is maturing as both a platform built upon a synthesis of many contemporary theories of argumentation in philosophy and also as an ecosystem in which various applications and application components are contributed by different research groups around the world. It already hosts the largest publicly accessible corpora of argumentation and has the largest number of interoperable and cross compatible tools for the analysis, navigation and evaluation of arguments across a broad range of domains, languages and activity types. (...) Such interoperability is key in allowing innovative combinations of tool and data reuse that can further catalyse the development of the field of computational argumentation. The aim of this paper is to summarise the key foundations, the recent advances and the goals of the Argument Web, with a particular focus on demonstrating the relevance to, and roots in, philosophical argumentation theory. (shrink)

In this paper, I respond to papers on my Manifest Rationality (2000) by Leo Groarke, Hans Hansen, David Hitchcock, and Christopher Tindale presented at the meetings of the Ontario Philosophical Society, October 2000. From the many useful challenges they have directed at my position, I have chosen to focus on two. The dominant issue raised by their papers concerns my definition of argument, and particularly problems with the idea of a dialectical tier. I have selected that as the first strand. (...) Second, several have raised questions that deal with the relationship between logic, rhetoric and dialectic. That is the second strand. (shrink)

A large body of research in cognitive science differentiates human reasoning into two types: fast, intuitive, and emotional “System 1” thinking, and slower, more reflective “System 2” reasoning. According to this research, human reasoning is by default fast and intuitive, but that means that it is prone to error and biases that cloud our judgments and decision making. To improve the quality of reasoning, critical thinking education should develop strategies to slow it down and to become more reflective. The goal (...) of such education should be to enable and motivate students to identify weaknesses, gaps, biases, and limiting perspectives in their own reasoning and to correct them. This contribution discusses how this goal could be achieved with regard to reasoning that involves the construction of arguments; or more precisely: how computer-supported argument visualization tools could be designed that support reflection on the quality of arguments and their improvement. Three types of CSAV approaches are distinguished that focus on reflection and self-correcting reasoning. The first one is to trigger reflection by confronting the user with specific questions that direct attention to critical points. The second approach uses templates that, on the one hand, provide a particular structure to reason about an issue by means of arguments and, on the other, include prompts to enter specific items. And a third approach is realized in specifically designed user guidance that attempts to trigger reflection and self-correction. These types of approaches are currently realized only in very few CSAV tools. In order to inform the future development of what I call reflection tools, this article discusses the potential and limitations of these types and tools with regard to five explanations of the observation that students hardly ever engage in substantial revisions of what they wrote: a lack of strategies how to do it; cognitive overload; certain epistemic beliefs; myside bias; and over-confidence in the quality of one’s own reasoning. The question is: To what degree can each of the CSAV approaches and tools address these five potential obstacles to reflection and self-correction? (shrink)

This paper responds to two aspects of Ralph Johnson's Manifest Rationality (2000). The first is his critique of deductivism. The second is his failure to make room for some species of argument (e.g., visual and kisceral arguments) proposed by recent commentators. In the first case, Johnson holds that argumentation theorists have adopted a notion of argument which is too narrow. In the second, that they have adopted one which is too broad. I discuss the case Johnson makes for both claims, (...) and possible objections to his analysis. (shrink)

We argue that Hilary Putnam's pragmatism provides an epistemological perspective which can help us understand--and can positively inform--the development of informal logic.

Argument evaluation, one of the central problems in argumentation theory, consists in studying what makes an argument a good one. This paper proposes a formal approach to argument evaluation from the perspective of justification logic. We adopt a multi-agent setting, accepting the intuitive idea that arguments are always evaluated by someone. Two general restrictions are imposed on our analysis: non-deductive arguments are left out and the goal of argument evaluation is fixed: supporting a given proposition. Methodologically, our approach uses several (...) existing tools borrowed from justification logic, awareness logic, doxastic logic and logics for belief dependence. We start by introducing a basic logic for argument evaluation, where a list of argumentative and doxastic notions can be expressed. Later on, we discuss how to capture the mentioned form of argument evaluation by defining a preference operator in the object language. The intuitive picture behind this definition is that, when assessing a couple of arguments, the agent puts them to a test consisting of several criteria. As a result of this process, a preference relation among the evaluated arguments is established by the agent. After showing that this operator suffers a special form of logical omniscience, called preferential omniscience, we discuss how to define an explicit version of it, more suitable to deal with non-ideal agents. The present work exploits the formal notion of awareness in order to model several informal phenomena: awareness of sentences, availability of arguments and communication between agents and external sources. We discuss several extensions of the basic logic and offer completeness and decidability results for all of them. (shrink)

a recent paper, Fábio Perin Shecaira proposes a defence of Waller’s deductivist schema for moral analogical argumentation. This defence has several flaws, the most important of them being that many good analogical arguments would be deemed bad or deficient. Additionally, Shecaira misrepresents my alternative account as something in between deductivism and non-deductivism. This paper is both an attempt at solving this misunderstanding and an analysis and criticism of Waller and Shecaira’s forms of deductivism.

