Mortalium animos (“The minds of mortals”) is one of the most important documents from the pontificate of Pius XI, right along Quas primas on the kingship of Christ and Casti conubbii on Christian marriage. Its main topic is the relationship between the Catholic Church and the other denominations and how it is not permissible to attend or support ecumenical gatherings. When one reads this document, one is immediately struck how all of its main tenets are being contradicted constantly by the recent alleged “popes”.
This document explains well how “unity” can only mean unity of faith, and that unity of all Christians can only be achieved if all non-Catholic Christians return to the one true Church established by Christ.
Jesus prayed to the Father in John’s Gospel, Chapter 17: “I do not pray for these only, but also for those who believe in me through their word, that they may all be one; even as thou, Father, art in me, and I in thee, that they also may be in us, so that the world may believe that thou hast sent me.” (John 17:20-21) His prayer was 100% effective, since He is God and the Father is also God. As Pius XI explains, this prayer was not a desire for an ideal at some point in the future.
As all Catholics should know, the Church is “one, holy, catholic and apostolic”. The Church is “one” and has been “one” since day one. Unity is already present, and is a divine guarantee. Those who have left the Church have fallen away from unity.
“4. Is it not right, it is often repeated, indeed, even consonant with duty, that all who invoke the name of Christ should abstain from mutual reproaches and at long last be united in mutual charity? Who would dare to say that he loved Christ, unless he worked with all his might to carry out the desires of Him, Who asked His Father that His disciples might be ‘one.’ And did not the same Christ will that His disciples should be marked out and distinguished from others by this characteristic, namely that they loved one another: ‘By this shall all men know that you are my disciples, if you have love one for another’? All Christians, they add, should be as ‘one’ […] But in reality beneath these enticing words and blandishments lies hid a most grave error, by which the foundations of the Catholic faith are completely destroyed. […]”
“7. And here it seems opportune to expound and to refute a certain false opinion, on which this whole question, as well as that complex movement by which non-Catholics seek to bring about the union of the Christian churches depends. For authors who favor this view are accustomed, times almost without number, 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 consider that this unity may indeed be desired and that it may even be one day attained through the instrumentality of wills directed to a common end, but that meanwhile it can only be regarded as mere ideal. […]”
“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? […]”
“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. […] How so great a variety of opinions can make the way clear to effect the unity of the Church We know not; that unity can only arise from one teaching authority, one law of belief and one faith of Christians. But 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. […]”
“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. […]”
“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, We repeat, which is ‘the root and womb whence the Church of God springs,’ 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. […]”
Lights in the Church of the Nativity, in Betlehem (occupied West Bank). Image by Templar1307, CC-BY-NC-ND 2.0, here.