An agent-centered, goal-directed, resource-bound logic of human reasoning would do well to note that individual cognitive agency is typified by the comparative scantness of available cognitive resourcess ignorance-preserving character. My principal purpose here is to tie abduction’s scarce-resource adjustment capacity to its ignorance preservation.

Enthymemes are traditionally defined as arguments in which some elements are left unstated. It is an empirical fact that enthymemes are both enormously frequent and appropriately understood in everyday argumentation. Why is it so? We outline an answer that dispenses with the so called "principle of charity", which is the standard notion underlying most works on enthymemes. In contrast, we suggest that a different force drives enthymematic argumentation—namely, parsimony, i.e. the tendency to optimize resource consumption, in light of the agent's (...) goals. On this view, the frequent use of enthymemes does not indicate sub-optimal performance of arguers, requiring appeals to charity for their redemption. On the contrary, it is seen as a highly adaptive argumentation strategy, given the need of everyday reasoners to optimize their cognitive resources. Considerations of parsimony also affect enthymeme reconstruction, i.e. the process by which the interpreter makes sense of the speaker's enthymemes. Far from being driven by any pro-social cooperative instinct, interpretative efforts are aimed at extracting valuable information at reasonable costs from available sources. Thus, there is a tension between parsimony and charity, insofar as the former is a non-social constraint for self-regulation of one's behaviour, whereas the latter implies a pro-social attitude. We will argue that some versions of charity are untenable for enthymeme interpretation, while others are compatible with the view defended here, but still require parsimony to expose the ultimate reasons upon which a presumption of fair treatment in enthymeme reconstruction is founded. (shrink)

This article reviews David Hitchcock’s selected papers, On Reasoning and Argument.

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)

My project is a systematic inquiry into the problem of relevance, which has been identified as an enduring difficulty in, for example, informal logic and information science where it plays a fundamental role in argument and information searches, respectively. My first task involves determining exactly what the problem of relevance is. To achieve that, I collected problem statements from the literature but I also analysed literature on relevance to discover further problems. The key problem that I investigate concerns the question, (...) 'What is relevance?', which I take to concern the meaning and occurrence of relevance. Concerning the semantic question, I suggest that it demarcates a point of time prior to asking it. Subsequently, I identified and evaluated approaches to elucidating the notion of relevance, rejected intuitionism and stipulation as suitable approaches, and selected philosopher/physicist Mario Bunge's approach to scientific philosophy and his conceptual system to frame my study. I also assess potential information sources; rejected constructed examples that prove to be contrived or are used to illustrate a stipulated definition; and selected dictionary definitions, actual statements, and carefully constructed examples as information sources to complement my review of the literature on relevance. To elucidate relevance, I traced the concept back to its Greek roots, analysed statements, and concluded that the term 'relevance' since its inception in Scottish law in the early 1500's has been limited largely to relations of significance. Understanding relevance in terms of both connection and significance is crucial to construct, identify, or evaluate relevance statements and thereby develop a representative theory of relevance. It also provides a solution to many controversies such as degree of relevance and it helps elucidate notions such as strength and sufficiency of an argument. I suggest that as significance can vary in degree, so too can relevance but a connection between objects is presupposed in both cases. Strength is a measure of significance and sufficiency is the strength required to establish a conclusion. Finally, I offer a provisional and partial theory of relevance where I summarize my prior analyses and integrate/comment on published positions on relevance. (shrink)

I characterize the deductivist ideal of justification and, following to a great extent Toulmin’s work The Uses of Argument, I try to explain why this ideal is erroneous. Then I offer an alternative model of justification capable of making our claims to knowledge about substantial matters sound and reasonable. This model of justification will be based on a conception of justification as the result of good argumentation, and on a model of argumentation which is a pragmatic linguistic reconstruction of Toulmin’s (...) model of argument. (shrink)