This book is not a collection of new historical materials on Auschwitz, but a commentary on the testimonies. It makes an independent and fundamental attempt to clarify the meaning and possibility of testimony in general. Agamben takes a stance against the topos of the unspeakability of the camp. At the same time, he raises the question of the witness's authority: How can the survivors speak for the lost? How can they report on an experience they have not fully lived through to the core and to the last? In doing so, Agamben engages with authors and intellectuals who themselves experienced the camp or Nazi persecution (Levi, Antelme, Bettelheim, Arendt) and theoretically connects to Benveniste's theory of language as well as Foucault's concept of biopolitics, which is already central in Homo sacer I.