NATIONALITY, PRINCIPLE OF. - The origin of the principle of nationality is linked to that of contemporary nationalism. Having sprouted from the trunk of agnostic rationalism, after a certain period of incubation, during which it was warmed by Romantic sentimentality, it was explicitly formulated by the Italian nationalist school, which sought in the Risorgimento justification for the movements for national unity.
According to the theory outlined by MANCINI and developed by MANNIO, only in the nation would the unique form of social life be realized, corresponding to the laws of nature established by God, while the multinational State, or one that in any way does not coincide with the borders of the nation, would be an artificial and arbitrary entity. In this way, the concept of the perfect natural identity between nation and State was introduced into the theory of the State, a concept hitherto unknown. This concept provided the springboard to leap into international law and to model the doctrine on the constitution of the society of nations according to the criterion of nationality. Indeed, developing the principle that only nations are natural social entities and that the State cannot remain distinct from the nation, it was deduced that the international society had to be considered as a collectivity composed of nation-States, to which alone legal personality in the relevant order would have to be recognized.
Upon these concepts was founded the supposed joint right of every nation or fraction thereof to rise to the perfection of a political entity and to enter into conflict with the artificial entity of the State, in order to conquer full independence if it did not possess it, or to gather around the same national center the scattered members of the nation, so as to make political borders coincide with the ethnic group. In the affirmation of this right lies, precisely, the core of the principle of nationality.
At the present time it is a historical memory. Both Catholic doctrine and the common juridical doctrine have abandoned it as lacking in substance, for reasons intrinsic to the theory and for extrinsic reasons.
Once the principle of the natural identity between nation (v.) and State has been demonstrated false, the entire theoretical framework upon which the right of the nation to constitute itself as an independent State rested is ruined. If the State is a natural formation in the same way as the nation, indeed more imperative, and if nothing forbids that it may live within it in political unity, then the demands of human life require that one submit to the duties of subjection, loyalty, and obedience to the competent authority for the attainment of the common good, as long as that authority does not prejudice, through oppressive action, the being and culture of the nation.
It has also been pointed out that, since the nation does not of itself postulate a central power and a legal order, it cannot be considered a subject of international society, which, according to the most common doctrine, is composed predominantly of States. This observation, correct in its foundation, does not, however, seem conclusive today. Since international society has broadened its scope with the admission of subjects that do not have the quality of independent States, nothing would prevent the admission of the nation as well.
More to the point, instead, is the observation regarding the impossibility of applying the criterion of nationality to international arrangements, both because the criterion is vague and fluid in its context, like the very concept of nation, and because objectively not all national fractions are capable of conducting an independent political life, nor do economic, commercial, geographical, border, and strategic considerations always permit the separation of peoples according to membership in different national cores, which are often so mixed, particularly in border regions, as to make the granting of political independence impossible.
In the principle of nationality there nonetheless resides a soul of truth, and this consists in the demand that the rights of the nation be respected by the State, and that in territorial divisions the just aspirations of peoples be taken into account, according to the express teaching of Benedict XV and Pius XII. V. SELF-DETERMINATION.