That is what history has to say of the early Church in the Roman Empire. The Gospels, the Acts, the Canonical Epistles and those of Clement and Ignatius may tell a true or a false story; their authors may have written under an illusion or from a conscious self-deception; or they may have been supremely true and immutably sincere. _But they are contemporary._ A man may respect their divine origin or he may despise their claims to instruct the human race; but that the Christian body from its beginning was not “Christianity” but a Church and that that Church was identically one with what was already called long before the third century [Footnote: The Muratorian Fragment is older than the third century, and St. Ignatius, who also uses the word Catholic, was as near to the time of the Gospels as I am to the Crimean War.] the _Catholic_ Church, is simply plain history, as plain and straightforward as the history, let us say, of municipal institutions in contemporary Gaul. It is history indefinitely better proved, and therefore indefinitely more certain than, let us say, modern guesswork on imaginary “Teutonic Institutions” before the eighth century or the still more imaginary “Aryan” origins of the European race, or any other of the pseudo-scientific hypotheses which still try to pass for historical truth. So much for the Catholic Church in the early third century when first we have a mass of evidence upon it. It is a highly disciplined, powerful growing body, intent on unity, ruled by bishops, having for its central doctrine the Incarnation of God in an historical Person, Jesus Christ, and for its central rite a Mystery, the transformation of Bread and Wine by priests into the Body and Blood which the faithful consume. This “State within the States” by the year 200 already had affected the Empire: in the next generation it permeated the Empire; it was already transforming European civilization. By the year 200 the thing was done. As the Empire declined the Catholic Church caught and preserved it. What was the process of that decline? To answer such a question we have next to observe three developments that followed: (1) The great increase of barbarian hired soldiery within the Empire; (2) The weakening of the central power as compared with the local power of the small and increasingly rich class of great landowners; (3) The rise of the Catholic Church from an admitted position (and soon a predominating position) to complete mastery over all society.