The main objective of this book is to present the pathways of the National Truth Commission (CNV) in Brazil, as well as the attempt at a social memory that recovers the historical truth of the authoritarian periods that took place in the history of the present time. The initial aim of the book is to show the decision to set up the CNV as an attempt by the state to reconcile with Brazilian society. It then discusses the structure and implementation of the Commission in a democratic government that encouraged investigations into authoritarianism during the period from 1948 to 1988, a period that was the target of research by the CNV committee. Based on documentation available for research, we have shown how the Commission was structured and its tasks for the investigations proposed in the initial project. In order to work more effectively, subcommittees were set up to make it possible to investigate the different parts of the period analysed. From the investigations into the authoritarian periods, the CNV's goal is to build a social and underground memory of all the investigated cases of torture, imprisonment, disappearances and deaths.