He fed them with corn fat
and filled them with
honey from the rock.
—INTROIT, CHOSEN BY THOMAS AQUINAS, FOR THE FEAST OF CORPUS CHRISTI
THE LONG JUDEO-CHRISTIAN HISTORY of God’s interventions in human affairs—from the feeding of the Chosen People in the parched Sinai desert to the feeding of the baptized people of Europe with Corpus Christi, the Flesh of God’s Son—suggested to the medieval mind that reality was not pedestrian but fabulous, that is, replete with incredible marvels. Medieval lives may have been, by our standards, prosaic and predictible, but medieval imagination, the lens through which medieval men and women viewed the world, gave its viewers a more lively and grand account of reality than anything we would dare assay.
Nonetheless, the wave that emanated from Thomas Aquinas intellectualized Europe beyond any surge previously known, drawing the attention of all to the primacy of human reason in the struggle to come to terms with human experience. Not even God’s revelation, filtered through scripture and church, could replace reason’s role in tackling and settling questions—since even God’s revelation must be approached, absorbed, and digested by human reason. Just as the five senses are the mind’s windows on the world, the individual mind’s reasoning capacity must be for each one of us the final interpreter of the extraordinarily diverse and often confusing data that the senses supply us with. Such a philosophy must necessarily reduce the role of revelation and of church in the lives of those who subscribe to it, for it is the human mind, and it alone, that ultimately sits in judgment on the meanings of the scriptures and the pronouncements of the church, as on all else. “Reason in a human being,” reasoned Thomas analogously, “is rather like God in the world.” Just as it is God who animates the world and its myriad manifestations and enables them to function, so reason animates the human being and enables him to function. Reason, therefore, is what gives human beings their link to divinity, for it is the possession of reason that makes us most like God.
Though the new intellectualism necessarily confined religion somewhat, it hardly eliminated it. Thomas, like all his colleagues, was an orthodox believer. He might, for the sake of a particular disputation, take an atheistic or heretical position, but he never adopted such a position as his own. He, too, found reality fabulous—and far too serious for intellectual clowning. “Three things are necessary,” he wrote, “for a human being’s salvation: to know what he ought to believe; to know what he ought to desire; and to know what he ought to do.” Reasonable, yes, and respectful of rational knowledge above all else, but sober and focused on what truly mattered.
The unicorn, a symbol of Christ, about to lay his head in the lap of a virgin. The holly tree behind the unicorn is also a symbol of Christ. From a fifteenth-century French tapestry. (Photo Credit 5.1)
There was, however, a nonphilosophical form of knowledge far more appealing to the mass of human beings who hardly had time or aptitude for the endless disputations of the schoolmen: pictures, whether actual pictures or word pictures. From the twelfth century onward, an explosion of storytelling and a riot of color and form begin to invade street corner, church, castle, and library to the delight of ordinary people, who could find little or no delight in Thomas’s tight reasoning. The famous series of stained-glass windows (in every cathedral and abbey church) that tell the stories of the Old Testament and the life of Christ, so often called “the Bible of the poor,” were not the only visual feasts. There were tableaux, verbal and visual, that went beyond the scriptures to speak more theoretically, if always appealing as much to the eye and the ear as to the mind.
One of these was the story of the unicorn, who purifies water with his horn and can be captured only if he lays his head in the lap of a virgin. He is of course Christ, who lays his being in the womb of the Virgin and cleanses the world of its impurities. Another was the story of the pelican, who was believed to tear her breast with her beak to feed her young. She, too, was Christ, who nourishes us through excruciating but self-inflicted suffering. Both stories were told and retold in the illustrated books known asbestiaries, which purported to explain the symbolic significance of all God’s creatures.
In the twelfth-century church of San Clemente in Rome, the brilliant mosaic apse over the main altar presents us with a view of reality that is both cosmic and eucharistic; and there is no sight in all of Rome more worthy of contemplation. The central image is of the crucified Christ, mildly accepting his suffering and death, his face full of peace. Perched on the four extremities of the dark, red-rimmed cross are twelve white doves, symbolic apostles, rapt in contemplation though about to fly off to the ends of the earth. Jesus’s mother, Mary, and the Beloved Disciple stand in mourning beneath the arms of the cross. But spiraling forth from the foot of the cross, where it is watered by the blood of Christ, a stupendous acanthus bush curls outward and upward, encircling nearly a hundred separate images. These include flowers of many varieties, an oil lamp, a basket of fruit, beasts wild and tame, and people of all kinds involved in all kinds of labor. Each figure has a special meaning: a caged bird, for instance, represents the Incarnation, whereas wild birds flying upward are souls freed by death on their way to union with God. The humility of many of the figures is meant to remind us that not only have we been redeemed, but so has the whole world and everything in it. The spiraling branches of the acanthus embrace even two pagan Roman gods, Baby Jupiter, formerly king of the gods, and Baby Neptune, formerly king of the deep, who rides a slippery-looking dolphin. Even the ancient pagans have been redeemed, and their mythologies are usable by us, so long as we reduce them to less fearful and more apposite dimensions.