The informal logic movement began as an attempt to develop – and teach – an alternative logic which can account for the real life arguing that surrounds us in our daily lives – in newspapers and the popular media, political and social commentary, advertising, and interpersonal exchange. The movement was rooted in research and discussion in Canada and especially at the University of Windsor, and has become a branch of argumentation theory which intersects with related traditions and approaches (notably formal (...) logic, rhetoric and dialectics in the form of pragma-dialectics). In this volume, some of the best known contributors to the movement discuss their views and the reasoning and argument which is informal logic’s subject matter. Many themes and issues are explored in a way that will fuel the continued evolution of the field. Federico Puppo adds an insightful essay which considers the origins and development of informal logic and whether informal logicians are properly described as a “school” of thought. In considering that proposition, Puppo introduces readers to a diverse range of essays, some of them previously published, others written specifically for this volume. (shrink)

What is an inference and when is an inference deductive rather than inductive, abductive, etc. The goal of this paper is precisely to determine what is that we, humans, do when we engage in deduction, i.e., whether there is something that satisfies both our pre-theoretical intuitions and theoretical presuppositions about deduction, as a cognitive process. The paper is structured in two parts: the first one deals with the issue of what is an inference. There, I will defend the hypothesis that (...) an inference is a causal process where an initial cognitive state causes another in such a way that the causal translation depends essentially on the content of the involved states. In other words, in an inference, a mental state A causes another B, partially because they have the content they have. Based on the conclusion from the first part, I will develop an account of deductive inference in the second part of the article. In order to achieve this, I will start by setting the stage and developing four constraints that an adequate account of deductive inference ought to satisfy. Then, I will present six different hypotheses that one might propose to characterize inferences of this kind. I have divided the proposals in two groups, the first one – which I will call the “logical proposals” – assume that whether an inference is a deduction or not depends exclusively on the content of the mental states involved in the inference, while the second – which I will call the “cognitive proposals” – reject the aforementioned assumption and instead recognize that extra cognitive information is required to determine whether an inference is a deduction or not. I will evaluate each proposal in turn, according to whether they satisfy the constraints introduced at the beginning of this second part. As a result of such evaluation, I will conclude that only one of the cognitive proposals actually satisfies the four constraints and therefore should be considered to give an adequate characterization of deductive inference. (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.

In The Uses of Argument, Stephen Toulmin proposed a model for the layout of arguments: claim, data, warrant, qualifier, rebuttal, backing. Since then, Toulmin’s model has been appropriated, adapted and extended by researchers in speech communications, philosophy and artificial intelligence. This book assembles the best contemporary reflection in these fields, extending or challenging Toulmin’s ideas in ways that make fresh contributions to the theory of analysing and evaluating arguments.

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)

Christian Kock’s essays show the essential interconnectedness of practical reasoning, rhetoric and deliberative democracy. They constitute a unique contribution to argumentation theory that draws on – and criticizes – the work of philosophers, rhetoricians, political scientists and other argumentation theorists. It puts rhetoric in the service of modern democracies by drawing attention to the obligations of politicians to articulate arguments and objections that citizens can weigh against each other in their deliberations about possible courses of action.

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)

Cogency is the central normative concept of informal logic. But it is a loose evaluative concept and I argue that a generic notion covering all of the qualities of a well-reasoned argument is the most plausible conception. It is best captured by the standard RSA criterion: in a good argument acceptable (A) and relevant (R) premises provide sufficient (S) grounds for the conclusion. Logical qualities in a broad sense are affected by the epistemic qualities of the premises and “consequence” in (...) a broad sense exhibits an interplay of form and content. There are four proposals for the premise—conclusion relation: (i) no strictly logical connection (“non-logical” consequence); (ii) one type of connection only (deductivism); (iii) a few types of connection (deduction, induction, perhaps conduction and analogical reasoning); (iv) many types of connection (argumentation schemes). Deductivism is a serious option but in its strong version, as the discussion about petitio shows, it fails to establish that arguments which are not cogent are thereby invalid. And weak deductivism, very attractive from the pedagogical point of view, has some deficiencies (implausible hidden premises; preservation of truth, not probability). I argue that the idea of a counterexample, when we regard certain components of the argument as fixed and others as variable, is the best approach to the analysis of the illative core of every-day arguments (the approach of David Hitchcock on material consequence). (shrink)

