of acquisition were
obtained by the elder jurisconsults, as I have attempted to explain,
by abstracting a common ingredient from the usages observed to prevail
among the various tribes surrounding Rome; and, having been classed on
account of their origin in the "law common to all nations," they were
thought by the later lawyers to fit in, on the score of their
simplicity, with the more recent conception of a Law Natural. They
thus made their way into the modern Law of Nations, and the result is
that those parts of the international system which refer to
_dominion_, its nature, its limitations, the modes of acquiring and
securing it, are pure Roman Property Law--so much, that is to say, of
the Roman Law of Property as the Antonine jurisconsults imagined to
exhibit a certain congruity with the natural state. In order that
these chapters of International Law may be capable of application, it
is necessary that sovereigns should be related to each other like the
members of a group of Roman proprietors. This is another of the
postulates which lie at the threshold of the International Code, and
it is also one which could not possibly have been subscribed to during
the first centuries of modern European history. It is resolvable into
the double proposition that "sovereignty is territorial," _i.e._ that
it is always associated with the proprietorship of a limited portion
of the earth's surface, and that "sovereigns _inter se_ are to be
deemed not _paramount_, but _absolute_, owners of the state's
territory."

Many contemporary writers on International Law tacitly assume that the
doctrines of their system, founded on principles of equity and common
sense, were capable of being readily reasoned out 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 modern history. It is not true that the
authority of the Jus Gentium in the concerns of nations was always
uncontradicted; on the contrary, it had to struggle long against the
claims of several competing systems. It is again not true that the
territorial character of sovereignty was always recognised, for long
after the dissolution of the Roman dominion the minds of men were
under the empire of ideas irreconcileable with such a conception. An
old order of things, and of views founded on it, had to decay--a new
Europe, and an apparatus of new notions conge