Introduction
The thesis of this essay is that there is a very strong connection between the form of Synodality that has been and is being espoused by Pope Francis and Pope Leo XIV and the very strong allegiance of those two popes to the teachings of the Second Vatican Council. There is, in addition, a third factor that haunts our Church’s current dalliance with Synodality—the Heresy of Modernism, named and condemned as such way back in 1907 by Pope Saint Pius X in his encyclical Pascendi Dominici Gregis, and all-but-forgotten or deliberately-ignored by our current Catholic Hierarchy.
“Synodality is the Second Vatican Council in a Nutshell”[1]
The Synod on Synodality was originally billed as a three-year process of listening and dialoguing, which was to conclude in October of 2023 but was extended to October of 2024. And, at its “closing” in October of 2024, Pope Francis engrafted or absorbed its format into the structure of the Church itself. It had, as its apparently official theme, the catchy phrase: “For a Synodal Church: Communion, Participation and Mission.” It’s been billed as a “journey of discernment” supposedly rooted in the Holy Spirit, and structured as a consultative process that involves each diocese, even reaching down to Catholic parishes and individual Catholics.
The Synod on Synodality touts itself to the Catholic world as a refreshingly attractive way of accumulating input and advice from every member of the Catholic Church (from Church leadership on down to rank-and-file parishes and parishioners)—input on the directions which the inputters want the Church to take now that it has entered the Third Millennium.
A very authoritative explanation of the synodal movement exists in a very lengthy document published by Secretary General of the Synod of Bishops in the Vatican in September of 2021.[2] In it, the Secretary General acknowledged that the Synodality phenomenon follows “in the wake of the renewal of the Church proposed by the Second Vatican Council.”
Most of the early Synod-on-Synodality literature conveys the impression that the predetermined, mandatory starting point for input into the synodal process is a full and enthusiastic acceptance of all of the teachings of the Second Vatican Council. There is a definite, predetermined, umbilical connection between (1) the directions for the Third Millennium that the current Synod on Synodality has been inviting Catholics to comment on, and (2) the commenters’ mandated enthusiastic acceptance of all the teachings of the Second Vatican Council. Almost every document issued by the Synod in its early days mentions that connection prominently. One of the clearest explanations of that connection appears in an October 2022 “Message from the General Secretariat of the Synod on Synodality on the occasion of the 60th anniversary of the opening of the Second Vatican Council”:
“The 60th anniversary of the opening of the Second Vatican Council is a moment of particular grace also for the Synod [on Synodality], which represents a fruit of that ecumenical assembly, indeed one of its “most precious legacies” (Francis, Apostolic Constitution Episcopalis Communio, Sept. 15, 2018, 1).
“The purpose of the Synod was and remains to prolong, in the life and mission of the Church, the spirit of the Second Vatican Council, as well as to foster in the People of God the living appropriation of its teaching, in the awareness that that Council represented “the great grace from which the Church has benefited in the 20th century” (John Paul II, Apostolic Letter Novo millennio ineunte, Jan. 6, 2001, 57). This task is far from being completed since the reception of the conciliar magisterium is an ongoing process; in some respects, it is still in its infancy.
“The synodal process currently underway, dedicated to “Synodality in the Life and Mission of the Church,” is also within the Council’s wake. The concept of “Synodality” is found throughout the Council, even though this term (only recently coined) is not found expressly in the documents of the ecumenical assembly. The magna charta of Synod 2021-2023 is the Council’s doctrine on the Church, particularly its theology of the People of God, a People whose “condition is the dignity and fredom of the children of God, in whose heart the Holy Spirit dwells as in a temple” (Lumen Gentium 9) [i.e., the Second Vatican Council’s Dogmatic Constitution on the Church].”[3]
And finally, in an interview, Nathalie Becquart, a French Catholic nun (a member of the Congregation of Xavières) who is an Undersecretary of the General Secretariat of the Synod on Synodality, outlined the Implementation Phase of the Synod on Synodality, discussed the meaning of synodality and the reception of the Synod, and explained the goals of the then-new document “Pathways for the Implementation Phase of the Synod”. Her words:
. . . I often quote an Australian theologian who was at our Synod, Ormond Rush, who states “Synodality is the Second Vatican Council in a nutshell.” And all our documents, and still in these pathways, in the Final Document, highlight that what we are doing is really referred to the vision of the Second Vatican Council.
We can say synodality is the way to understand the ecclesiology of the Second Vatican Council in this stage of the reception of the Council.
So, it’s nothing else but just continuing the reception of the Second Vatican Council. Because the council is not yet implemented everywhere, in a way. So that’s the way to understand it. [4]
The Heresy of Modernism—Yes, It Is a Heresy
What is the Heresy of Modernism? First of all, Modernism in Catholic theological doctrine is indeed a Heresy—a Heresy that progressive-minded Catholics often dally with, and that tradition-minded Catholics have always avoided like the plague.
