Our Medieval Scientific Heritage

We owe a lot more of our progress to the Christian Middle Ages than most people seem to realize.

Most Americans and Europeans are well aware that they belong to a culture that has long been shaped by its love of science and engineering. But ask them what era in our history that technological impulse can be traced too, and I suppose that most would either say that it began with the ancient Greeks, or else during the Renaissance and the “Scientific Revolution” around the year 1500.

Few think of the Christian Middle Ages as a time of great innovations, a time when mathematics, science, and especially engineering came to matter in daily life to a degree that would have stunned the ancients. And this ignorance, on the part of most people now living, is a crying shame.

I trust that most of my readers, even if they have not read Geoffrey Chaucer’s Canterbury Tales, are at least familiar with the basic premise of this greatest work of Middle English poetry. The Knight’s Tale is followed by the Miller’s Tale, then the Reeve’s Tale, then the Cook’s Tale, and so forth, as twenty-four pilgrims tell stories to entertain one another on their way to venerate the martyred St. Thomas Becket at Canterbury Cathedral.

While Chaucer gives some of his characters personal names (i.e. Robin the Miller), they’re mainly known to us by their occupations, and they identify themselves that way, too. So, for instance, when Robin the Miller tells a derogatory (and very lewd!) story about a carpenter, the Reeve (who had been a carpenter as a young man) feels honor-bound to tell a derogatory story about a miller.

Of course, nothing about this strikes 21^st century Americans as unusual – we too are a society where our occupations (which we usually arrived at by personal choice) are the most basic way we identify ourselves. It takes a fair bit of historical perspective to realize how rare this is – how few premodern societies, apart from medieval Western Europe, did this. (For instance, in the New Testament St. Paul introduces himself as a Jew from the tribe of Benjamin, a Pharisee, a native of Tarsus, and a student of the rabbi Gamaliel; it is almost by chance that we learn that he was also a tentmaker, when he briefly takes up his old trade with Aquila and Priscilla in Corinth.)

Of course, the high degree to which medieval Christians identified with their trades was not something that happened in isolation. It came hand-in-hand with the high status which their society granted to its increasingly numerous middle classes, and also the inventiveness with which millers, carpenters, shipwrights, masons, accountants, and other skilled workers were continually improving their various crafts.

There are two books on this subject which I have recently read, and which I can enthusiastically recommend to people with some spare reading time and a desire to really understand and appreciate our medieval scientific heritage.

Frances and Joseph Gies’ 1994 book Cathedral, Forge and Waterwheel: Technology and Invention in the Middle Ages is a thorough, if rather dry, account of the many inventions that reshaped Europe between the fall of Rome and the 15^th century Renaissance, and which turned Europe from a backwater that could only envy Arabic and Chinese engineering into a continent on the edge of world domination.

Seb Falk’s 2020 book The Light Ages: The Surprising Story of Medieval Science gives a panoramic tour of 14^th century mathematics, science, astronomy, and education as it would have looked from the point-of-view of one man – an English Benedictine Monk named John of Westwyk, whose most famous work was a set of instructions on how to make and use the Equatorie of the Planetis – a sort of mechanical computer for doing Ptolemaic astronomy. While Falk’s book is more narrowly focused than that of Gies, it is also more pleasurable to read. (Cathedral, Forge and Waterwheel is the sort of book that’s more likely to show up on a college syllabus, though someone as interested in technology and history as I am would almost certainly enjoy both of them.)

Cathedral, Forge, and Waterwheel is divided into seven chapters, and tells a roughly chronological story of European engineering between the fall of Rome, c. AD 500, and the end of the Middle Ages a thousand years later. A typical chapter might have a few pages each devoted to ploughing, waterpower, weaving, dying, carpentry, glasswork, Gothic architecture, military engineering (castles, trebuchets, etc.), road and bridge building, navigation, naval architecture, and bookmaking.

The myth of the Middle Ages as a time of stasis, where curiosity dwindled and hardly anything was done to improve on Greek and Roman science, is quickly dispelled. Although some technologies were lost at the very beginning of the period, most of them were recovered fairly quickly, and in a few areas – especially agriculture and weaponry – progress continued without the slightest interruption. Even before the year 1000, when written records were scarce and the population remained well below its Roman peak, new spinning and weaving methods, new animal harnesses, new kinds of ships, and the first water-powered mills had revolutionized life in Christian Europe.

By the twelfth and thirteenth centuries – with the Renaissance and its conscious attempts to revive Greek and Roman lore still a century away – devout master masons were adorning England, France, and the Low Countries with their highly innovative Gothic cathedrals, marvels of architecture far in advance of anything the Romans ever had. One of these, Lincoln Cathedral, was the tallest building in the world at its completion in 1311; it would not be surpassed until the Washington Monument was erected in 1884.

