Aeterni Patris and 21st Century Catholic Theology

With the encyclical letter Aeterni Patris (1879), Pope Leo XIII initiated a “Thomistic Revival” ordered to engagement with contemporary culture and modern intellectual currents. As historians have observed, the predominant orientation of the Leonine Revival was one of response.¹ Leo XIII was concerned that Christians were falling prey to the deleterious influence of modern ideas.² A corruption of sound thinking eventually results in a deterioration of holy living. The pontiff recognized that the thought of St. Thomas Aquinas could serve as an effective resource for responsible engagement with the questions, concerns, and the errors of the modern period. Thomism would thus serve the intellectual, spiritual, and cultural health of the modern world.³

Specifically, the Leonine Revival was primarily philosophical in nature.⁴ Although theological concerns were not completely outside the purview of the 19^th century rediscovery of the person and the work of St. Thomas Aquinas, matters residing within the domain of reason were the main focus of the revival. The impetus for this focus, of course, was the rising influence of modern philosophy—even upon Christian thought. Philosophical ideas tied to Kant and Hegel (and soon Marx), for example, raised significant questions and proposed radical alternatives to the philosophical methods of more realist thought.⁵ The questions of the modern world were primarily philosophical (and political) at this time.⁶ Hence, the Church’s response to the questions of the time met the world on its own plane, so to speak.

The philosophical response of the Leonine Revival took place during a time when Catholic (and, broadly, Christian) culture still enjoyed a certain prominence and integrity. The Christian religion was still widely practiced in the late 19^th century. Indeed, even after the damage society suffered after the World Wars of the early twentieth century, Christianity continued to shape society and culture. The atrocities associated with these global conflicts did not immediately dampen the culture of faith. Rather, many people instinctively turned to the Church for answers to the existential crises of the given moment. The number of vocations during the post-War periods attest to the search for answers in the Church. After returning from the War, for example, many former veterans entered the seminary or religious life in an effort to find meaning in the face of the destruction that they had experienced.

Christianity prospered during and after the wars.⁷ Although the “problem of evil” had assumed an empirical form and an international scope, the vast majority of world members hesitated to embrace a godless world. Indeed, the world’s desire for a religious interpretation of these atrocities thrust the Christian intellectuals of the time into the spotlight. The world wanted answers to the questions that everyone grappled with. And the Christian intellectual—and the theologian in particular—was the one from whom many sought the answers.

As the 19th century ceded to the 20th century, philosophical concerns likewise ceded to more theological concerns in the public arena. One could argue about whether or not philosophy actually ceded to modern theology. Perhaps it is more accurate to say that the philosophical concerns of the 19th century were assimilated into the theological presentations of faith that occupied the attention and interest of 20^th-century thinkers. Nonetheless, the prominence of theological questions during the 20^th century is above dispute.

With the rise of theology, inextricably conjoined as it is to the concerns of evangelization, those who employed Thomism in various ways and to various degrees found themselves, as theologians, standing in the spotlight (e.g., Yves Congar). In the first part of the 20th century, people cared what theologians thought. And the movement on the part of the Church’s intellectuals was more that of engagement than it was of response. Many Thomistic theologians also participated in this movement of engagement.

Thus, we see the interesting shift from a primarily responsive and even defensive posture vis-à-vis contemporary and modern thought, to a more conversational and evangelistic posture. Finding themselves within the regard, and even at times, the respect of secular thought, theologians began to try to enter into the dialectic and structures of 20^th-century academia. The prominence of theology was due in no small part to the significance of the Second Vatican Council. In the period before, during, and after Vatican II, theology was something that the world took note of. Indeed, as the Benedictine theologian Patrick Granfield observed in 1967: Theologians and theology were “in.”⁸

Theology gradually would eventually lose its public standing, however, as the years after the Second Vatican Council increased. The Christian theologian was no longer on the cover of Time magazine. Theological works were no bestsellers—they were not even published by the large publishing houses, at least, not like in times previous. Theology faculties were eventually replaced by departments of “religious studies.” In a word, the world was no longer interested in theology or theologians.⁹ This indifference to theology and theologians has, more or less, continued to the present day. And Thomism itself was held in a degree of suspicion because of the earnest desire to move beyond the defensive and apologetic concerns associated with the Leonine Revival.

In sum, Thomism’s Leonine prominence is linked to its 19^th-century philosophical response. The momentum of the Leonine Revival continued into the 20^th century, but the focus shifted. The focus of the 20^th century was upon theological topics and questions. The theological topics and questions that attracted interest were quite different. Engagement and dialectic was the order of the day. After the mid-20^th century, however, theology began to fall out of public interest (or, at least, theology did not enjoy the enthusiasm of previous times). Thomism’s utility for the renewal of theology in the 20^th century was initially called into question. Towards the end of the 20^th century, Thomism began to attract interest yet again.

Today, Thomism is no longer a marginalized presence in philosophical and theological literature. Thinkers from a variety of backgrounds and religious convictions find the thought of Thomas Aquinas (at least) interesting (if not insightful). This renewed interest in Thomistic thought invites reflection upon the nature of Thomism itself.

21^st Century Questions: What is Theology? What is Thomism?

What is the role of Thomism in 21^st-century Catholic theology? The types of publications that continue to appear (in a variety of forms and from a variety of presses) suggest that Thomism does have a role to play. But what kind of role?

The answer to this question, I propose, is linked to both (1) the nature of Thomism, and (2) the nature of theology. In other words, the role of Thomism in 21^st-century Catholic theology can only be clearly identified after two foundational questions receive adequate answers: What is Thomism? What is sacred theology? Interestingly, both of these questions are not easy to answer—even as Thomism and sacred theology enjoy renewed interest.

