For many years it has been characteristic to portray the Middle Ages as a time of scientific ignorance, where superstition and religious faith supplanted science as a means of understanding the world. Usually, the Catholic Church is assigned blame as an oppressive institution that sought to impose religious orthodoxy at all costs, even suppressing scientific advancement. The very name “Middle Ages” is derogatory, considering the millennium between the fall of Rome and the Renaissance a mere intermission sandwiched between the classical age and modernity. Historian Daniel Boorstin referred to this period as “the great interruption.” (1) Other modern historians have made similar assessments, such that the very word medieval is synonymous with ignorance and barbarism. The Middle Ages has not fared well in contemporary historiography, especially when assessed for its scientific contributions.
This is, of course, a biased narrative; no historical age is ever universally good or bad, and what constitutes something as vague as “progress” is largely dependent on how we define progress to begin with. Despite lingering prejudices against the Middle Ages and the medieval Church, contemporary scholarship has thankfully started to move beyond these old biases to give us a richer, more nuanced view of the period; James Hannam’s 2011 book The Genesis of Science deserves particular praise for demonstrating how modern science was built on medieval foundations.
A comprehensive study of science in the Middle Ages is beyond the scope of this essay; our goal is more modest, focusing specifically on the Catholic faith and its relationship to science. This entails several lines of inquiry: How did the Catholic faith relate to the pre-Christian scientific heritage it inherited from pagan Greece and Rome? What sorts of attitudes did the institutional Church adopt towards scientific endeavors? Did theological considerations support or stifle scientific inquiry?
The Church and Pagan Science
One of the most pervasive myths about medieval Christianity is that it took a disparaging attitude towards pagan science. We have seen that early Christianity wrestled with the place of Greek scholarship within Christian thought. Having resolved that dispute in favor of retaining the scientific and philosophical ideas of the ancients, medieval Christians embraced pagan science enthusiastically. Pagan authorities like Ptolemy, Galen, and Aristotle were held in extremely high regard. Medieval Christians were anything but disparaging of pagan science; if anything, they sometimes held it in too high a regard, embellishing the pagan sages of old with an aura of infallibility that was only dislodged with tremendous effort. The idea, therefore, that there was some sort of Christian reaction against pagan science is erroneous.
That’s not to say Christian cosmology had no impact on medieval scientific theory. Medieval theorists tended to utilize the core principles of Greco-Roman natural philosophy while adapting them to the Christian faith in certain points. For example, Aristotle had explained the soul as the life principle of a living being which gave “form” to the body; Christian thinkers adopted Aristotle’s theory of the soul but modified it to specify the soul’s immortality, thus harmonizing it with Christian theology. (2) Or certain Greek philosophers theorized the existence of a celestial realm that was the home of fire (aether in the Aristotelian system); those influenced by Plato considered this a realm of pure ideas. Later medieval theologians reworked this into the idea of the Empyrean Heaven, a realm beyond the stars that was the dwelling place of God and the angels. (3) Christianity thus adopted and adapted pagan theoretical science to create a cohesive theological-scientific framework, situating the fundamentals of Greek science within a biblical worldview.
If the Christian Middle Ages stuck closely to its pagan precursors in theoretical science, the same cannot be said for mechanical science. Here the Middle Ages surpassed the developments of Greece and Rome. Medieval inventions such as the mouldboard plough and padded harness improved agricultural output far beyond ancient standards, contributing to the population boom of the high Middle Ages. Engineering advancements such as the vaulted arch made possible the impressive Gothic cathedrals, which demonstrated intricacies beyond anything the Greeks or Romans could have conceived.
The Middle Ages was thus a time of continuous mechanical advancement, a fact that often goes unrecognized as most people identify science with theoretical science. The word science conjures up images of physicists and astronomers formulating theories, not engineers working on more efficient ways to use levers for moving a block of stone. Furthermore, since the mechanical developments of the Middle Ages were often anonymous, they lack the sort of dramatic flair that accompanies the scientific discoveries of known individuals, like Galileo, Newton, or Einstein. As medievalists Joseph and Frances Gies put it:
The innovative technology of the Middle Ages appears as the silent contribution of many hands and minds working together. The most momentous changes are now understood not as single, explicit inventions but as gradual, imperceptible revolutions…taking place through incremental improvements, large or small, in tools, techniques, and the organization of work. (4)
The Monastic Culture of Learning
But interesting as it is, we are not here to study medieval innovation as such, but only where touched upon by the Catholic religion. Our study of this period should thus begin in the Benedictine monasteries.
