Book review

Seb Falk’s The Light Ages: book review

This is my review of the book "The Light Ages" by Seb Falk. Turns out, there was much learning and scientific inquiry going on in the Middle Ages!

We tend to see the Middle Ages as the Dark Ages, ignorant times when superstition ruled and reason was absent. Our popular assumption is that in between the philosophy of the ancient Greece and the European Renaissance awakenings led by the holy trinity of Copernicus, Galileo and Newton, humanity spent their days praying to God and murdering each other. Sure, people did lots of that for sure in the Middle Ages, and even now many haven’t stopped, turn the TV on to check.

In reality, things are more complicated. As “The Light Ages” by the Cambridge historian Seb Falk shows, the Middle Ages were actually the times of learning and indeed of science (science as profession is a very modern concept anyway). Maybe not of natural sciences as we know them, but people still sought out knowledge, invented, measured, calculated and strived to understand the natural world. The book’s protagonist is the English Benedictine monk John Westwyk, a 14th century scholar of astronomy and mathematics and a designer of a planetary computer named Equatorium (Falk offers a virtual model here).

Unlike our popular belief goes, nobody half-way educated believed back then that the Earth was flat. That assumption about the Middle Ages was actually invented in the 19th century. The medieval knowledge was that the earth was very much round, some calculations even managed to estimate its correct size. Obviously everyone assumed that the Sun, the planets and the stars (all made of fire, one of the four elements) rotate around the Earth, with water and air mixed in. A standard model was that of the so-called celestial spheres, where the Moon orbited nearest to Earth, the sphere of the fixed stars was the furthest, and the spheres of the Sun and the planets moved in between.

The Middle Ages were the times Europe rediscovered the writings of the Greek natural philosopher Aristotle (who postulated the four element theory, among other things), and the Egyptian astronomer and inventor of the celestial sphere model, Ptolemy (who was a Roman citizen but wrote in Greek). These two were seen by the scholars both Latin and Arabic as the greatest minds and highest authorities of all times.

Maybe I should admit in advance that I was way above my head with Falk’s mathematical diagrams and explanations and ended up not understanding anything at all about how Westwyk’s Equatorium worked. In fact I was already rather overwhelmed with Falk’s calendrical and astronomical calculations as well as his much simpler handling instructions for the astrolabe, a common device invented already in the ancient Greece and used throughout the Middle Ages in Europe and Asia. The astrolabe was basically a 2D projection of the spherical model of the cosmos and used to compute many things, including your latitude or the time of the day, from the positions of the stars and the sun in the heavens. I may have failed there, but I am sure many of my readers will enjoy such mathematical challenges!

Astrolabe of Jean Fusoris [fr], made in Paris, 1400 (Wikipedia)

Astronomy was the central pillar of medieval knowledge, both in Europe and Asia, not just because it was absolutely required for nautical navigation (and in fact for every form of long-distance travel), but also because it gave people the understanding of the nature of the creation and a glimpse into the mind of God (at least this is how they saw it). Their other assumption was that by understanding how the heavens operate, you can understand everything which happens down here on Earth. This is why the medieval medicine was actually a branch of astronomy, which in turn was at those times almost inseparable from astrology, which existed in two forms in the middle ages: the highly scholarly predictive form (astrological tables were immensely popular), and the much less respectable magical form where you tried to influence the future.

Medieval medicine was part of astronomy and influenced by astrology. It was believed that the four elements and the heavens influence the balance of the four humours of the body (blood phlegm, yellow and black bile), astrological assessments of stellar constellations were needed to decide the course of a medical therapy. The top medical authorities in this regard were the Greek Hyppocrates, the Roman Galen and the Persian Ibn Sena (Avicenna), plus various other Islamic sources. Meanwhile, the learning continued: in medieval Italy, corpses were dissected to teach anatomy and forensic autopsies were performed. Yes, the medieval medicine mostly did not work and often caused more damage than it helped, but no need to feel arrogant: the modern germ theory is not that old actually. Even in the late 19th century surgeons refused to wash their hands.

In any case, it was also believed that the astrological analyses have successfully predicted the plague, which boosted the astrology’s authority in those times. But not just for health: you needed to know the positions of the stars, the Moon and the planets to make predictions on weather, agriculture, travel, business and politics. Looking back, it all may seem ridiculous, but that is only due to the benefit of our today’s accumulated knowledge which we learn at school.

