The big, new ideas of high medieval academia were Aristotle’s.
The Church reform of the high middle ages was a movement of the highest significance to European culture and society. From its beginnings as an effort to free monasteries from secular interference, the movement eventually led to a major restructuring of the relations between the institutional Church and the laity, the general population. The effects of reform and its underpinning ideology can be seen in the growth of papal power, the rise of new religious orders, increasing concern with heresy, and the crusades. For us, here, however, of particular importance was a newfound emphasis upon clerical education and a corresponding search for intellectually satisfying and rational bases for Christian doctrine. Without these parallel developments within the Church, the achievements of early modern science would probably have been impossible.
Some modicum of education had always been required of Christian clergy, of course, and through the early middle ages monasteries and cathedral schools had preserved the basics of the classical Roman curriculum. This consisted of a sequence of two courses of study. The first, the trivium, was based around language, and included the study of grammar, logic, and rhetoric. The second, the quadrivium, focused on mathematics – arithmetic, geometry, music, and astronomy. Together, these comprise the liberal arts, which the Romans thought all free men (liberi) should master. With the reform movement, however, educational requirements became more uniform and more exacting. Even parish priests were now expected to read and speak competent Latin and to compose sermons regularly. Priests in large urban churches also had to have some understanding of biblical exegesis to ensure that their sermons were properly orthodox and to counter a rising tide of heresy. To meet these needs, as well as to supply a growing demand for academically trained professionals in government, business, and urban society, new forms of schools arose, and, of these. by far the most important was the studium generale, the university.
Curiously, the very first European university was an exception, for it was founded in Bologna by laymen who wanted to study Roman law. Bologna was unusual in this as well: the students ran the school. This makes perfect sense because they were the ones paying tuition: in order to safeguard their investment, they formed a kind of corporation, a students’ guild, which hired faculty, set the curriculum, and ensured that academic standards were maintained. Faculty who were late to class or droned on too long could be fined or fired. Thankfully for generations of professors, though, everywhere else it was a different story, and the faculty, with support from the Church and local governments, ran the show. In all cases, however, medieval universities took the form of guilds, collective associations of teachers and students who banded together to protect their rights and privileges, set standards, and resist unwelcome interference. Thus European universities were from the outset exceptional in that they were largely autonomous but united by a common language (Latin) and a common intellectual heritage. Their curricula, too, was uniform. Everywhere students began with the study of the Arts—the trivium and quadrivium—before moving on to more advanced subjects such as medicine, law, and theology. After sufficient study, a student who had already become a Master of Arts, might achieve his doctorate, his licentia ubique docendi (his license to teach anywhere) and join the faculty at some other institution. The universal acceptance of this credential meant that new ideas travelled quickly between schools, while promoting a uniform academic culture.
The big, new ideas of high medieval academia were Aristotle’s. The Romans seem never to have bothered to translate his work into Latin, for the simple reason that if a Roman were to be interested, he would certainly already know Greek. For this reason, Aristotle remained almost completely unknown to medieval European scholars until Latin translations from Arabic versions of his texts began to filter across the border from Spain in the twelfth century. Aristotle’s thought transformed the medieval intellectual world. His was a comprehensive philosophical system of enormous persuasive and explanatory power: through a combination of logic, empiricism, and basic principles, his system was capable of explaining almost anything. Even better, because Aristotle explained the workings of the cosmos without reference to supernatural power (“philosophical naturalism”), his thought, for the most part, did not contradict Church teachings. There were a few exceptions—Aristotle denied the immortality of the soul, for example—but since, as a pagan, he was not expected to be an authority in theological matters, these errors could be ignored. Indeed, it did not take long for Christian scholars to realize that Aristotle’s philosophy could provide insight into all aspects of the natural world, even those that impinged upon religion.
For Aristotle, the goal of philosophy was explanation, which meant that natural philosophy entailed the search for the causes of natural phenomena. Aristotle believed that inherent purpose determined the essential characteristics of all natural things. For this reason, his philosophy is often called “teleological,” or purpose oriented, from Greek telos, meaning “end,” or “purpose.” For example, Aristotle would argue that cats have claws because they are predators, and need to be able to catch and grasp their prey—that’s what claws are for. Determining a phenomenon’s cause, however, could often be much more complicated and require careful observation, rigorous logic, and the appropriate application of the principles that provided the essential framework from which the Aristotelian universe depended. This Aristotelian cosmos was composed of matter; indeed, it was filled to the brim with it; it was a plenum (a spaced filled with matter, as opposed to a vacuum) in which true emptiness was impossible. All things were composed of varying proportions of the four basic material substances: earth, air, water, and fire. (As this arrangement makes perfectly clear, Aristotle knew that the earth was a globe, as did most everyone else in the ancient world, and medieval scholars knew this too; so let’s put to rest the old fib that prior to Columbus everyone thought the world was flat.)
