It is to be noted that in this period the whole doctrine concerning the Person of our Lord Jesus Christ went through the most complete sifting and discussion in the Councils of the Church. During it, from St. Silvester to Gregory IV., seventy pontiffs sat in the chair of Peter. They lived in full five hundred years of perpetual struggle. One after another “apparent diræ facies inimicaque Troiæ numina”—Arius in the foreground heralding Mohammed in the rear; Nestorius and Eutyches tearing the unity of the Church on opposite sides; an able bishop of Constantinople seizing the moment of Rome’s temporal captivity under Arian strangers to raise his see to parity: the East well nigh devoured by opposing sects. After this, an insidious Byzantine couple, Heraclius and Sergius, emperor and patriarch, covering up deep wounds with ambiguous words, and sacrificing the empire by their sacrifice of the faith; and lastly, emperors who disregard things human and divine, and mark their mastery over doctrine by the subversion of worship, a Leo III. and a Constantine Kopronymus. All secular power is in the hands of Nova Roma which Constantine has set up to be the Christian city from its cradle: the seven greater hills to take the place of the hills by the Tiber, and in these very hills of Constantine from age to age the evil vision nestles—his successor and his patriarch are the chief performers in this ever recruited drama of heresy. But through all these attacks the seventy successors on St. Peter’s throne have kept the doctrine of the Church, that is the doctrine of the Incarnation itself, one and unchanged. The infidel has trampled upon Alexandria, Antioch, and Jerusalem; but while the old Christendom has sunk from debased nations into Saracen serfdom, a new Christendom has arisen among Teuton settlers, making their first steps in national life. Nova Roma has been false to the purpose for which Constantine founded it; and Old Rome has found among those whom the rival counts as barbarians, one more faithful as well as more powerful than she has been. Charlemagne stands at the end of the vista which Constantine begins. Of the two, does he not merit most in the Church of God?