As defined by Aristotle, rhetoric is faculty of observing in any given case the available means of (Rhetoric I:2 rev. Oxford trans., 1355b:27-28). The inquiry on the means of persuasion is the very purpose of rhetoric since this discipline emerged from the needs of the citizens to win their cases in the new democratic institutions of ancient Greece (Kennedy, 1998, pp. 191-214). The problem, as Perelman and Obrechts-Tyteca (1958) put it, is that the of an is not only uneasy to define (is it a normative or a descriptive concept?) but it also would be difficult to study since it depends both on the aim of the discussion and on the nature of the audience (pp. 610-617). In the introduction of his Theory of Communicative Action, Habermas (1984) uses several times the concept of the of the better argument (e.g., pp. 24, 25, 28, 36, 42). One might therefore expect Habermas's reflection on argumentation to be of great help for rhetoricians. However, as conceived by Habermas (1984), the of the better argument refers not only to a rhetoric-free but also to a that can only exist in the absence of rhetoric. The aim of this paper is to reflect on this incompatibility between rhetoric and argumentation in the Habermasian approach. A CONSTRAINT-FREE FORCE Although Habermas does not clearly define the of the better argument, it is the only he seems to tolerate in his ideal speech situation: Participants in argumentation have to presuppose in general that the structure of their communication, by virtue of features that can be described in purely formal terms, excludes all force-whether it arises from within the process of reaching understanding itself or influences it from the outside-except the of the better (and thus that it also excludes, on their part, all motives except that of a cooperative search for the truth). (Habermas, 1984, p. 25) It seems that the idea of of the better argument relies on a dissociation between a that is acceptable and a that is not. Behind this dissociation lies the long lasting opposition between convincing and persuading, that is, following Perelman & Olbrechts-Tyteca (1958, p. 36), between a that would convince any rational being and a that would only persuade a given audience in a given context. But for the of conviction to exist, the communication should, in Habermas's view, be free from any other kind of forces: The of the better is a constraint-free force (Habermas, 1984, p. 28). This constraint-free force is opposed to another kind of that has to do with rhetorical technic. This appears, in my view, in Habermas's (1970) article Toward a Theory of Communicative Competence. In this article, he stresses the importance of insuring symmetry between the arguers for an ideal speech situation to be optimal: Pure intersubjectivity exists only when there is complete symmetry in the distribution of assertion and dispute, revelation and concealment, prescription and conformity, among the partners of communication. As long as these symmetries exist, communication will not be hindered by constraints arising from its own structure. (Habermas, 1970, p. 371) It seems that some of the unacceptable has to do with the influence an arguer might exercise through his or her authority, that is, his or her ethos, one of the technical proofs of rhetoric. One might therefore define the of the better argument as a that might exist if communication was rhetoric-free (i.e., without of conviction originating from the technic of speech itself). Now that we have an idea of the nature of the acceptable side of the force, I would like to ask what is this of the better argument good for. Indeed, it has sometimes been argued that Habermas's view on argumentation might be counterfactual with the way people actually use argumentation in the public sphere. …