The Rest Is History - 112. Medieval Science

Episode Date: October 28, 2021

The word ‘medieval’ is often used to mean backward, benighted, unscientific. But is this fair? Historian of science Seb Falk joins Tom and Dominic to explore how the Middle Ages shaped and influenced the development of science. *The Rest Is History Live Tour 2023*: Tom and Dominic are back on tour this autumn! See them live in London, New Zealand, and Australia! Buy your tickets here: restishistorypod.com Twitter:  @TheRestHistory @holland_tom @dcsandbrook Learn more about your ad choices. Visit podcastchoices.com/adchoices

Thank you for listening to The Rest Is History. For weekly bonus episodes, ad-free listening, early access to series, and membership of our much-loved chat community, go to therestishistory.com and join the club. That is therestishistory.com. At the turn of the 6th century BC, a man called Thales of Miletus did something truly extraordinary. He argued that instead of relying on myths and legends, the best way to understand the world was through theories and hypotheses drawn from real-world experiments, something we would call science. Where Thales led, other Greeks followed. For centuries, they made spectacular advances in understanding their world, inventing geometry, astronomy,

physics and chemistry. And then came darkness. With the end of the classical age, the world fell back into ignorance and superstition. People live like dogs in the gutter. Give a medieval churchman a science kit and he'd be roasting on the bonfire before you knew it so tom holland you can't surely disagree with such a nuanced account of the history of science can you dominic i feel like walking off this podcast right now that is i've never heard such nonsense you know the best thing about it is that yesterday you sent me an introduction that you'd written yourself for me to use quoting from one of your own essays and i just refused to use it it's from dominion yeah it's a fantastic passage

and i just refused to use it on principle i know you did just against the spirit of the podcast oh what promote promoting our books is against the spirit of the podcast promoting your books is against my spirit of my podcast so already you've so i thought that i you know i thought that that opening thing was the most ludicrous thing you could possibly have said. Right. Well, obviously, I was setting it. Yes, I know. I know.

So, OK, so today's topic is, we're titling it Medieval Science. And we need a top historian. We always need a top historian. Medieval science. And you, in your your introduction were kind of casting the middle ages as a dark age obscurantism yes obscurantism um we need someone who's written a book called the light ages we do about how the middle ages was far from being a period of of ignorance and superstition was um kind of opened up all kinds of astonishing ways of seeing the world that that we uh still um

benefit from today and that person is Seb Falk author of The Light Ages joining us from Cambridge Seb are you? That's right yeah hi Seb thanks for joining us. So thanks so much for coming on the on the show and as I said we're talking about medieval science. And as you kind of tease out in your fabulous book, which I strongly recommend to anyone who's interested in this subject, even if you're not, you'll find it incredibly interesting. You kind of say that both the words medieval and science are kind of tricky, that they imply slight degrees of anachronism. Could we just look at the word medieval first? Because it does still have a kind of slightly pejorative sense, doesn't it?

Yeah. Medieval today is often used as a kind of synonym for backward or barbaric you know we talk about those medieval taliban or um you know medieval lack of wi-fi in my favorite cafe um and and things that we do like if they happen to happen uh between let's say the year 1000 and the year 1500 we call them something else we call them renaissance or or whatever it might be. But historically, the word medieval is already a bit of a way of dismissing the period, right? Because it means the bit in the middle, the bit that's less interesting. And that comes from the Renaissance when they were trying to cast themselves as the heirs to ancient Greece and Rome. And they said that everything that had happened since the fall of Rome had been just an uninteresting bit in the middle. So that history of medieval as being uninteresting

and not worthy of consideration goes way back. But I'm trying to rehabilitate it. As you do brilliantly. And that sense of the Middle Ages as something backward obviously continues into the present. So we have a question from Tim O'Neill on whose podcast I know you have appeared. Indeed, I think you've appeared on almost every podcast. And Tim, who runs a website called, what is it, History for Atheists. And his kind of

