In recent decades, trauma has become an organizing principle of western cultures - one of the most powerful frameworks through which individuals make sense of suffering. But what exactly is 'trauma'? And how does it shape social life? This book develops a sociological theory of trauma as both lived experience and cultural category. From the micro-politics of flashbacks to global psychiatric discourses, from the biographical disruptions of violence to the historical legacies of war, it traces how traumatic experiences surface in everyday gestures, spread across interactions, reshape lives and haunt human collectives, to become a generative social process. At the heart of this approach is the concept of the traumatic imagination : a shared disposition to experience the present through the imprint of painful pasts. Brossard explains that this imagination configures how individuals come to live with, through and against their memory, and how societies mourn, cope and control. Ultimately, Trauma in Social Life calls for a renewed task for the social sciences: to treat mental health not merely as a clinical object or a cultural construct, but as a site of political reflexivity and subversion.