The twelfth-century apse of San Clemente, Rome. (Photo Credit 5.2)
Most tender of all are the depictions of ordinary medieval life, shepherds with their flocks and herds, farm children helping their parents, a lord and a lady watching the proceedings, a tonsured monk giving food and water to a colorful bird, and a bosomy lady in white, wearing flowing sleeves and an enormous brooch (neither of which would have found approval with Bernard of Clairvaux) while feeding her excited hens. One soon notes how many of these images are of creatures nourishing creatures or of creatures taking nourishment on their own, as in the case of two stags drinking directly from streams that flow from the root of the acanthus. “As the hart panteth after the water brooks, so panteth my soul after thee, my God,” we are meant to recall in the words of Psalm 42.
Detail of San Clemente apse: a woman feeding her hens. (Photo Credit 5.3)
Detail of San Clemente apse: one of two stags drinking from the streams of water that flow from the acanthus bush below the cross of Christ. (Photo Credit 5.4)
To appreciate the impact of this mosaic it is nearly necessary to attend a mass celebrated at the altar below the apse. As the ritual of the mass unfolds beneath the cosmic wildness of the apse, we reflect that we are all caught up in the universal mystery of Christ, who has redeemed us and all of creation, even the humblest humans and the humblest things, so that he might come to us as bread.
It may strike the reader that a meditation on the meaning of the Eucharist is an extremely odd way for science to rise from the ashes of the Dark Ages, but that is more or less how it happened. Not only the mysterious bread and wine but the mysterious pelican, the mysterious bear, the mysterious lion, the mysterious stars, and even the lowly ant (whose economic thrift is a lesson in how to conduct our lives)—all these and many more natural phenomena presented themselves to the medieval observer first of all as God’s creations, as gifts descended from Heaven to us below. But at length the desire to interpret their meaning, to understand what they were there for, was refined—under the persistent influence of philosophers like Abelard and Aquinas—by Aristotle’s logic and Aristotle’s stress on the importance of natural observation. And so, in its rudimentary essentials, science may be said to have risen in the medieval world in a cloud of Christian imaginings, but borne aloft on an air current of new respect for reason and observation.
Detail of San Clemente apse: symbolic animals and objects, as well as scenes of various medieval people at their labors (including the woman feeding hens, lower left), all within the curled branches of the acanthus bush that is nourished by the blood of Jesus. (Photo Credit 5.5)
Nowhere in Europe did the new scientific sensibility stride more boldly into view than at the University of Oxford in the time of Roger Bacon. Though Oxford was then one of the newly chartered European universities, it had like Paris existed as a center of learning for longer than anyone could remember. Bacon was already a student at Oxford when Thomas Aquinas was a boy, for he was a decade older than Thomas (and would survive him by eighteen years, dying in 1294 when he was in his late seventies). Bacon’s first model of the inquiring scientist was Oxford’s broadminded chancellor Robert Grosseteste, later bishop of Lincoln, just about the first European to employ controlled experiments, using data that could be measured, quantified, and cross-checked mathematically. Bishop Grosseteste’s range was as broad as his industriousness was deep: in addition to philosophical tracts and commentaries on many of the books of the Bible, he wrote groundbreaking treatises on the tides, solar heat, colors and the rainbow, meteors and comets. His Latin translation of Aristotle’s Nichomachean Ethics and his commentaries on other works of Aristotle, such as the Physics, advanced the work of both general philosophers and those specialized philosophers who would come to be called scientists.
If little remains today (at least beyond the bourne of Merton, the university’s oldest college) of the Oxford of Bacon’s time, the town must already have had some of the feeling of antiquity that Matthew Arnold loved, “so venerable, so lovely … steeped in sentiment as she lies, spreading her gardens to the moonlight, and whispering from her towers the last enchantments of the Middle Age.” It certainly boasted many of the miniature delights that Hopkins enumerates in his vision of medieval Oxford: “Towery city and branchy between towers; / Cuckoo-echoing, bell-swarmed, lark-charmed, rook-racked, river-rounded …” It was far less bustling than Paris and far less international, but the very insularity of its “folk, flocks, and flowers,” its polished brasses and painted doors, its happy conjunction of town and countryside, gave Oxford its own well-swept, tucked-in charm. Though Latin was the only language officially permitted to students, we know that Chaucerian English—that wonderful mishmash of Anglo-Saxon and French—often resounded through the quads, if only because of the punishments meted out to any scholar who lapsed into his mother tongue. (He was, upon a second offense, obliged to eat his dinner alone in a corner of the refectory.)