Tracing the evolution of new technologies is no easy task for a historian, and it is often a great mystery whether a particular invention – the padded horse collar, for instance, or the blast furnace, or the magnetic compass – arose independently or was brought from Asia.

For evidence of which technologies were known in a certain country in a certain century, scholars often turn to the beautiful illuminated Bibles into which medieval scribes put so much labor. There, illustrations of the ancients hard at work building Noah’s Ark or the Tower of Babel would reveal how carpentry or masonry was done in the illustrator’s century – the irony being that it was those men’s lack of interest in historical accuracy that gives us our best window into the past.

One memorable scene in the 9^th-century Utrecht Psalter illustrates some verses from the 63^rd Psalm: “But those that seek my soul, to destroy it, shall go into the lower parts of the earth. They shall fall by the sword: they shall be a portion for foxes….” The wicked (“those that seek my soul”) are preparing for battle by sharpening their swords the old-fashioned way, with hand-held whetstones, while the righteous use the new rotary grindstone, a machine unknown in earlier centuries.

To medieval men and women, hard work and innovation were spiritual callings. This was obviously so for the priests, monks, and nuns who almost alone kept literacy and mathematics alive, as well as for the architects who built the churches, the sculptors and glaziers who adorned them with “a Bible in glass and stone,” and men like the “Fréres Pontifes,” or Brothers of the Bridge, a small order of monks devoted to bridging the treacherous rivers of southern France in the 12^th and 13^th centuries, and who built (among other edifices) the famous Pont d’Avignon.

But it was also true for all of the craft guilds that made up that rapidly growing middle class in medieval Europe’s cities. They all had their patron saints, they all had their peculiar donations to the parish churches and the great cathedrals, they each had a mystery play to perform in the festivals at Christmas and Easter, and they all exhorted their members to remember that their curiosity was a gift of God, and that it was by Christ’s grace that they exercised their talents upon the elements.

And it was largely through the work of these guilds that many European countries –most especially Italy, England, and Holland – made the slow journey from being nations of serfs to nations of freemen.

The Church had already seen to it that, from the very beginning of the Middle Ages, the masses had far more rights than the Roman slaves from whom they were often descended. A serf was bound to work his master’s land, but he could own property in his own right as well, and he could not be sold, or even compelled to work on the sabbaths and the saints’ days that the Church had set aside for rest.

The lack of a cheap supply of movable chattel slaves drove medieval entrepreneurs to put much more effort into discovering labor-saving devices than their Roman forbears ever had. And as the cities with the skilled laborers became ever more important to the public good, kings and emperors began granting these bustling settlements new privileges – such as the right to elect their own mayors, or the “freedom of the city” whereby any serf who escaped to a city and managed to live there for a year and a day was a free man, entitled to pursue whatever occupation he liked without fear of being returned to his master.

It was then only a matter of time until characters like Chaucer’s Miller and Reeve and Franklin and Merchant, upwardly-mobile citizens proud of their various professions, began filling the pages of medieval literature.

When one is aware of all this history, it will seem baffling that the myth of a stagnant Middle Ages still holds sway over so many minds. Its persistence can really only be understood by remembering the anti-clericalism that gave rise to it: basically, a lot of 18^th century intellectuals – the same sorts of people whose theories produced the French Revolution – couldn’t give the Catholic Church credit for fostering so much learning and social progress.

Also, one must consider the modern left’s general mixture of ignorance and disrespect for the cultural heritage of white Europeans, plus its hatred of capitalism. For it was the wish “to serve God and his Majesty… and to grow rich as all men desire to do,” as the conquistador Bernal Díaz so memorably put it, that had turned peasants into townsmen, and townsmen into inventors and engineers, and eventually sent the most ambitious of them to make their fortunes in the New World.

Cathedral, Forge, and Waterwheel takes the big picture view, with individuals rarely showing up long enough for me to remember their names. But Seb Falk’s book The Light Ages is its opposite in two ways. In addition to focusing on a single historical person (the English monk John of Westwyk) and his times, it is also more concerned with philosophy and pure science than with engineering.

We follow John from his boyhood in the village of St. Albans into the Benedictine monastery of St. Albans, which stood on a nearby hill. (At this time, the monastery owned the land the village was on and functioned as its feudal lord.) At around age ten, children like John who were considering becoming monks would begin learning monastic discipline, and they also learned how to read, write, and use numbers.

As we read Falk’s book, we too learn how to multiply and divide Roman numerals, and we too learn the basics of the medieval calendar, with its feasts and holy days, and its specific prayers and psalms for each hour which made timekeeping – and hence astronomy – so important to the monks.

