always to discover whether they are discussing law or morality—whether the state of international relations they describe is actual or ideal—whether they lay down that which is, or that which, in their opinion, ought to be.
The assumption that Natural Law is binding on states inter se is the next in rank of those which underlie International Law. A series of assertions or admissions of this principle may be traced up to the very infancy of modern juridical science, and at first sight it seems a direct inference from the teaching of the Romans. The civil condition of society being distinguished from the natural by the fact that in the first there is a distinct author of law, while in the last there is none, it appears as if the moment a number of units were acknowledged to obey no common sovereign or political superior they were thrown back on the ulterior behests of the Law Natural. States are such units; the hypothesis of their independence excludes the notion of a common lawgiver, and draws with it, therefore, according to a certain range of ideas, the notion of subjection to the primeval order of nature. The alternative is to consider independent communities as not related to each other by any law, but this condition of lawlessness is exactly the vacuum which the Nature of the jurisconsults abhorred. There is certainly apparent reason for thinking that if the mind of a Roman lawyer
