In this chapter, I am interested in the notion of natural person and the way people orient to it in the judicial context of law in action. The notion of natural or physical person, which is closely associated with the concept of mental capacity and incapacity, is organized as an artefact with a moral and normative character, resulting from its association with a “natural order” of things. By observing the contextualized usages of a category like that of the person, it is possible to describe the deployment of mechanisms through which nature becomes a normative referent, by virtue of appearing to impose itself objectively.