The primary type of monasticism in the west was formulated by St. Benedict of Nursia (480-547). Benedict was the son of a minor noble from Nursia, a town of Umbria. As a young man he was sent to Rome to study but was disappointed with the immoral manner of city living. He left Rome for the countryside to find a more simplistic life. His devotion to God grew, and Benedict began to seek solitude to nurture his spiritual development. He came to the wild slopes of Mount Subiaco, about forty miles distant from Rome, and made a home for himself in one of the many caves of the rugged mountainside. In his cave, Benedict began a life of prayer and solitude that forged him into one of the greatest spiritual masters of Christendom.
St. Benedict eventually left Subiaco and went on to found twelve monasteries throughout Italy organized around the principles he had discerned from his own experience. These principles would be codified in a document known as the Rule of St. Benedict. The core of Benedict’s rule is the idea of balance—a wholesome spiritual life requires a man to find an equilibrium between work, prayer, and study. The Rule stipulates that a monk’s day should be punctuated by prayers seven times during the day and once at night. The time not devoted to prayer should be taken up by manual labor for the support of the monastery, as well as spiritual reading for personal edification. The idea was that ordering one’s physical routine in such a manner would bring about a corresponding ordering of the soul.
Because of its inherent stability, Benedictine monasticism became the dominant form of monasticism in western Europe. The spread of the Benedictines conferred many temporal and spiritual benefits upon early medieval Europe, but we are mostly interested in how Benedictine spirituality intersected with science. This is a very relevant question, as for the first seven hundred years of the Middle Ages, almost every major scientific achievement of the west came out of a Benedictine monastery. First we shall explore why this was so, then we will highlight a few of the major mechanical innovations of the Benedictines.
The Rule of St. Benedict stipulates that the monks should spend time engaged in spiritual reading. This was part of the monk’s labora, his “labor,” by which he combatted the idleness that was so destructive to Christian holiness:
Idleness is an enemy of the soul. Because this is so, the brethren ought to be occupied at specific times in manual labor, and at other fixed hours in holy reading…From the fourth till the close upon the sixth hour let them employ themselves in reading. On rising from table after the sixth hour let them rest on their beds in strict silence; but if any one shall wish to read, let him do so in such a way as not to disturb anyone else. (5)
Reading is also prescribed every Sunday to everyone “save those who are assigned to various offices.” (6) Extra reading was undertaken during Lent, when St. Benedict directed that each monk should be given a book for additional study: “On the days of Lent, from the morning till the end of the third hour, the brethren are to have time for reading…During these Lenten days let each one have some book from the library which he shall read through carefully. These books are to be given out at the beginning of Lent.” (7) Spiritual reading was not merely a private endeavor, however. Meals were a time when the monks were read to collectively by a lector— “There ought always to be reading whilst the brethren eat at table…The greatest silence shall be kept, so that no whispering, nor noise, save the voice of the reader alone, be heard there.” (8) St. Benedict presumes his monks are literate and that they have access to enough reading material to fulfill the various prescriptions of the Rule. As St. Benedict’s ideal monastery is a self-sufficient entity supported by the labor of the monks, this presumes the books themselves are produced within the confines of the monastery. We have seen in Benedict’s Lenten prescription that the Rule assumes each monastery is equipped with a library. To stock this library would have required the labor of monks working as copyists in a scriptorium, a room for the copying of manuscripts.
What was copied in these monastic scriptoria? In the beginning it would have been simply the Bible and the works of the Church Fathers, but over time this expanded to include Greco-Roman works as well, both literary and scientific—although, among the Benedictines, this was generally restricted to texts written in Latin, as knowledge of Greek was increasingly rare in the west. (9) Many ancient works would have been lost to us if it were not for these monastic copyists. For example, the Natural History of the Roman author Pliny the Elder was copied widely in the 8th and 9th centuries and survives only because of these monastic editions. (10) This is true of many such ancient texts.
