Passion of the Western Mind

by Tarnas, Richard

  For Aquinas, like Aristotle, we know concrete things first, then we can know universals. For Plato and Augustine, the reverse was true. Augustine’s theory of knowledge rested on the epistemological certainty that man could know truth by being illuminated directly from within by the knowledge of God’s transcendent Ideas. These Ideas constitute the Logos, Christ, Augustine’s inward teacher, who contains all Ideas and who in an interior manner illuminates the human intellect. Although Aquinas would retain aspects of Augustine’s view, he could not embrace Plato’s epistemological dependence on the Ideas alone. Man is matter as well as spirit, and human cognition must reflect both principles: knowledge is derived from the sensory experience of concrete particulars, from which universals can be abstracted, and this knowledge has validity because in recognizing the universal in singular things the human mind is intellectually participating, however indirectly, in the original pattern by which God created that thing. Here Aquinas again integrated Plato with Aristotle by identifying the soul’s capacity for such participation with Aristotle’s active intellect, or nous—though he strenuously opposed those interpreters of Aristotle who would make the nous a single separate entity common to all mankind, which would tend to deny individual intelligence and moral responsibility, as well as the immortality of the individual soul.

  Aquinas agreed that a kind of reality can be ascribed to the Ideas, as eternal types in the divine intellect akin to the forms that exist in an architect’s mind prior to his constructing a building, but he denied that human beings can directly know them in this life. Only a more perfect (i.e., angelic) intelligence can enjoy intimate contact with God’s eternal notions and grasp them directly. Earthly man, however, understands things in the light of those eternal types in the same way that he sees things in the light of the Sun. The mind without sensory experience is a blank slate, in a state of potentiality with regard to things intelligible. But sensory experience without the active intellect would be unintelligible, and thus effectively blind. In his present condition, man must focus his active intellect, which contains within it the likeness of the divine light, onto his sensory experience of the physical world if he is going to attempt to grasp truth, and from that point he may proceed by means of discursive reasoning in the Aristotelian manner. In Aquinas’s philosophy, the Ideas recede into the background, and emphasis is instead placed on sensory experience as that which provides the necessary particular sense images that the active intellect illuminates so as to abstract intelligible species or concepts.

  Aquinas thus offered a solution to one of the central and most enduring problems of Scholastic philosophy, the problem of universals. The early medieval doctrine of universals was characteristically that of “Realism”—i.e., the universal existed as a real entity. Since the time of Boethius, opinion was divided as to whether the universal was real in the Platonic sense, as a transcendent ideal independent of the concrete particular, or in the Aristotelian sense, as an immanent form fully associated with its individual material embodiment. Under Augustine’s influence, the Platonic interpretation was usually favored. Yet in either case the reality of universals was so generally affirmed that Anselm, for example, argued from the existence of the Idea to the existence of the particular, the derivative of the Idea. But Roscellinus, a contemporary of Anselm and teacher of Abelard, criticized the belief in real universals, asserting that the latter were merely words or names (nomina)—thus giving voice to the philosophical doctrine of nominalism. Aquinas, using distinctions formulated by Albertus Magnus, strove to resolve the dispute by suggesting that the Ideas had three kinds of existence: as exemplars in the mind of God independent of things (ante rem), as intelligible forms in things (in re), and as concepts in the human mind formed by abstracting from things (post rem).

  These meticulous epistemological distinctions and others like them were important for Aquinas because for him the nature and processes of human knowledge bore directly on matters of weighty theological concern. In Aquinas’s view, man could strive to know things as they are because both the things and man’s knowledge of them were determined by and, like man himself, expressive of the same absolute being—God. Like Plato and Aristotle, Aquinas believed in the possibility of human knowledge because he was convinced of an ultimate identity between being and knowledge. Man could know an object by comprehending its formal, or universal, aspect. Man possessed this capacity for comprehension not because his mind was merely impressed by superior separated entities, the Ideas, but because his own mind possessed a superior, “nobler” element by which it could abstract valid universals from sense impressions. This capacity was the light of the active intellect—lumen intellectus agentis. The light of human reason derived its power from the divine Truth which contained the eternal types of all things. In endowing man with this light, God had given him the potential for knowledge of the world, just as God had endowed all beings, as possible objects of knowledge, with intelligibility. Thus the human mind could make true judgments.

  Yet Aquinas held that, because of the relationship of being and knowledge, something of deeper significance was involved in the process of human cognition. To know a thing was in a sense to have that thing in the knower. The soul received the form of an object into itself. The soul could know a thing by receiving its universal aspect, that which represented every instance of it—the thing’s form apart from its individuating material embodiment. As Aristotle had said, the soul was in a sense all things, because it had been created in such a way as to have the whole order of the universe inscribed within it. But the highest condition of this knowledge Aquinas recognized as the vision of God—not so much the state of philosophical contemplation recognized by Aristotle as the final end of man, but rather the supreme beatific vision of Christian mysticism. By expanding his own knowledge, man was becoming more like God, and to be like God was man’s true desired end. Because pure being and pure knowledge were both expressive of God (with knowledge constituting the “being to itself” of being, the self-illumination of being), and because a finite being participates, in a partial way, in those absolutes, every act of knowing was not only an expansion of one’s own being but an expanding participation in God’s nature. And by knowing existence in created things, the mind could gain a positive—though ever imperfect—knowledge of God, by virtue of the analogy between finite being and Infinite Being. Thus for Aquinas, the human effort to know was endowed with profound religious significance: The way of truth was the way of the Holy Spirit.