Astronomical and astrological tables for the movements of the Sun, the Moon and the five known planets (Mercury, Venus, Mars, Jupiter and Saturn) were therefore extremely important, and those were made, copied and also corrected and re-calculated by monks. Most scholars of the European Middle Ages were indeed monks, which Falk explains by the simple fact that at those times monasteries were the only place offering access to books, which had to be copied manually on expensive parchment those days. Monks also had to study foreign languages, not just the Greek or the ubiquitous Latin which was the language every monk and educated person had to learn and the only way scholars from England, Germany, Italy and France could communicate with each other.

Now, the Latin translations of Aristotle, Ptolemy and others were not always done from the original Greek though, but from Arabic and Hebrew. Our European arrogance makes us believe that all science and reason happened exclusively in Europe, but reality is different. Much of the original Middle Age astronomy was originally written in Arabic, by Arabian, Persian, Turkish, Andalusian Islamic and other oriental scholars, who built their knowledge on the translation of the works by Aristotle and Ptolemy. Some of these scholars were Jewish and wrote in Hebrew, Jews were also the mediators of the intellectual exchange between the Christian Europe and the Muslim orient. A give-away are the names which Latin scholars gave to stars, devices and to those great scholarly works: for example Ptolemy’s Almagest means The Greatest in original Arabic, while our term algorithm honours the Persian mathematician Muhammad ibn Musa al-Khwarizmi.

I personally also think that scientifically-inclined people from farmer families like John Westwyk were attracted to monastic life because it was the only way for them to learn, to propagate and even to create knowledge, even women could participate in the studies by joining the nunneries. Sure, there was the strict monastic hierarchy and daily regime, but you had this everywhere at those times. The only obvious drawback was that, married to the Church, you could not start a family.

Wallingford’s clock, smaller-scale modern reconstruction (St Albans museum)

Westwyk, who lived ca 1350-1400, came to the right place with the St Albans monastry. The previous abbot Richard of Wallingford (a blacksmith’s son, btw) was truly a scientist and inventor, who designed a monumental and incredibly ingenious clock which could predict not just the time, but also all possible astronomic events. Westwyck’s period was that of great changes: the Indo-Arabic number system arrived previously via translated manuscripts and began replacing the previously common Roman numerals. This in turn transformed the way people counted and later the wider mathematics, because calculations with Indo-Arabic numbers are much more advanced than those with Roman ones. Calenders were being adjusted to correlate the Roman Sun-cycle based with the Arabic-Jewish Moon-cycle based system to reflect the exact movement of the Earth around the Sun – back then of course, the movement of the stars, the planets and the Sun around the Earth, yet mathematically, as Falk shows, there was little difference when all you wanted was a reliable calender. And such calenders were much needed, for example to predict moving church holidays. The word Computus originally stood for calendrical astronomy, this is why Westwyck’s Equatorium was in fact a very advanced computer of celestial constellations, its design based on the works of Westwyk’s Muslim and Christian predecessors.

Equatorium from Johannes Schöner (Wikipedia)

Falk presents the life of John Westwyck, reconstructed from records, clues and of course his own manuscripts. We learn that Brother John obtained his knowledge of mathematics and astronomy at St Albans, was probably attending the University of Oxford (without a degree, as many monks did to save money), wrote and annotated books based on the works of Richard of Wallingford, and eventually was for some reason sent to a far away Tynemouth monastry at the Scottish Border where he still managed to continue studying. From Tynemouth, John Westwyck even went on an actual crusade to France, against the loyalists of the Antipope in Avignon. Upon his return from that embarrassing and failed crusade, Westwyk moved to a St Albans guesthouse in London, where he wrote his final magnus opus on the Equatorium, in English, and not in Latin. This manuscript, when first discovered in 1950ies, was initially attributed to the famous English poet and astronomer Geoffrey Chaucer (whom Westwyk personally interacted with and mentioned in his manuscript). Westwyk’s authorship was established much later by Kari-Anne Rand who compared the writing style of the Equatorium to Westwyk’s previous and signed manuscript Albion, another work of astronomical calculations which was based on Richard of Wallingford.

Westwyk was living literally in changing times, because time was not the same thing in the Middle Ages as it is now. The Egyptians, and later the Israelites, Greeks and Romans never bothered with it really, the days initially all had 12 hours from sunrise to sundown. Their length obviously changed with the seasons, while you measured your own shadow in the field if you wanted to know what time it roughly is. The ancient system was good enough for the farmers, but not good enough for astronomers. The Middle Ages of John Westwyk’s period saw the transition from the unequal daylight hours of the Romans to the equal hours we all know today from our clocks, and you needed to do some serious astronomy calculations to get there. The astrolabe was able to show you both, the traditional unequal hours everyone was used to, and the fancy modern exact hours. Important: the very first mechanical clocks were built in the medieval times, and Falk calls it “the most significant invention of the Middle Ages“.