Even pagan texts that were not inherently scientific could be culled for nuggets of scientific wisdom. A curious example is the early medieval fascination with the late Roman author Martianus Capella. Martianus’s work De nuptis (“On the Marriage of Philology to Mercury”) was an allegorical exposition of classical Roman paganism viewed through a Neoplatonic lens. On its face, we would not expect De nuptis to attract the interest of Christian monks. But the opposite was true; the Benedictine scholars of the 8th and 9th centuries were fascinated with De nuptis, believing that profound truths about the universe were hidden beneath the surface of pagan knowledge. Monastic commentators interpreted Martianus’s religious images to be allegories for scientific ideas: the seven rivers crossed by the god Mercury are the seven planets, and the dragon kept by the god Saturn symbolizes the solar year. Other passages were interpreted to refer to mathematics, the harmony of the spheres, and the physical order of the universe. (11)
Monks also produced their own original scientific treatises. For example, St. Bede (d. 735), an Anglo-Saxon monk of Jarrow Monastery in Northumbria, wrote several works of natural science, the most notable being De natura rerum (“On the Nature of Things”) and De temporum ratione. (“On Reckoning Time”); the former was a text on cosmology, the latter concerning the measurement of time. De temporibus is notable for its explanations of how the changing of daylight related to the sphericity of the Earth, how the seasonal movements of the sun and moon determined the appearance of the new moon, and a hypothesis about the connection between the moon and the tides.
Though he was not a monk, we should also mention St. Isidore of Seville (d. 636). St. Isidore was the most renowned Spanish bishop in the early 7th century, a luminary of the Church and advisor of kings. St. Isidore was a voluminous writer on matters spiritual and scientific. Among his scientific works we find treatises on linguistics, cosmology, and anthropology. His most notable work was the Etymologies, an encyclopedia of ancient knowledge drawn from a multitude of pre-Christian sources. It includes essays on grammar, rhetoric, geography, mathematics, cosmology, music, astronomy, music, medicine, law, metals, buildings, agriculture, and much more. The Etymologies were extremely popular throughout the medieval era. Almost 1,000 manuscript copies of it have survived to this day.
Thus, we see that Christian monks (and to a lesser degree bishops like St. Isidore) served as custodians of learning. Scientific works were eagerly read, copied, commented upon, and imitated. Monks were the intellectual class of early medieval Europe, and their work was pervaded by what we might call a culture of scholarship that valued education highly. Though obviously the paramount concerns of any monk were spiritual, scientific knowledge was highly prized as a means of understanding the creator through His creation.
Monks as Technical Innovators
So far, we have considered the monks as bearers of intellectual knowledge, but we must now consider them as innovators of technical knowledge—that is, as inventors. This can be attributed to diversification of time in the monastic lifestyle. Western monastic observances—whether Benedictine, Gaelic, or other—divided the day between hours of prayer and hours of labor. This meant that a monk’s time was not unlimited; multiple times throughout the day he was required to stop whatever he was working on to pray the Divine Office. This division of time and the diversification of monastic obligations incentivized labor-saving innovations.
The best example of this is the greatest of medieval innovations, the waterwheel. (12) Waterwheels were originally used to grind grain into flour. Grinding grain into flour was particularly laborious work. Grains of wheat had to be crushed by the rotation of a heavy stone wheel to turn them into powder. It was difficult and time-consuming work; in pre-Christian times, it was reserved for women, slaves, and prisoners. Sometime in the early 6th century, Irish monks in monasteries near the Atlantic coast began harnessing coastal tides to power their mills. (13) As the tide came in, it entered an artificially constructed mill pond through a one-way gate. This gate closed automatically when the tide began to fall. When the tide was low enough, the stored water was released to turn a water wheel, which spun an axle attached to the grindstone. This relieved the monks of having to power the grindstone by hand, saving considerable time and energy.
