Leo Groarke

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

In the last quarter-century, the emergence of argumentation theory has spurred the development of an extensive literature on the study of argument. It encompasses empirical and theoretical investigations that often have their roots in the different traditions that have studied argument since ancient times – most notably, logic, rhetoric, and dialectics. Against this background, I advocate a “thick” theory of argument that merges traditional theories, weaving together their sometimes discordant approaches to provide an overarching framework for the assessment of arguments in a broad range of contexts. In sketching such a theory, I propose six steps that can “thicken” traditional approaches to argument in the interests of a comprehensive theory.