This institutional interdependence seems to be generally recognised now. "The web of history," said Professor Hatch in beginning his great work at Oxford, "is woven of one piece; it reflects the unity of human life, of which it is the record. We cannot isolate any group of facts and consider that no links of causation connect them with their predecessors or their contemporaries. Just as Professor Freeman insists on the continuity of history, so I wish to insist on its solidarity."[4:1] The mutual labours of scholars in correlating fields have revolutionised our historical knowledge of the early and later Middle Ages. A multitude of controverted points have vanished like ghosts. We see the old Church now as we never saw it before. The Catholic Church and the mediæval papacy were the greatest of the creations of the first fifteen centuries of the Christian era. The mediæval Church was not exclusively a religious organisation. It was more of an ecclesiastical state. It had laws, lawyers, courts, and prisons. If not born into it, all the people of western Europe were at least baptised into it. It levied taxes on its subjects. Standards of patriotism and treason were more sharply defined than in the modern state.[5:1] The evolution of this great organisation is the central fact of the first thirteen centuries after Christ. It aimed to control the whole life of its subjects here and to determine their destiny hereafter. Well may our greatest American Church historian, Henry C. Lea, ask: "What would have been the condition of the world if that organisation had not succeeded in bearing the ark of Christianity through the wilderness of the first fifteen centuries?"[5:2] The history of Europe, then, after the Roman period must be looked at through the eyes of the Church. The character and works of that great institution must first be studied, not pathologically but sympathetically. The historian, if honest, dare not show a "lack of appreciation of the service rendered to humanity by the organisation which in all ages has assumed for itself the monopoly of the heritage of Christ."[5:3] He must recognise the fact that "ecclesiastical history is simply the spiritual side of universal history."[6:1] "The value of a science depends on its own intrinsic merits," says Alzog.[6:2] When the great Teacher commanded from the Mount of Olives, "Go ye into all the world and preach the gospel," that mount became the pivot on which the whole world's history has turned.