Monastic watermills start popping up in literature from the 6th century on. The historian Gregory of Tours (d. 594) described several watermills, including one on the French river Indre built by Ursus, Abbot of Loches, made “with wooden stakes packed with large stones and sluice-gates to control the flow of water into a channel in which the mill-wheel turned.” (14) The innovation soon spread, and we see a boom in waterwheel construction throughout the following centuries. Monks on the continent began building their mills beside rivers to harness the current to turn the wheel. This led to the development of the undershot waterwheel (where the water turns the wheel by passing under it) and the more powerful overshot wheel (where the water turns the wheel by passing over it, combining the power of the current with the force of gravity). Before long, waterwheel technology spread beyond the monasteries and was adopted by the European peasantry. Their use exploded in the centuries between 1000 and 1200. The Domesday Book, a survey prepared in England in 1087 on order of William the Conqueror, records 5,624 watermills in England, whereas a century earlier there had been fewer than 100 in the entire country. (15) In France we see a similar trend: in Picardy, 40 mills in 1080 had expanded to 245 by 1175; in the district of Aube, only 14 watermills were recorded in the eleventh century but 200 were operating by the thirteenth. (16) It is thus not an overstatement to say that the monastic waterwheel constituted a true revolution in medieval industrial power.
France was also the site of another monastic innovation—the deep-well dug by percussion drilling. Percussion drilling is the method used today to dig wells. This innovation can be dated to the Carthusian order in 1126 at Lillers, in Artois. A shaft only a few inches in diameter was sunk through impermeable strata using a rod with a drilling tool on the end struck with successive blows until it reached a deposit of water under pressure. The result is a well that needs no pumping. Incidentally, this first deep-drilled well at Artois is where we get the name “artesian” well. (17)
The self-sufficiency of early Benedictine abbeys was another incentive to innovate. “The monastery,” the Rule stated, “ought, if possible, to be constructed as to contain within it all necessities, that is, water, mill, garden, and [places for] the various crafts exercised within a monastery, so that there be no occasion for monks to wonder abroad.” (18) The ideal of the self-sufficient monastery was a noble one, but difficult to achieve. It was challenging to maintain the balance between the spiritual obligations of the Rule and the burdens of time that economic self-sufficiency imposed upon the monastery. The demands of agricultural life did not easily yield to a monastic schedule. What was a brother to do when he was assisting a cow birthing a calf, his arms up to his elbows covered in blood and fluid, and the bell rang for Nones? How did the monks handle it when they were in the middle of Vespers and the sluice-gate to their millrace broke, releasing all the stored-up water that powered their mill? What did they do when they were done with the Compline and prepared to turn in for the night, but their pigs broke free from the pen and ran amok? As you can imagine, the vicissitudes of agricultural self-sufficiency probably strained the tidy liturgical schedule envisioned by the Rule.
The necessity of balancing their various obligations drove the monks to optimize their manual activities through trial and error. The monks were the original tinkerers of medieval Europe, working patiently to discover best practices of agricultural life. They bred cattle over multiple generations to create stronger, healthier breeds; they did the same with strains of wheat. They drained water from the marshes around their monasteries to put more land under tillage. They perfected methods of rearing livestock to maximize the health and usefulness of their animals. Their specific activities might be varied in different regions; in Sweden they focused on corn, in Parma, cheese, in France, wine growing. (19)They were the first to add hops to malted barley to make beer, and their experiments producing wine for the Eucharist led to the great diversity of wines western Europe is known for today. (20)
The Benedictines did not keep this knowledge to themselves. Rather, they shared their collective knowledge with the surrounding communities. The monasteries thus became the heart of an agricultural revolution in early medieval Europe. Historian Alexander Clarence Flick said that “every Benedictine monastery was an agricultural college for the whole region in which it was located.” (21)
The innovative spirit of the monks extended beyond agriculture. Metallurgy, mining, forging, and quarrying were all subjects of monastic curiosity, imbuing them with a refinement and methodological precision not previously known in Europe. The Cistercians in particular were renowned metallurgists; the remains of their blast furnace at Laskill, England, was 15 feet wide and capable of generating temperatures over 2000° F with its water-powered bellows, producing high-quality pig iron on an industrial scale—around 1 ton per day. (22)
Ultimately, these developments were not enough to fully integrate agricultural life within the monastic schedule—most monasteries eventually secured lay workers to tend to their material needs while the brothers devoted themselves fully to prayer. They did, however, push Europe’s monasteries to the cutting edge of technological and agricultural development.
To See the Words and Sound the Hours
We should also note two monastic developments that arose not from the monks’ manual labor, but rather from their spiritual obligations: spectacles and the mechanical clock.
