John Anthony Blair

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 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

In Logical Self-Defense , Johnson and I introduced the criteria of acceptability, relevance and sufficiency as appropriate for the evaluation of arguments in the sense of reasons offered in support of a claim. These three criteria have been widely adopted, but each has been subjected to a number of criticisms; and also 30 years of research have intervened. How do these criteria stand up today? In this paper I argue that they still have a place in argument analysis and evaluation, but in much-modified roles

Informal logic began in the 1970s as a critique of then-current theoretical assumptions in the teaching of argument analysis and evaluation in philosophy departments in the U.S. and Canada. The last 35 years have seen significant developments in informal logic and critical thinking theory. The paper is a pilot study of the influence of these advances in theory on what is taught in courses on argument analysis and critical thinking in U.S. and Canadian philosophy departments. Its finding, provisional and much-qualified, is that the theoretical developments and refinements have had limited impact on instruction in leading philosophy departments

Do not define argument by its use to persuade. for other uses of arguments exist. An argument is a proposition and a reason for it. and argumentation is an interchange involving two or more parties resulting in the assertion of one or more arguments coupled with anticipated or actual critical responses. A logically good argument has grounds adeq uate for the purposes at hand (true, probable, plausible, acceptable to the audience) and the grounds provide adequate support for the conclusion. The norms for good logic in arguments are different from the norms for the good use of arguments

In Jonathan Adler argued that conductive arguments, as they are commonly characterized, are impossible—that no such argument can exist. This striking contention threatens to undermine a topic of argumentation theory originated by Trudy Govier based on Carl Wellman and revisited by the papers in “Conductive argument, An overlooked type of defeasible reasoning”. I here argue that Adler’s dismissal of conductive arguments relies on a misreading of the term ‘non-conclusive’ used in the characterization of this type of reasoning and argument, and that as a result, his refutation fails. However, Adler’s critique raises other questions about conductive arguments that have to be answered.

The question, “What norms are appropriate for the evaluation of the probative merits of visual arguments?” underlies the investigation of this paper. The notions of argument and of multimodal visual argument employed in the study are explained. Then four multimodal visual arguments are analyzed and their probative merits assessed. It turns out to be possible to judge these qualities using the same criteria that apply to verbally expressed arguments. Since the sample is small and not claimed to be representative, this finding can at best be regarded as suggestive for the probative assessment of multimodal visual arguments in general