The arguments for and against the doctrine of national self-determination may be summarized as follows. The opponents of the doctrine agree that to legitimatize a title gained by conquest the express consent of the two contracting powers and the tacit assent of the inhabitants are sufficient. Against the method of the plebiscite they advance arguments attacking both the validity of its underlying theory and the expediency of leaving to a vote by universal suffrage a question of such importance as sovereignty. Their first argument is that the cession of sovereignty is outside the domain of international law and is of merely political importance, concerning only the two States involved. This position appears to result from a failure to analyze the threefold aspect of a cession of sovereignty, namely, alienation, transfer and integration. It is true that these three phases are of unequal interest in international law. The first phase, alienation, corresponding to “divesting of title,” is obviously a matter largely of constitutional law, but a matter certainly open to regulation by international law, as it involves national debt, police and, if done during war, questions of neutrality and blockade. The second stage, that of transfer, clearly concerns international law, for it has to do with the relations of two States at least. The third stage, that of integration, is of a mixed character, concerning the municipal or constitutional law of the annexing State and, as it involves a question of title, concerning international law also. The subject of validity of title has long occupied the attention of writers on international law, for, as is well known, discussion of title by conquest, discovery, preemption, occupation and treaty occupy a place in the treatises, and the doctrines have broadened and developed to meet geographical and political exigencies.