Book Review: God’s Philosophers by James Hannam

Book Review: God’s Philosophers by James Hannam

As I continue to examine the myths the circulate in the atheist community, it was inevitable that I would come across, and have my eyes opened by, God’s Philosophers: How the Medieval World Laid the Foundations of Modern Science by James Hannam (which in the US goes by the title The Genesis of Science: How the Christian Middle Ages Launched the Scientific Revolution).

God’s Philosophers is the latest book in my exploration of lost ages and names in science. If there’s any age that’s lost or underappreciated in modern science, it’s the Middle.

The Middle Ages is certainly a lost age among atheists because we tend to do our best to forget it ever happened. I’ll borrow a line from Tim O’Neill’s review of God’s Philosophers, as he is a fellow atheist who is dedicated to getting history right, albeit sometimes rudely.

One of the occupational hazards of being an atheist and secular humanist who has the lack of common sense to hang around on atheist discussion boards is to encounter a staggering level of historical illiteracy.

. . .

The myth goes that the Greeks and Romans were wise and rational types who loved science and were on the brink of doing all kinds of marvellous things (inventing full-scale steam engines is one example that is usually, rather fancifully, invoked) until Christianity came along, banned all learning and rational thought and ushered in the Dark Ages. Then an iron-fisted theocracy, backed by a Gestapo-style Inquisition, prevented any science or questioning inquiry from happening until Leonardo da Vinci invented intelligence and the wondrous Renaissance saved us all from Medieval darkness.

I recommend reading Tim’s review as well if you have the time. He approaches his writing from a different angle and thus has a very different review from mine, even though we both loved the book. If you have a ton of time, you might enjoy perusing his newer website, History for Atheists, which is where I discovered God’s Philosophers in the first place.

Were the Middle Ages actually scientific?

At first I almost expected to have my mind blown: that exponentially more science was done in the Middle Ages than we ever knew about. Maybe these people were geniuses, inventing things left and right?

But Hannam named the book How the Medieval World Laid the Foundations of Modern Science, not How the Medieval World Was the True Age of Science or something like that. Even so, most of the book didn’t entirely shatter my view that the years from 1066 to 1500 were somewhat stunted by the Catholic Church and superstition. These factors certainly did hold back science, but not to the extent of The Chart.

A chart showing that the "Dark Ages" ended an upward trajectory of science, causing the trajectory to continue in the 1500s rather than the 1000s

Not to sound cliché, but the Middle Ages was a different time intellectually (and pretty much in every other way). Like, extremely different. Yes, the Church ruled, but I don’t think that most citizens would have been able to imagine it any other way. They were the fish and the Church was the water. Except for a select few heretics, everything that the thinkers pondered, they pondered from within a Christian worldview. Most of them were theologians or members of the clergy. This didn’t stop them from doing natural philosophy—the closest term to science at the time—but their interest in God’s creation as a way to discover him was their motivation to learn. Thomas Aquinas, a medieval theologian, famously said “Philosophy is the handmaiden of theology.” And it was.

Adopting a medieval mindset

To fully appreciate the scientific roots in the Middle Ages is hard because, especially for fellow atheists and science enthusiasts, you have to completely reorient the way you think. One of the many atheist myths is that science and religion have always been at odds. This is false.

In the Middle Ages, theology and science were so intertwined that science was considered part of philosophy and people debated about where theology ended and where philosophy started. In many cases, natural philosophy was just a way of learning about God by studying creation, so it really was both science and religion at once. No one would have batted an eye at that like we would now.

That said, much of the intellectual debates described by Hannam involved things that I can’t help but see as pointless metaphysical squabbling. So much of it was about ideas that I’ve entirely dismissed, like what happens to our souls after we die, how atomic theory impedes transubstantiation, and whether calculating Jesus’s horoscope was a sin. (A handful of people were condemned as heretics for doing that.)

Of course it seems like debating about that is a waste of time now, and that these people instead should have devoted their energy to science, but science literally didn’t exist yet in Europe. And it wouldn’t exist now if it weren’t for these people and their odd bickering. They were inching closer to what we recognize as science one person at a time, as they answered these questions that we now find silly.

