This article offers an approach to the general structure of the rhetoric in economy. In our case we adopted a perspective to study a particular aspect of the rhetoric that comes from the context of a particular controversy: the controversy on the advantages of the free commerce between Daly and Bhagwati. It is sustained that the positions in economy present with relative frequency interest conflicts that are revealed in the dialectic one of the arguments. A proponent in open defense of the free commerce is not released of presumptions reflected in the field of the rhetoric. Reason why to include the language dimensions of the argumentation in economy has advantages for the field of the explanation and the epistemology in the social sciences.