Abelard, claimed St. Bernard, was a logic-chopping rationalist whose writings were symptomatic of the anti-contemplative theology of the universities. The true theologian is a monastic contemplative. Luther had harsh things to say about Aristotle and the Scholastics who appealed to him. The age we live in challenges any claim to a universal philosophy of enduring historical import, and many Christians concede the matter: We should accept the practical irrelevance of philosophy for the Christian life. Why so?

For one thing, it is said by many Christian thinkers, we no longer live in the age of grand metaphysical schemes. Whatever the glories of Thomism, the old Catholic claim to a universal philosophical patrimony was mind-numbingly naive. This was the error of thinking oneself in possession of a comprehensive form of thought that was applicable to all but that in fact was simply excessively abstract and ahistorical. One of the key insights of modernity is that we are historically conditioned, meshed with other persons relationally in culturally situated contexts outside of which we become unintelligible.

Consequently, there is no way to freeze the process of thought around a set of ahistorical essences or ideas that endure through all of time.

Modern Christianity, we are told, needs to move in the inverse direction: to adopt a narrative vision of reality. Primacy of place should be accorded to experience and phenomenological description, not to intellectual systems. If we want to find God, we need to experience him in history, not try to escape into an abstract universalism. The historical God has wed himself to our fragile human condition, bound himself to us within time and place, and so it is there we can look for him. This way of thinking leads into the contextual theologies of our time: liberation and feminist theologies, dialogue with the world religions, and various forms of pragmatic evangelical theology (promoted both by Protestant evangelicals and by Catholics) that focus on the ethical and psychological concerns of our contemporaries.

A very different objection to emphasizing the importance of a metaphysically ambitious philosophy in Christian life comes in response to scientism, the view that the only real knowledge worth having is that procured through the empirical studies of the modern physical sciences. The hard-core empirical scientist, it is argued, thinks that classical philosophy is nearly as useless a folk medicine as the theologian’s potions. When thought gets serious, it gets scientific.

Given that this is the prevalent worldview of many of our secular contemporaries, why should we work very industriously to articulate a vision of reality that is merely philosophical when that is just a doomed apologetic? We should simply articulate our core Christian beliefs lucidly, try to live an integral Christian witness, and believe in the power of the Resurrection and the grace of God to convert even the most hardened hearts. St. Paul would counsel us to do nothing less; to seek to do more is implicitly to evade the formal imperatives of the gospel.

Last, but not least common, there is the postmodern objection, the most friendly but also the most deadly. It is the viewpoint most prevalent among the professional theologians. Talk of a perennial philosophy”of an analysis of reality that is of enduring and universally applicable import”is intrinsically attractive. But this is fool’s gold. No one human articulation of meaning is necessarily binding on the human intellect. Man is not only a factory of idols but also an endless forger of intellectual systems, and the metaphysics he formulates are pluralistic and mutually exclusive in their incompatibility. Tertullian asked, “What has Athens to do with Jerusalem?” but we can also ask, “What has Athens to do with Königsberg, or the Sorbonne to do with Cambridge?”

Philosophies endlessly and inevitably refute philosophies, and there is no common ground from which to adjudicate what is true philosophically. In fact, people inevitably disagree even on the first principles of rational thought. Our innate aspiration toward universal knowledge can be redeemed only “from above””that is to say, from recourse to divine revelation. The theological truth of the gospel alone, explicated through Christian doctrine, provides a universal and enduring intellectual science of reality. Everything else is a false substitute.

Whatever the power of these objections, they are not novel. Nor are they uniquely Christian in origin. The ancient Greek sophists and atomists employed similar arguments against philosophical realism long ago, and they were contravened by the best classical practices of philosophy itself. Plato and Aristotle, for instance, showed that philosophy can identify a set of enduring structures in reality and that it can offer a perennially valid account of ethical norms. True philosophy cannot be reduced, therefore, to a mere exercise in political manipulation or to a discourse relative only to a given age. Nor can the meaning of things be reduced to a mere study of material parts, such that basic questions about goodness and being are ignored.

