Taken from The Vatican Decrees in their bearing on Civil Allegiance. By Henry Edward Archbishop of Westminster. New York : The Catholic Publication Society. 1875
We are bound to believe and to hold, by the obligation of faith, one Holy Church, Catholic and also Apostolic ; and this (Church) we firmly believe and in simplicity confess : out of which there is neither salvation nor remission of sins. As the Bridegroom declares in the Canticles, “One is my dove, my perfect one, she is the only one of her mother, the chosen of her that bore her :” who represents the one mystical Body, the Head of which is Christ ; and the Head of Christ is God. In which, (the one Church) there is one Lord, one Faith, one Baptism. For in the time of the Flood the ark of Noe was one, prefiguring the one Church, which was finished in one cubit, and had one governor and ruler, that is Noe ; outside of which we read that all things subsisting upon earth were destroyed. This also we venerate as one, as the Lord says in the Prophet, “Deliver, O God, my soul from the sword : my only one from the hand of the dog.”
For He prayed for the soul, that is, for Himself ; for the Head together with the Body : by which Body He designated the one only Church, because of the unity of the Bridegroom, of the Faith, of the Sacraments, and of the charity of the Church. This is that coat of the Lord without seam, which was not rent but went by lot. Therefore of that one and only Church there is one body and one Head, not two heads as of a monster : namely, Christ and Christ’s Vicar, Peter and Peter’s successor ; for the Lord Himself said to Peter, “Feed my sheep.” Mine, He says, generally ; and not, in particular, these or those : by which He is known to have committed all to him. If, therefore, Greeks or others say that they were not committed to Peter and his successors, they must necessarily confess that they are not of the sheep of Christ, for the Lord said (in the Gospel) by John, that there is “One fold, and one only shepherd.” By the words of the Gospel we are instructed that in this his (that is, Peter’s) power there are two swords, the spiritual and the temporal. For when the Apostles say, “Behold, here are two swords,” that is, in the Church, the Lord did not say, “It is too much,” but “it is enough.” Assuredly, he who denies that the temporal sword is in the power of Peter, gives ill heed to the word of the Lord, saying, “Put up again thy sword into its place.” Both, therefore, the spiritual sword and the material sword are in the power of the Church. But the latter (the material sword) is to be wielded on behalf of the Church ; the former (the spiritual) is to be wielded by the Church : the one by the hand of the priest ; the other by the hand of kings and soldiers, but at the suggestion and sufferance of the priest. The one sword ought to be subject to the other, and the temporal authority ought to be subject to the spiritual power. For whereas the Apostle says, “There is no power but from God ; and those that are, are ordained of God ;” they would not be ordained (or ordered) if one sword were not subject to the other, and as the inferior directed by the other to the highest end. For, according to the blessed Dionysius, it is the law of the Divine order that the lowest should be guided to the highest by those that are intermediate. Therefore, according to the order of the universe, all things are not in equal and immediate subordination ; but the lowest things are set in order by things intermediate, and things inferior by things superior. We ought, therefore, as clearly to confess that the spiritual power, both in dignity and excellence, exceeds any earthly power, in proportion as spiritual things are better than things temporal. This we see clearly from the giving, and blessing, and sanctifying of tithes, from the reception of the power itself, and from the government of the same things. For, as the truth bears witness, the spiritual power has to instruct, and judge the earthly power, if it be not good ; and thus the prophecy of Jeremias is verified of the Church and the ecclesiastical power : “Lo, I have set thee this day over the nations and over kingdoms,” &c. If, therefore, the earthly power deviates (from its end), it will be judged by the spiritual ; but if a lesser spiritual power trangresses, it will be judged by its superior : but if the supreme (deviates), it can be judged, not by man, but by God alone, according to the words of the Apostle : “The spiritual man judges all things ; he himself is judged by no one.” This authority, though given to man and exercised through man, is not human, but rather Divine—given by the Divine voice to Peter, and confirmed to him and his successors in Him whom Peter confessed, the Rock, for the Lord said to Peter : “Whatsoever thou shalt bind upon earth, it shall be bound also in heaven : and whatsoever thou shalt loose on earth, it shall be loosed also in heaven.”
Whosoever therefore resists this power that is so, ordered by God, resists the ordinance of God, unless, as Manichæus did, he feign to himself two principles, which we condemn as false and heretical ; for, as Moses witnesses, “God created heaven and earth not in the beginnings, but in the beginning.” Moreover, we declare, affirm, define, and pronounce it to be necessary to salvation for every human creature to be subject to the Roman Pontiff.