Persona, Homo, Res: Building a Boundary in Early Modern European Legal Thought

According to Roman law the same human being, the servus, can be understood as res mancipi or as persona, being part of the different kinds of persons described in Justinian’s Institutiones. But in the third decade of the 18th century, it would be written that »Certissimum ergo iuris axioma est: quicunque nullo statu gaudet, iure Romano non persona, sed res habetur« (Heinecke). How and why did this distinction become so precise, and the boundary between the two concepts so impassable? Underlying this distinction is the joint action of two phenomena: serfdom and slavery in the modern age. Serfs and slaves define the concept of person because they constitute its boundary: on one side of the boundary there are persons, on the other res. Indeed, slavery and serfdom are at the basis of the legal concept of persona, which was transmitted from the ancient regime to 19th-century legal thinking. Comparing the many possible legal conditions between persona and res, legal thought established a moving boundary, located within individuals, making them sometimes the subject, sometimes the object of legal relationships. The mobility of this boundary, its uncertainty, its susceptibility to being the subject of continuous gradations, would be passed down to the concept of legal capacity.