The friend, the enemy, the stranger, the refugee or deportee, and the survivor. In singular and provocative fashion, Gregg Lambert’s Philosophy after Friendship introduces us to the key social personae that have populated modern political philosophy. Drawing on the philosophies of Deleuze and Derrida, as well as the work of Indo-European linguist Émile Benveniste, Lambert constructs a genealogy to demonstrate how political thought has been structured by the emergence of such “conceptual personae.” At the center of Philosophy after Friendship is the persona of the friend, together with the idea of friendship, on which the democratic ideals of consensus, fraternity, and equality are based. Lambert argues that the vitality of this conceptual persona, originated by the Greeks, has been exhausted by centuries of war. In fact, we might today be witnessing the overturning of an earlier philosophical idealism that saw friendship as the destination of the political and, in its place, the emergence of a nonphilosophical understanding that has set perpetual war as the ultimate ground from which future thinking of the political must depart. In his Conclusion, Lambert proposes a truly “postwar philosophy” that takes as its first principle the idea of perpetual peace, which would require nothing less than a complete reevaluation of the goals of any future political philosophy, if not the meaning of philosophy itself.