Since true marriage is the primary legal relationship, exploring its anthropological nature provides a tool for better understanding the phenomenon of law. John Paul II’s theology of the body is an invaluable source for an adequate anthropology describing the relationship between a man and a woman. The aim of this paper is to analyze some fundamental aspects of the marriage consensus in the light of the premises provided by this anthropology. The conclusions will be used to show the human right to be a subject of law in the perspective of the made separation between the law seen as a thing due (res iusta) and the subjective law (facultas). The meaning of gender difference will be used to show marriage as a paradigmatic system of law.Poniewa...