The classical universe from a sixteenth-century cosmographical treatise. At the center is the earth and spheres of water, air, and fire, then the transparent crystalline spheres of the seven planets and the fixed stars.
Within the cosmos, these were arranged hierarchically, with earthy matter in the very center, surrounded by a watery sphere, then a sphere of air, and finally one of fire. All matter sought to find its appropriate sphere, which is why fire always goes upward, but stones fall downward. If something floats on water, it means simply that its substance contains more aerial and fiery matter than earth. Beyond the sphere of fire were the celestial spheres of the seven planets—the Sun, Moon, Mercury, Venus, Mars, Jupiter, and Saturn—and beyond them was the sphere of the fixed stars. These celestial spheres were basically unknowable to humans, and so their composition and the physical laws that determined their motion were subjects for speculation, but not for science.
Here in the terrestrial realm, however, the substance of a thing determined its essential nature, and not its appearance, size, form and so forth. These, in Aristotelian terms, were “accidents,” which were external traits that differentiated particular individual things from others, but that did not pertain to their essence. So, for example, a pencil might be yellow or green, sharp or dull, long or short, but these characteristics have no bearing on its essential “pencil-ness.”
For medieval scholars, this way of understanding the physical universe was the key to solving a famous riddle: it was then a doctrine of the Church, as it remains for modern Catholics, that during the Mass, the Host, which is the consecrated bread, is miraculously transformed into the literal body of Christ prior to being consumed by the faithful. But if this is true, a cynic might ask, why does the bread still look and taste just like bread?
Aristotle’s matter theory provided the answer: the substance of the bread was transformed into the very substance of Christ, while its accidents, its externals, remained those of bread. After a certain amount of debate, this process, called “transubstantiation,” was accepted as the necessary way to understand the Eucharist or communion. This was just one of the ways—although perhaps the most important—that Aristotelian philosophy was turned to the service of the medieval Church. Similarly, theologians used Aristotle’s rules of logical deduction and physical science to prove the existence of God, to explain the divine paradox of the trinity, and to provide a rational explanation of how Christ could be both wholly human and at the same time completely divine .
In this way, Aristotelian natural philosophy became an essential bulwark of Church doctrine in addition to offering a comprehensive philosophical framework through which to understand the natural world. Little wonder, then, that Aristotle became an integral part of the new universities’ arts curriculum, despite the fact that many within the Church remained suspicious of the Philosopher’s skepticism and pagan background. The problem was how to make Aristotle compatible with medieval Christianity without fatally damaging the intricately interwoven strands of his thought. This became the essential project of medieval academia, which we commonly refer to as “scholasticism”: an attempt to explicate a thoroughly rational Christianity and an acceptably Christian Aristotle, and join the two together. This was the all-consuming project and crowning achievement of Thomas Aquinas (1225 – 1274), the greatest medieval theologian and philosopher, whose masterpiece, the Summa Theologiae, created just the necessary “amalgam” to reconcile Aristotelian natural philosophy with the truth of divine revelation, using metaphysics as the necessary bridge between the two.
This clerical embrace of Aristotle had a number of interesting consequences relevant to the development of medieval science. First, Aristotle believed that all knowledge originated in sense experience, which was a major departure from the epistemology (way of knowing) of St. Augustine and the earlier middle ages. High medieval churchmen certainly did not deny that direct revelation from God was possible, but insisted that it was unusual, and so the best way to understand God was to understand what we could perceive directly, that is, the natural world. As the theologian, Hugh of St. Victor put it in the twelfth century, “The whole of the sensible world is like a kind of book written by the finger of God… and each particular creature is somewhat like a figure, not invented by human decision, but instituted by the divine will to manifest the invisible things of God’s wisdom.” The work of natural philosophy , then, was to decode the book of nature, so to speak, in order to reveal the hidden hand of God. This led medieval scholars to study animals and plants, stars and planets, water, fire, and all manner of natural phenomenon. Further, although understanding God was the ultimate goal, his creation was assumed to follow rules that did not require His constant intervention, and so, like Aristotle, they described nature in what we would call “natural” terms. Miracles could, of course, still happen, but that was the provenance of theologians; natural philosophy dealt with nature, not with God directly.
In this way, medieval scholars were encouraged to explore the natural world, to build upon the work of their classical predecessors, but at the same time to acknowledge that the wonder of nature was a testament to the glory of God. Although they worked within an Aristotelian cosmos, and accepted as complete truth the great Philosopher’s (Aristotle’s) basic assumptions, they also recognized that their own work surpassed that of the ancients, both in its Christianity and in its capacity to build upon the achievements of the past. Bernard of Chartres, a twelfth-century philosopher and theologian, put it neatly when he observed that the scholars of his day were like “dwarves on the shoulders of giants and thus we see more and farther than they did.” This meant that when necessary they were even prepared to try to correct the great Philosopher’s mistakes.
