The article discusses the contributions of anthropology to the interdisciplinary dialogues on the scientific status of knowledge and on the relationship between the sciences. It attributes to the discipline a privileged position, founded on the distinctive character of ethnography: the development of a scientific discourse on humankind based on a personal experience. The intense involvements of the ethnographers in the research process and in the relations with their interlocutors - as well as the relativizing and cross-cultural disciplinary outlook - question the neutrality that other sciences idealize or can more easily take for granted and challenge the ideals of objectivity. The paper intends to contribute to the epistemological debate and to the understanding of the social role of science. It proposes the notion of objectivation (i.e. the study of the condition of the constitutions of scientific objects) to think the relations among the sciences and to propose a unifying perspective, albeit open, plural and contingent.