Abstract

The article focuses on the new rhetoric category of quasi-logical arguments, defined as arguments similar to logical or mathematical demonstrations, and therefore having an effect on the audience. Connecting the similarity of arguments to formal demonstrations with the claim of effect on audience is conceived in this article as the thesis of effectiveness of quasi-logical arguments. The components of the thesis are reconstructed and analyzed, and their precise definitions are proposed. The analysis shows that the category of quasi-logical arguments is ambiguously defined and currently includes three different concepts based on a different understanding of similarity. Subsequently, it is showed that based on Perelman and Olbrechts-Tyteca’s works, the explanation of quasi-logical arguments’ effect on an audience can be offered in terms of socially shared standards of community or in terms of individual processing of arguments. It is shown that these explanations can be in conflict each other regarding the assumption of the addressee’s acquaintance with formal principles.