The common if not universal belief among Catholics is that reconciling our Church with the Modern World became the purpose of the Second Vatican Council shortly after it was convened in 1962. The problem with this well-founded belief is that reconciling our Church with the Modern World implicates the very essence of the Heresy of Modernism.
Modernism was present in our Church for a long time before Pope Saint Pius X officially named and condemned it as a Heresy in 1907.[5] Its presence in the Church had grown significantly during the 19th and into the early 20th century . The Church’s 1907 condemnation of Modernism as a Heresy stifled its 20th-century growth, at least superficially, for a generation or two, but the specter of Modernism never ceased haunting the corridors of the Vatican until Modernism itself broke forth big-time—in the open—in the teachings of our Church’s Second Vatican Council (1962-65).[6]
It is difficult to get an exact, literal handle on the content of Modernism in Catholic theological doctrine, precisely because of what heretical Modernism is. When Saint Pius X named and condemned it as a heresy in 1907 in his encyclical Pascendi, there were several then-well-known (and now all but forgotten) advocates of various forms of Modernism among the clergy within the Catholic Church at the time, but the Pope was condemning Modernism itself in all of its manifestations—pre-1907, contemporary, and post-1907—on into the indefinite future. That became clear in paragraph 39 of Pascendi.
Saint Pius X Defined Modernism as ‘The Synthesis of All Heresies’
Pope Saint Pius X clearly acknowledged that he was condemning Modernism itself in all of its manifestations—pre-1907, contemporary, and post-1907—on into the indefinite future when he defined Modernism as “the synthesis of all heresies”:
“It may be, Venerable Brethren, that some may think We have dwelt too long on this exposition of the doctrines of the Modernists. But it was necessary, both in order to refute their customary charge that We do not understand their ideas, and to show that their system does not consist in scattered and unconnected theories but in a perfectly organised body, all the parts of which are solidly joined so that it is not possible to admit one without admitting all. For this reason, too, We have had to give this exposition a somewhat didactic form and not to shrink from employing certain uncouth terms in use among the Modernists. And now, can anybody who takes a survey of the whole system be surprised that We should define it as the synthesis of all heresies? Were one to attempt the task of collecting together all the errors that have been broached against the faith and to concentrate the sap and substance of them all into one, he could not better succeed than the Modernists have done”[7] [Emphasis added.]
The “synthesis of all heresies” (we are told near the end of the above quote from Saint Pius X) is to be found in “the sap and substance” of all heresies. A question presents itself: What, then, is the “sap and substance” that the Heresy of Modernism shares with all other heresies? It’s at this point that we confront the fact that Pope Saint Pius X was condemning Modernism itself in all of its manifestations—pre-1907, contemporary, and post-1907—on into the indefinite future—including, most importantly, our own time. What, then, is the “sap and substance” that the Heresy of Modernism shares with all other heresies?
In 1954, Igino Giordani, the biographer of Pope Saint Pius X, helpfully gave us a hint in his explanation of the Modernism that plagued Saint Pius X’s papal reign (1903-1914) in words that apply to our present-day encounters with it:
“Modernism consisted principally in a state of mind and way of life that sought to make over Christianity, rationalistically explaining away its difficulties to make the religion acceptable to the thinking of the day.”[8] [Emphasis added.]
The Heresy of Modernism consisted principally in a state of mind and way of life that departed markedly from the state of mind and way of life instilled in us by Catholicism itself in order to change Catholicism and thereby make it “acceptable to the thinking of the day.”
Because Modernism seeks to make “the thinking of the day” an influential criterion for explaining Catholic doctrine, understandings of Catholic doctrine will evolve with “the thinking of the day.” Think about it: Accessing the thinking of the day in order to reconcile our Church with the “wisdom” of modern thinking means that there can be no Eternal Catholic Truth at all in “Modernist” Catholicism.
Modernist thought changes with the times to conform to the times. It is what Cardinal Joseph Ratzinger (who became Pope Benedict XVI) was referencing when he cautioned against an unrestrained and unfiltered openness to “the wisdom of the world.”[9]
God, however, regards “the wisdom of the world” as “foolishness”—we know this from the Bible itself. Saint Paul actually warned us about the very essence of what we’re discussing today as the Heresy of Modernism: “[T]he wisdom of this world is foolishness with God.”[10]
Moreover, an openness to “the wisdom of this world” in order to make Catholic Truths acceptable to this world’s ever-changing “wisdom” seems to fit neatly into the “sap and substance” of all heresies in Pope Saint Pius X’s condemnatory definition of Modernism as “the synthesis of all heresies.”
