Introduction

After the “invention” of formal logic, in particular deductive syllogism, of demonstrative value, for the purpose of theoretical (scientific) reasoning in the Prior Analytics, Aristotle devoted his study to practical reasoning or argumentation (in the Topics and On Sophistical Refutations), where he discussed dialectic. ¹ Finally, in Rhetoric, he introduced the idea, arguing that: “Rhetoric is a counterpart of dialectic.” While (formal) logic was important for discussing arguments in their static capacity of the premises and their inferential relationship establishing truth, dialectic introduced their (i) dynamic or procedural aspect through the exchange of views by two opposing sides in a dialogue; as well as (ii) logic that is not formal but presumptive and defeasible, establishing a probability of the premises. Finally, what rhetoric in the Classical tradition brought to the argumentative situation was the role of the audience to be persuaded by orators, not only by the means of logos but also ethos (the arguer’s credibility) and pathos (the audience’s sentiments), thereby joining logic and psychology (Frost 2005) into one package.