The Late Middle Ages

In his treatise De regimine principum (1277-80), Giles of Rome too discussed ius gentium and its relation to ius naturale. After elaborating on ius naturale and ius civile, Giles points out that â€?jurists' had also come to refer to another concept, that of ius gentium. He draws on Justinian's Institutiones to distin­guish ius naturale, which is common to all animals, from ius gentium, which is part of ius naturale and specifically pertains to man. In his view, however, this notion of ius naturale is still too narrow, so he develops his analysis by intro­ducing another category, that of ius animalium. Indeed, ius naturale, as he un­derstands it, is a threefold concept, which can be broken down according to the kind of â€?inclination' considered. It may be common only to mankind, as exemplified by the inclination to live in society, in which case it is properly called ius gentium. It may be common to all animals, as exemplified by the in­clination to procreate, and in this case it is properly called ius animalium. But in its broadest sense, ius naturale is common to all things (â€?omnia entia') and consists of their desire to preserve their own being?⁴

2.3 The Commentators

The observations of the glossators of the twelfth and early thirteenth centu­ries were collected, selected, and consolidated in the Magna Glossa compiled by Accursius in the 1230s and 1240s. Although numerous, they are scattered and little developed. From the mid-thirteenth century onwards, jurists, freeing themselves from the teaching methods that had been exclusively based on the direct reading of legal texts, adopted a renewed approach based on a greater use of dialectical legal reasoning (especially oppositiones and quaestiones).^{[558] [559] [560] [561]} This new approach had two consequences for the study of ius gentium. First, jurists started to elaborate on the various institutions listed in the passages of Ulpian, Hermogenian, Gaius, and Marcianus, carrying out more in-depth analyses than were possible in short and fragmentary glosses?⁶ An early ex­ample of this is Jacques de Revigny’s repetitio on lex Ex hoc iure (Dig. 1.1.5), in which private ownership, dominium utile, war, slavery, obligations and several contracts are investigated^ Other commentaries can be found dealing with these and other institutions, like marriage, dowry, filiation and self-defense?⁸ The institution of government itself and its attendant instruments were even considered in the frame of ius gentium. Noteworthy in this respect is the rising speculation, caused in part by the lex Omnes populi (Dig. 1.1.9), over the power of different peoples to legislate and thus to create their own bodies of law. Bal- dus de Ubaldis was in fact commenting on this lex and the â€?foundations of king­doms’ mentioned in Dig. 1.1.5 when, in the second half of the fourteenth cen­tury, he legitimated the existence of autonomous city-republics and kingdoms, turning ius gentium - to quote Joseph Canning - into â€?the juristic expression of the this-worldly dimension of human government and society’.^[562] The idea of an historical development of ius gentium was also taken up by several jurists in their endeavour to explain legal changes occurred over time, sometimes with regard to international law institutions. For instance, arguing against the occupation of land and the prescription of fines publici, Henricus de Segusio (Hostiensis, c. 1200-71) wrote that, although at the beginning of the world such occupations were certainly licit under ius gentium, and although they were possibly still licit with regard to the land of infidels, in his days among Chris­tians everybody had to be satisfied with their own boundaries, since it was ut­terly impious and unjust that someone should occupy the territory of others.^[563] Some decades later, discussing the law of captivity and postliminium, Bartolus de Sassoferrato (1313-57) maintained that â€?under the ius gentium introduced by old usages’ the rights to appropriate captured goods, or enslave prisoners, ought to apply between cities that recognised no superior (Florence and Pisa, in his example); nevertheless, he went on to say that â€?in accordance with the usages of modern times, and of a custom long observed among Christians’, the law of captivity and postliminium was no longer observed with regard to per­sons, but only with regard to goods^[564]

The second consequence of the new approach to the study of legal sources was a development of the conceptual analysis of ius naturale and ius gentium already outlined by the glossators. Towards the end of the thirteenth century, the French jurist Pierre de Belleperche dwelt at length on these two concepts in his Lectura Institutionum. He first distinguished ius naturale primaevum, common to all animals in Ulpian’s sense, from ius gentium defined as the �ius naturale that pertains to men’.^{[565] [566] [567] [568] This was by now a common view, expressed by Revigny, or by his pupil Raoul d’Harcourt (Belleperche’s teacher), in the Lectu­ra Institutionum published under the name of Bartolus de Sassoferrato,83 and taken up by Belleperche himself in a repetitio on Dig. 46.1.1.84 jt would also be adopted by Cynus de Pistoia and Albericus de Rosate in their later treatments of obligations ex iure gentium.85 Oldradus de Ponte would also do so in his famous consilium 69 concerning the question as to �whether all kings and princes must de iure be subject to the emperor’.[569] In the course of his discus­sion, Belleperche then drew another distinction between two kinds of ius gen­tium, which, although he did not label them as primaevum and secundarium, roughly correspond to the notions that would subsequently be known by these terms. In fact, he defined ius gentium as the law that was created simultane­ously with mankind, and the use of which is based on natural instinct; but, he added, ius gentium is also the law that men established among themselves, driven by necessity, and that - unlike ius civile - they all observe, whether Jew­ish, Greek or pagan[570] [571] This allowed him to conjoin the two definitions of ius gentium found in Justinian’s Institutiones, and to connect them with the con­cept of ius naturale.}

