E. C. W. Krabbe characterizes a metadialogue as a dialogue about a dialogue, which in turn, is characterized as a ground level dialogue. Krabbe raises a number of interesting questions about this distinction, of which the most pressing is whether the difference between ground level and metadialogues can be drawn in a principled and suitably general way. In this note, I develop the idea that something counts as a metadialogue to the extent that it stands to its ground level counterpart (...) in a relation of irrelevance. The irrelevance in question subsumes a triple of subconcepts: strategic relevance, agenda-relevance and irredundancy-relevance. (shrink)

Contemporary theory of argumentation offers many insights about the ways in which, in the context of a public controversy, arguers should ideally present their arguments and criticize those of their opponents. We also know that in practice not all works out according to the ideal patterns: numerous kinds of derailments are an object of study for argumentation theorists. But how about the use of unfairstrategiesvis-à-vis one’s opponents? What if it is not a matter of occasional derailments but of one party’s (...) systematic refusal to take other parties seriously? What if one party continually forgoes any form of critical testing and instead resorts to threats or blackmail? Can this be countered by the tools of reason? Or should one pay one’s opponent back in the same coin? To gain some grasp of these issues, we describe a number of strategies used in the public controversy about induced earthquakes in Groningen. We check whether these strategies arefair,i.e.balanced, transparent,andtolerant.We also investigate the effects of the choice for a particular kind of strategy. It appears that, in circumstances, choosing a fair strategy may be detrimental for resolving the controversy and choosing an unfair one beneficial. Following up ideas from social psychology and political science, we formulate some guidelines for the choice of strategies. At the end, we stress the importance — especially for those whose opinions carry little weight — of having a society in which the knowledge and skills needed for assessing the fairness of strategies are widespread. (shrink)

In all three of its manifestations, —abusive, circumstantial and tu quoque—the role of the ad hominem is to raise a doubt about the opposite party’s casemaking bona-fides.Provided that it is both presumptive and provisional, drawing such a conclusion is not a logical mistake, hence not a fallacy on the traditional conception of it. More remarkable is the role of the ad hominem retort in seeking the reassurance of one’s opponent when, on the face of it, reassurance is precisely what he (...) would seem to be ill-placed to give. Brief concluding remarks are given over to an examination of rival approaches to the ad hominem, especially those in which it is conceived of as a dialectical error. (shrink)

This paper studies general numerical networks with support and attack. Our starting point is argumentation networks with the Caminada labelling of three values 1=in, 0=out and ½=undecided. This is generalised to arbitrary values in [01], which enables us to compare with other numerical networks such as predator?prey ecological networks, flow networks, logical modal networks and more. This new point of view allows us to see the place of argumentation networks in the overall landscape of networks and import and export ideas (...) to and from argumentation networks. We make a special effort to make clear how general concepts in general networks relate to the special case of argumentation networks. We pay special attention to the handling of loops and to the special features of numerical support. We find surprising connections with the Dempster?Shafer rule and with the cross-ratio in projective geometry. This paper is an expansion of our 2005 paper and so we also consider higher level features such as numerical attacks on attacks, and propagation of numerical values.We conclude with a brief view of temporal numerical argumentation and with a detailed comparison with related papers published since 2005. (shrink)

This volume presents mathematical game theory as an interface between logic and philosophy.