A consistent problem faced by medieval monks was poor eyesight, specifically myopia, or near-sightedness. The reasons for this are debated. The conventional theory is that monks spent a considerable amount of time pouring over manuscripts, often by candlelight. Reading by candlelight over many years created problems for monks’ eyes, as eye muscles became strained by continuously having to readjust to the changing light output. This theory has been challenged, however, by modern studies suggesting it was not prolonged reading by candlelight, but rather diminished levels of exposure to natural, outdoor light that caused monastic myopia. (23) Whatever the cause, many medieval monks suffered from various maladies of the eye. This was particularly debilitating, as so much of monastic life was bound to the texts they read, copied, prayed, or sang. By the high Middle Ages, curious monks were experimenting with artificial means of aiding their failing eyesight.
It had long been known that certain translucent elements, such as quartz, could be polished until attaining near transparency. It was also observed that light was distorted when passing through quartz, bending it at the edges, but also magnifying the image. Around the year 1000 in Venice, the first “reading stones” were invented. Flattened, circular pieces of beryllium or quartz were polished to transparency. These could then be laid on top of reading material, functioning as a magnifying glass. The monk would slide the reading stone across the page with his hand as he read. These reading stones allowed monks to continue to read, write, and illuminate manuscripts into old age.
The only problem with reading stones was that they still required the user to hunch over, peering into the stone which magnified only a small amount of text at a time. A more ergonomic use of the reading stone would be to attach them directly to the face, thus relieving the wearer of having to constantly hunch over the page while also allowing the magnification of the entire field of vision at once. The first pair of corrective eyeglasses—or spectacles as they were known—was invented in Italy sometime between 1268 and 1300. These were basically two reading stones connected with a hinge and balanced on the bridge of the nose. We can see these early eyeglasses in a series of mid-14th-century paintings by Tommaso da Modena, which featured monks using monocles and wearing these early pince-nez (French for “pinch nose”) style eyeglasses to read and copy manuscripts.
It is not known who exactly the innovator of eyeglasses was, but the invention was universally lauded as a boon, not only to monks, but to all mankind. In 1306, the Dominican preacher Giordano of Pisa preached a sermon praising the invention: “It was not twenty years since there was discovered the art of making spectacles that help one see so well; an art which is one of the best and most necessary in the world. And that in such a short time ago that new art had never before existed was invented. I myself saw the man who discovered it and practiced it, and I talked with him.” (24) How historians wish that Giordano would have bothered to record the name of the man he spoke with!
The other grand invention of the monks was the mechanical clock. Its origins are shrouded in obscurity; even scholars of medieval technology disagree on the details. It is certain, however, that they began as aids to the monastic schedule. Most monastic usages called monks to communal prayer at certain hours; the canonical hours of the Rule of St. Benedict are the best known. Since the 4th century, these hours were tolled by the ringing of bells. Bells had the advantage of being loud enough to be heard throughout the monastic grounds, capable of summoning monks to the chapel from wherever they might be working. Some of the earliest bell towers were built by the Irish. Called “round towers”, many still exist today. These were primitive medieval clocks, used to toll the hours of the divine office throughout the Christian world.
But this method was not without its difficulties. How was one to know when it was time to ring the bells? How did anyone know specifically what time it was? The problem with ancient timekeeping methods was that they were all bound to the vagaries of nature. Sundials were useless on overcast days or at night. More sophisticated was the klepsydra, or water clock. Water clocks used the dripping of water through a tiny hole to tell the passing of the hours. But the gradual decrease in pressure as the water drained out made the rate of drainage inconstant. Engineers got around this by maintaining a second tank filled higher than the primary tank to keep the pressure in the first tank constant. But that in turn meant the second tank had to have its own constant water supply fed into it, which was very inconvenient if it was not in proximity to a spring or river. And such clocks were useless in the northern climes of Europe where temperatures were below freezing for significant parts of the year. In the 8th century, a Benedictine monk of Chartres named Liutprand invented the first hourglass, two glass bulbs connected vertically by a narrow neck allowing a regulated flow of sand to pass from the upper to the lower bulb. The intervals measured by an hourglass were generally too small to be of use for the canonical hours, however. A dependable way to toll the hours seemed elusive.
The sounding of the canonical hours was not the only chronological need of the monks. Accurate astronomical calculations were required as well. This was necessary for the proper calculation of Easter, the anchor-feast of the Christian holy year and the date upon which so many other feasts depended. The calculation of Easter required a precise knowledge of the solstices, which in turn necessitated other reliable astronomical data. The date of Easter was not merely of religious import; throughout the Middle Ages the ecclesiastical calendar functioned as the civil calendar, so the cycles of civic life were bound to it as well. For example, in England, Michaelmas was the day rents were due, and Pentecost occasioned the opening of a season of grand fairs, called “Whit Fairs.”