The early Church was not indifferent to the arguments of the Greeks but took over this classical form of thought and developed it, as thinkers like Augustine and John Damascene made ambitious use of the philosophical argumentation of Aristotle and Plato. Of course Scholastics like Bonaventure and Aquinas mastered the disciplines of this classical heritage, placing philosophical realism in the service of the Christian faith.

Nor are such practices alien to the Catholic Church in modern times. Already in 1563, the twenty-third session of the Council of Trent underscored the necessity of distinct formation in philosophy for every candidate to the Catholic priesthood, and this emphasis on philosophy (Scholasticism in particular) was taken up in more recent times by the First Vatican Council’s document Dei Filius, Leo XIII’s famous encyclical Aeterni Patris, the statements on priestly formation in the Second Vatican Council’s Optatum Totius, and John Paul II’s Fides et Ratio. John Henry Newman famously argued that, when an idea is essential to the Christian religion, we see it continually reasserted through time in the doctrinal life of the Church as it undergoes development of expression in consistent ways. Scandalous as it may seem to some, by these standards, it pertains to the essence of modern Catholicism to insist on the importance of systematic philosophical studies as an integral part of Christian identity. Why is this?

St. Thomas articulates powerfully why philosophy is important even at the heart of Christian faith. In his commentary on Boethius’ De Trinitate, he gives three reasons why philosophy is essential even to the study of sacred theology. The first concerns the so-called praeambula fidei, or “preambles of faith.” Christian culture has need of philosophy to articulate truths of reason that overlap with truths of revelation, a fact that shows the compatibility and harmony of biblical revelation and natural reason. Philosophy can demonstrate the well-founded character of our core religious aspirations.

Some pertinent examples include the rational acknowledgment of the spiritual soul as a principle of personal identity, which makes human animals radically different from the other animals, despite a shared ancestry; the arguments regarding the existence and nature of God, which also entail apophatic arguments, or arguments concerning what God is not (as a corrective to our caricatures of the divine); and fundamental truths of human morality touching on issues like human equality and the dignity of human life from conception to natural death. In demonstrating these truths, natural intelligence certainly cannot demonstrate the truth of Christianity as such, but it can show”from rational starting points alone”our inherent openness to core biblical truths of faith.

Aquinas is not arguing that philosophy should be instrumentalized into a merely apologetical tool, even less that philosophy should play the role of a substitute for the grace of faith (a kind of epistemological Pelagianism that passes the work of salvation off onto human reason). The issue is the integration of faith and reason within a culture of the intellectual life that is fully respectful of the native powers of human intelligence and, at the same time, of the demands of grace. We must recognize not only where human reason leaves off and revealed mystery begins, but also where revealed mystery presupposes and assumes the truths of natural reason.

Second, Aquinas argues that philosophy allows Christians to challenge the nonbeliever’s objections to Christianity on the grounds of reason alone. To transpose his affirmation into a contemporary idiom, we might say that natural reason can challenge the secularist mentality to acquire a more honest rational openness to religious claims. Philosophy comes to the aid of theology insofar as it is concerned with the inherent vocation of human culture to seek wisdom, or ultimate perspective, in light of the true ultimate causes of reality. At the start of the Metaphysics, Aristotle claims that human beings by nature desire to know, and to know the first causes of everything. Realism means coming to terms with what is first not in our consciousness but in the order of reality, whether that be matter, the demiurge, pure chance, a world-soul, or the transcendent God.

Our university system excels in communicating expertise on a range of disparate subjects, from modern political economy to the poetics of Chaucer, and from microbiology to the study of Confucius, but not in integrating these diverse forms of knowledge into a vision of the whole. Whereas philosophy should arbitrate human reason’s search for the unity of the sciences and first causes, we often see instead either an indifferent resignation in the face of the deeper questions or the arbitrary ideological assertion of false absolutes (often secular ones) by recourse to unargued intuition.

A real response to this dilemma cannot be found only through the promotion of theological doctrine. It requires a philosophical renewal of the capacity of the human person for metaphysical realism. In the face of realist philosophical arguments, the ills of postmodernist perspectivism, the lassitude of indifferentism, and the smugness of anti-supernaturalism can all be seen themselves to be forms of unrealistic thinking, the indulgences of minds that have failed to acknowledge the noble vocation of the human intelligence relentlessly to seek the truth.