Like Thomas Aquinas, Roger Bacon studied under Albert the Great and taught for a while at Paris (when Aquinas was there), but it is with Oxford and its heralded spirit of no-nonsense practicality and experimental positivism that he will ever be associated. Bacon took the great Dominican’s enshrinement of reason and brought it a step further. “Reasoning,” he wrote, “draws a conclusion and makes us grant the conclusion, but does not make the conclusion certain, nor does it remove doubt so that the mind may rest on the intuition of truth—unless the mind discovers it by the path of experience.” Bacon then imagines a man coming upon the phenomenon of fire for the first time. The man might by reason arrive at the conclusion that fire burns, injures, and destroys. But this reasoning would not in itself tell him all we know of fire. He would need to put his hand in it, or, if not his hand, “some combustible substance,” and “prove by experience what reasoning teaches. But when he has had the actual experience of combustion, his mind is made certain and rests in the full light of truth. Therefore,” concludes Bacon axiomatically, “reasoning does not suffice, but experience does!”
Experience, by way of observation and experiment, beats unaided reason every time. Reason is necessary; we cannot function without it. But only experience can confirm what reason proposes. Albert had already taken a turn in this direction, declaring that in many matters “Experimentum solum certificat” (Experiment—or experience—alone gives certainty). But though Albert was for his time a great botanist, cataloguing and accurately describing a staggering profusion of trees, plants, and herbs, it would fall to his English pupil to embark upon seas of experience previously uncharted.
We know that Thomas was a fat friar and Francis a bone-thin ascetic, that Hildegard was a sickly nun and Eleanor a radiant queen. Of Roger we have no description at all, and he seems at times in his surviving writings so much a sprite, a will-o’-the wisp, that he would be too quick for anyone’s pen to capture on a page. Realizing the need for accurate translations from foreign tongues, he compiled extensive grammars of the Greek and Hebrew languages and attempted, though never completed, a grammar of Arabic. But more important than these tremendous accomplishments (which would have been for most men the work of a lifetime or two), Bacon was the first medieval Christian to set forth an entire system of natural knowledge, based wholly on observation and experiment.
He experimented with lenses and mirrors; he seems to have invented a telescope and perhaps, as he is credited in Umberto Eco’s The Name of the Rose, eyeglasses. He demonstrated that white light can be broken up into the spectrum of colors by passing it through glass beads. (Four and a half centuries ahead of a similar experiment that Isaac Newton would one day perform, Bacon alarmed his students by the uncanny magic of bringing a rainbow to earth.) His writing on the subject of the human eye remained the standard text till Johannes Kepler would take up optics and visual theory in the year 1600. Bacon declared that the speed of light, though enormous, was finite. But since this phenomenon cannot be observed by the naked eye and since it would take many more centuries to establish it as scientific fact, no one is sure how he came by his insight. He created astronomical tables far more accurate than anything previously conceived; and he urged the pope to reform the calendar, a reform that was accomplished by Pope Gregory XIII only in the late sixteenth century (and that produced what remains our calendar to this day, despite occasional, usually religious, objections).a
He was the first systematic geographer since ancient times, describing Europe, Asia, and much of Africa after doggedly collecting information from travelers; and he recognized that the earth was a sphere. (But then, so did virtually everyone in the medieval world. The stuff about “flat-earthers,” medieval churchmen who condemned as heretics all who claimed that the earth was round, was a calumny invented by two fabulists working separately: Antoine-Jean Letronne, an anticlerical nineteenth-century Frenchman, andWashington Irving in the same century in his unreliable biography of Columbus.) Bacon, in particular, wrote as clearly and dispassionately as did the ancient Greeks on the “curvature of the earth.”
