The Ius Commune, a Medieval Concept

Abstract

THE IUS GENTIUM IN THE MIDDLE AGES The doctrine of ius gentium was adopted in full by jurists (both civil and canon law writers) and by medieval theologians, although in a radically different context, where the law of nations occupies only a secondary place. The paradigm for the application of the law of nations in the Middle Ages was the law of the sea, employed, for example, at England's High Court of Admiralty, which ruled according to the universal law of the sea based on the lex Rhodia and customs of Oleron. Among civil law writers, intriguing references are found to ius gentium in Accursius' Ordinary Gloss and in the Commentaria of the great Bartolus de Saxoferrato, perhaps the most important jurist of the Middle Ages. Here are two examples. In the gloss “ex hoc bella” on Hermogenian ( Digest 1.5.5), it is noted that the law of nations, if it permits wars, “may lead to injustice” ( inducere iniquum ). In his commentary on Gaius' passage in Digest 1.1.9, the great Bartolus writes that people with jurisdiction may establish their own law. Despite this, the law of nations “must be equally observed by all” ( ab omni genere aequaliter custoditur ). The law of nations is also mentioned in the original sources of the canon law and common law traditions, which will be discussed further in the following. Thus, in the canon law tradition, the Decree of Gratian mentions ius gentium .