In 1980 L. M. de Rijk edited some texts connected with medieval disputation (Die mittelaterlichen Traktate De modo opponendi et respondendi), towards which he showed a strikingly contemptuous attitude. The reason for his contempt was that the treatises did not fit the obligationes and sophismata tradition. In this article I focus on the original version, the Thesaurus Philosophorum, to highlight the distinction of this family of treatises with respect to the “modern” tradition. First, I study the features of the disputation that can be recognised through the collection of fallacious arguments contained in the Thesaurus. Second, I briefly examine the contents of the treatise and their arrangement, showing that they are closely related to the kind of disputation in question. I hope to support the idea that neither the technique of disputation nor the contents and their arrangement deserve a straightforward rejection.