Ian Albornoz Tomas

This paper examines the nature of deep disagreements in philosophy, taking the debate between determinism and free will as a paradigmatic case study. Drawing on Robert Fogelin's framework, deep disagreements are characterized as disputes that arise when interlocutors lack a shared background of commitments and preferences, clashing instead over fundamental structural propositions. While conventional argumentative exchanges rely on common ground to produce and evaluate justifying reasons, deep disagreements undermine the necessary conditions for rational persuasion. By exploring how the determinist framework (rooted in strict causality and physical laws) and the defense of free will (premised on autonomous agency and moral responsibility) rest on mutually incompatible underlying principles, this study demonstrates why traditional argumentation fails to resolve such conflicts, shedding light on the structural limits of rational consensus in philosophical inquiry.