Nicole Oresme

It felt so obvious to me as a reader when Thomas Bradwardine thought, “Hey, I really think we should put physics and math together and not keep them separate,” and Nicole Oresme thought, “Hey, we should try using graphs to demonstrate mathematical concepts.” These are things I’ve known since my early school days, but for these men they were unheard of in their society. Medieval Europeans were not sitting around mindlessly chanting and thinking about how the world was flat (they did not think that); instead, they already had complete worldviews. It takes a lot of bravery to question an ancient worldview held by everyone you’ve ever met, when you have no reason to abandon it. In the Middle Ages, that worldview was the one created by Aristotle.

Aristotle the antagonist

If I could pick one antagonist in God’s Philosophers, it wouldn’t be the Catholic Church, but Aristotle. For nearly 2,000 years after his death, Aristotle had a firm grip on the worldviews of what seems like all of Europe. Aristotelianism might not sound exactly Christian to us today, but for so long it seems that the Church was bending its doctrines to fit into the ones already made by Aristotle. From what I’ve gathered, almost all of Aristotle’s scientific ideas were wrong, but they went mostly unquestioned for centuries because people simply didn’t have any better ideas. Hannam explains,

Despite their critics, the combination of apparently sound common sense and cogent argument made Aristotle’s theories extremely attractive. They also formed a consistent whole that gave a full description of reality. Taken together, Aristotle’s philosophy makes for a deeply impressive package. This is the reason, more than any other, why it took such a long time for natural philosophers to realise that he was wrong about so many things.

The trouble is that it is impossible just to tinker with Aristotle’s natural philosophy at the edges. It goes so much deeper than that. His was a complete theory of reality and rejecting any significant chunk of it would cause the whole edifice to collapse.

James Hannam, God’s Philosophers, p. 174

Thus, even in the Middle Ages, the only way forward was to question what you’ve been taught, what’s been taken as the gospel truth by everyone since Day One. This was especially difficult because Christianity and Aristotelianism became a dynamic duo that tended to get in the way of big moves forward in natural philosophy. According to Hannam, Thomas Aquinas’s claim to fame was marrying together Christianity and Aristotelianism by clearly outlining their relationship.

The 1277 Condemnations

But during Aquinas’s lifetime, Aristotelianism was still reaching far beyond where it belonged, to the point that it was becoming a threat to Church doctrine. So in 1277 the Church created the 219 Condemnations, which suffer from their unfortunate name and make the Church look worse than it was.

The main point at issue was whether God was constrained by natural laws himself or whether he was above them. The condemnations are fairly confusing to read because they consist of a list of things that people were not allowed to say, rather than setting out what people should believe. . . . 

. . . The bishop of Paris was just telling everyone that they should never say never. Science could not make final pronouncements, especially those that limited the freedom of God. This meant that the bishop was not stopping people from investigating how the world worked, he was merely preventing them from saying that God was constrained in how he could organize the world. Rather than restricting the work of natural philosophers, the condemnations actually freed them up. They no longer had to doggedly follow Aristotle, but could invoke God’s freedom to do things differently and develop theories outside the Aristotelian paradigm.

James Hannam, God’s Philosophers, p. 103

Look at it this way: as Hannam explained in the first quote above, Aristotle’s philosophy was a complete, defined worldview and if you wanted to stay within its boundaries, there were many lines you couldn’t cross. Christianity was also a complete worldview but in many ways it was more open. As long as you believed that God was the master of creation and you didn’t insult his abilities, or encroach on things like transubstantiation, most of the exploration of math and science was fair game.

When the Church freed people from the shackles of Aristotelianism, telling them to just be sure to keep their theories within the boundaries of Christianity, they were opening philosophers to a world of opportunity. Many scholars went on to question and advance the teachings of Aristotle until the Renaissance.

