On the whole, however, it is astonishing, as I have observedbefore, how small a proportion the additions made tointernational Law since Grotius's day bear to the ingredientswhich have been simply taken from the most ancient stratum of theRoman Jus Gentium. Acquisition of territory has always been thegreat spur of national ambition, and the rules which govern thisacquisition, together with the rules which moderate the wars inwhich it too frequently results, are merely transcribed from thepart of the Roman law which treats of the modes of acquiringproperty jure gentium. These modes of acquisition were obtainedby the elder jurisconsults, as I have attempted to explain, byabstracting a common ingredient from the usages observed toprevail among the various tribes surrounding Rome; and, havingbeen classed on account of their origin in the "law common to allnations," they were thought by the later lawyers to fit in, onthe score of their simplicity, with the more recent conception ofa Law Natural. They thus made their way into the modern Law ofNations, and the result is that those parts of the internationalsystem which refer to dominion, its nature, its limitations, themodes of acquiring and securing it, are pure Roman Property Law-- so much, that is to say, of the Roman Law of Property as theAntonine jurisconsults imagined to exhibit a certain congruitywith the natural state. In order that these chapters ofInternational Law may be capable of application, it is necessarythat sovereigns should be related to each other like the membersof a group of Roman proprietors. This is another of thepostulates which lie at the threshold of the International Code,and it is also one which could not possibly have been subscribedto during the first centuries of modern European history.. It isresolvable into the double proposition that "sovereignty isterritorial," i.e. that it is always associated with theproprietorship of a limited portion of the earth's surface, andthat "sovereigns inter se are to be deemed not paramount, butabsolute, owners of the state's territory."Many contemporary writers on International Law tacitly assumethat the doctrines of their system, founded on principles ofequity and common sense, were capable of being readily reasonedout in every stage of modern civilisation. But this assumption,while it conceals some real defects of the international theory,is altogether untenable, so far as regards a large part of modernhistory. It is not true that the authority of the Jus Gentium inthe concerns of nations was always uncontradicted; on thecontrary, it had to struggle long against the claims of severalcompeting systems. It is again not true that the territorialcharacter of sovereignty was always recognised, for long afterthe dissolution of the Roman dominion the minds of men were underthe empire of ideas irreconcileable with such a conception. Anold order of things, and of views founded on it, had to decay --a new Europe, and an apparatus of new notions congenial to it,had to spring up before two of the chiefest postulates ofInternational Law could be universally conceded.
It is a consideration well worthy to be kept in view thatduring a large part of what we usually term modern history nosuch conception was entertained as that of "territorialsovereignty." Sovereignty was not associated with dominion over aportion or subdivision of the earth. The world had lain for somany centuries under the shadow of Imperial Rome as to haveforgotten that distribution of the vast spaces comprised in theempire which had once parcelled them out into a number ofindependent commonwealths, claiming immunity from extrinsicinterference, and pretending to equality of national rights.