Bacon’s Opus maius is an enormous encyclopedia of all medieval knowledge in the arts and sciences. He created a general systemization of chemical knowledge; and his description of the composition and manufacture of gunpowder is the earliest known in the West: “One may cause there to burst forth from bronze [ordnance] thunderbolts more formidable than those produced by nature. A small quantity of prepared matter occasions a terrible explosion accompanied by a brilliant light. One may multiply thisphenomenon so far as to destroy a city or an army.” He even predicted the inventions of the steam engine and internal combustion: “Art can construct instruments of navigation such that the largest vessels governed by a single man will traverse rivers and seas more rapidly than if they were filled with oarsmen. One may also make carriages which without the aid of any animal will run with remarkable swiftness.” In addition to foreseeing the coming of automobiles and steamships, he made plans, despite incredulous responses from his contemporaries, to construct a flying machine in which he believed men would one day travel.
For all that, Bacon was in some respects more medieval than the philosophers Abelard and Aquinas. For despite his status as “the first man of science in the modern sense” (in the accurate description of the British historian of science Charles Singer), Bacon was also an astrologer who raised his eyes to the heavens and an alchemist who searched beneath the earth—like the Alexandrian mathematicians who were his true forebears, a reader of stars and their significance and a practitioner of “this cursed craft,” as the alchemist’s assistant in The Canterbury Tales names the dark art of mining base metals for the purpose of changing them into gold. To appreciate how a great scientist could also be a magus and sorcerer, we must consult what we have already learned about the medieval worldview.
All early societies and civilizations believed that patterns in the heavens were predictive of life on earth and that the stars controlled our destinies. Such ideas entered the medieval world indirectly by way of the ancient civilizations of Egypt, India, and China and more directly by way of Greece, Rome, and, during the twelfth-century recovery of additional Greek texts, Arabia. These heavy influences were countered, to some extent, by the inconstant condemnations of the church, which could never approve wholeheartedly ofastrology because it seemed to erase the moral contribution of the human will in decision making. Augustine of Hippo, in particular, had heaped scorn on the whole business. But it would take the elaboration of a solidly based science of astronomy in the time of Galileo and Shakespeare (both born in 1564) to render the claims of astrology incredible—at least among well-informed people.
Shakespeare’s famous lines “The fault, dear Brutus, is not in our stars, / But in ourselves” are unlikely to have been expressed so definitely much before his time. In Bacon’s time, what appears to us a confusion of astrology and astronomy was still unresolved. It was indeed Aquinas, rather than Bacon, who gave the first push toward separating the two. Aristotle, like all ancient philosophers, thought the universe eternal. Aquinas knew it had been created by God.b Building his exposition on an earlier one by the seminal Jewish philosopher Moses Maimonides, Aquinas argued that though Aristotle’s analysis was logically correct, God had in fact created all things from nothing, choosing in his overflowing generosity that there be Something—the original mystical miracle—rather than nothing. Once the eternality of the universe was done away with, the inexplicably independent power of the stars was doomed to follow. One cannot logically believe in both free will and a provident God and yet continue to hold to belief in separate arbitrary powers.
Even deeper in the subconscious of medieval Europe than its superstitious reverence for the stars was its pagan nightmare of a world of shapeshifters, where anything might turn into anything else. German stories of a prince turned into a frog or a revolting beast by an evil witch vied with Celtic stories of druids who turned themselves into ravens and children who in their sorrow turned into swans. The prehistoric Irish wizard Tuan Mac Cairill celebrated his ability to turn himself into just about anything:
A hawk to-day, a boar yesterday,
Wonderful instability! …
Among herds of boars I was,
Though to-day I am among bird-flocks;
I know what will come of it:
I shall still be in another shape!
Knowing nothing of science in our modern sense, people of the centuries before Abelard believed that anything might become anything else—and that anyone might become anyone else (as can still happen so easily on a blind date).
But this prejudice in favor of shapeshifting melded well with Aristotle’s theory that four elements—earth, air, fire, and water—were the building blocks for everything in our world. If everything was composed of these four in different proportions, it must be possible to make one thing into another by recombining the elements in a new balance. Thus, both the surviving manuscripts of Greek science and the underground imaginings of European paganism encouraged a predisposition toward finding alchemy credible. Within even the most orthodox forms of Christianity, one can find evidence of this predisposition. For who was a greater alchemist than the priest who changed bread and wine into the body and blood of Christ? Who were greater quarriers of hidden gold than the faithful who harvested the grain and baked the bread, who grew the grapes and trod the winepress, decanted the brew and consumed the sacrament?