The big bad church vs. the humanists

Much of what God’s Philosophers refutes involves the idea that the Church was the bad guy who wanted to stop science at all costs. Hannam mentions a handful of people remembered as martyrs for science—most of which I hadn’t even heard of—who were mostly punished over theological disputes or for peddling magic. (Probably the best known of these is Giordano Bruno, who was condemned not for belief in heliocentrism but rather for his weird new religion based on magic.) The Inquisition did happen of course, and people were tortured and executed for heresy, but this was not common. These were last resorts and people were usually just asked to stop. And I haven’t come across any examples of people being executed or tortured for just “doing science.”

Giordano Bruno portrayed as a martyr for science in Cosmos: Spacetime Odyssey

Humanists were actually some of the first people to see medieval scientists as dunces; the early humanists actually came up with the term “dunce” as an insult based off of the name of John Duns Scotus, a philosopher who followed in the footsteps of Aquinas and the Condemnations of 1277 and took questioning Aristotle to a new level. Importantly, a humanist in the fifteenth and sixteenth centuries wasn’t someone with the worldview of humanism but rather “someone who was interested in classical Greek and Latin literature.”

The humanists had a great appreciation for the ancient Latin and Greek languages and a disdain for the current, more accessible Latin of the day. This translated (literally) into finding medieval science, frankly, stupid, and not worthy of being studied. They cared only for the original works of Aristotle and now Plato as well. Their error was that they ignored all of the advances to Aristotle’s views that had been made for hundreds of years throughout all of the Middle Ages.

In combination with printing, humanism had one other damaging effect. As printed books replaced manuscripts, the old tomes became waste paper. Combined with the changes in taste and the lack of interest in medieval writing, this meant that entire libraries could disappear. Sometime between 1535 and 1558, Oxford University contrived to lose every single manuscript in its collection and even sold off the bookcases. Merton College, home of the Calculators, threw out three quarters of its ancient library, as many as 900 manuscripts, in the same period.

James Hannam, God’s Philosophers, p. 219

The real destruction of libraries (in which the books were recycled, not the libraries burned down) was not due to the Church closing minds but was instead due to the humanists who accused medieval minds of being closed and so did away with anything that might have come from them.

Galileo, bad friend and copycat

Finally, Hannam spends the last four chapters of God’s Philosophers telling what actually happened with Galileo. Long story short, his trial and sentence had more to do with his betrayal of his friend the Pope than with going against Scripture. We know that Galileo proposing heliocentrism can’t be the reason that he got in trouble, because Copernicus and Kepler had both already done that, Kepler more successfully, and neither was condemned.

Galileo’s greatest sin was putting the words of the Pope from a private conversation into the mouth of the dim-witted fictional geocentrist Simplicio in his 1632 book Dialogue Concerning the Two Chief World Systems. Galileo was technically threatened with torture by the Inquisition, but it was more of a technicality than anything. Galileo was well off, with friends in high places, and everyone knew he would be safe from the Church’s worst wrath.

More interesting to me, however, was Hannam’s description of the book Galileo wrote in house arrest, Discourses on Two New Sciences. The book was a resounding success. It described the existence of vacuums, the physics of falling objects, gravity, and projectile motion. What I didn’t know was that most of the ideas Galileo shared had already been theorized by the natural philosophers that came in the centuries directly before him, and we have evidence that Galileo was familiar with several of them when writing his own book.

Galileo’s achievement lay in bringing together what had been done before, disposing of the vast amount that was irrelevant or simply wrong, and then proving the remainder with controlled experiments and brilliant arguments. A new kind of science did indeed begin with him, but there is no denying that he built on medieval foundations. Without them, he would never have been able to cover a fraction of the ground that he did, even in the long life he was granted.

. . . To historians who want to learn where Galileo and Kepler found their ideas, medieval natural philosophy is indispensable. The achievements of their generation, outstanding as they were, should not obscure the breakthroughs made by Thomas Bradwardine, John Buridan, Nicole Oresme and others.

