Developing the foundations laid in Chap. 2 , this chapter applies the analysis of heresy as intellectual myopia to a dramatic case study: Dante’s depiction of his pilgrim’s encounters with Farinata and Cavalcante. Farinata’s obsession with partisan politics and Cavalcante’s tragic misinterpretation of the pilgrim’s words reveal the ethical dangers of arrogance and despair, both rooted in a failure of interpretive humility. Drawing on Aristotelian and Ciceronian conceptions of magnanimity, the analysis shows how Dante recasts Farinata’s grandeur as a parody of true greatness, exposing a false magnanimity bound to factional pride. Cavalcante’s despair, by contrast, dramatizes the risks of interpretive hubris and the limits of temporal knowledge. Together, these figures embody heresy as an existential refusal to remain open to other perspectives.