Aristotle explained most things quite well, but his rules of motion were an exception. Aristotle dictated that inanimate objects move naturally to their proper sphere, but, otherwise, they only move if they are pushed by something else. This makes sense at first: if I want to move a piano, I’m going to have to push it, and once I stop, so will the piano. But what about an arrow? The motive force of the bow is removed when the arrow leaves the string, but the arrow clearly continues to move. Aristotle’s answer, like the rest of his physics, is extremely complicated, but he argues in effect that the force of the bow not only moves the arrow but the air around it, and that the air continues to push the arrow proportionally to the force that initially sets it in motion. This seems pretty ridiculous on its face, but medieval scholars had a serious vested interest in maintaining the integrity of the Aristotelian cosmos, and so they began to investigate motion diligently. One of main ways that their approached differed from the Aristotle’s was that they tried to describe motion mathematically. For Aristotle, this was a huge mistake, because numbers were completely abstract concepts that exist only in the mind, not in nature. To describe nature in such “unnatural” terms was invalid. Similarly, Aristotle would have rejected what would later come to be called “experiments,” because they artificially constrained nature to behave in unnatural ways. Rather, the Aristotelian scientist observed nature passively, recording what it did, not what it was made to do.
Yet, in an attempt to salvage his cosmos, medieval natural philosophers rejected Aristotle’s methodological criticism, and tried to figure out exactly how projectiles move. They failed, unsurprisingly, because they could not abandon the basic principles of the Aristotelian cosmos, but their failures nonetheless foreshadowed the mathematical modeling that was such an essential part of the new science of the sixteenth and seventeenth centuries. In the early fourteenth century, a series of remarkable scholastic physicists at Oxford’s Merton College, sometimes dubbed the Merton Calculators, tried to solve to the problems of motion using only mathematics and what we might call “thought experiments.” Many of their results, in retrospect, proved quite wrong, but they did show conclusively that mathematics could be used to model natural phenomena, and eventually expounded what we now call “the mean speed theorem” (that a moving body undergoing continuous acceleration will travel a distance in a given time exactly equal to that of a body moving at a constant speed equal to the mean speed of the accelerating body).
Equally significant, the community of medieval scholars built on this work. So, a few years after the Merton Calculators, Nichole Oresme (d. 1382), bishop of Orleans, developed a geometric proof of the Merton theorem that provides us with one of the very eariiest examples of the use of a graph to model a mathematical function. (A purely mathematical proof of the theorem would await the development of the calculus.) Oresme, by the way, was also notable for proposing that the earth revolved. He remained committed to the notion that the earth was at the center of the cosmos, but argued that it was more economical to suggest that the earth turned while the surrounding heavens stood still. He systematically replied to various counterarguments, including suggesting that the reason that an arrow shot straight upwards comes straight back down, instead of being offset by the motion of a revolving earth, was that the arrow, like the air surrounding it, was spinning at exactly the rate of the earth to begin with.
- Michael Shank, “Schools and Universities in Medieval Latin Science,” in David Lindberg and Michael Shank, eds., The Cambridge History of Science, vol. 2, Medieval Science (NY: Cambridge UP, 2013): 207-239; 210.
- For the origins of medieval universities, see Shank, 207-239.
- Ibid, 214-215.
- Kay Slocum, Medieval Civilization (Belmont, CA: Thomson Wadsworth, 2005), 376.
- Shank, 229-233.
- Ibid., 210
- Edward Grant, “Reflections of a Troglodyte Historian of Science,” Osiris 27.1 (2012): 133-155; 136-137.
- Edward Grant, “Cosmology,” in David Lindberg and Michael Shank, eds., The Cambridge History of Science, vol. 2, Medieval Science (NY: Cambridge UP, 2013): 436-455.
- Stephen Gaukroger, The Emergence of a Scientific Culture: Science and the Shaping of Modernity, 1210-1685 (Oxford: Oxford University Press, 2006), 65.
- David Lindberg, “Science and the Medieval Church,” in David Lindberg and Michael Shank, eds., The Cambridge History of Science, vol. 2, Medieval Science (NY: Cambridge UP, 2013): 268-287; 279.
- Gaukroger, 80.
- Hugh of St. Victor, De tribus diebus (migne 1844-1905, 122, 176.814 B-C). trans. Peter Harrison, in Harrison, “Hermeneutics and Natural Knowledge among the Reformers,” in Jitse M. van der Meer, and Scott Mandelbrote, Nature and Scripture in the Abrahamic Religions: Up to 1700 (Leiden, Brill, 2009) 346.
- Cited in Shank, 216.
- This argument and its particulars are taken from James Hannam, The Genesis of Science (London: Icon Books, 2009), 166-187.
- Eriola Kruja, Joe Marks, Ann Blair, Richard Waters, “A Short Note on the History of Graph Drawing,” in P. Mutzel, M. Jünger, S. Leipert, eds., Graph Drawing, Lecture Notes in Computer Science, vol. 2265 (Berlin: Springer Verlag, 2002): 1-15.
- Hannam, 183.