James Hannam, God’s Philosophers, pp. 335-336


I want to conclude by echoing what Hannam says at the end of God’s Philosophers: it’s admirable and frankly very impressive that medieval scholars were able to accomplish all that they did given the circumstances. One of the greatest things that held people back, especially before the twelfth century, was that all of the scholarly literature at the time came from Greek and Arab thinkers—and everyone spoke Latin. People desperately wanted to learn, but translators were few and far between. Translating everything they could get their hands on into Latin is one of the few things we can thank those early humanists for.

I think it’s clear by now, but I wholeheartedly recommend God’s Philosophers. In addition to introducing me to the great unknown world of Middle Age science, Hannam told every story in an engaging way, and not one of the 336 pages was dry. (The story of Peter Abelard and Heloïse was one of the strangest and craziest that I’ve ever read.) Hannam is well aware that this book has a lot of names and developments, so he includes not only a full timeline of significant events but a glossary of all important names in the end. (These made it much easier to find things as I was writing this post.)

Thanks to God’s Philosophers, I know that I have even more to learn and unlearn regarding atheist myths, and I can’t wait to continue. I’m bound to get things wrong as I overhaul much of my picture of science’s past, but I know one thing for certain: I’ll never believe in the Dark Ages ever again.

6 thoughts on “Book Review: God’s Philosophers by James Hannam

  • December 26, 2021 at 11:00 am

    Re “Except for a select few heretics, everything that the thinkers pondered, they pondered from within a Christian worldview. Most of them were theologians or members of the clergy.” This may have been true for a tiny minority, but the vast populations was ignorant of most Christian ideology. (Remember services were still mostly in Latin.)

    As evidence of this, we have the records, very detailed records, of the Inquisition. Over and over again the recordist commented how ordinary people cheerfully shared heretical ideas, thinking they were what they were taught; astonishing to the inquisitors because these people were damning themselves to torture and often death. They suffered because of a complete lack of education of what the inquisitors thought they should have.

  • January 2, 2022 at 4:32 am

    “we tend to do our best to forget it ever happened”
    Who are those “we”? Not me. Sure, I find the eternal family quarrels of kings and other nobility tedious. Why would I care about the partition of Louis the Pious’ empire after his death? The three resulting kingdoms hardly survived one generation.
    However the main political theme of the Middle Ages, the relation Church – secular authorities (emperors, kings, dukes, counts), is fascinating.

    “These factors certainly did hold back science”
    I’m not a big fan of the idea that christianity founded modern science; christianity was neither a sufficient condition (or modern science would have originated in the Byzantine Empire) nor a necessary one (India, China). I’m rather with Bertrand Russell here (someone Tim O’Neill doesn’t like very much either): christianity maintained an intellectual framework that kept the scientific revolution of the 16th Century possible. India and China had other worldviews that played a similar role.
    However what you write here is incorrect. Science as we know it didn’t exist in the Middle Ages and hence could not be held back. Again I’m with Russell: the RCC (and absolutely not the Pope himself, but rather synods) set boundaries to natural philosophy. And that did not use the scientific method, which had not been developed yet. So the error you make is pit religion against science, while the (natural) p[hilosophers of the Middle Ages thought such an opposition/contradiction impossible. It’s odd that you recognize this in the next alineas and hence contradict yourself.

    “I don’t think that most citizens would have been able to imagine it any other way.”
    That’s also incorrect. Most citizens were well aware of civilizations where the RCC did not rule. Some could be direct enemies (the islamic countries), others were far away (China).

    “They were inching closer to what we recognize as science one person at a time”
    I don’t think so. Thomas Kuhn has written about paradigm shifts. As you rightly point out (and it’s something Tim O’Neill has neglected thus far) the medieval intellectual paradigm was completely different, even from the paradigm developed in the 17th Century (ie after the scientific revolution). That one still wasn’t what we call science, ie methodological naturalism, either. I think staying within the medieval paradigm makes it impossible to even inch closer to what we recognize at science.
    This should not be taken as a dismissal, On the contrary, given their now outdated paradigm I can only admire the intellecutal activities, creativity and resourcefulness of those natural philosophers. It’s just that most of their conclusions have become useless (math is a possible exception, but math in my view is not a science – no methodological naturalism). The same applies to intellectuals from Antiquity. Exactly that makes Archimedes such a genius.