perspective is that atheists are as likely to believe nonsensical things about history as Christians or Muslims or whoever. And Tim asks, why is a period which gave us the optics that led to eyeglasses, the mechanics of complex astronomical clocks, logarithmic expression, the mean speed theorem and successful experiments in man flight depicted as a science-free dark age? And is it all the fault of people in the Renaissance saying that everything should be owed to the Renaissance? Or does it go deeper than that? Slightly. It's also the fault of Protestants after the Reformation and sort of into the Enlightenment

casting Catholics as superstitious and backward and witch-burning. Actually, a lot of the stereotypes that are associated with the Middle Ages, like the burning of witches, are really more properly associated with the early modern period, or at least the beginning of the early modern period.

So, yeah, there's a bit of a bit of kind of edward gibbon talking about how uh people uh in in the dark ages uh were just following superstition and some of that is a way of beating up the catholics essentially and so if we then also look at the word science so i mean science in the sense that we use it today, that's quite late, isn't it? I mean, basically, it's kind of the word scientist we only get in the 19th century, mid 19th century in Oxford. The word science is kind of being used to describe the works of Aristotle or Greek philosophy or a whole range of things. So the idea of science that we have now, I mean, where does that come from? And to what extent does our use of it kind of get in the way of our understanding what people in the Middle Ages are doing?

Yeah, that's absolutely part of the problem, that the idea of a kind of modern science that's practiced by professionals in purpose-designed spaces with very specific and expensive equipment is a modern concept. But that doesn't mean that people weren't kind of looking around themselves and wondering about the universe, but they might have been doing it in different ways and for different reasons. And I think part of the problem is that we assume that there's only one way of doing science, there's only one reason to do science. But even if you actually look at modern science today, there are different motivations. Are you trying to understand the universe in a disinterested way, purely for the pleasure of finding things out, or are you trying to improve people's lives? And those are two potentially conflicting motivations

for doing science. And in the Middle Ages, a lot of the motivations for doing science or for trying to understand the universe are for things that turn out to be somewhat misguided, perhaps, or that many people today would say are wrong. Trying to understand God's universe from the point of view of religious people, many atheists today would say is completely pointless. Or trying to understand the motions of the planets in order to be able to provide an astrological cure for somebody's disease, again, would be thought to be slightly misguided. But that doesn't mean that underneath those misguided motivations or overlaying those false premises isn't some really interesting

methodology, some really interesting science, and some really fantastic ideas and measurements and instruments. So let's go back to the beginning of the period. So somebody asked a question online, Humphrey Clarke, he asked a question about Dan Jones's new history of the Middle Ages, in which Dan Jones talks about the late Roman Empire and its Byzantine successor kind of blocking knowledge by sort of shutting off classical learning. Do you think that's true? Is there a period at the end of the Roman Empire, in the beginning of what we'd call the Middle Ages, when people almost deliberately turn their backs on what we would now call the scientific learning of the classical era? Or does that learning

sort of continue unbroken as it were i mean there are cases of um church fathers saying you know you don't need to worry about this stuff there's a very famous quotation which is i think often misinterpreted by tertullian saying you know what does athens have to do with jerusalem in other words um and i'm sure tom would would weigh in on this um don't don't worry i'm itching i'm'm itching too, but I'm going to restrain myself. But I think there's equally church fathers like St. Augustine who says, you know,

knowledge, pagan knowledge is like the Egyptian gold that the Israelites stole out of Egypt, except it wasn't stealing because they were putting it to better use. And so pagan knowledge in the same way could be put to better use by Christians. So, you know, there's always arguments and differences of opinion uh if there was um a period of kind of intellectual

stagnation um it was i would say more structural it was about economic decline that uh falls the kind of uh that follows the um decline of the roman Empire. And therefore, networks of communication, systems of knowledge production were all destroyed and decaying. And so it was harder for information to be shared. But let's not forget that the Roman Empire continues in Byzantium, and knowledge continues to be spread and communicated. And then, of course, translated from Greek into Syriac and from Syriac into Arabic. And the centres of knowledge are perhaps passed to the Islamic world. So I don't think there's ever really a period when you can say that people were uninterested in knowing stuff about the world.

