Modern India presents a spectacle of unity in diversity to which history provides no parallel, except perhaps in the Roman Empire. The diversity has existed from time immemorial and has been the subject of many books, whereas the unity is of recent growth and still takes observers by surprise. That growth, however, was only rendered possible by certain facts of history and geography. The great barrier to the north makes India what a recent geographer has called 'an intelligible isolate'--an entity sufficiently cut off from the outside world for long periods, to allow its inhabitants to develop characteristics of their own. Under these favourable geographical circumstances, Hinduism was able to build up throughout India a common culture and a uniform way of life. For centuries the people of India were included in the fold of caste and subjected to the discipline of a hierarchy whose main gradations were acknowledged throughout the country. The foundations thus existed on which, under favourable political conditions, a structure of true unity might be erected. British rule provided the necessary conditions. The uniform rule of law, the administration of India as a single country, the use of the English language and, above all, the nineteenth-century liberal thought which all educated Indians absorbed with such avidity, gradually gave rise to a sense of nationality and then to a feeling of ardent nationalism, in which militant Hinduism had a large part to play. The recent controversies and disturbances over the formation of linguistic states may warn us not to exaggerate the strength of the new unity, but it is nevertheless true to say that the deepest political emotion of the great majority of educated Indians to-day is pride in their Indian nationality.
In the course of the psychological struggles which have led to this new unity, Hinduism has had to meet a great challenge. Many writers on Indian affairs have dwelt on the absorbent capacity of Hinduism--its power to assimilate alien beliefs and feelings without undergoing radical transformation itself.