This article is concerned with the concept of ambiguity in argumentation. Ambiguity in linguistics lies on the coexistence of two possibly interpretations of an utterance, while the role of contextual factors and background/encyclopedic knowledge within a specific society seems to be crucial. From a systemic point of view, Halliday has proposed three main language functions (meta-functions): a) ideational function, b) interpersonal function, c) textual function. Language could reflect speaker’s experience of his external and internal world, interpersonal relationships and organization of (...) text, respectively. Lexico-grammatical choices under a micro-level perspective and context (the environment of language) may lead to inconsistent interpretations through semantic or syntactic ambiguities. In philosophy and argumentation logic, strategies of ambiguity have been investigated by Aristotle, since the first sophistic movement. In his Topics, Metaphysics and Rhetoric, has pointed out the notion of “τὸ διττῶς / διχῶς λεγόμενον”, meaning that a term can have different senses and double interpretation. In this paper we discuss how we reconstruct the meaning of an utterance in dialogue through the mechanism of interpretation and how we analyze and construe ambiguities, combining the insights of argumentation theory and text linguistics. Research results show that in case of misunderstanding, the “best interpretation” is the less defeasible one according to contextual presumptions. (shrink)

Just as Aristotelian dialectic sharply distinguishes between real and fallacious arguments, Aristotelian rhetoric distinguishes between real and fallacious enthymemes. For this reason Aristotle’s Rhetoric includes a chapter – chapter II.24 – that is exclusively devoted to what Aristotle calls “topoi” of fallacious enthymemes. Thus, the purpose of this chapter seems to be equivalent to the purpose of the treatise Sophistici Elenchi, which attempts to give a complete list of all possible types of fallacious arguments. It turns out that, although the (...) Rhetoric’s list of fallacious types of rhetorical arguments basically resembles the list from the Sophistici Elenchi, there also are some striking differences. The paper tries to account for the relation between these two, more or less independent, Aristotelian approaches to the phenomenon of fallacious arguments. Can one of these two lists be seen as the basic or original one? And what is the point in deviating from this basic list? Are all deviations occasioned by the specific contexts of the rhetorical use on the one hand, and the dialectical on the other? Or do the two lists display different logical assumptions? Even an only tentative answer to this set of questions will help to clarify another but closely related scholarly problem, namely the relation between the Rhetoric’s list of topoi for real enthymemes and the Topics’ list of topoi for real dialectical arguments. It will also help to account for the general place of fallacious arguments within Aristotle’s dialectic-based approach the rhetoric. (shrink)