Third, philosophy is essential to theology for its health as theology. Christian thought is not an exercise in mere moral posturing or unstructured spirituality. It is serious thought about reality conducted in a human mode: by discursive reasoning that seeks explanations and insights into God based on the things he does in the world, things that are both natural and supernatural.

This is why Aquinas will say that argumentation and demonstration are intellectual activities that are proper to a theologically informed faith, even when that faith takes its starting points from revealed premises. We don’t know by mere natural reason that Jesus Christ is God or that God is triune. But we can reason in light of this revelation that, if Christ is truly God and man, he must possess in himself all that is truly human, such as the capacity to learn intellectually and a human body capable of suffering, as well as all that is properly divine, such as the power to raise the dead. Theology assimilates philosophical methods and claims to consider theologically, then, what it means to speak of the vulnerability of Christ crucified as man, or of his saving power as God, and how the two are present simultaneously in one person: the saving power of the crucified Lord.

Likewise, philosophical reflection helps us to identify concepts that can be used to express the inner mystery of the life of God itself. In his De Trinitate, Augustine saw in effect that he could employ insights into human personhood and the soul from the Greek philosophical tradition in order to speak analogously of the personal life of the Trinity. Aquinas notes that such reflections are based on the solid indications of Scripture but, through recourse to philosophical methods of reflection, simultaneously seek to clarify what the Scriptures indicate. What does it mean to say, for instance, that in God there is an eternal procession of wisdom that we designate as a person under the proper name of the “Word” or Logos (John 1:1“3)? Here the Scriptures themselves invite us to a more precise form of speculative thinking, in the service of the Word of God.

To return to our three objections, then: What should we say about the claim that the return to classically inspired philosophy is a flight toward irrelevant ahistorical abstraction? This is an ironic objection, since classical Scholastic philosophies of the sort once so influential in theology are tradition-based forms of inquiry, historical forms of learning that safeguard reference to classical sources and renew them within new contexts by giving them new applications. This contrasts with many forms of Enlightenment and contemporary Anglo-American philosophy that seek to promulgate an ahistorical, intuitive appeal to universality, absent the encounter with historical tradition.

But we can also make some caveats: The turn that Jean Daniélou, Henri de Lubac, and their peers took toward historical ressourcement in modern theology procured valuable resources for theological reflection against some of the less-than-reasonable objections of Scholastic philosophers. Daniélou and de Lubac wanted to emphasize the dynamic character of history and the role of spiritual experience over and above the study of supposedly abstract metaphysical concepts. The modern theological recovery of an emphasis on experience and historical consciousness does have potential points of contact with the classical insistence on the role of mystical experience, spiritual affectivity, and the contemplative life as a necessary context for theological reflection.

This being said, however, the naivete of the modern critics of Scholastic philosophy (and of some of classical philosophical thinking in general) is to think that a tradition can live by historical erudition alone, or by embracing the philosophical toolkit of the particular moment, without ontological study of the enduring natures and structures of reality. Of course Christian intellectuals need to be concerned about widening the conversation of their interlocutors”both historically and culturally”as a necessary safeguard against intellectual provincialism, but this conversation is intellectually fertile only if it leads back to a deeper synthetic consideration of the very nature of reality.

The aspiration to take different viewpoints and attempt to find the truth implicit within them presupposes that we can build up conclusions around some solid idea of what natures are, what human persons are, what the soul is, what we can know (or not know) of God, and so forth. So principled knowledge is just as essential as the process of conversation, and conceptual understanding is just as crucial as experience of our time and epoch.

This issue becomes more acute when we consider the question of God. For, though God has come to exist among us as a subject of history, the transcendent author of creation is himself neither a history nor a prisoner of our immediate experience. Kant’s influential idea that human understanding cannot consider “causalities” that extend beyond the spatiotemporal realm dooms human thought to intra-historical immanence. A theology that can no longer think philosophically about the transcendence of God is simply no study of God at all. It is perhaps a description of man’s experience of the encounter with God in time, but ultimately it receives its intellectual determinations from the study of man and reinterprets the divine anthropocentrically. To be about God, and to be theocentric in orientation, Christianity has need of a classical philosophical realism.

