The Foundations of Science in the Middle Ages

by Edward Grant

“Remember to anticipate the negative consequences that might arise from succeeding beyond your highest ambitions.” 

Had I followed this advice, my experience with the Computer Game Developers Conference would not have been so painful. But the most spectacular demonstration of the value of this advice is provided by Aristotle. We can’t blame him for the way his towering intellectual achievement backfired — that happened more than 1500 years later, and none of us can reasonably foresee the consequences of our efforts so far into the future. Still, there is a fascinating irony in the tale of how Aristotle’s huge leap forward later held back intellectual progress.

The crunch came in the late Middle Ages, in the period between about 1200 CE and 1500 CE. Now, we all learn that there was this momentous event just afterwards called “The Scientific Revolution”. First Copernicus got the ball rolling with his heliocentric model of the solar system; then Galileo pushed forward on several fronts such as kinematics, dynamics, and astronomy. Newton triumphed with his three laws of motion, which appeared to solve everything. The Scientific Revolution was made concrete. That’s what they teach us in high school, but it’s not quite right.

Of late there has been a lot of scholarly interest in what got all this started. After all, Copernicus didn’t just pop out of thin air; he was building on the work of earlier thinkers. But what work was that? Who set the stage for the Scientific Revolution? I’ve been reading a lot of books on this subject of late (Reason and Society in the Middle Ages, The Genesis of Science, The Victory of Reason, The House of Wisdom, Copernicus and Modern Astronomy), but most of these are fairly straightforward narratives: who wrote what, when they wrote it, and how others reacted. This book delves deeper.

Perhaps I just needed the preparations provided by the earlier books, but this book caused the pieces to fall together for me. The difference, I think, lay in the fact that the author really took the time to truly grasp the entirety of Aristotelian thought, quite a feat in itself. This in turn enabled him to understand and explain what really happened during those crucial centuries — and it truly was a magnificent intellectual acheivement.

The starting point of this was the Western discovery of Islamic intellectual achievements in the 12th century. Islamic thinkers had assembled quite an intellectual edifice, which in turn was founded firmly on Greek, and especially Aristotelian foundations. Here we come to the first crucial step: the willingness of Islamic intellectuals to recognize the superiority of Greek thought and their embracement of that thought. Sadly, their work was viewed with suspicion by the theological establishment, a suspicion that hardened into condemnation. Fortunately, the Latin West picked up this new thinking just as the Islamic world began to stamp it out. Islam fumbled, and Christendom recovered the ball. 

This is not to say that Christendom snatched up the ball with unerring fingers; resistance to all this new-fangled “rationalism” stuff was strong among theological conservatives, who rightly feared that rationalism might question some of the dogmas derived from Scripture. Their fears were justified, for well they knew that Scripture is riddled with logical absurdities and outright contradictions. But they had little choice: if Scripture were not the ultimate authority, then there was no basis for commonality and Christendom would surely fracture into a hundred warring sects. And indeed, that is precisely what happened some centuries later when the Reformation tore Christianity apart and launched a plague of wars. The conflict continues to this day, with fundamentalist Christians insisting that the Bible is literally true, that the earth is 6,000 years old, that dinosaurs co-existed with early humans, and all manner of other absurdities.

But where Islam snuffed out the spark of rationalism, Christian conservatives couldn’t quite stamp it out; it took hold and grew in strength. I suspect that this crucial difference arose from the fractured nature of Christian feudalism. We enlightened moderns like to the think of feudalism as a cruel and barbaric system, but its fragmented nature opened the door to rationalism. 

The benefits of feudalism
The feudal system had no concept of central authority; feudal society was too fragmented to need or value central authority. Territory wasn’t the measure of a political unit, because there was plenty of unpopulated territory in Europe. Christendom wasn’t neatly divided territorially into kingdoms composed of principalities composed of duchies composed of counties composed of baronies… Don’t think of Europe as a map subdivided into neatly bordering units. Think instead of a bunch of disconnected spots scattered across the map. Each spot had its own ruler who, depending on heritage, tradition, and size, might be called a king, a prince, a duke, a count, a baron, or a knight. That little unit was completely self-sufficient and sovereign. Diplomatic and military necessity required collective action, which was not accomplished by treaties — these were too complex and tricky to maintain. Instead, a simpler system was adopted: one sovereign would place himself under the protection of a more powerful sovereign, his “liege”. The relationship was simple: the liege was required to defend the vassal against invaders, and the vassal was required to provide a specified number of knights to the army of the liege. What he did back home was entirely his own business, and the liege had absolutely no right to interfere. This simple, robust system worked perfectly in those chaotic times. 

