Manca Erzetič takes Heidegger’s set of existence, facticity and decay as a model for establishing the testimonial set of eyewitness-witness-testimony. The relevance of considering the phenomenon of witnessing is shown once again, on the one hand, in the author’s confrontation with the most hermeneutically refined consideration of witnessing by the French philosopher Paul Ricoeur, and on the other hand, in the encounter with Agamben’s discovery of the meaning of witnessing in the historical situation of the 20th century, as marked by totalitarian violence . The case studies that Manca Erzetič considers in the work itself point to anthropological, sociological, political, cultural and media influences that determined the witnesses of the 20th century, and at the same time remain relevant in the 21st century.