The Sly and Tacit Nullification of the Heresy of Modernism
Ever since the Second Vatican Council, the Heresy of Modernism (especially as sagely understood as quoted above in paragraph 39 of Pascendi) has been a growing phenomenon within our Catholic Church. During that same period of time, Modernism as a Heresy has been a matter of rapidly diminishing concern to the Hierarchy of our Catholic Church (as incongruous as that might seem at first glance). Few if any of our current Catholic Hierarchy write about or even mention Modernism as a genuine heresy.
It’s not as if Pope Saint Pius X just dropped his definition of Modernism as a Heresy into his encyclical and then let it fade away into oblivion. He took serious and forceful steps to insure its implementation for the future.
On September 1, 1910, Pope Saint Pius X issued a motu proprio entitled Sacrorum Antistitum[11] in which he mandated that an Oath Against the Heresy of Modernism be taken by all Catholic seminarians before being ordained to the sub-diaconate on their way to the priesthood. Then, in 1918, four years after the death of Saint Pius X, the Vatican’s Sacred Congregation of the Holy Office declared that the motu proprio on the Oath Against the Heresy of Modernism must remain in full force until the Holy See declares otherwise.[12] The Holy See did declare otherwise, but not until July 17, 1967 (more than a year after the closing of the Second Vatican Council).[13]
Members of Vatican II Violated Their Oath Against Modernism
Yes, every member of the Second Vatican Council who cast his final vote of approval for all the teachings of the Council, including the problematic teachings implicating the Heresy of Modernism, had taken the Oath Against the Heresy of Modernism mandated by Pope Saint Pius X—a mandate that remained in full force until more than a year after the closing of the Second Vatican Council. The one lone exception was Pope John XXIII, who was ordained in 1904 (six years before Pope Saint Pius X’s oath requirement) and died in June of 1963, early in the Vatican II proceedings, long before the casting of a final vote.
The implications are startling. With only that one lone exception, every bishop, archbishop, and cardinal who participated in the Second Vatican Council and every Vatican II peritus who was also a priest had taken the Oath Against the Heresy of Modernism.
Archbishop Carlo Maria Viganò, who served as Apostolic Nuncio to the United States from 2011 to 2016, has confirmed the massive violation of the Oath Against the Heresy of Modernism:
“I confirm that, according to the canonical norms then in vigor, all the bishops who participated in the Second Vatican Council and all the clerics with positions in the commissions swore the Iusiurandum anti modernisticum [i.e., the Oath Against Modernism] together with the Professio Fidei [Profession of Faith]. Certainly those who at the Council rejected the preparatory schemas prepared by the Holy Office and played a decisive role in the drafting of the most controversial texts violated their oath sworn on the Holy Gospels; but I do not think that for them this posed a serious problem of conscience.”[14]
Every ordained participant in the Second Vatican Council (except Pope John XXIII) was under an oath-bound obligation to Almighty God, “with due reverence [to] submit and adhere with [his] whole heart to the condemnations, declarations, and all the prescripts contained in the encyclical Pascendi.”[15]
How can one who is oath-bound to support the papal condemnations of Modernism as a Heresy vote to “correct” or “counter” those condemnations? What are we to believe? Are we to believe that those who voted in favor of the heretical teachings of Vatican II intentionally violated the Oath Against Modernism that they had taken? That they forgot their oath? Archbishop Carlo Maria Viganò has given the most candid and (in my opinion) most obvious answer to those quandaries. His answer is key to his understanding of why the obligation to take the Oath Against Modernism was abolished in the aftermath of Vatican II:
“The abolition of the Iusiurandum Antimodernisticum [i.e., the Oath Against Modernism] was part of a plan to dismantle the disciplinary structure of the Church, precisely at the moment in which the threat of the adulteration of Faith and Morals by the Innovators was greatest.”[16]
In the aftermath of Vatican II, when enthusiasm for regarding “the thinking of the day” as being a proper criterion for discerning religious truth was rampant, and when the “spirit of Vatican II” was loudest in proclaiming an unrestrained and unfiltered openness to “the wisdom of the world”—at that moment “in which the threat of the adulteration of Faith and Morals by the Innovators was greatest”—our Catholic Church set itself (and us) on the path that it has now followed for more than six decades in the wake of the Second Vatican Council.
Our current Holy Father, Pope Leo XIV, has recently begun a series of talks on the Second Vatican Council urging Catholics throughout the world to familiarize themselves with the documents of the Second Vatican Council so that they will “continue to be inspired by its prophetic teachings.”[17] His complete commitment to all the teachings of the Second Vatican Council became evident very early in his papacy.
