Twentieth-century Catholic theology was marked by intense debates, especially around the so-called "new theology" (or nouvelle théologie), a movement that sought to renew ecclesial thought by incorporating elements of modern philosophy and reinterpreting patristic and scholastic sources. In this context, Karl Rahner (1904-1984), a German Jesuit, emerged as a central figure, often considered the "father" of this post-conciliar progressive current. However, his ideas have been the subject of severe criticism from traditionalist theologians, among whom Monsignor Jaime Mercant Simó stands out. A priest of the Diocese of Mallorca (Spain), a professor, and a doctor in Thomistic Studies and in Law and Social Sciences, he is the author of works such as La metafísica del conocimiento de Karl Rahner: análisis de "Espíritu en el mundo" (2015) and Los fundamentos filosóficos de la teología trascendental de Karl Rahner (2017). Mercant Simó accuses Rahner of distorting the authentic Thomism of St. Thomas Aquinas, promoting an idealistic subjectivism that compromises fundamental Catholic dogmas.
📜 The Context of the New Theology and the Rise of Rahner
The "new theology" emerged in the 1930s, influenced by theologians like Henri de Lubac, Pierre Teilhard de Chardin, and Rahner himself, who sought to overcome what they saw as a rigid and "extrinsic" neo-scholasticism. Inspired by Pius X's encyclical Pascendi Dominici Gregis (1907), which condemned modernism as a synthesis of all heresies, critics like Mercant Simó see in this current a veiled continuation of modernism: an immanentism that reduces divine Revelation to subjective human experience, prioritizing anthropology over divine ontology.
After the Second Vatican Council (1962-1965), Rahner became the "prince of the new theologians," with works such as Geist in Welt (Spirit in the World, 1939) and Hörer des Wortes (Hearers of the Word, 1941). His transcendental anthropological theology starts from the idea that man is a "hearer of the Word," a priori open to divine transcendence. Concepts like the "supernatural existential" (a grace inherent to human nature) and "anonymous Christianity" (salvation possible outside the visible Church) aim to dialogue with the secular world, but for Mercant, they represent a reduction of theology to a philosophy of religion, where God is accessible only through human self-awareness.
Mercant Simó argues that Rahner, despite profusely citing Aquinas, "deforms Thomistic texts at his pleasure," adapting them to non-Thomistic influences like Kant, Hegel, Heidegger, and Francisco Suárez. This criticism is not isolated: it echoes thinkers like Cornelio Fabro (The Anthropological Turn of Karl Rahner, 1974), who saw Rahner as a "refuted guest" in Thomism.
🔀 The Fundamental Dichotomy: Metaphysics of Knowledge versus Metaphysics of Being
The core of Mercant Simó's critique is not merely philosophical, but ontological-epistemological: Rahner replaces the metaphysics of being (centered on esse as the act of being, the foundation of extramental reality) with a metaphysics of knowledge (centered on the knowing subject as the constitutive principle of being). This inversion is the axis of the entire Thomistic deformation operated by Rahner.
🕯️ Metaphysics of Being in St. Thomas Aquinas
In classical Thomism, metaphysics is primarily realist ontology: being (ens) is the first object of the intellect, and esse (the act of being) is the deepest principle of reality. Human knowledge begins with the external sensible (phantasmata), through abstraction reaches the essence (quidditas), and, through judgment, arrives at esse as real existence. The conversio ad phantasmata is a return to the sensible world to ground intelligible knowledge. The intellect does not create being but receives and participates in it. God is known analogically, as the First Cause of being, not as the object of a subjective anticipation. This approach safeguards the transcendence of God and the objectivity of truth, indispensable foundations for a theology that does not dissolve into subjectivity. The soul, though spiritual, intrinsically depends on the body to know in this life, which reinforces the realism of knowledge (Garrigou-Lagrange, 1989, v. 1, p. 49).
🧠 Metaphysics of Knowledge in Karl Rahner
Rahner, in Geist in Welt, inverts this order: knowledge does not start from being but constitutes being. The central concept is the Vorgriff (pre-apprehension) of being in general, an a priori movement of the spirit that precedes any contact with the world. The agent intellect does not abstract from the sensible but illuminates itself, transforming the subject into a "spirit in the world." The phantasm is not a source but a product of the subject's transcendental structure. Thus:
Being (Sein) is reduced to the being of consciousness (beisichselbstsein).
The world has no independent existence: it is a totality immanent to the spirit.
Knowledge is not the reception of the real but the self-positing of the subject.
Mercant Simó demonstrates, through a textual comparison between Aquinas (in Latin) and Rahner (in German), that this structure is Kantian-Heideggerian, not Thomistic: the transcendental subject constitutes the object, and being is a phenomenon of consciousness. This eliminates the Thomistic distinction between essence and existence, reducing esse to a mental judgment, not a real act.