Curiously, it was in this book that I learned, for the first time, why the days of the week come in the order that they do. Just about everyone knows that, in most European languages, they’re named after the planets, but why is their order Sun-Moon-Mars-Mercury-Jupiter-Venus-Saturn?

The answer, as it turns out, is astrological. To a traditional astrologer, not only the days, but also the hours of the days, have planetary rulerships: the first hour of Sunday is ruled by the sun, the second hour by the next planet inward, Venus, the third by Mercury, then the Moon, Saturn, Jupiter, Mars, and the Sun again (the classical order having the Sun rather than the Earth between Venus and Mars). Since the twenty-fourth hour of Sunday is ruled by Mercury, the first hour of the next day goes to the Moon, hence the name Monday, and so the cycle continues until Saturday is again followed by Sunday.

As we follow John of Westwyk through the pages of The Light Ages, we see more and more sides to medieval scientific life. The young Westwyk would have learned how to copy books in St. Albans’ scriptorium, where not only Christian writings but also those of many Pagan and Islamic philosophers were held in highest regard. Muhammad ibn Musa al-Khwarizmi, a prolific Persian scholar of the 9^th century, produced writings that later became so fundamental to European mathematics that his name evolved into our word “algorithm.” The 10^th-11^th century Persian Ibn Sina (“Avicenna” in Latin) wrote the Canon of Medicine, a book second only to Galen’s work in its authority among medieval Christians. And in Dante’s Divine Comedy, Ibn Rushd, or “Averroes,” a 12^th-century Andalusian commentator on Aristotle, is given one of the most exalted places in limbo (as a Muslim, he can’t get into heaven, but he’s still in a paradise by earthly standards).

As a young monk, John of Westwyk goes to university, and we readers are treated to a long chapter about medieval universities. The early universities were essentially craft guilds or “corporations” for students and lecturers, where both had more academic freedom than was ever found in earlier societies; they also spread the philosophical and mathematical knowledge of antiquity over a much wider portion of society than had had access to it in Greek and Roman times. Later, in a chapter on astrology, Falk’s readers learn the basic spiritual attributes of the seven classical planets, as well as how to use an astrolabe to tell time and (more importantly) to figure out which planets and signs are about to rise at any hour of the day or night.

Medieval men and women are often ridiculed for falling prey to superstitions, but it’s important to remember that sciences like alchemy and astrology were not universally believed in. For instance, Chaucer devoted an entire Canterbury Tale, the Canon Yeoman’s Tale, to a long and detailed harangue about the creative ways that alchemists swindle the gullible. Thomas Aquinas argued in the Summa Theologica that, while Christians may believe in astrology, they are not required to do so. And in The Light Ages, Seb Falk tells the story of how, in 1437, the instrument-makers of Paris persuaded that city’s university to help them enact a law that required all physicians to own an astrolabe (for determining the best times for bloodletting and other treatments) whether they wished to or not.

Some of us may be tempted to scoff at these instrument-makers and their leader, the physician-turned-metalworker Jean Fusoris. But when you consider just how many people in our own day and age also make their livings by lobbying the government to force their fellow citizens to pay for useless or even harmful medical innovations, you’ll realize that the spirit of Jean Fusoris has never gone away.

Other chapters follow John of Westwyk as the middle-aged monk goes on crusade (unfortunately there are no records of how he performed in battle) and as he writes his masterpiece, the manual for the Equatorie of the Planetis. Astronomy back then involved doing math in base sixty – not just for degrees, arcminutes, and arcseconds, but all the way out to nine sexagesimal places! – with each ‘digit’ written out in Roman numerals. And while Westwyk and his contemporaries were mistaken in thinking that the planets went around the Earth, their observations were still careful enough to discover the cycle of apsidal precession that, for Saturn (the slowest planet) takes about forty-nine thousand years to complete a full revolution.

One cannot even scratch the surface of what has been written about medieval science and technology (and reading Cathedral, Forge, and Waterwheel and The Light Ages is just scratching the surface) without coming away with an immense degree of admiration for the thinkers and inventors of the Christian Middle Ages.

It is true that these men had their faults, mostly on the pure science side – the philosophers and the clergy were usually too keen to defend ancient authorities like Aristotle and Pliny when they should have been making observations for themselves. (The humbler carpenters and smiths and masons had no such luxury; for them the test of an invention was whether it worked.)

But it is equally obvious that nothing that happened during what we call the Renaissance or the Scientific Revolution would have been possible without centuries of lesser-known, but equally-vital, medieval progress. And that progress was made by thousands of hard-working smiths and masons, bookmakers and lecturers, philosophers and mathematicians and naturalists (and these latter usually clergy) who saw curiosity as a virtue, and who devoted their life’s labor to plumbing the mysteries of God’s creation.

A shorter version of this essay originally appeared at the American Thinker.