The distinction between two iura gentium was taken up again in the first half of the fourteenth century by Bartolus de Sassoferrato. In his comment on lex Ex hoc iure (Dig. 1.1.5), Bartolus first cited the distinction between ius natu­rale primaevum, common to all animals, and the ius naturale �that may be called [ius] gentium, and proceeds from natural reason'.88 Then, while dealing with the legal status of slaves, Bartolus went on to note that the concept of ius gentium �consists of two parts, one that proceeds from natural reason, as keep­ing one’s promises [...], another that proceeds from the custom of the various gentes’. If lacking legal status under the latter part, slaves could undertake legal obligations under the former, in this formulation.^{[572] [573] This was reiterated later in the comment on Dig. 12.6.64, again with regard to the legal status of slaves, where Bartolus evoked the notion of a historical development by specifying that ius gentium primaevum (as he called it here) was created along with the gentes by natural reason, whereas the other ius gentium was introduced later by the gentes themselves, and �sometimes against [natural reason],.9°}

The terminology in which this doctrine was eventually expressed appears to have been established by Baldus de Ubaldis (1327-1400), Bartolus' outstanding pupil. In a short passage of his comment on lex Manumissiones (Dig. 1.1.4), he considered the vexed question of whether the manumission of a slave was the revelation and releasing of primordial and natural freedom (which ius gentium had only obscured), or a true gift of freedom (since under iusgentium primordi­al and natural freedom had totally disappeared)^{[574] [575] Baldus argued for the latter option, maintaining that �primum ius gentium has been completely overturned by secundum ius gentium’?2 The old opposition between ius naturale and ius gentium - which Baldus himself had previously adopted in his commentary on Cod. 6.1.1, in which he spoke of a liu[s] natural[e] primae intentionis’ and a �iu[s] natural[e] secundae intentionis, idest [...] iu[s] gentium’[576] - was thus moved onto different grounds, those of primum and secundum ius gentium. In the same vein, Baldus began his comment on lex Ex hoc iure (Dig. 1.1.5) by say­ing that �haec lex tractat de secundis inventionibus iuris gentium’, thereby put­ting all the institutions listed by Hermogenian in the category of secundum ius gentium.[577] [578]}

The way was now paved for the systematisation of the conceptual relations between ius naturale and ius gentium, and for a tentative taxonomy of the vari­ous institutions they encompassed. Another step in this direction was made by Paulus de Castro, a pupil of Baldus'. Firstly, Paulus seems to have presupposed the scheme set forth by Bartolus and Baldus, based on the distinction between ius naturale primaevum and secundarium, and the identification of the latter to ius gentium primaevum. 9⁵ Secondly, Paulus emphasised the notion of historical development by clarifying that ius gentium primaevum had been created si­multaneously with mankind, whereas ius gentium secundarium had been es­tablished subsequently by men themselves.^[579] Thirdly, he proposed a partial reordering of the natural law institutions listed by Isidore de Seville in the canon Ius naturale of the Decretum, assigning them to either ius naturale or ius gentium according to the time of their introduction (either the creation of men or later, respectively)^[580] Lastly, he distributed the ius gentium institutions into ius gentium primaevum and secundarium based on the same criterion^{[581] [582]}

Despite some ambiguity, this doctrine, and the categorisation upon which it rested, succeeded in bringing some order to the various passages of the le­gal sources to which they referred.99 Other explanations would be proposed in the following century,^[583] but the doctrine of the commentators reflected a general analytical framework which exercised a long-lasting influence on late- medieval legal scholarship. It went onto be taken up by Fernando Vazquez de Menchaca (1512-69) in his Controverses illustres and by the young Hugo Grotius (1583-1645) in his De iure praedae, to offer only a few notable and subsequently influential examples.^{[584] [585] [586] Nevertheless, no facet of ius gentium specifically des­ignated the domain of relations between polities. True it was that the inclu­sion of certain institutions pertaining to foreign relations, starting with war, in Hermogenian's and Marcianus' definitions, permitted this kind of application, as did the occasional if unconventional references to ius gentium in arguments for or against the independence of kingdoms.ω2 As an idea, however, the scope was far wider than interpolity law alone.}

3