It is Edmund Husserl’s birthday, and the “Master” has retired to his study, away from the bustle of his party. It is late in the evening, and he is seeking some quiet. He does remark to himself, though, that after all the chatter of the night, “I would appreciate a decent conversation on philosophy to get my mind back on track.”¹ Lo and behold, a knock on the door issues and in walks Thomas Aquinas, the medieval master, on an errand from beyond the grave. It turns out that Heaven’s occupations have not left Aquinas ignorant of Husserl, as the friar confesses: “from afar have I followed with great interest how your philosophy arose and evolved.” Aquinas accepts the invitation to take a seat, and the meeting of Husserl’s hidden wish for a late-night philosophic discussion is underway.

Thus begins Edith Stein’s “What is Philosophy? A Conversation Between Edmund Husserl and Thomas Aquinas.” Written as a dialogue, the work commemorated Husserl’s seventieth birthday. Stein had been a stand-out student of Husserl, and was for a time his assistant. Later in life, she would be baptized into the Catholic Church and, eventually, enter the Discalced Carmelite order. Along this path, she would come to appreciate and inhabit the thought of Thomas Aquinas. Thus, the essay’s framing and form is quite fitting. While the scope of that essay is rather sweeping, will content itself with a look at the dialogue’s treatment of the relationship between faith and reason.

Husserl and Aquinas begin by discussing the very nature of philosophy. Early on Thomas tells of the philosophia perennis: “the spirit of genuine philosophy alive in every true philosopher, in anyone who cannot resist an inner need to search out the λόγος [logos, mind, reason] of this world, its ratio.” It is the “born philosopher” that “brings this spirit with him into the world as potency.” This potency’s actualization occurs when the born lover of wisdom comes under the influence of a “mature philosopher,” even if this traverses time and place. It is this dynamic that made Plato, Aristotle, and Augustine teachers for Aquinas.

But philosophy is not just a spirit—an ethos—but a science, and a rigorous one at that. Aquinas and Husserl agree on this point: “philosophy is not feeling and fancy, soaring enthusiasm; it is a matter of the serious, sober inquiry of reason.” It is the logos that is “the force behind all that is,” and “understanding can uncover step by step first one aspect of this λόγος, then another, and so on, as long as it moves ahead in accordance with the principle of the most stringent intellectual honor.”

Agreeing on this general commitment, the two now wade into a region of difference. As Aquinas discourses on the relationship between natural and supernatural reason, a point of divergence between Husserl’s phenomenology and Thomas’s Scholasticism emerges. It pertains to the limits of human reason. As Aquinas tells Husserl:

You proceed as though our reason had no limits in principle. Certainly, its task is endless and knowledge is an unending process. But it heads straight for its goal: the full truth. . . . [its] way is endless, and this implies that it can never reach its goal but only approach it step by step.

Consequently, philosophy will ultimately be fragmentary in its knowing. Yet, this is only to be said of human reason, natural reason. There is still yet another way of knowing. As Aquinas states: “I can never admit that this is the only way of knowledge, nor that truth is but an idea that must be actualized in an unending process—and hence never fully.” He acknowledges that the fullness of truth simply is: “Full Truth is.” And there is a kind of knowledge that thoroughly knows this truth in restful fullness, that is, divine knowledge. But this knowledge need not remain sequestered in the divine mind, it “can impart of its fullness to other minds and in fact does so in the measure of their capacity to understand.”

Interestingly, Stein has Aquinas then tell of natural reason’s ultimate teleological goal in reference to its prelapsarian nature. Natural reason can presently share in divine knowledge, though it has limits in the here and now. But, in light of “its original makeup,” our minds have the capacity to access something of what is “beyond our knowledge naturally.” Though now journeying through life, one day it will reach that ultimate goal, “our heavenly fatherland,” where it “will embrace everything it can grasp.” Even more, “it will see this everything in a single intuition.”

At this point, Thomas broaches the realm of faith and its relation to reason, for something of what our vision will behold in the “heavenly fatherland” has, in fact, been revealed already. It has been shown so as to illumine the path toward itself, the straight and narrow road to the satisfaction of all our longing. Before entry to this joy, faith grasps that which has been revealed. And this is yet a “second way of gaining knowledge alongside the natural way.” Strictly speaking, something is a matter of faith only if it lies beyond the powers of our natural capacity for discovery. Yet, there are elements of revelation that could have been arrived at by the powers of natural reason, though these would be known “by only a few people or without sufficient certainty.”

Husserl now responds. He has never, he says, contested the “right to faith.” It is to religion what the senses are to experiences external to the self. As such, “faith is the proper appeal for religion, but not for philosophy.” It is true that the philosophy of religion is a matter of reason and not faith. It seeks a rational understanding of faith, but, “the theory of faith does not consist of acts of faith.” It is, rather, “rational knowledge that can bear upon and reflect upon acts of faith.” The act of faith proper, however, should not impact other realms of philosophic inquiry. As Husserl somewhat critically summarizes Aquinas at this point: “Indeed what you were saying seems to be nothing short of giving faith a deciding vote on crucial questions in the theory of knowledge.”

