Erat Ioseph et Maria mater Iesu, mirantes super his quæ dicebantur de illo. Et benedixit illis Simeon, et dixit ad Mariam matrem eius: "Ecce positus est hic in ruinam, et in resurrectionem multorum in Israël: et in signum cui contradicetur..." (From the Gospel for the Sunday within the Octave of the Nativity of the Lord, St.Luke ii, 33-34: "Joseph and Mary, the mother of Jesus, were wondering at those things which were spoken concerning Him. And Simeon blessed them, and said to Mary His Mother: 'Behold, this child is set for the fall, and for the resurrection of many in Israel: and for a sign which shall be contradicted...'.")
On the feast of the Epiphany of Our Lord, 1928, in the very center of the period between the two great conflicts of the 20th Century, the Successor of Peter clearly exposed the perennial doctrine of the only Church of Christ "on fostering true religious unity". Pope Pius concluded his brief and solid encyclical, Mortalium Animos, with the expression of his heartfelt desire:
...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.
What a thorn Mortalium Animos is to many in the Church! - today as it was then: as the Baby in the Temple, a "sign of contradiction"; as the Instrument of Redemption, it is "scandal" to some, and "folly" to many others. It certainly is a difficult document for the modern age and one that, while an expression of the unchanging Faith of Holy Mother Church, has been carefully avoided in the Conciliar and post-Conciliar years. Of the major encyclicals of Pope Ratti, it is the only one that, even by indirect reference, is completely omitted from the Catechism of the Catholic Church. The last major ecclesiastical document to mention it, curiously enough, was the first encyclical of Pope Blessed John XXIII (Ad Petri Cathedram, 1959: "...this unity, Venerable Brethren and beloved sons, must be solid, firm and sure, not transient, uncertain, or unstable. Though there is no such unity in other Christian communities, all who look carefully can see that it is present in the Catholic Church.")
In the years before a "hermeneutic of continuity" was included in Papal discourse, Father Chad Ripperger, FSSP, introduced to the wider English-speaking Catholic audience the notion that the absence of such hermeneutics in the matters involved in the "extrinsic tradition" of the Church has necessarily led to confusion and worse (from his famous article "Conservative vs. Traditional Catholicism", The Latin Mass, Spring 2001):
...in the document of Vatican II on ecumenism, Unitatis Redintegratio, there is not a single mention of the two previous documents that deal with the ecumenical movement and other religions: Leo XIII's Satis Cognitum and Pius XI's Mortalium Animos. The approach to ecumenism and other religions in these documents is fundamentally different from the approach of the Vatican II document or Ut Unum Sint by Pope John Paul II. While the current Magisterium can change a teaching that falls under non-infallible ordinary magisterial teaching, nevertheless, when the Magisterium makes a judgment in these cases, it has an obligation due to the requirements of the moral virtue of prudence to show how the previous teaching was wrong or is now to be understood differently by discussing the two different teachings. However, this is not what has happened. The Magisterium since Vatican II often ignores previous documents which may appear to be in opposition to the current teaching, leaving the faithful to figure out how the two are compatible, such as in the cases of Mortalium Animos and Ut Unum Sint. This leads to confusion and infighting within the Church as well as the appearance of contradicting previous Church teaching without explanation or reasoned justification.
Such reasoned justification has never been put forward; even when trying to summarize the history of Catholic participation in "ecumenical dialogue", Cardinal Kasper, current President of Pontifical Council for Promoting Christian Unity glosses over the radical change between both sets of documents:
"The Catholic Church abstained [from ecumenical dialogue] at the beginning. The encyclical letters Satis cognitum of Leo XIII (1896) and Mortalium animos of Pius XI (1928) even condemned the ecumenical dialogue which seemed to relativise the claim of the Catholic Church to be the true Church of Jesus Christ. Yet Pius XII already paved the way to a more open attitude, albeit with caution, in an Instruction of the Holy Office of 1949. However, only the initiative of Pope John XXIII (+1963) and the Second Vatican Council (1962-65) brought a shift. The conciliar Decree on Ecumenism Unitatis Redintegratio stated that the ecumenical movement was a sign of the work of the Holy Spirit in our time (Unitatis redintegratio, 1), opening the way for the ecumenical movement and highlighting the importance of dialogue with separated brothers and sisters and with separated churches and church communities."
It is in fact quite devious to present the warning set forth in Mortalium Animos as a mere policy of "abstention" from ecumenical dialogue. Pius XI identified what seem to be clear errors in ecumenical dialogue:
Therefore, one cannot even say that the "apparent contradiction" has not been properly explained, for it has actually been completely ignored. The Catholic faithful are left with documents which seem mutually contradictory - and it is certainly not the obligation of the lay faithful to test multifarious possibilities of interpretive harmonization.
All Christians, they add, should be as "one": for then they would be much more powerful in driving out the pest of irreligion, which like a serpent daily creeps further and becomes more widely spread, and prepares to rob the Gospel of its strength. ... 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.
...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 today exist....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?
Our intent in this series, indeed, is not to resolve a theological battle, but to celebrate the crystalline doctrine of a stellar Pontiff, Pius XI.