Of course, the calculation of hours is just part of the larger calculation of astronomical phenomena: hours are parts of days, which are parts of lunar months, which are parts of solar years. What was needed was a single device that could accurately track the movement of time—both astronomical and daily—without recourse to complicated mathematical tables, and with a mechanical regularity unperturbed by changes in temperature or weather.
Sometime at the end of the first millennium, monastic tinkerers adopted system of gears turned by weights as the likeliest mechanism to provide the regularity they needed. The Archdeacon Pacificus of Verona (776-844) was reputed to have invented a “nocturnal clock” (horologium nocturnum), but this was most likely a star clock or nocturlabe. The nocturlabe, though not a mechanical device, was quite sophisticated. Medievalist Marek Otisk describes the nocturlabe thus:
It was an adjustable observation tube (referred to as fistula in contemporary texts) with a fixed stand and was connected to circular disc (rota) on which the lines of hours were inscribed as well as solstitial days (solstitial) and equinoctial days (aequinoctial) which together formed a cross (crux Christi). With the help of the observation tube, the highest star closest to the northern pole of the celestial sphere (polus) was found. The celestial sphere (spera caeli) goes around (revolvere) its axis passing through its poles once per 24 hours (horae quarter senis) and the observation tube followed the axis of the world sphere in this way. The location of the machine was fixed as it was adjusted for the given observation place according to the celestial sphere. (25)
In 996, Gerbert of Aurillac—the future Pope Sylvester II—apparently introduced some kind of mechanical time keeping instrument at Magdeburg Abbey, although it is uncertain what sort of device it was. (26) Whatever it was, it must have been impressive—multiple medieval chronicles mention Gerbert’s mechanism, suggesting that his astrological knowledge was so accurate that they suspected he obtained his it by sorcery. (27)
The period between 1000 and 1200 was an era of constant experimenting and improvement on timekeeping, with craftsmen attempting to make water clocks more accurate by using friction or the force of gravity to keep the flow constant. The Bible of St. Louis, composed between 1226 and 1234 for St. Louis IX of France, depicts a clock constructed of a gear using water to slow the rotation of the wheel. This demonstrates that clockmakers of this time were experimenting with weights to control rotational motion, a significant step forward in design. By 1271, the English astronomer Robertus Anglicus describes medieval craftsmen attempting to create a mechanical clock regulated solely by gravity without the necessity of water (28) A few years later, the English Benedictine abbot Richard of Wallingford invented a device called the Albion. Consisting of brass discs that rotated around a central pivot, a series of curved lines and silk threads allowed its user to determine the positions of stars and planets quickly. The Albion, however, was not mechanically powered, as it had to be “set” or recalculated each time the user wanted to take a reading. (29)
The pivotal innovation that made the mechanical clock possible was the verge and foliot escapement mechanism, invented sometime before 1250. (30) The verge and foliot mechanism allowed the rotation of the clock to be regulated by gravity using falling weights. The verge and foliot escapement consists of a crown-shaped wheel (the “escape wheel”) with sawtooth-shaped teeth oriented towards the front. A vertical rod with two metal plates—the “verge”—is placed before it. The plates engage the teeth of the escape wheel at opposite sides. These plates are constructed so that the teeth can only latch one at a time. Atop the verge is a weighted balance wheel, known as a “foliot,” which acts as an internal oscillator, allowing the gear mechanism to advance at regular intervals, or “ticks.” The verge and foliot escapement made an all-mechanical clock possible by substituting continuous processes—such as the flow of water—for a repetitive, oscillatory process. Oscillatory processes are much more accurate; despite all the technological advancements since 1250, mechanical clocks to this day still rely on oscillatory processes.
