This book is a theoretical essay that lays a few foundations on which to build an anthropology directly focusing on human units. In the first chapter, the author will attempt to show that the evolutionary specificity of humans constitutes an argument in favour of this perspective. The consciousness of existing in time and nuanced modalities of presence call for a detailed observation of humans. The second chapter is a critique of the abundant use of the notion of relations in social anthropology. It invites for the observation of individuals through successions of moments and situations. The third chapter concerns nonhumans, another major theme of contemporary anthropology. About this point, the author sees a certain debasement of the notion of existence and proposes a realist ontology, considering what does and does not exist, from the examples of divinities, animals and collective institutions.