The purpose of this paper is to analyze the structure and the defeasibility conditions of argument from analogy, addressing the issues of determining the nature of the comparison underlying the analogy and the types of inferences justifying the conclusion. In the dialectical tradition, different forms of similarity were distinguished and related to the possible inferences that can be drawn from them. The kinds of similarity can be divided into four categories, depending on whether they represent fundamental semantic features of the (...) terms of the comparison or non-semantic ones, indicating possible characteristics of the referents. Such distinct types of similarity characterize different kinds of analogical arguments, all based on a similar general structure, in which a common genus is abstracted. Depending on the nature of the abstracted common feature, different rules of inference will apply, guaranteeing the attribution of the analogical predicate to the genus and to the primary subject. This analysis of similarity and the relationship thereof with the rules of inference allows a deeper investigation of the defeasibility conditions. (shrink)

In the present article I attribute to the common topic in the Rhetoric a two-fold suggestive function and a guarantee function. These three functions are possible because this type of topic, while often quite abstract, nevertheless contains thought-steering, substantial terms, and formulates a generally empirical or normative endoxon. Assuming that according to Aristotle an enthymeme has at least two premises, it would appear that a common topic is the abstract principle behind the often implicit major premise. This means that the (...) topic may be regarded as the – generalizing – if-then statement in a modern argumentation scheme. Therefore it should be possible to see the enthymemes of Rhetoric 2.23 as a combination of a logical argument form (which can usually be reconstructed as modus ponens) and an argumentation scheme – even though we may not attribute this idea to Aristotle himself. (shrink)

This paper aims to single out and to highlight the fundamental tenets of Agricola’s De inuentione dialectica. After the structure of the volume, its theoretical perspective and its educational concern are illustrated, Agricola’s understanding of the fundamental notion of locus is expounded. In this relation his particular use of the medieval term habitudo and the exclusion of maxims, which had been the main concern of the Medieval doctrine of loci, show a certain distance from the Medieval tradition. Several innovative and (...) constructive contributions of Agricola’s work are stressed, in particular the elaboration of a new taxonomy of loci and the discovery of the relevant role played by loci not only in argumentation but also in exposition and in explanation. In this way, loci acquire the status of intentiones secundae, i.e. of meta-categorical concepts which govern the connections ensuring textual congruity. A reading of this text in the light of contemporary argumentation theory reveals a surprising topicality and richness of concrete contributions in some dialectical and rhetorical domains, like argument schemes, topical potential, and presentational techniques. (shrink)