The paper discusses some controversial questions concerning the role of rhetoric within Canto XIII of the ‘Inferno’ in the Divine Comedy . According to the point of view adopted in contemporary Dante studies, the canto’s sumptuous rhetorical orchestration was designed by Dante to create a stylistic portrait of the canto’s main character, the Chancellor of Emperor Frederick II and a distinguished dictatore Pier della Vigna, in whose tragic destiny the poet allegedly saw parallels with his own life. The direct consequence of the theory of “Pier as Dante’s alter ego ” is a widespread tendency to reduce the role of rhetoric in ‘Inferno’ XIII to simple mimesis and to identify ars dictaminis as the canto’s only default model. The author first exposes the weak points of this interpretative approach, then analyses an alternative hypothesis (formulated by D. Higgins) of Cicero’s “De inventione” and the ancient forensic rhetorical tradition as Dante’s primary sources of inspiration. Finally, she gives a few insights on how this last thesis changes our perception of the role of rhetoric in the poem’s poetics.