All the Catholic Clergy in the United States, for instance, were ordained only by Bishops who are in active communion with the See of Rome. These Bishops themselves received their commissions from the Bishop of Rome. The present Bishop of Rome, Pius IX., is the successor of Gregory XVI., who succeeded Pius VIII., who was the successor of Leo XII. And thus we go back from century to century till we come to Peter, the first Bishop of Rome, Prince of the Apostles and Vicar of Christ. Like the Evangelist Luke, who traces the genealogy of our Savior back to Adam and to God, we can trace the pedigree of Pius IX. to Peter and to Christ. There is not a link wanting in the chain which binds the humblest Priest in the land to the Prince of the Apostles. And although on a few occasions there happened to be two or even three claimants for the chair of Peter, these counter-claims could no more affect the validity of the legitimate Pope than the struggle of two contestants for the Presidency could invalidate the title of the recognized Chief Magistrate. It was by pursuing this line of argument that the early Fathers demonstrated the Apostolicity of the Catholic Church, and refuted the pretensions of contemporary sectaries. St. Irenæus, Tertullian and St. Augustine give catalogues of the Bishops of Rome who flourished up to their respective times, with whom it was their happiness to be in communion, and then they challenged their opponents to trace their lineage to the Apostolic See. “Let them,” says Tertullian, in the second century, “produce the origin of their church. Let them exhibit the succession of their Bishops, so that the first of them may appear to have been ordained by an _Apostle, or by an apostolic man who was in communion with the Apostles_.”(99) And if the Fathers of the fifth century considered it a powerful argument in their favor that they could refer to an uninterrupted line of fifty Bishops who occupied the See of Rome, how much stronger is the argument to us who can now exhibit five times that number of Roman Pontiffs who have sat in the chair of Peter! I would affectionately repeat to my separated brethren what Augustine said to the Donatists of his time: “Come to us, brethren if you wish to be engrafted in the vine. We are afflicted in beholding you lying cut off from it. Count over the Bishops from the very See of St. Peter, and mark, in this list of Fathers, how one succeeded the other. This is the rock against which the proud gates of hell do not prevail.”(100) Chapter VI. PERPETUITY OF THE CHURCH.