Of course, Aquinas admits, if faith is understood as being irrational and solely the realm of sentiment and feeling, it should have no part in delimiting the boundaries of human reason, and “I would not give it a say in philosophical issues either.” But faith is not irrational; it bears upon questions of truth. In fact, faith is a path to truth, “indeed, in the first place it is a way to truths—plural—which would otherwise be closed to us, and in the second place it is the surest way to truth.” As Aquinas’s reasoning unfolds, Stein will even go so far as to have him state that the knowledge acquired through faith possesses a certainty that no other knowing in this life can attain.

As it is, then, faith is relevant to philosophy in two ways: philosophy has a material as well as a formal dependence on faith.

The material dependence results from philosophy’s aspiration to the fullness of truth and the greatest certainty. As faith makes available truths that cannot be arrived at by natural reason alone, and makes them known with such a level of certitude, philosophy cannot ignore or reject faith’s knowledge, “without renouncing its universal claim to truth.” Further, to reject those aspects of truth revealed through faith would render the remainder of human knowledge vulnerable to the corruption of falsehood, this due to the “organic interrelationship to all truth.” Without faith’s knowledge, human knowing remains fragmented, with some regions cut off from others, and in this state that which remains “can appear in a false light.”

This leads, then, to the formal dependence of philosophy on faith. If faith’s certainty is the best we can hope for, and philosophy, nonetheless, aspires to the greatest certainty, “then philosophy must make the certainty of faith its own.” Philosophy can do this by accepting the truths of faith as its own, and then, in order to secure its certitude, philosophy can use the datum of faith “as the final criterion by which to gauge all other truths.”

Perhaps, then, it is better to speak of a natural and supernatural philosophy—is it not possible to speak of theology in this way? These two modes are not hermetically sealed off from one another. They can, in fact, aid each other on the way to truth, which is the goal of reason, as it were. Supernatural reason can recognize and mark off the limits of natural reason. It can also vet the veracity of the findings of natural reason. Supernatural reason also bestows upon natural reason truths that would have been otherwise inaccessible to it. In this way, the goal of all philosophy—“a rational understanding of the world, that is, a metaphysics”—can be arrived at “only by natural and supernatural reason working together.” For itself, natural reason is to analyze the truths revealed by faith, utilizing them in its own endeavors. Thus enlightened, it can, as Stein’s Aquinas has it, go “its own way in harmony with supernatural truth.”

Husserl, understandably, is discomfited by Aquinas’s discourse. Stein’s Husserl leaves much unsaid and to the side. At this point he relegates himself to but one question: “if faith is the final criterion of all other truth, what is the criterion of faith itself? What guarantees that the certainty of my faith is genuine?” The reader almost senses a pause before Aquinas’s response: “probably the best answer is that faith is its own guarantee.” The God that has revealed is the guarantor of this revelation’s veracity. Lest we fall into some circuitous tail-chasing, Thomas assures us that these are but two sides of the coin, so to speak.

Surely this would not satisfy his interlocutor, so Aquinas continues: “all we can do is point out that for the believer such is the certainty of faith that it relativizes all other certainty.” This certainty of faith is a “gift of grace,” and the recipient is now willing to abandon any “supposed knowledge” that stands in contradiction to this faith. Having thus accepted this certain revelation, it is now the task of the “understanding and will to draw the theoretical and practical consequences there-from.”

The dialogue goes on to discuss philosophy’s starting point, the nature of truth, some metaphysical considerations, and other matters aside. But this present essay’s recounting suffices to open up a number of germane questions elicited by Stein’s narrative. Perhaps to close we can point to three in particular:

1. Is it, in the end, acceptable to have philosophy depicted as so very beholden to, and dependent upon, supernatural reason, faith, and theology? Can it not stand alone? Can the believing philosopher ever conduct a sustained philosophical inquiry, or must all such endeavors be done with at least the periodic crossing into theological matters, if not methods? Alternatively, if philosophy is to attain its inherent goals—truth and certainty—must it ultimately cease being itself? Is becoming theology philosophy’s apotheosis?
2. If faith is a “gift of grace,” are some truths unavailable to certain individuals, those that have either not been given or having been offered it, have not accepted, the gift of faith? Or, is it possible that the truths of the faith can be received by those that have been so gifted, who in turn can pass along these truths to the non-believer, such that even non-believers can have some share in supernatural knowledge?
3. If Stein is right, then, which personalities emerge in the tradition of rational enquiry as philosophers par excellence? Who would show themselves as seriously deficient due to a cordoning off of natural reason from the influence of the supernatural (either to maintain philosophy’s independence or through the denial of the divine as such)?

These questions, ultimately, vex any person committed to both philosophy and a reasonable faith. And answers emerge and reemerge throughout the Tradition. Nonetheless, while we grasp and grapple in the dimmed and refracted light shown in this life, I’m confident the answer to these questions will be luminously shown in the Full Truth seen presently by Husserl, Aquinas, and Stein.

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