Despite the weight and authority of his school of origin—the “critical theory” of Adorno and Horkheimer—the philosophy of Jürgen Habermas established itself from the outset as a distinct and independent theoretical undertaking. The young doctoral student from Düsseldorf, working on his dissertation on the “public sphere,” was carving out his own direction in rethinking the relationship with the Enlightenment legacy, with Kant, Hegel, and Marx. That direction required a break with negative thought and with the radical critique of the Enlightenment—in which the Frankfurt masters saw the paradoxical source of calculative reason, of a distorted instrumentalization of human relations, and of the monstrosities of fascism and communism, of Hitler and Stalin.