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.

Current practice in logic increasingly accords recognition to abductive, presumptive or plausible arguments, in addition to deductive and inductive arguments. But there is uncertainty about what these terms exactly mean, what the differences between them are (if any), and how they relate. By examining some analyses ofthese terms and some of the history of the subject (including the views of Peirce and Cameades), this paper sets out considerations leading to a set of definitions, discusses the relationship of these three forms (...) of argument to argumentation schemes and sets out a new argumentation scheme for abductive argument. (shrink)

Douglas Walton has done extensive and valuable work on the concepts of presumption and practical reasoning. However, Walton’s attempt to model practical reasoning as presumptive is misguided. The notions of “inference” and of the burden of proof shifting back and forth between proponent and respondent are misleading and lead to counterintuitive consequences. Because the issue in practical reasoning is a proposal, not a proposition, there are, in the standard case, several perfectly good reasons on both sides simultaneously, which implies that (...) argument appraisal necessarily contains a subjective element—a fact argumentation theory needs to conceptualize. (shrink)

Everyday life reasoning and argumentation is defeasible and uncertain. I present a probability logic framework to rationally reconstruct everyday life reasoning and argumentation. Coherence in the sense of de Finetti is used as the basic rationality norm. I discuss two basic classes of approaches to construct measures of argument strength. The first class imposes a probabilistic relation between the premises and the conclusion. The second class imposes a deductive relation. I argue for the second class, as the first class is (...) problematic if the arguments involve conditionals. I present a measure of argument strength that allows for dealing explicitly with uncertain conditionals in the premise set. (shrink)

Este artículo presenta un análisis comparativo de los modelos de argumentación basados en las nociones de probabilidad subjetiva y de razonamiento plausible. Se hacen explícitos los “parecidos de familia” entre probabilidad y plausibilidad, y se examinan las diferencias en las prescripciones invocadas para la evaluación de tres tipos de falacias informales: apelación a la autoridad, a la popularidad y petición de principio. Se concluye que el razonamiento plausible, como Rescher y Walton lo describen, no proporciona una alternativa sólida a la (...) probabilidad como modelo normativo o descriptivo de la evaluación de argumentos. (shrink)