This article analyses the place of literature in a “system of truth,” relating to specific periods, and much more conflictual than what is assumed by the assertion that there would be some “knowledge of literature.” A detour through writings of the seventeenth century – the moment of the institutionalization of literature – provides a better understanding of its historicity, by asking why, how and for what purposes a writing then presents itself as literature. It thus highlights the importance of historiographical actions that make literature a place for writing history, and of a highly conflictual history, wether the history of the origins of Catholicism (Honoré d’Urfé in L’Astrée) or the history of the Fronde (Vie du Cardinal de Retz). This approach is reinvested in a completely different « system of truth » – our own system of truth –, through the recent example of the Karski case (2009). I try to question what, in this novel, has affected the historians’ procedures for establishing the truth, including the erection of the witness as a sanctuary of historical truth.