People's motivations change and people's ability to protect and preserve and communicate and build on ancient knowledge had its peaks and troughs. But I think to cast the whole period as a period in which people just didn't want to know anything is a modern stereotype, basically based on kind of our own prejudices about the past, because they don't look like us and they don't think like us. And Seb, isn't it also, I mean, just to go back to this thing about how science is a recent coinage, really. And basically what science comes to mean in the 19th century is something that's not religion. And likewise, religion comes to mean something that's not science.

And the two are kind of separated out. But before that, it was always accepted that the attempt to understand the universe and to fathom its workings and to explain it in ways that perhaps today we would cast as science, I mean, that was always interfused with theology or with metaphysics. So Greek philosophers, I mean, you know, they believed by our lights, all kinds of mad things. And so the idea that there was, you know, that the ancient Greeks did science, and then Christians came in and stopped it because they did religion. I mean, it's a very, very seductive idea. And it's one that, you know, Kalsargen famously kind of basically promoted. But it is, I mean, that is itself a myth. Everybody right the way up to the 19th century are assuming that the world is expressive of metaphysical or indeed theological truths. I mean, wouldn't you think? Yeah, broadly speaking, I think people often assume that the world is expressive of metaphysical or indeed theological truths? I mean, wouldn't you think?

Yeah, broadly speaking, I think people often assume that the ancient Greeks were atheists, which is clearly nonsense. You know, there's a huge amount kind of going on behind the scenes there. But no, I agree with you that I think the trouble is that we assume that the kinds of questions that people are asking about nature have remained unchanged, and that's simply not the case. And that people who wanted to understand the world could blend their religious beliefs with their observations of nature in trying to explain how things worked. Let me pick up on that question, Seb. So we had a question from Owen Williams about the church, and he says,

to what extent was the medieval church in favor of scientific research i mean i guess what you might say i'm anticipating your answer is that the medieval church maybe doesn't have a blanket position but also there's no the idea of scientific research being separate from things that churchmen do is a modern is a kind of anachronism is that right yeah so the the the sciences as tom already said already said, can mean a whole bunch of things because the word scientia in Latin means knowledge and any kind of system of knowledge can be a science. So astronomy can be a science. Music can be a science. Theology can be a science. And so even the statement that the church is anti-science doesn't really make any sense.

You know, how can the church be anti-knowledge there's different forms of knowledge uh of course institutions often try and preserve their power so if um the if if the church and even talking about the church as a kind of monolithic body is problematic because of course the church has uh different networks and different uh abilities to to control um people's behavior in different places. Yeah, well, Seb, you've talked about how there are different institutions in the church. And so obviously one of them is the institution of monasticism. And in your book, The Light Ages, you focus on the great Benedictine monastery at St Albans. And you focus on one particular monk there who will tell us about him because because he's he's a kind of shadowy figure who essentially you kind of almost give form to. But tell us something about his life and what he is able to do, because I think that would give listeners a sense of of exactly what we're talking about when we talk about medieval science.

Yeah. So this man's name is John of Westwick or John Westwick. Westwick was a little hamlet just to the west of St Albans, and he was born probably sometime in the 1350s, but we can't be entirely sure. And the point about him is not that he's massively important in the history of science. In fact, the reason I chose him was to get away from this idea that science is produced by great men plucking ideas out of thin air and bestowing them on a grateful public. Science is the work of countless people, many of whom we've never heard of and will never hear of, and it is done through their practices. So what I wanted to show was what was it that John Westwick was doing when he was doing science and how is he

kind of representative of the medieval way of doing science and thinking about nature. And so he's in many ways an ordinary monk but in some ways unusual and extraordinary particularly in the fact that he'd never, he didn't stay in one monastery for his whole career, he travelled around quite a lot, he went from the wealthy monastery of St Albans up to their daughter house at Tynemouth on the cliffs overlooking the North Sea, which was sometimes an exile or an outpost for monks from St Albans. They were sent there either to prove themselves in this inhospitable environment or perhaps as punishment if they got into trouble in St Albans, which they did quite a lot so dan jackson wouldn't like to hear that no no he would jonathan wilson they