The first truly mechanical clocks appeared in England and are testified as early as 1273 at Norwich Priory; another at Dunstable Priory in Bedfordshire is recorded in 1283. From there, clocks proliferated across European churches and abbeys. These early clocks did not merely tell the hours. Known as horologes, they showed the positions of the sun, the moon, planets, and major stars relative to each other. The 14th century horologe of Ottery St. Mary in Devon—which still works today—is an excellent example of an early horologe. It features three balls representing the earth, moon, and sun. The half-white, half-black moon ball rotates on its axis to show the phases of the moon while simultaneously rotating around a central dial signifying the lunar months. The golden sun ball rotates around the outer dial, showing the time while at the center is the black ball of the earth, stationary, presuming a geocentric model of the universe. Sometimes the horologe would have a secondary face that showed the hours and minutes, such as the horologe of Wells Cathedral (c. 1386) which features a two-sided clock facing inside and out. The outer clock is a standard 12-hour clock, but the interior clock has a 24-hour universe dial, with two sequences of Roman numerals. When the clock strikes, two figures of knights emerge and joust at each other while the bell is struck by a figurine known as Jack Blandifers—Jack strikes one bell with his tongs while two other bells below are struck by his feet.
The mechanical clock made the observance of monastic life substantially easier. Bells tolling the hours were done with mechanical regularity, doing away with the need of a designated monk to wake up at certain hours of the night and ring the bells by hand. The astronomical displays of the horologe made it possible to easily calculate solstices and other astronomical phenomenon without recourse to complicated tables. And the tolling of the bells, ringing over the countryside from the countless spires of abbey and cathedral, were of such great utility that laypeople, too, began regulating their lives around the donging of the church bells. By the 14th century, the mechanical clock had become detached from its religious origins as towns across Europe vied with each other to build the most magnificent clocks. Usually set upon the facades of town halls, these city clocks were emblems of civic pride. One of most fabulous surviving examples of a medieval civic clock is the Orloj, an astronomical clock mounted on the wall of Prague’s Old Town Hall. Dating from 1410, the Orloj features multiple faces depicting the movements of the sun, moon, changing of seasons, times of day, and other astronomical details, all embellished with images of saints, apostles, and a skeletal figure representing death.
The Catholic Impetus for Mechanical Advancement
Despite the immense amount of ground we have covered in this essay, we have really only scratched the surface in our study of the scientific endeavors of the monks of Christendom. A study of any one of the subjects we have touched on could be its own volume. Far from being centers of intellectual stagnation, the monasteries of medieval Europe were on the forefront of technological innovation. Their contributions to the scientific knowledge of the West are truly incalculable. The Catholic faith was not incidental to monastic scientific achievements; it was the guiding principle, the lodestar of all monastic aspirations. Monastic innovations were done in service of their routine of life, whether the Rule of St. Benedict or some other rule. In a sense, innovation is presumed in the structure of the Rule of St. Benedict itself. We have seen St. Benedict specifically mandated the keeping of libraries and regular periods of study. These monastic libraries gave monks access to the accumulated wisdom of mankind, while their rule of life afforded the time and incentive to innovate, finding more efficient ways to farm, grind wheat, breed cattle, find water, tell time, and read. This was all done so that the rule might be kept with greater exactitude, that the soul might be sanctified as a pure sacrifice unto God. The innovations of monastic Europe, from the simple reading stones to the complex verge and foliot mechanisms, all began as efforts to render monastery life more efficient. And all this happened within the larger worldview, in which uncovering the mysteries of nature was seen as way of approach to God.
This essay is an excerpt from Phillip Campbell’s book In Pursuit of Wisdom: Science and Catholicism Through the Ages (Our Sunday Visitor: 2024)
(1) Daniel J. Boorstin, The Discoverers (Vintage: New York, 1985), 102
(2) See Aristotle, De Anima, Book I, Ch. 1
(3) Nicholas Porter, “Aquinas and the Theory of the Empyrean Heaven”, The Thomist: A Speculative Quarterly Review, Vol. 85, Num. 3, July 2021, pg. 443-478
(4) Frances and Joseph Gies, Cathedral, Forge, and Waterwheel: Technology and Invention in the Middle Ages (Harper Collins: New York, 1995), 2
(5) The Rule of St. Benedict, Chap. 48
(6) Ibid.
(7)Ibid.
(8) Ibid., Chap. 38
(9) In East, meanwhile, Greek monks preserved manuscripts in the Greek language. For example, the oldest extant copy of the Elements—the famous mathematical text of Euclid of Alexandria (c. 300 B.C.)—is a monastic manuscript dated from 888 A.D. Thus, whether we consider East or West, we see monastic scribes behind the survival of the knowledge of antiquity.
