Sri Aurobindo poses the question as to the importance of distinguishing real internal unity of a societal formation from one that is purely based on some external form cobbled together either for a temporary economic or political convenience, or through the exercise of some kind of force. The answer lies in the internal coherence and consistency found in the real unity, which tends to keep the people joined together, as opposed to the political unity with little commonality among the disparate parts, which will tend to disintegrate or drift apart when the force that is acting to hold it together weakens.
We can see a similar reality in the world of science and chemistry, with strong atomic bonds holding together while weak atomic bonds are subject to being broken apart, and the elements dispersed or joined elsewhere.
Sri Aurobindo observes: The distinction “…must be made because it is of the greatest utility to a true and profound political science and involves the most important consequences. When an empire like Austria, a non-national empire, is broken to pieces, it perishes for good; there is no innate tendency to recover the outward unity, because there is no real inner oneness; there is only a politically manufactured aggregate. On the other hand, a real national unity broken up by circumstances will always preserve a tendency to recover and reassert its oneness. The Greek Empire has gone the way of all empires, but the Greek nation, after many centuries of political non-existence, again possesses its separate body, because it has preserved its separate ego and therefore really existed under the covering rule of the Turk.”
“This truth of a real unity is so strong that even nations which never in the past realised an outward unification, to which Fate and circumstance and their own selves have been adverse, nations which have been full of centrifugal forces and easily overpowered by foreign intrusions, have yet always developed a centripetal force as well and arrived inevitably at organised oneness.”
There are a number of examples that illustrate this principle, including the Greek nation and the development of the Germanic nation. “In both of these historic instances, as in so many others, the unification of Saxon England, mediaeval France, the formation of the United States of America, it was a real unity, a psychologically distinct unit which tended at first ignorantly by the subconscious necessity of its being and afterwards with a sudden or gradual awakening to the sense of political oneness, towards an inevitable external unification. It is a distinct group-soul which is driven by inward necessity and uses outward circumstances to constitute for itself an organised body.”
Sri Aurobindo, The Ideal of Human Unity, Part I, Chapter 5, Nation and Empire: Real and Political Unities, pp. 35-37