This article argues that Cervantes’s Numancia stages the modern emergence of what Max Horkheimer calls “subjective reason,” focused on the means by which to attain a given goal without ever interrogating the rationality of the goal itself. As represented by the Roman general Scipio, subjective reason entails a disjunctive and exclusionary mentality, for which the triumph (or victory) of the aggressors necessarily implies the fall (or defeat) of their enemies. If, at the outset, the Numantians uphold the Erasmian ideals of social harmony and peaceful co-existence, they subsequently find themselves compelled to assume Scipio’s disjunctive viewpoint, thus transforming their collective suicide into a symbolic triumph. The price of this form of radical heroism is the disintegration of the Numantian community, a process interpreted here according to the distinction drawn by Burke and Kant between the beautiful and the sublime. The article demonstrates that the heroic sublimity of the inhabitants of Numantia forces them to betray their constitutive social values.