The supremely important fact in early Christian history is the development of the concept of "The Church" as an independent, self-existing, metaphysical entity. This metaphysical entity was conceived as embodying itself in the whole body of believers; living, dead, and yet to be born. The entity was eternal, indestructible, and in its essence immutable. Although partially embodied in a visible society its essential being was conceived as independently sustained in the nature of the universe. It was an idea in the strict Platonic sense. No concept like this is found in the contemporary pagan cults. Even the Jewish concept of the 'chosen people' is ethnic or national rather than purely religious and it has no tinge of that metaphysical existence which is the most notable element in the Catholic concept of the Church. The elements out of which 'the Church' concept was constructed were four: two Roman, one Greek and one Hebrew. The Roman lawyers, in the process of fitting a municipal legal system to a world empire, evolved the twin legal entities, 'state' and 'sovereignty.' These entities were endowed with divers qualities; eternity, immutability, etc., but especially with the quality of having existential reality apart from any individual embodiment thereof. Greek philosophy contributed the idea of the Cosmopolis, the ideal world-city in which the fullest development of human personality was to be attained. This concept was as purely metaphysical as the self-existing, absolute 'state' of the Roman law, but unlike the Roman concept it had no concrete existence. The Jewish contribution was that of the 'chosen people,' 'the elect nation.' These four concepts were transferred from their original loci to the Christian society. The fact that all of these concepts were combined and centered on the same social group and the further fact that each of these concepts supplemented the others in a remarkable way resulted in the formation of one of the most powerful ideas in religious history. This Church concept, thus built up, had already become widespread in the time of Augustine and this fact helps us to understand the otherwise unintelligible success of that saint in combatting Chiliasm. The real truth is seen to be that Augustine's ideas succeeded because they were not peculiarly his at all--they already existed, implicitly but really, in the mind of the generation which he addressed. The elements of the concept 'the Church' being what they were, Augustine's explanation of, or rather abolition of, Chiliasm follows of inevitable logical and intellectual necessity. It was the genius of Augustine that he recognized and gave formulated, concrete expression to this accomplished fact and it is no derogation of his genius to say that had he never existed the accomplished fact would eventually have been given expression to by some one else.