(10) For the textual history of Pliny’s Natural History, see Roger Pearse, “The Manuscripts of Pliny the Elder’s ‘Natural History,’” accessible online at https://www.roger-pearse.com/weblog/2013/06/22/the-manuscripts-of-pliny-the-elders-natural-history
(11) Sinéad O’ Sullivan, “Martianus Capella and the Carolingians,” Listen O’ Isles unto Me: Studies in Medieval Word and Image, ed. Elizabeth Mullins and Diarmuid Scully (Cork University Press: Dublin, 2011), 32-33
(12) Medieval monks certainly did not invent water-driven mechanics. The Romans had even created a large waterwheel mill at Barbegal in Arles, France. But medieval monks were the first to harness the power in a methodical way, utilizing coastal tides, rivers, and waterfalls in a systematic manner to increase wheat production.
(13) Watermills were likely introduced to Ireland by the Church, as the Old Irish word for mill, muilenn, comes from the Latin word for mill, molina. The presence of a Latin cognate in Old Irish generally denotes an ecclesiastical origin. See Clare Downham, Medieval Ireland (Cambridge University Press: Cambridge, 2018), 37.
(14) Gregory of Tours, Lives of the Fathers, cited in Philip A. Rahtz and Donald Bullough, “The Parts of an Anglo-Saxon Mill, Anglo-Saxon England 6 (1977), p. 20
(15) Frances and Joseph Gies, Cathedral, Forge, and Waterwheel (Harper Collins: New York, 1995), 113
(16) Ibid.
(17) Ibid., 112. Percussion drilling was also known in ancient China, but it is likely the Carthusians discovered it independently.
(18) The Rule of St. Benedict, Chapter 66
(19) Thomas Woods Jr., “What We Owe to the Monks,” LewRockwell.com, May 25, 2005
(20) Ivan Kinsman, “The Benedictine Monks – as Distillers and Brewers (France, Italy Poland),” August 25, 2021, available online at https://rainwaterrunoff.com/the-benedictine-monks-as-brewers-and-distillers-france-and-poland/ [Accessed 30 June 2022]
(21) Alexander Clarence Flick, The Rise of the Medieval Church (Burt Franklin: New York, 1909), 223
(22) Gerry McDonnell, “Monks and Miners: The Iron Industry of Bilsdale and Rievaulx Abbey,” in Medieval Life, No. 11, Summer 1999, pg. 18-20. See also “Henry’s Big Mistake,” Discover Magazine, available online at https://www.discovermagazine.com/planet-earth/henrys-big-mistake [Accessed 30 June 2022]
(23) See Tim Lougheed, “Myopia: the evidence for environmental factors,” Environmental Health Perspectives, January 2014, Volume 122, No. 1, pp. 12-19
(24) Lynn White, Medieval Religion and Technology: Collected Essays (University of California Press: Berkley, 1978), 221
(25) Marek Otisk, “Gerbert of Aurillac (Pope Sylvester II) as a Clockmaker,” Theory of Science, Sept. 2020, Vol. 42, No. 1, pg. 41
(26)Dr. Otisk also hypothesizes that Gerbert’s clock may have actually been an early astrolabe. Ibid. 32-38.
(27) Ibid., 28-29. See also James Hannam, The Genesis of Science (Regnery Publishing: Washington, D.C., 2011), 22
(28) Lynn White, Medieval Technology and Social Change (Oxford University Press: New York, 1964), 122. See also, Lynn Thorndike, “Robertus Anglicus and the Introduction of Demons and Magic into Commentaries upon the Sphere of Sacrobosco,” Speculum, Apr. 1946, Vol. 21, No. 2, pp. 241-243
(29) Hannam, 156-157
(30) The verge and foliot escapement was first documented in a drawing by Villard de Honnecourt in 1250. G.H. Baillie, C. Clutton, & C.A. Ilbert, Britten’s Old Clocks and Watches and their Makers, 7th ed. (Eyre & Spottiswoode: London, 1969), 4
Phillip Campbell, “Benedictines as Technical Innovators,” Unam Sanctam Catholicam, Sept. 29, 2025. Available online at https://unamsanctamcatholicam.com/2025/09/benedictines-as-technical-innovators