  The extraordinary impact Aquinas had on Western thought lay especially in his conviction that the judicious exercise of man’s empirical and rational intelligence, which had been developed and empowered by the Greeks, could now marvelously serve the Christian cause. For it was the human intellect’s penetrating cognition of the multitude of created objects in this world—their order, their dynamism, their directedness, their finiteness, their absolute dependence on something more—that revealed, at the culmination of the universe’s hierarchy, the existence of an infinite highest being, an unmoved mover and first cause: the God of Christianity. For God was the sustaining cause of all that exists, the ultimate unconditioned condition for the being of all things. The final result of the metaphysical quest, of which the Greeks were the prime exemplars, was discovered to be identical to that of the spiritual quest, of which Christianity was the definitive expression. Faith transcended reason, but was not opposed by it; indeed, they enriched each other. Rather than view the workings of secular reason as a threatening antithesis to the truths of religious faith, Aquinas was convinced that ultimately the two could not be in conflict and that their plurality would therefore serve a deeper unity. Aquinas thereby fulfilled the challenge of dialectic posed by the earlier Scholastic Abelard, and in so doing opened himself to the influx of the Hellenic intellect.

  It is true that rational philosophy could not on its own offer compelling proof for all the spiritual truths revealed in Scripture and Church doctrine. But it could enhance the spir
itual understanding of theological matters, just as theology could enhance the philosophical understanding of worldly matters. Because God’s wisdom permeated all aspects of creation, knowledge of natural reality could only magnify the profundity of Christian faith, although in ways that might not be knowable in advance. Certainly the philosophy of the natural mind alone could not penetrate fully into the deepest meanings of the creation. For this, Christian revelation was necessary. Human intelligence was imperfect, darkened by the Fall. To approach the highest spiritual realities, human thought required the illumination of the revealed Word; and only love could truly reach the infinite. But the philosophical enterprise was nevertheless a vital element in the human search for spiritual understanding. And if Aristotle for Aquinas (like Plato for Augustine) lacked an adequate conception of the Creator, Aquinas saw how to build on Aristotle while correcting and deepening him wherever necessary—whether by infusing Neoplatonic conceptions, by employing the special insights of Christian revelation, or by drawing on his own philosophical acuity. Thus Aquinas gave to Aristotelian thought a new religious significance—or, as it has been said, Aquinas converted Aristotle to Christianity and baptized him. Yet it is equally true that in the long run Aquinas converted medieval Christianity to Aristotle and to the values Aristotle represented.

  Aristotle’s introduction into the medieval West as mediated by Aquinas opened Christen thought to the intrinsic worth and autonomous dynamism of this world, of man and nature, while not forsaking the Platonic transcendent of Augustinian theology. In Aquinas’s view, an understanding of Aristotle paradoxically allowed theology to become more fully “Christian,” more resonant with the mystery of the Incarnation as the redemptive reunion of nature and spirit, time and eternity, man and God. Rational philosophy and the scientific study of nature could enrich theology and faith itself while being fulfilled by them. The ideal was “a theologically based worldliness and a theology open to the world.” For Aquinas the mystery of being was inexhaustible, but that mystery opened up to man, radiantly if never completely, through the devout development of his God-given intelligence: so God drew man onward from within to seek perfection, to know a fuller participation in the Absolute, to move beyond himself and return to his source.6

  Aquinas thus embraced the new learning, mastered all the available texts, and committed himself to the Herculean intellectual task of comprehensively uniting the Greek and Christian world views in one great summa, wherein the scientific and philosophical achievements of the ancients would be brought within the overarching vision of Christian theology. More than a sum of its parts, Aquinas’s philosophy was a live compound that brought the diverse elements of its synthesis to new expression—as if he had recognized an implicit unity in the two streams and then set about drawing it out by sheer force of intellect.

  Further Developments in the High Middle Ages

  The Rising Tide of Secular Thought

  Aquinas’s optimistic confidence in the conjunction of reason and revelation was not shared by everyone. Other philosophers, influenced by Aristotle’s greatest Arabic commentator, Averroës, taught Aristotle’s works without seeing the need for or the possibility of consistently coordinating his scientific and logical conclusions with the truths of Christian faith. These “secularistic” philosophers, centered in the arts faculty at Paris and led by Siger of Brabant, noted the apparent discrepancies between certain Aristotelian tenets and those of Christian revelation—particularly such Aristotelian concepts as the single intellect common to all mankind (which implied the mortality of the individual human soul), the eternity of the material world (which contradicted the creation narrative of Genesis), and the existence of many intermediaries between God and man (which overruled the direct workings of divine Providence). Siger and Ivs colleagues asserted that if philosophical reason and religious faith were in contradiction, then the realm of reason and science must in some sense be outside the sphere of theology. A “double-truth” universe was the consequence. Aquinas’s desire for fundamental resolution between the two realms thus found itself opposed not only to the position of the traditional Augustinians, who rejected the intrusion of Aristotelian science altogether, but also to the Averroists’ heterodox philosophy, which Aquinas viewed as inimical to an integrated Christian world view and as undercutting the potential of a genuine Christian interpretation of Aristotle. But with better translations of Aristotle’s writings and with their gradual separation from the Neoplatonist interpretations with which they had long been conflated, the Aristotelian outlook was increasingly recognized as a naturalistic cosmology not readily combined with a straightforward Christian outlook.