Although many contemporary thinkers find Thomas Aquinas to be interesting, many are skeptical about whether there really is such a thing as “Thomism.” Often, the historical person and the concrete writings of Thomas Aquinas are held up as preferable to the seemingly more elusive phenomenon of “Thomism.” Thus, at times, it can appear that many theologians appreciate the person and the work of Aquinas as something akin to a “Quest for the Historical Thomas.”

Admittedly, historical inquiry is most useful to the work of theologians. Historical methods have proven a positive and formidable presence in the modern academy. Nonetheless, all Catholic theologians would agree that Catholic theology itself transcends the historical plane. In other words, the focus and the ultimate interest of the Catholic theologian today is the same as that of the Catholic theologian in the 13^th century: to know the truth about God. Although historical analysis is certainly useful for theological contemplation, the two cannot be identified with each other. Even if the study of Catholic theology is not opposed to the study of history, Catholic theology is something more than the study of history.

And this point brings us back to our second point: the nature of theology. The practice of Catholic theology continues in the 21^st century. Because of the rational nature of the human person—a nature inclined to know and to love—God will always be an ultimate object of the human person’s contemplation and the final objective of the human person’s life. Fides quaerens intellectum will never go out of style because the God who reveals and the human inclination to know will always remain what they are. Everyone, by nature, is inclined to Catholic theology. And yet there does not seem to be a great deal of formal agreement among Catholic theologians about their shared discipline. What does it mean to “do” Catholic theology?

Few would advocate for an unnuanced return to the program of the Leonine Revival. Not only would such a return be anachronistic it would be ineffective. The concerns and the challenges of our 21^st-century moment are quite different from the concerns and the challenges of Leo XIII’s 19^th-century moment. Catholic thought, as a whole, is also more intent upon expressly theological concerns. (And this is because the program of theological renewal initiated by the Second Vatican Council is still underway.) The agenda of Catholic thought today is not primarily that of response but that of engagement. Most recognize—and, indeed, many celebrate—this agenda and orientation.

And yet, it is certain that participants in the Leonine Revival had a greater awareness of the nature of Thomism, philosophy, and theology than we do today. Or, at least, they recognized the nature of Thomism, philosophy, and theology were important topics of consideration. I propose that further clarity about the nature of Thomism and theology today would also serve the renewal of theology in the 21^st century.

In conclusion, the 19^th-century is not the 21^st-century. The Thomistic Revival of Leo XIII is very different from the theological renewal of the Second Vatican Council. And yet, today, Thomas Aquinas has reemerged as a figure of interest and influence in 21^st century Catholic thought. It would seem, then, that the time is right for deliberate consideration about what Thomism and Catholic theology really are (and what they are not).

Without clarity about the nature of Thomism and Catholic theology, we students of Thomas Aquinas and practitioners of Catholic theology run the risk of losing our identity—and, subsequently, our utility in the 21^st-century renewal of Catholic thought.

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1. See the lecture by James A. Weisheipl, O.P., titled: “Thomism as a Perennial Philosophy” (Chaplain’s Day Address, The Cardinal Stritch College, Milwaukee, WI, March 14, 1965). A version of this lecture was later published as “The Revival of Thomism as a Christian Philosophy” in New Themes in Christian Philosophy, ed. Ralph M. McInerny (Notre Dame, IN: University of Notre Dame Press, 1968), 164–85. See also James Hennesey, S.J., “Leo XIII’s Thomistic Revival: A Political and Philosophical Event,” The Journal of Religion 58 (1978): S185–S197.↩︎

2. Historians have argued that, in this respect, Leo XIII stood both in continuity and in discontinuity with his papal predecessors: “For Leo XIII, no less than for Pius IX before him and for Pius X after him, the combat was joined with modernity. In ways that were true for neither of them, the combat was for Pope Leo an intellectual combat” (James Hennesey, S.J., “Leo XIII: Intellectualizing the Combat with Modernity,” U.S. Catholic Historian 7, no. 4 [1988]: 393–400).↩︎

3. For more about the cultural and political motivations that informed Aeterni Patris, see Russell Hittinger, “Pascendi Dominici Gregis at 100 – Two Modernisms, Two Thomisms: Reflections on the Centenary of Pius X’s Letter Against the Modernists,” Nova et Vetera 5, no. 4 (2007): 843–80.↩︎

4. The title of the emblematic encyclical, Aeterni Patris, explicitly notes this theme: “On the Restoration of Christian Philosophy” (encyclical letter of Pope Leo XIII, August, 4, 1879). Of course, references to “sacred theology” and “scholastic theology” appear in Aeterni Patris. The explicit focus of the encyclical, however, is evidently within the domain of philosophy.↩︎

5. See Hennesey, “Leo XIII,” 394.↩︎

6. “Whoso turns his attention to the bitter strifes of these days and seeks a reason for the troubles that vex public and private life must come to the conclusion that a fruitful cause of the evils which now afflict, as well as those which threaten, us lies in this: that false conclusions concerning divine and human things, which originated in the schools of philosophy, have now crept into all the orders of the State, and have been accepted by the common consent of the masses” (Aeterni Patris, no. 2).↩︎

7. For interesting historical work about the dynamics of Christianity surrounding the international conflicts, see Jonathan H. Ebel, Faith in the Fight: Religion and the American Soldier in the Great War (Princeton, NJ: Princeton University Press, 2010); and Jan Bank and Lieve Gevers, Churches and Religion in the Second World War, trans. Brian Doyle (London: Bloomsbury Academic, 2016).↩︎

8. Patrick Granfield, O.S.B., “Introduction, in Theologians at Work, ed. Patrick Granfield (New York: The Macmillan Company, 1967), vii–xxvi at vii.↩︎

9. See my “The Disappearance of Public Theology from the Public Square” (Church Life Journal, June 25, 2024).↩︎