We have thus seen that time has only brought about slight modifications in the liturgy of the Church; on the other hand, we can satisfy ourselves that nothing is left to conjecture or hypothesis; the most searching criticism only affirms the truths of tradition. M. Paul Allard, a distinguished writer, has expressed this in a very happy manner in his work, “Subterranean Rome.” “For two centuries,” he says, “the soil of Rome has been searched and dug up with indefatigable ardour, in the hope of discovering the source of the first Christian institutions, the very origin of the Church, catacombs have been thrown open to the day, thousands of inscriptions have been laid bare, and rare and precious paintings have been copied, or are still to be seen. From these subterranean labours, which have left nothing to conjecture, the history of the origin of Christianity has emerged, complete and renovated, but differing in nothing from that which tradition has handed down to us, and which, confirmed as to a great number of points, has been shaken in none.” THE POPES. Influence of the Papacy in the Reformation of Early Society.--St. Leo the Great.--Origin of the Temporal Power of the Popes.--Gregory the Great.--The Iconoclastic Emperors.--Stephen III. delivered by France.--Charlemagne crowned Emperor of the West.--Photius.--The Diet of Worms.--Gregory VII.; his Plan for a Christian Republic.--Urban II.--The Crusades.--Calixtus II.; Termination of the Dispute as to Investiture.--Innocent III.--Struggle of Boniface VIII. against Philippe le Bel.--The great Western Schism.--Council of Florence.--Battle of Lepanto.--Council of Trent. During the Middle Ages the popes exercised an appreciable influence upon society, personifying as they did the Christian element which was destined to regenerate the old world. “A doctrine emanating from Asia was not to subjugate, but to convert Europe, to associate political and religious truth, and, by the force of conscience against idolatry, and of resignation against tyranny, to restore the human race in all its dignity under the one true God. With the power of the sword sprung up that of opinion, which, independent of its rival, sustained the cause of progress in its struggle against this same power of the sword, and prevented it from being overthrown. The Church, representing the people and opening the way to the emancipation of all who were weighed down by conquest and by force, was unable to destroy servitude, legalised violence, and rapine at one blow, but it encountered them with a reproving doctrine and a condemning God.