Today, we'll finish looking at this great encyclical, one which has as much resonance for us in the early twenty-first century as it did for Pope Pius' contemporaries.
7. And here it seems opportune to expound and to refute a certain false opinion, on which this whole question... depends. For authors who favor this view are accustomed...to bring forward these words of Christ: "That they all may be one.... And there shall be one fold and one shepherd," with this signification however: that Christ Jesus merely expressed a desire and prayer, which still lacks its fulfillment. For they are of the opinion that the unity of faith and government, which is a note of the one true Church of Christ, has hardly up to the present time existed, and does not to-day exist... They add that the Church in itself, or of its nature, is divided into sections; that is to say, that it is made up of several churches or distinct communities, which still remain separate, and although having certain articles of doctrine in common, nevertheless disagree concerning the remainder; that these all enjoy the same rights; and that the Church was one and unique from, at the most, the apostolic age until the first Ecumenical Councils. Controversies... and longstanding differences of opinion (on articles of the faith)... must be entirely put aside, and from the remaining doctrines a common form of faith drawn up and proposed for belief (a "mere Christianity), and in the profession of which all may not only know but feel that they are brothers. The manifold churches or communities, if united in some kind of universal federation, would then be in a position to oppose strongly and with success the progress of irreligion...Among them there indeed are some, though few, who grant to the Roman Pontiff a primacy of honor or even a certain jurisdiction or power... Others again, even go so far as to wish the Pontiff Himself to preside over their motley, so to say, assemblies. But, all the same, although many non-Catholics may be found who loudly preach fraternal communion in Christ Jesus, yet you will find none at all to whom it ever occurs to submit to and obey the Vicar of Jesus Christ either in His capacity as a teacher or as a governor (which is the goal of true ecumenism)...
8. This being so, it is clear that the Apostolic See cannot on any terms take part in their assemblies, nor is it anyway lawful for Catholics either to support or to work for such enterprises; for if they do so they will be giving countenance to a false Christianity, quite alien to the one Church of Christ. Shall We suffer, what would indeed be iniquitous, the truth, and a truth divinely revealed, to be made a subject for compromise? (how many today would answer 'yes') For here there is question of defending revealed truth. ...If our Redeemer plainly said that His Gospel was to continue not only during the times of the Apostles, but also till future ages, is it possible that the object of faith should in the process of time become so obscure and uncertain, that it would be necessary to-day to tolerate opinions which are even incompatible one with another? If this were true, we should have to confess that the coming of the Holy Ghost on the Apostles, and the perpetual indwelling of the same Spirit in the Church, and the very preaching of Jesus Christ, have several centuries ago, lost all their efficacy and use, to affirm which would be blasphemy. ...
9. These pan-Christians who turn their minds to uniting the churches seem, indeed, to pursue the noblest of ideas in promoting charity among all Christians: nevertheless how does it happen that this charity tends to injure faith? Everyone knows that John himself, the Apostle of love, who seems to reveal in his Gospel the secrets of the Sacred Heart of Jesus, and who never ceased to impress on the memories of his followers the new commandment "Love one another," altogether forbade any intercourse with those who professed a mutilated and corrupt version of Christ's teaching: "If any man come to you and bring not this doctrine, receive him not into the house nor say to him: God speed you." For which reason, since charity is based on a complete and sincere faith, the disciples of Christ must be united principally by the bond of one faith. Who then can conceive a Christian Federation, the members of which retain each his own opinions and private judgment, even in matters which concern the object of faith, even though they be repugnant to the opinions of the rest? ...We do know that from this it is an easy step to the neglect of religion or indifferentism and to modernism, as they call it (or religious relativism as we call it, this of course is what has happened since Pius wrote this)... Besides this, in connection with things which must be believed, it is nowise licit to use that distinction which some have seen fit to introduce between those articles of faith which are fundamental and those which are not fundamental (these are the forefathers of today's 'fundementalists'), as they say, as if the former are to be accepted by all, while the latter may be left to the free assent of the faithful: for the supernatural virtue of faith has a formal cause, namely the authority of God revealing, and this is patient of no such distinction...
10. So, Venerable Brethren, it is clear why this Apostolic See has never allowed its subjects to take part in the assemblies of non-Catholics: for the union of Christians can only be promoted by promoting the return to the one true Church of Christ of those who are separated from it, for in the past they have unhappily left it. To the one true Church of Christ, we say, which is visible to all, and which is to remain, according to the will of its Author, exactly the same as He instituted it. During the lapse of centuries, the mystical Spouse of Christ has never been contaminated, nor can she ever in the future be contaminated... For since the mystical body of Christ, in the same manner as His physical body, is one... it were foolish and out of place to say that the mystical body is made up of members which are disunited and scattered abroad: whosoever therefore is not united with the body is no member of it, neither is he in communion with Christ its head.
11. Furthermore, in this one Church of Christ no man can be or remain who does not accept, recognize and obey the authority and supremacy of Peter and his legitimate successors. Did not the ancestors of those who are now entangled in the errors of Photius and the reformers, obey the Bishop of Rome, the chief shepherd of souls? Alas their children left the home of their fathers, but it did not fall to the ground and perish for ever, for it was supported by God. Let them therefore return to their common Father, who, forgetting the insults previously heaped on the Apostolic See, will receive them in the most loving fashion. For if, as they continually state, they long to be united with Us and ours, why do they not hasten to enter the Church, "the Mother and mistress of all Christ's faithful"? Let them hear Lactantius crying out: "The Catholic Church is alone in keeping the true worship. This is the fount of truth, this the house of Faith, this the temple of God...
12. Let, therefore, the separated children draw nigh to the Apostolic See, set up in the City which Peter and Paul, the Princes of the Apostles, consecrated by their blood; to that See... not with the intention and the hope that "the Church of the living God, the pillar and ground of the truth" will cast aside the integrity of the faith and tolerate their errors, but, on the contrary, that they themselves submit to its teaching and government. Would that it were Our happy lot to do that which so many of Our predecessors could not, to embrace with fatherly affection those children, whose unhappy separation from Us We now bewail...
13. You, Venerable Brethren, understand how much this question is in Our mind, and We desire that Our children should also know, not only those who belong to the Catholic community, but also those who are separated from Us: if these latter humbly beg light from heaven, there is no doubt but that they will recognize the one true Church of Jesus Christ and will, at last, enter it, being united with us in perfect charity. While awaiting this event, and as a pledge of Our paternal good will, We impart most lovingly to you, Venerable Brethren, and to your clergy and people, the apostolic benediction.
Given at Rome, at Saint Peter's, on the 6th day of January, on the Feast of the Epiphany of Jesus Christ, our Lord, in the year 1928, and the sixth year of Our Pontificate.