Universities were also founded in the Middle Ages in the 12 century, driven by the flood of Arabic and Greek translations and evolving from the monastic and cathedral schools. The need for universities was there simply because wealthy professional classes were also keen on getting some education, the Latin name universitas meant actually the union of students and masters who organised themselves like a kind of teaching guild. The first universities originally taught the Trivium of verbal sciences: grammar, rhetoric and logic, followed by the advanced Quadrivium: arithmetic, geometry, music and astronomy. But right away, newly founded universities started to specialise according to local needs: Bologna focussed on law, Padua and Montpellier on medicine (branch of astronomy, don’t forget!), Paris and Oxford went for theology, the latter however also included liberal arts and thus grew strong in mathematics.

The arts faculties became more and more a thing of their own and started to define the curriculum, with Aristotle’s teachings as its model. Three branches of philosophy were taught: the moral philosophy, the natural philosophy and the metaphysics. The foundation for all university astronomy studies at the Middle Ages was provided by Johannes de Sacrobosco, who in turn build on Aristotle, Ptolemy and Arabic scholars like Al-Farghani, and also proved that the Earth was round, and even referenced ancient Greek sources about its correct size. Falk mentions that Columbus later used the wrong calculation by Prolemy and Al-Farghani to travel to India, which predicted a smaller Earth.

Sure, the Church controlled the universities (as it controlled everything else back then), and there were indeed some issues with Aristotle’s teachings that the universe is eternal, as opposed to created. And yet, as the Aristotelian science was embraced by monks and university scholars alike, the Church eventually conceded, although its previous ban prompted people to question the Aristotelian theories (which for example reject the concept of vacuum), and eventually the modern astronomy began its evolution. Interesting is also that monks were regularly send to study at universities at the expenses of their abbeys, so much for religion prohibiting learning. There were even papal decrees on how many monks are to be sent for university education each year.

Other things were invented in those supposedly dark times of ignorance, I wish Falk has told more details about those. Optics theories were imported from Arabic sources and further developed by Latin religious scholars like Robert Grossetesta, while Italian glass craftsmen started to produce first lenses and soon, first spectacles. The magnetic compass, a critical instrument for nautical navigation, was already in use in 8th century China, in the form of a magnetised needle floating on water, it was then (apparently independently) invented again in the medieval Europe. Alchemy, much popular in the middle Ages, proved the existing interest in elements, substances and their reactivity and transformation, which led it eventually to evolve into chemistry of today. Even Isaac Newton dabbed in alchemy while revolutionising physics. His modern science as well as Nicolaus Copernicus‘ and later Johannes Kepler‘s astronomy arrived not from nowhere, but from their studying the works of their medieval predecessors, from Europe and Asia.

There would be no heliocentric astronomy and laws of planetary motion without the medieval astronomers struggling to understand their own scientifically observed irregularities in the context of the accepted system of geocentricism and celestial spheres. By the time Copernicus and Kepler (or Galileo, whom we prefer to credit in such things) arrived, the Ptolemeic astronomy and cosmology became such a philosophical and mathematical mess that it was clear to everyone it all made no sense. We must thank those medieval scholars for getting us to such an understanding, even if their own models of the cosmos were hopelessly wrong.

Disclaimer: As usual, I receive no payment or incentive to write this review, but I did receive the book gratis from the publisher upon request.

P.S: Now, if you are interested in the emergency of modern astronomy, Thony Christie is your source (I stumbled over Falk’s book via his tweets, and here is Christie’s review). Just pop over to his very informative and highly entertaining blog, The Renaissance Mathematicus!


If you are interested to support my work, you can leave here a small tip of $5. Or several of small tips, just increase the amount as you like (2x=€10; 5x=€25). Your generous patronage of my journalism will be most appreciated!


4 comments on “Seb Falk’s The Light Ages: book review

  1. Thank you for the review. I’m heading off (electronically) to buy the book now.

    I’m curious whether you or the author sees any influence from the ancient East in any of the European advancements or were the Europeans of the Middle Ages largely unaware of any scientific explorations there.


  2. At last one of your articles that I actually enjoyed! Who would have thought of it.


  3. I agree that this is an interesting book. It is my current lockdown reading. Also of interest on the same subject is the BBC series: The Dark Ages – An Age of Light by Waldemar Januszczak, which looks at some wider cultural aspects.


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