Alienation (Vefremdung) as a dramaturgical device has come to be inextricably linked with the name of German twentieth-century playwright and theorist, Bertolt Brecht - with the context of Modernism, the Avant garde, and Marxist Theory. As a sociological and aesthetic notion avant la letter, it did however already exist in the thought of eighteenth-century French philosopher and writer Denis Diderot. This original study of scholar and theatre director Phoebe von Held destabilises the conventional understanding of alienation through a reading of Le Paradoxe sur le comedien and Le Neveu de Rameau, thereby opening it up to new ways of interpretation and aesthetic practices. If for the Marxist Brecht, alienation constitutes a historical development, for Diderot it is an existential condition. If Brecht uses the alienation-effect to preclude a theatrical experience based on subjectivity, identification and illusion, one can derive from Diderot's reflections an aesthetic of alienation that includes these modes of perception as crucial to the dialogical relation between artist and audience.