  • January 2, 2022 at 4:57 am

    “Thomas Bradwardine thought, “Hey, I really think we should put physics and math together and not keep them separate,”
    Hardly new. Archimedes was both a physicist and a mathematician. Aristoteles’ pupils did the same. Compare*.html

    “for so long it seems that the Church was bending its doctrines to fit into the ones already made by Aristotle”
    Actually it was not that long; Thomas of Aquina fought for this (not literally). Before the christian worldview was mainly (neo-)platonic. So we’re left with about three centuries. And we shouldn’t be harsh on either Aristoteles or the medieval philosophers, because this

    “Aristotle’s scientific ideas were wrong, but they went mostly unquestioned for centuries because people simply didn’t have any better ideas.”
    applies to 21st Century scientists just as well. If you don’t know what you don’t know (and I’ve seen estimates in physics of 90% !) you hardly have a choice.

    “His was a complete theory of reality”
    This is the paradigm (shift) I talked about. I don’t see how this is compatible with “medieval christian natural philosophers laying the foundation of modern science”.

    “When the Church freed people from the shackles of Aristotelianism”
    Again incorrect. Before Thomas of Aquino medieval natural philosophers were not aristotelian but (neo-)platonic thinkers. Thomas of Aquino was successfull exactly because the synthesis of christian theology and Aristotelian philosophy was so promising – a Grand Unified Theory, something we still lack.

    “Much of what God’s Philosophers refutes involves the idea that the Church was the bad guy who wanted to stop science at all costs.”
    Thanks for justifying my intention to not read the book. I’ve known this for several decades.

    “people being executed or tortured for just “doing science.”
    Of course not. Nobody “did just science” in those days.

    “Humanists were actually some of the first people to see medieval scientists as dunces”
    What atheist “critics” usually forget is that all those humanists were christians too. My compatriot Desiderius Erasmus was a famous example. Read his famous In Praise of Folly. It’s funny, makes mincemeat of scholasticism – and is thoroughly christian.

    “all of the advances to Aristotle’s views”
    Yeah – and still almost all became irrelevant in the 17th Century.

  • January 2, 2022 at 5:26 am

    “A new kind of science did indeed begin with him”
    No. It began with Tycho Brahe, the first one since the Babylonian astronomers to systematically collect observations. In between there were the already mentioned Johannes Kepler and the Flemish/Dutch Simon Stevin.
    Apparently also Hannam totally ignores the importance the paradigm shift that happened in the 16th and 17th Century, resulting in the magnificent works of Newton and Huygens. Bradwardine, Buridan and Oresme were teleological thinkers, Newton and Huygens largely replaced teleology with causality. BBO were positivists, looking for facts that confirmed their Aristotelean thinking. Newton and Huygens were fully aware that observations could and should decide between two competing hypotheses. In mechanics the Aristotelean principle (fully supported by BBO) that the purpose of force is motion was replaced with the Newtonian principle that force causes change of motion.
    I do not doubt that Galilei was familiar with medieval natural philosophers. But it’s clear that Hannam and I suspect with him O’Neill do not appreciate but very much underestimate how far the great and arrogant Italian had moved away from them. Galilean Transformations are not mentioned after him for nothing and are simply incompatible with medieval, ie Aristotelean natural philosophy. In fact that manuscript I linked to above came closer than BBO and all others.
    Again, this is not meant to look down on medieval natural philosophers. That’s as stupid as blaming Galilei for not understanding particle/wave duality. But I won’t accept any conclusion that totally ignores how irrelevant their thinking had become in say 1700 CE. That fact simply doesn’t fit in any story of christianity founding modern science – which always is totally eurocentric too. Again: China and India, but not Byzantium.
    Tim O’Neill btw in such cases likes to forget the principle that theory A is better than theory B when it explains more relevant facts. I predict that he will reply with something like “Hannam’s book is not about China, India and Byzantium”. He’s a eurocentrist.


What do you think?