Historia de la atribución de categorías o predicamentos a "derecho" ("ius")

in the history of juridical thinking, laws (iura) have been considered under different categories or predicaments: as entities, as faculties or legal authority, as relations; and they have to belong to one of them, but only to one, because nothing can be ascribed to two categories or more. the study examines the several points of view regarding this matter in ancient rome, the middle ages and the early modern period by the authors.