Nor was that which may be called the inner life of the Empire less momentous in its influence upon the minds of men than were its outward dealings with the Roman church upon her greatness and decline. In the Middle Ages, men conceived of the communion of the saints as the formal unity of an organized body of worshippers, and found the concrete realization of that conception in their universal religious state, which was in one aspect, the Church; in another, the Empire. Into the meaning and worth of the conception, into the nature of the connexion which subsists or ought to subsist between the Church and the State, this is not the place to inquire. That the form which it took in the Middle Ages was always imperfect and became eventually rigid and unprogressive was sufficiently proved by the event. But by it the European peoples were saved from the isolation, and narrowness, and jealous exclusiveness which had checked the growth of the earlier civilizations of the world, and which we see now lying like a weight upon the kingdoms of the East: by it they were brought into that mutual knowledge and co-operation which is the condition if it be not the source of all true culture and progress. For as by the Roman Empire of old the nations were first forced to own a common sway, so by the Empire of the Middle Ages was preserved the feeling of a brotherhood of mankind, a commonwealth of the whole world, whose sublime unity transcended every minor distinction. [Sidenote: Principles adverse to the Empire.]