But it literally had holes in it: places lacking feudal lords. Towns were the first of these entities. They had no feudal lord because they were not self-sustaining economic units; they depended upon the agricultural production controlled by neighboring lords for their survival, yet they were not part of those lords’ domains. Once towns grew rich enough, the envious eyes of neighboring lords looked threateningly upon the towns, which, in essence, got themselves their own liege in the form of the most powerful lord in the region. Instead of providing knights to the leige’s army, they provided revenue from their commerce. In return, the liege guaranteed their independence with a charter. 

This idea of a charter as a guarantee of independence was soon extended to other social groups: guilds, trade associations, and, most important, universities. These institutions were unlike anything before. They were politically independent communities of scholars under the protection of the nearest king. Many earlier civilizations had developed schools for advanced scholars, but the feudal university was much more powerful: it ruled itself under a charter granted by the king. The officials of the city in which the university was embedded had no authority inside the walls of the university. 

Of course, the Church enjoyed considerable authority (although not absolute control) over the university, because all the scholars were clerics; education was available only to members of the Church. Still, the general fissiparousness of the feudal structure insured that many universities operated with considerable independence.

Thus, Western scholars enjoyed more intellectual freedom than scholars in any other civilization. This is what made it possible for them to make intellectual progress.

Getting from A (Aristotle) to S (science): an astounding leap
But these scholars faced a huge problem. Aristotelianism was their inspiration and their starting point. They saw their task as a matter of filling in the gaps in their knowledge of Aristotle’s thinking. They set out only to wrap up Aristotelian thought, because, after all, Aristotle was so far ahead of everybody else that he just had to be right about everything.

Here is where the author of this book reveals the central problem: Aristotelian thought constituted a paradigm (an entire system of thought) that was completely incompatible with what we call science. Aristotelian thought wasn’t just wrong — it was nowhere near the ballpark. Here’s a highly simplified analogy: it’s not as if Aristotle answered the question “What does 2 + 2 equal?” with the answer “5”; no, his answer might be “turtle”. Aristotelian thought was a highly formalized and internally consistent expansion of common sense. Every object had innate properties that endowed it with certain behaviors. Fire wanted to go up; earth wanted to go down. Every object in the world consisted of some combination of the four basic elements (earth, water, air, and fire), and the combination of those elements determined the behavior of the object. 

I won’t go into the details of Aristotelian physics, but you need know only three basic notions about it: a) at the surface level, it appeared to be based on solid common sense; b) it organized and extended common sense in a highly logical and very complex system; and c) it was completely, totally wrong-headed in its basic concepts. 

As the scholars of the later Middle Ages struggled to sort out the Aristotelian mess, they encountered ever worsening problems. The closer they looked, the less sense it made. Yet they couldn’t just toss it out; Aristotelian thought was the basis of all education in Christendom; a huge intellectual edifice had been erected on top of Aristotelian thought that covered just about everything, including theology. Tossing Aristotelian thought was not an option. Yet it just didn’t make sense. The scholars faced a problem similar to the one of transforming a Boeing 747 into a Saturn V rocket — while in flight and without spilling the passengers’ drinks. 

Yet that is precisely what those scholars did. It took them centuries, and needed the combined efforts of hundreds of brilliant thinkers. Bit by bit, these people effected a paradigm shift larger than anything in intellectual history before or since. I will not explain the complicated twists and turns in this story; that’s what this book does. Having read it, I now stand in awe of the acheivement of the scholars of the late Middle Ages. It’s ironic that most people see that period as a time of intellectual stagnation, when in fact it appears to me to be the most revolutionary period in intellectual history. Copernicus, Brahe, Kepler, Galileo, and Newton didn’t just pop up out of thin air; they took the ideas bequeathed to them by their predecessors and pushed them even further.

To give you an idea of just how great this achievement was, let me explain just one rather small aspect of the revolution they wrought. They integrated mathematics and science. This might not seem like much to you; after all, everybody knows that math is fundamental to science, right? Well, Aristotle didn’t know that, and neither did the Chinese, nor the Arabs, nor the Hindus. The idea slowly dawned on the Christian scholars, and was championed by a group of four called “the Oxford calculators”. They pushed the notion that numerical calculations could be used to evaluate ideas about the real world, and they demonstrated that such methods were successful. Indeed, lots of ideas that we take for granted were developed by the scholars of that period: empiricism, the scientific method, expressing scientific ideas in mathematical form, and many more.

One last observation: we usually talk about the history of science as if science existed in ancient times. Yes, there was certainly inquiry in to physical reality in ancient times, some of it quite sophisticated, but the modern meaning of ‘science’ simply doesn’t apply to these efforts. Science, in the sense we think of it, was developed over the centuries between 1200 CE and 1700 CE. At the beginning of this period, there was no such thing as science; there was instead “natural philosophy”, which was nothing like science. The scholars of the late Middle Ages transformed natural philosophy into the fetus of science; men like Copernicus, Galileo, and Newton gave birth to science.