  Faced with this disturbing outbreak of intellectual independence in the universities, ecclesiastical authorities condemned the new thought. Sensing the secularizing threat of the pagan Aristotelian-Arabic science, of an autonomous human reason and its embrace of profane nature, the Church was pressed to take a stand against the antitheological thinking beginning to spread. The truths of Christian faith were supernatural, and needed to be safeguarded against the insinuations of a naturalistic rationalism. Aquinas had not succeeded in resolving the heated differences between the opposing camps, and after his early death in 1274 the rift grew more profound. Indeed, three years later when the Church made its list of condemned propositions, some of those taught by Aquinas were included. Thus the division between the warring adherents of reason and faith was further deepened, for by its initial censure of not only the secularists but also Aquinas, the Church cut off communication between the scientific thinkers and the traditional theologians, leaving the two camps increasingly aloof and distrustful toward each other.

  The Church’s prohibition did not stop the new thinking. In the eyes of many philosophers, the die was already cast. Having tasted the power of the Aristotelian intellect, they rejected a return to the previous status quo. They recognized that their intellectual duty was to follow the critical judgments of human reason wherever these led, even if that contradicted the traditional verities of faith. Not that the truths of faith could ultimately be doubted; but such truths could not necessarily be justified by pure reason, which had its own logic and its own conclusions, and which found its application in a realm perhaps irrelevant to faith. The potential divorce between theology and philosophy was already visible. And once opened, the Pandora’s box of scientific inquiry would not shut.

  In these final centuries of the Middle Ages, however, the Church’s authority was still secure and could accommodate itself to doctrinal shifts without endangering its cultural hegemony. Despite repeated censure by the Church, the new ideas were too attractive to be altogether suppressed, even among devout Church intellectuals. Half a century after Aquinas’s death, his life and work were reevaluated by the Church hierarchy and he was canonized, a scholar-saint. All Thomist teachings were removed from the list of condemned propositions. Recognizing Aquinas’s prodigious achievement in interpreting Aristotle in Christian terms, the Church began incorporating this modulated Aristotelianism into ecclesiastical doctrine, with Aquinas as its most authoritative expositor. Aquinas and his Scholastic followers and colleagues thus legitimated Aristotle by working out in painstaking detail the unification of his science, philosophy, and cosmology with Christian doctrine. Without that synthesis, it is questionable whether the force of Greek rationalism and naturalism could have been so fully assimilated into a culture as pervasively Christian as the medieval West. But with the Church’s gradual acceptance of that work, the Aristotelian corpus was elevated virtually to the status of Christian dogma.

  Astronomy and Dante

  With the discovery of Aristotle came as well Ptolemy’s works on astronomy explicating the classical conception of the heavens, with the planets revolving around the Earth in concentric crystalline spheres, and with the further mathematical refinements of epicycles, eccentrics, and equants. Although disparities between observation and theory continued to arise and demand new solutions, the Ptolemaic system still
reigned as the most sophisticated astronomy known, capable of modifying itself in details while maintaining its basic structure. Above all, it provided a convincing scientific account for the natural perception of the Earth as fixed with the heavens moving around it. Taken together, the works of Aristotle and Ptolemy offered a comprehensive cosmological paradigm representing the best science of the classical era, one that had dominated Arabic science and that now swept the universities in the West.

  From the twelfth and thirteenth centuries even the classical astrology codified by Ptolemy was being taught in the universities (often linked to medical studies), and was integrated by Albertus and Aquinas into a Christian context. Astrology in fact had never entirely disappeared during the medieval era, periodically enjoying royal and papal patronage and scholarly repute, and constituting the cosmic framework for an ongoing and growingly vital esoteric tradition. But with paganism no longer an immediate threat to Christianity, theologians of the high Middle Ages more freely and explicitly accepted the relevance of astrology in the scheme of things, especially given its classical pedigree and Aristotelian-Ptolemaic systematization. The traditional Christian objection to astrology—its implicit negation of free will and grace—was met by Aquinas in his Summa Theologica. There he affirmed that the planets influenced man, specifically his corporeal nature, but that through the use of his God-given reason and free will man could control his passions and achieve freedom from astrological determinism. Because most individuals did not exercise this faculty and were therefore subject to planetary forces, astrologers were able to make accurate general predictions. In principle, however, the soul was free to choose, just as, according to astrologers, the wise man ruled his stars. Aquinas thus maintained the Christian belief in free will and divine grace while acknowledging the Greek conception of the celestial powers.