This response ties into the question raised by the second objection. How ought Christian thought to situate itself vis- -vis the culture of reductionist scientific empiricism? The issue here is not what we should say to a few angry atheist scientists who are jealous of the intellectual prerogatives of metaphysics and who would seek to ape theology in a scientific mode. As long as there are book contracts and Manhattan cocktail parties, there will be people of such ilk.

The main issue is that our culture is so often divided between scientism, which has difficulty acknowledging the specifically human spiritual life; and postmodern relativism, which acknowledges the freedom of thought and self-determination to the denigration of scientific objectivity. Classical philosophy (and particularly the hylomorphism of Aristotle and Aquinas) enables us to hold together a plenary realism regarding the physical world of the human body and the cosmos with an objective study of the irreducible spiritual life of the human person. This spiritual life is exemplified particularly in the manifold works of human reason, which strives for the truth, and in the life of human free will, which strives for happiness through love.

Man is a complex being and so requires a complexity of sciences and arts to be rightly understood. Classical philosophies helps us see the underlying unity in this complexity and so assures a larger form of balanced humanism, one that makes room for all the sciences of man, within a larger conversation of concord and mutual enrichment.

Last, consider the postmodern concern. Do we lack foundations or necessarily binding starting points through which natural reason might convey a universally compelling vision of the tasks of human thought? Is all authentic universality implicitly theological? Perhaps, in our frail and fallen state, it is only under the stimulating and strengthening effects of grace that weakened reason is healed. It does not follow that there are no such things as essentially necessary rational arguments, but only that in the openness to a philosophical argument more is at work than the operation of a mere neutral rationality.

Consequently, universal truth cannot be determined by consulting democratic majorities. The truth of the claim, for instance, that each human being has a spiritual soul does not depend uniquely on whether or not a cogent argument is presented, even if the learner has received sufficient intellectual preparation to understand such an argument. It also depends on a complex existential and religious context: For I am more likely to consider arguments that I have a soul if at the same time I am otherwise seeing, through the eyes of faith, that the spiritual person who I am needs his soul to be saved. The opposite is true as well, however: Even if by faith I believe in the reality of the soul, if I cannot see the rationality of the belief, the faith remains something extrinsic to reason and therefore inherently unstable for me, and potentially painful to embrace.

Philosophical arguments are part of an integral natural search for understanding, and without them a culture of Christian rationality becomes inherently unstable. Whatever its intentions, a postmodern theology that would like to forgo appeal to distinctly philosophical formation will inevitably doom itself not only to cultural irrelevance but even to internal incoherence. For without recourse to the explicit practice of philosophical study in its own right, Christians are unable to receive from the tradition they espouse its own classical practices of thought.

Ignorance of philosophy sterilizes the intellectual reception of the Christian tradition. By failing to sufficiently awaken and maintain in our human culture the native capacity for metaphysical reflection about God, the postmodernist project has become inadvertently but inevitably a further source of the secularization of the human intellect and of human civilization. It thus reproduces the very problem it seeks to contradict.

Western Europe and to some extent North America continue to secularize dramatically. Christian recovery of the classical philosophical heritage will help us address the true challenge of our age: the effective communication of the one Christian faith in the face of the questions and problems of our contemporaries. We should look forward to the task with hope. It has been done before, and, with the help of God, we can do it again. The classical philosophical heritage offers us a powerful resource. It has been tested by the fires of time, and its wisdom endures through the ages. If we engage with it intelligently, this tradition will cast intense light even into the heart of our contemporary world, inviting it to turn away from the irrational shadows of secularism and toward the mystery of God.

Thomas Joseph White, O.P., is director of the Thomistic Institute at the Dominican House of Studies in Washington, D.C., and author of Wisdom in the Face of Modernity: A Study in Thomistic Natural Theology (Sapientia Press).