If there was any philosophical-theological thinker of importance during the Middle Ages who remained untouched by the spirit of the Areopagite, it was the 11th-century Benedictine St. Anselm of Canterbury, a highly cultivated Franco-Italian theologian who for years was prior and abbot of the abbey Le Bec in Normandy and then became, somewhat violently, the archbishop of Canterbury. In Anselm’s entire work there is not a single quotation from Denis; not even the name is mentioned. Consequently, Anselm’s thinking, thus freed from the corrective embodied in the Areopagite’s negative theology, displayed a practically unlimited confidence in the power of human reason to illuminate even the mysteries of Christian faith; he thus frequently approached a kind of rationalism, which did not shrink from the attempt to demonstrate, on compelling rational grounds, that salvation (for example) through God incarnate was philosophically necessary. To be sure, a theologian such as Anselm certainly would never have subscribed to the extreme thesis that nothing exists that is beyond the power of human reason to comprehend: the two famous phrases, coined by him and expressing again, in a grandiose formulation, the principle of Boethius, “faith seeking to be understood” and “I believe in order to understand,” clearly proclaim his faith in the mysteries of revelation as constituting the very basis of all reasoning. Nevertheless, in the case of Anselm, the very peculiar conjunction of faith and reason was accomplished not so much through any clear intellectual coordination as through the religious energy and saintliness of an unusual personality. It was accomplished, so to speak, rather as an act of violence, which could not possibly last. The conjunction was bound to break up, with the emphasis falling either on some kind of rationalism or on a hazardous irrationalization of faith.

That this split did actually happen can be read to some extent in the fate of the “Anselmic argument,” which Immanuel Kant, 700 years later, was to reject as the “ontological proof of God”—connecting it, however, not with the name of Anselm but with that of Descartes, the earliest modern philosopher. It is, in fact, significant that Descartes, in his proof of the existence of God, imagined that he was saying the same thing as Anselm, and that, on the other hand, Anselm would scarcely have recognized his own argument had he encountered it in the context of Descartes’s Discours de la méthode (1637; Discourse on Method), which claims to be “pure” philosophy based upon an explicit severance from the concept of God held by faith. But given Anselm’s merely theoretical starting point, that severance was not merely to be expected; it was almost inevitable.

But, also within the framework of medieval Scholasticism, a dispute was always brewing between the dialecticians, who emphasized or overemphasized reason, and those who stressed the suprarational purity of faith. Berengar of Tours, an 11th-century logician, metaphysician, and theologian, who was fond of surprising formulations, maintained the preeminence of thinking over any authority, holding in particular that the real presence of Christ in the Eucharist was logically impossible. His contemporary the Italian hermit-monk and cardinal St. Peter Damian, however—who was apparently the first to use the ill-famed characterization of philosophy as the “handmaid of theology”—replied that, if God’s omnipotence acts against the principle of contradiction (according to which it is impossible for a proposition to be both true and false), then so much the worse for the science of logic. Quite analogous to the foregoing controversy, though conducted on a much higher intellectual level, was the bitter fight that broke out almost one century later between a Cistercian reformer, St. Bernard of Clairvaux, and a logician and theologian, Peter Abelard. Bernard, a vigorous and ambivalent personality, was in the first place a man of religious practice and mystical contemplation, who, at the end of his dramatic life, characterized his odyssey as that of anima quaerens Verbum, “a soul in search of the Word.” Although he by no means rejected philosophy on principle, he looked with deep suspicion upon the primarily logical approach to theology espoused by Abelard. “This man,” said Bernard, “presumes to be able to comprehend by human reason the entirety of God.”

Logic was at that time, as a matter of fact, the main battleground of all Scholastic disputations. “Of all philosophy, logic most appealed to me,” said Abelard, who by “logic” understood primarily a discipline not unlike certain 20th-century approaches, the “critical analysis of thought on the basis of linguistic expression.” From this viewpoint (of linguistic logic), Abelard also discussed with penetrating sharpness the so-called “problem of universals,” which asks, Is there an “outside” and objective reality standing, for example, not only for the name “Socrates” but also for such common names as “human,” “canine,” and the like? Or do common concepts (“universals”) possess only the reality of subjective thought or perhaps merely that of the sound of the word? As is well known, it has been asserted that this was the principal, or even the only, subject of concern in medieval Scholasticism—a charge that is misleading, although the problem did greatly occupy philosophers from the time of Boethius. Their main concern from the beginning was the whole of reality and existence.

The advance of medieval thought to a highly creative level was foreshadowed, in those very same years before Abelard died, by Hugh of Saint-Victor (an Augustinian monk of German descent), when he wrote De sacramentis Christianae fidei (On the Sacraments of the Christian Faith), the first book in the Middle Ages that could rightly be called a summa; in its introduction, in fact, the term itself is used as meaning a comprehensive view of all that exists (brevis quaedam summa omnium). To be sure, its author stands wholly in the tradition of Augustine and the Areopagite, yet he is also the first medieval theologian who proclaims an explicit openness toward the natural world. Knowledge of reality is, in his understanding, the prerequisite for contemplation; each of the seven liberal arts aims “to restore God’s image in us.” “Learn everything,” he urged; “later you will see that nothing is superfluous.”

It was on this basis that the university—which was not the least of the achievements of medieval Scholasticism—was to take shape. And it was the University of Paris, in particular, that for some centuries was to be the most representative university of the West. Though there are usually a variety of reasons and causes for such a development, in this case the importance of the university—unlike that of Bologna and also of Oxford—lay mainly in the fact that it was founded in the most radical way upon those branches of knowledge that are “universal” by their very nature: upon theology and philosophy. It is thus remarkable, though not altogether surprising, that there seems to have existed not a single summa of the Middle Ages that did not, in some way or other, derive from the University of Paris.

Strangely enough, the classical theological-philosophical textbook used in the following centuries at the universities of the West was not the first summa, composed by Hugh of Saint-Victor, but was instead a work by Peter Lombard, a theologian who probably attended Abelard’s lectures and who became magister at the cathedral school of Notre-Dame and, two decades later, bishop of Paris. Lombard’s famous Sententiarum libri iv (Four Books of Sentences)—which, though written one or two decades later than Hugh’s summa, belonged to an earlier historical species—contained about 1,000 texts from the works of Augustine, which constitute nearly four-fifths of the whole. Much more important than the book itself, however, were the nearly 250 commentaries on it, by which—into the 16th century—every master of theology had to begin his career as a teacher. In view of this wide usage, it is not astonishing that Lombard’s book underwent some transformations, at the hands, for instance, of its most ingenious commentator, Aquinas, but also (and even more so) at the hands of John Duns Scotus in his Opus Oxoniense, which, in spite of being a work of extremely personal cast, was outwardly framed as a commentary on the “Master of Sentences.”