📉 Consequences of the Ontological Inversion
This shift of axis—from being to knowledge—has devastating implications:
AspectMetaphysics of Being (Thomas)Metaphysics of Knowledge (Rahner)
First Object Esse (act of being) Vorgriff (pre-apprehension of being)
Subject-Object Relation Subject receives the object Subject constitutes the object
Knowledge of God Analogy of being (from created being) Self-transcendence of the subject
World Extramental reality, participated in Totality immanent to the spirit
Man Hylomorphic composite (body-soul) Spirit that self-posits in the world
Grace Elevation of created being (participation in the divine nature) Inherent supernatural existential
Mercant argues that by prioritizing knowledge, Rahner collapses the three metaphysical ideas (God, Soul, World) into the Soul (self-awareness), promoting an idealistic monism. This is not just a philosophical error: it is an ontological heresy, as it attributes to man a creative power that belongs only to God.
🔍 The Specific Criticisms of Rahner's Metaphysics of Knowledge
The core of Mercant's critique lies in the analysis of Geist in Welt, where Rahner founds his metaphysics of knowledge. Mercant dismantles it point by point, confronting original texts in Greek, Latin, and German:
Distortion of Abstraction and the Conversio ad Phantasmata: In Thomism, abstraction produces intelligible species as similitudo rei (likeness of external things). Rahner inverts this: the agent intellect is a "light" that illuminates itself, eliminating the distinction between the sensible and the intelligible. Mercant argues that this reduces metaphysics to anthropology, making man the center of being.
Subjectivism and Immanentism: Rahner identifies being (Sein) with the being of consciousness, promoting an idealistic monism. Mercant sees in this a Cartesian-Kantian heritage: knowledge is "being-with-oneself," without reference to external reality, leading to ontologism and pantheism.
The Anthropological Turn and the Reduction of Metaphysical Ideas: Rahner collapses the three metaphysical ideas into the Soul, ignoring Aquinas's hylomorphic view. Mercant highlights that this brings Rahner closer to Heideggerian existentialism.
Stylistic and Ideological Ambiguity: Mercant accuses Rahner of using obscure language to mask contradictions, violating Thomistic clarity.
⛪ Implications for Catholic Doctrine and the Church
Mercant's criticisms go beyond philosophy: they reveal how Rahnerian theology compromises central dogmas, because it starts from a metaphysics of knowledge, not of being:
Christology and Trinity: Rahner avoids the term "person" in Christology, questioning the hypostatic unity of Christ. In the Trinity, he reduces pluralism to "spirit," promoting unitarianism—because there is no distinct real esse, only consciousness.
Grace and Salvation: The "supernatural existential" makes grace inherent to nature, diluting the distinction between the natural and the supernatural—because there is no created esse that needs to be elevated. This directly contradicts the traditional doctrine that grace is a participation in the intimate life of God, a completely gratuitous gift that elevates the creature to an order immeasurably superior to its own nature. Sanctifying grace is not a demand of nature, but a "seed of glory" that makes us capable of the beatific vision (Garrigou-Lagrange, 1989, v. 1, p. 29, 34). Rahner's conception, by making grace a permanent structure of human existence, risks naturalizing it, diminishing the perception of its gratuity and its transcendent purpose, which is immediate union with God.
Ecclesial Consequences: Mercant links Rahner to the post-conciliar progressivism that fostered liturgical and ecumenical adaptations along a Protestant model, eroding Catholic identity. He sees in this a "liquidation of Catholic values." This "liquidation" can be seen as the result of a theology that, having lost its ontological foundation, becomes susceptible to the fluctuations of contemporary culture and philosophy, losing sight of the "eternal truth" of which the theologian should be a guardian. The result is a Christianity that, instead of elevating the world to God, lowers itself to the level of the world (Garrigou-Lagrange, 1989, v. 2, p. 347).
🕊️ Conclusion: A Call to Return to Authentic Thomism
Monsignor Jaime Mercant Simó's critique of Karl Rahner and the new theology is not mere academicism, but a passionate defense of Catholic orthodoxy. By exposing the fatal inversion—from the metaphysics of being to the metaphysics of knowledge—Mercant calls for a return to the realism of St. Thomas Aquinas, where theology is anchored in divine Revelation, not in subjective human experience. In a time of ecclesial confusion, his works serve as an antidote against anthropocentrism, reaffirming that divine truth transcends man. For the faithful and scholars, delving into this topic means confronting the tensions between tradition and modernity, opting for fidelity to the perennial doctrine of the Church—the one that begins with being, not with the self. The true interior life, after all, is not a conversation of man with himself, but an intimate conversation with God, in which the selfish "I" progressively gives way to the love of God and of souls in Him (Garrigou-Lagrange, 1989, v. 1, p. 4, 43).
📚 References
GARRIGOU-LAGRANGE, Reginald. The Three Ages of the Interior Life: Prelude of Eternal Life. Volume One. Rockford: TAN Books and Publishers, 1989.
GARRIGOU-LAGRANGE, Reginald. The Three Ages of the Interior Life: Prelude of Eternal Life. Volume Two. Rockford: TAN Books and Publishers, 1989.
MERCANT SIMÓ, Jaime. La metafísica del conocimiento de Karl Rahner: análisis de "Espíritu en el mundo". Barcelona: Scire, 2015.
MERCANT SIMÓ, Jaime. Los fundamentos filosóficos de la teología trascendental de Karl Rahner. Barcelona: Balmes, 2017.
