This article was originally published in 1981. It addresses ethical and methodological questions involved in fieldwork among people from the anthropologist’s own society, but from a subaltern social group. It asks: What does legitimate the scientific methods of investigating other people’s lives, making them appear as acceptable instead of as object of resistance? It uses Foucault’s analysis of social sciences’ regimes of power-truth to understand what frames different methodologies of research and the author’s practices. It considers that field research is structured in the context of a certain regime of production of scientific knowledge that legitimates relationships of power in which one asks to know everything and the others feel obliged to tell the truth that, however, only the questioner will be able to reveal. The article argues that what is presented as truth either in interviews or in the text of the analyst is the product of a certain relationship shaped by power imbalances and social inequality. Moreover, it suggests that the field relationship is productive: What is said did not exist before ready to be revealed, but was constructed in this uneven relationship. Therefore, the interpretation of field data must always consider the conditions of its production.