The Philosophical Antilogy in the Rhetorical Doctrine of “Decisive Issue” at Cicero

Placed in the ontological realism of the classical age, the rhetorical doctrine of “decisive issue” is an effort to grasp the complexity of reality and to find the true state of the case in a controversial challenge. In a dispute, at first it is necessary to qualify the genre of the case (status causae); then, only after several conflictions the point of issue emerges, and the rhetorician must choose the implicit premises (reputable opinions) and the inferential schemes (loci, topics) in the light of the particular case, that is relevant to the thing in question. A wrong tradition identifies genre of the case and “decisive issue”. Against this reductive approach, Cicero shows that the philosophical character of dialectic antilogy – i.e. the “refutatory completeness” taught by Plato and Aristotle – is necessary also in the judicial rhetoric and not only: I propose to call it “evidentiary insistence”. In the rhetorical domain, the complexity of reality emerges at the moment of identifying the object of the question: dialectical refutations not appropriate to the thing in question are fallacious by accident, according to Aristotle, and the doctrine of “decisive issue” avoids falling into sophistry in the field of civic discourse. This is one of many philosophical aspects of the Rhetoric of Hermagoras, and later of Cicero and of the Anonymous commentator on Hermogenes, rejected by Quintilian (I. O., 3.11.20; 24).