Pope Leo XIV Urges ‘Complete Commitment’ to Vatican II
Pope Leo XIV may have demonstrated his “complete” lack of concern over the heretical Modernist teachings in Vatican II’s documents very early in his papal reign. In his address to the College of Cardinals on Saturday, May 10, 2025, just two days after his election as pope, he invited all the cardinals to commit themselves completely to the Vatican II’s teachings:
“I would like us to renew together today our complete commitment to the path that the universal Church has now followed for decades in the wake of the Second Vatican Council. Pope Francis masterfully and concretely set it forth in the Apostolic Exhortation Evangelii Gaudium, from which I would like to highlight several fundamental points: the return to the primacy of Christ in proclamation; the missionary conversion of the entire Christian community; growth in collegiality and synodality; attention to the sensus fidei, especially in its most authentic and inclusive forms, such as popular piety; loving care for the least and the rejected; courageous and trusting dialogue with the contemporary world in its various components and realities; Second Vatican Council, Pastoral Constitution Gaudium et Spes.[18]
Pope Leo XIV is now committing all of us, i.e., the entire Catholic Church, to follow that path—i.e., “the path that the universal Church has now followed for decades in the wake of the Second Vatican Council” by joining together in a “courageous and trusting dialogue with the contemporary world in its various components and realities.”
Conclusion
We find ourselves in the midst of the covert nullification of the Heresy of Modernism—a nullification covertly orchestrated by members of the current hierarchy of our Catholic Church in order to turn our Church’s century-old dogma condemning Modernism as a Heresy into a forgotten, no-longer-operative nonentity—thus paving the way for the previously controversial Modernist teachings of the Second Vatican Council to be recognized as being super-dogmatically infallible, and for the very essence of the Heresy of Modernism to to be injected into the Synodality movement.
All of us, including the participants in the Synodality movement, are now ordered to follow all the teachings of the Second Vatican Council by engaging in a “trusting dialogue with the contemporary world.” Thus, those few Catholics who still accept Saint Paul’s clear biblical warning that “the wisdom of this world is foolishness with God”[19] find themselves in a dilemma of biblical proportions.
Raymond B. Marcin is Professor of Law Emeritus, The Catholic University of America
Footnotes
[1] The credit for this pithy (and arguably accurate) quote belongs to an Australian theologian, Rev. Ormond Rush. See, on the Internet, https://australiancardijninstitute.org/synodality-vatican-ii-nutshell/
[2] See, on the Internet, the “Vademecum” on the Synod at https://www.usccb.org/resources/Vademecum-EN-A4.pdf .
[3] See, on the Internet, https://www.synod.va/content/dam/synod/news/2022-10-10_cvii/2022.10.10_Messaggio-Segreteria-Sinodo_EN.pdf .
[4] See https://australiancardijninstitute.org/synodality-vatican-ii-nutshell/
[5] See Pope Saint Pius X’s encyclical Pascendi Dominici Gregis on the Internet at https://www.vatican.va/content/pius-x/en/encyclicals/documents/hf_p-x_enc_19070908_pascendi-dominici-gregis.html . Hereinafter cited as “Pascendi.”
[6] See Fr. Dominic Bourmaud, One Hundred Years of Modernism (Angelus Press, 2006). Also, for a first-hand account of the emergence of the heresy of Modernism in the culture of Catholic-Seminary life on the eve of the Second Vatican Council, see: https://www.lifesitenews.com/opinion/my-experience-with-modernism-in-a-catholic-seminary-in-the-late-1950s/ .
[7] See Pascendi, footnote 2, supra, paragraph 39.
[8] Igino Giordani, Pius X: A Country Priest, p. 153 (1954).
[9] Joseph Cardinal Ratzinger with Vittorio Messori, The Ratzinger Report: An Exclusive Interview on the State of the Church, pp. 36-37 (1985).
[10] 1st Corinthians. 3:19.
[11] See, in the Internet, https://www.fisheaters.com/sacrorum.html
[12] See The Code of Canon Law: A Text and Commentary (eds. James A. Coriden, Thomas J. Green & Donald E. Heintschel, Paulist Press, 1985), p. 585.
[13] See “Oath against Modernism” in The Harper Collins Encyclopedia of Catholicism, ed. Richard P. McBrien (1995), p. 926.
[14] “Abp. Viganò on St. Pius X’s ‘Oath Against Modernism’, Its Abolition by Paul VI,” Catholic Family News, Jan. 11, 2021.
[15] St. Pius X, Sacrorum Antistitum (The Oath Against Modernism).
[16] Abp. Viganò, “St. Pius X’s ‘Oath Against Modernism’, Its Abolition by Paul VI,” Catholic Family News, Jan. 11, 2021.
[17] According to an article published on the Internet by the United States Conference of Catholic Bishops. See https://www.usccb.org/news/2026/pope-leo-xiv-calls-catholics-rediscover-vatican-ii-teachings .
[18] https://www.vatican.va/content/leo-xiv/en/speeches/2025/may/documents/20250510-collegio-cardinalizio.html [Emphasis added.]
[19] 1 Corinthians 3:19.