Informal logic is an attempt to develop a logic that can assess and analyze the arguments that occur in natural language discourse. Discussions in the field may address instances of scientific, legal, and other technical forms of reasoning, but the overriding aim has been a comprehensive account of argument that can explain and evaluate the arguments found in discussion, debate and disagreement as they manifest themselves in daily life — in social and political commentary; in news reports and editorials in (...) the mass media ; in advertising and corporate and governmental communications; and in personal exchange. (shrink)

This presentation seeks to understand informal logic as a set of methods for the logical evaluation of natural language arguments. Some of the methods identified are the fallacies method, deductivism, warrantism and argument schemes. A framework for comparing the adequacy of the methods is outlined consisting of the following categories: learner- and user-efficiency, subjective and objective reliability, and scope. Within this framework, it is also possible to compare informal and formal logic.

The Toulmin diagram layout is very familiar and widely used, particularly in the teaching of critical thinking skills. The conventional box-and-arrow diagram is equally familiar and widespread. Translation between the two throws up a number of interesting challenges. Some of these challenges represent slightly different ways of looking at old and deep theoretical questions. Others are diagrammatic versions of questions that have already been addressed in artificial intelligence models of argument. But there are further questions that are posed as a (...) specific result of examining the diagram inter-translation problem. These three classes of problems are discussed. To the first class are addressed solutions based on engineering pragmatism; to the second class are addressed solutions drawn from the appropriate literature; and to the third class, fuller exploration is offered justifying the approaches taken in developing solutions that offer both pragmatic utility and theoretical interest. Finally, these solutions are explored briefly in the context of the Araucaria system, showing the ways in which analysts can tackle arguments either using one diagrammatic style or another, or even a combination of the two. (shrink)

Both 'persuasion' and 'rational convincing' play a major role in argumentative discourse but only the latter is said to constitute argument and be amenable to traditional logical analysis. I argue against this assumption by showing that there are many paradigmatic instances of persuasion which are best understood as implicit arguments. So understood, acts of persuasion can conform to well recognized argument schemata and are best assessed accordingly. I shall argue that the attempt to distinguish arg ument and persuasion is fraught (...) with difficulties. I contrast my conclusions with those of authors like Gilbert, Johnson, and Johnson and Blair. (shrink)

This paper challenges the idea that purely formal or syntactic concepts can, in general, supply criteria for certifying that the premisses of arguments and inferences support their conclusions. It will maintain that neither deductively valid arguments nor inductively strong arguments can, in general, be identified by their logical form. The paper will attempt to clarify the role that patterns play in appraising arguments. Using argument schemas as an example, it will try to show that the identification of patterns can facilitate (...) appraisal even when those patterns do not supply criter ia of support. (shrink)

The aim of this thesis is to understand and critically evaluate deductivism as a theory of inferential sufficiency in informal logic. I distinguish three different types of deductivism: strong normative deductivism, weak normative deductivism, and reconstructive deductivism. I also discuss some potential justificatory strategies that might be invoked in an attempt to justify strong normative deductivism and reconstructive deductivism. I apply this categorization scheme to develop an interpretation of Leo Groarke's version of reconstructive deductivism. I then evaluate some of the (...) criticisms of deductivism raised in the informal logic literature. I focus in particular on the criticisms of Ralph Johnson and Trudy Govier. I follow up this evaluation by raising some problems for the justificatory strategies used to support deductivism. I also show how these problems apply to Groarke's reconstructive deductivism. (shrink)

Even with Kientpointer's and Walton's valuable work, we do not yet have a complete theory of argument schemes. A complete theory of argument schemes should contain at least the following: its theoretical motivation, the denotation of "argument" or "ar gumentation" used in the theory, an analysis of the concept of an argument scheme, a theory of classification of argument schemes, a solution to the problem of identifying which scheme is correct, and an account of the grounds of the normativity or (...) normat ive argument schemes. The paper will supply these elements, worked out as fully as space permits. (shrink)