The medieval alchemists never succeeded in finding their “philosopher’s stone,” by the powder of which they believed base metals could be turned into gold and youth could be restored. This powder, they theorized, would prove an elixir (from the Arabic, al-iksir, thence from the Alexandrian Greek xerion for “healing powder”—thus demonstrating the ultimate paternity of this idea in the late antique civilization that rose from the mud of the Nile Delta). As the American historian of science Robert P. Multhauf has described the philosopher’s stone, “a substance capable of inducing a chemical transformation solely by its presence, and that in small quantity, its meaning comes very near to that of the modern term ‘catalyst’ ”—not in itself a crazy idea. At any rate, the alchemists’ patient experiments did succeed in isolating alcohol in the twelfth century and nitric, sulfuric, and hydrochloric acids in the thirteenth. Their bizarre laboratories, filled with urns and tubes, vials and vessels, lights and mirrors, fire and smoke, became, therefore, the forerunners of our chemistry labs, and they our proto-chemists. In later centuries, German and Low Country chemists—such as Botticher, van Helmont, and Glauber—still searching for the philosopher’s stone, will stumble on the manufacture of porcelain, the nature of gas, and the composition of many chemicals.
Why did the alchemists connect gold with eternal youth? Gold, they perceived correctly, is different from any other earthly substance. Unlike all other metals, which rust or gradually corrode, gold cannot be damaged by heat or by any other natural process. In the words of Terry Jones, the English comedian-turned-medievalist, “It can be hammered to one-thousandth of the thickness of a sheet of newsprint, and drawn into a wire finer than a human hair, and remains quite unchanged. In a mortal world, gold is incorruptible.” And if it is incorruptible, it may possess the ability to restore to human beings the incorruptibility that was lost when God banished Adam and Eve from eternal Eden, sending them into our world of death and decay.
It is easy, from the perspective of the twenty-first century, to dismiss an early scientist such as Bacon. It is easy to dismiss Richard of Wallingford, born around the time of Bacon’s death, a student at Oxford—by then Europe’s chief center for the study of the mathematical disciplines of the quadrivium—who later in life when he was abbot of the Benedictine motherhouse at nearby Saint Albans wrote the first medieval treatise on trigonometry and invented the first astronomical clock, a sort of mechanical astrolabe, despite the hideous deformations that leprosy was causing in his face and hands. It is easy to dismiss the fourteenth-century French cosmologists Jean Buridan and Nicholas Oresme, who were the first to realize that the earth rotates on its axis. It is easy to dismiss the enterprising Italian physicians Hugh of Lucca, Roland of Parma, William of Saliceto, and Mondino da Luzzi, who incorporated into their studies the recently recovered medical treatises of Hippocrates and Galen (whom we met previously in late antique Alexandria) and who added considerably to the knowledge of anatomy, especially because of their daring in dissecting human corpses. They all made mistakes; and their preference for a unified vision of reality, their refusal to be confined to discrete disciplines, often led them down blind alleys.
But their insistence on the essential unity of human knowledge remains the real philosopher’s stone, still sought by modern scientists with the same zeal with which it was sought by Roger Bacon. Albert Einstein’s attempts to uncover a “grand unified theory” that would explain the universe is one with Bacon’s encyclopedic efforts. “It was characteristic of the medieval Western thinker,” remarks Singer, “that, like the early Greek thinker, he sought always a complete scheme of things.” Once again, we hear echoes of Chesterton’s “great central Synthesis of history,” a synthesis that began with the Greeks, that medieval philosophers—including natural philosophers, or scientists—married to a Judeo-Christian worldview, and that flowed naturally into the thought of even the greatest theoretical physicist of the twentieth century.
a Medieval Christians used the Julian calendar, promulgated in the reign of Julius Caesar in the first century B.C. This calendar, because of an astronomical miscalculation, was about eleven minutes longer than the actual solar year. Bacon was aware of the discrepancy, which had grown to ten days by the time Gregory XIII resolved to correct the problem. Though the pope suppressed ten days of the year 1582, the role of the papacy was by then in dispute across Europe. It took Protestant England, for instance, almost two additional centuries to accept the Gregorian reform. The Orthodox Church has never accepted it, which is why major Christian feasts are normally celebrated later in Orthodox lands than in the West.
b May no one use this passage to bolster an argument for “intelligent design.” I am describing medieval science in the process of its being born—at a time when it was not yet absolutely separated from philosophy and theology. Science, as Bacon and others understood, must confine itself to experiment, observation, calculation, confirmation, and similar procedures. There is no way of devising a controlled experiment with God as its object, so God cannot be subjected to scientific proof—or disproof. Simply put, God cannot be made the subject of science. Despite this, it should be obvious that the Judeo-Christian prejudice in favor of a Creator (and of a beginning for time and for the universe) provides a much better prelude to the scientific enterprise than did the eternal universe of the Greeks.