To judge a ruling of the praetor : the relationship between law and fact in the passage of Paul (D 1,1,11) and in the case of Barbarius Philippus (D. 1,14,3)

Bibliogr. w przypisach.

The experience of Roman law makes it possible for us to understand better that the positivistic separation between «is» and «ought» is not the only proper model of law. Indeed, that model does not offer the flexibility that is desired in private law. It is interesting to use Roman law as a comparative perspective, not only in the case of the typical institutions of modern private law, but also in the case of the theory of law, and especially for legal science. In particular, for centuries Roman law served as the basis for jurisprudence and the philosophy of law. Now it can enrich the analysis of the distinction between «ought» and «is». This distinction does not involve a separation, but a division; it seems to highlight a different kind of problem —the problem of the criteria of law, and not the problem of the nature of normativity—. The legal perspective might be extended by focusing on the analysis of two passages from the first book of Justinian’s Digest, the passage of Paulus and the passage of Ulpianus that contains the case of Barbarius Philippus. In the first of these passages Paulus wrote about the four senses of ius (D. 1,1,11). In today’s literature this passage is considered in the context of the Kantian notions of Sein and Sollen. The only place in the Digest where these two concepts, ius and factum, are found connected is in the formulation ignorantia iuris et factis. This expression, however, does not suggest the idea that stands behind the modern separation between «ought»” and «is». Paulus’s distinction seems to be more useful: fecit and facere convenit. It can be analyzed in the context of the case in which a judge is responsible for the abuse of power or has admitted incorrectly actioni, interdicto, etc. In this light it is interesting to consider the famous case of Barbarius Philippus (D. 1,14,3) about whether decisions made by someone lacking the capacity to be a praetor —acting as a false official— could be effective law: what and which values might allow one to reach this conclusion. When Paulus wrote ius pluribus modis dicitur he did not invoke the sources of positive law. He was interested in determining where ius comes from: when can a legal decision, a statute, or anything that is considereded to be a law truly be called ius?