wouldn't the idea that you can exile to the northeast yeah well we have some fascinating letters back from monks at time earth back to st albans saying don't come up here the weather is awful you just get foam from the north sea and these shrieking gulls and all there is to eat is fish and it's just awful and anyone who's been to the northeast can attest that this is all completely true well one thing we can say about john westwick because we don't know for sure whether he was sent there as uh as kind of a test uh as a promising young monk or as a punishment but he didn't stay very long uh which is one reason why I think it might have been a punishment, because he was clearly keen to leave and he left by going on crusade.

He joined up the 1383 Bishop's Crusade, which didn't go to the Holy Land, but to Flanders. It was kind of an episode in the Hundred Years' War where the Bishop of Norwich said, we've got a problem with a trade embargo here and the English wool trade is just completely messed up. So it's kind of Brexit. Yeah. Kind of Brexit crusade. Yeah. Or the Phantom Menace. That's with a trade embargo here and the English wool trade is just completely messed up. So it's kind of Brexit. Yeah.

Kind of Brexit crusade. Or the phantom menace. That's about a trade embargo. But it was about a successful... It's kind of Lord Frost would do it. Well, what would Lord Frost do? Would Lord Frost besiege a friendly city? That's the question.

Almost certainly. Past him, yeah. Because that's what they did in 1383. They besieged the city of Ypres and they all got dysentery and the army had to retreat in ignominy, giving up the gains they had made. And the Bishop of Norwich who led the crusade was impeached before parliament.

So John Westwick was on this. And then when he turns up a little bit later in the early 1390s in London, where he was drawing up plans for this very complex astronomical instrument called an equatorium which is a sort of device for computing the positions of the planets so it's for astronomy and astrology and so he's got a bunch of interests he spends a lot of his time as monks do and as monks did copying and editing and glossing and commenting and translating. And these are the kind of basic scholarly activities of the Middle Ages,

which today we think are a little bit arid and a little bit lacking in creativity. But the period of the Middle Ages was very much one in which knowledge was gained by building on the achievements of your forebears and your predecessors. So standing on the shoulders of giants, as Newton says. Standing on the shoulders of giants, as Newton says. But Newton was quoting, of course, a medieval proverb in that respect. Newton himself, of course, said that the purpose of natural philosophy was to discourse of God. So we shouldn't make him the standard bearer for

some atheistic science either. So what exactly is it that John Westwick is doing? I mean, what is the focus of his interest? This kind of, well, you talked, I mean, you kind of said it was computer almost. Yeah. I mean, a computer in the very literal sense that a computer takes information that you put into it from some source, it processes it in some way and it spits out new information. I mean, that's literally, I suppose, what a computer does. And this one takes the basic parameters and components of the motions of the planets and you put them in and you turn a little dial and you pull some strings and then you read on the rim of this brass and wooden disc the positions in longitude and celestial longitude

of the planets along the ecliptic, which is the zodiac where the sun travels against the background of stars throughout the year. So you can find the positions of the planets, and by doing so you can draw up a horoscope. And again, astrology seems to us to be quite superstitious and nonsense, but in the Middle Ages it was a very serious science, and it was based on the principle that if the sun heats up the earth, you know, creates the seasons and the moon pulls the tides, then why shouldn't the other planets also affect things down here on earth? And humans as a microcosm of the macrocosm, humans as a sort of mini version of the universe, containing elements as the universe contains elements, reflect the makeup of the universe. So we're

always in some sense reflecting what's around us. And the weather as well is predictable if you understand what's happening up there in the heavens. So knowledge of astrology was profound and important, but also astronomy was really the first mathematical science, the first truly precise science. So to us, it really does look quite scientific, because they're devising instruments, instruments like astrolabes, to find the positions of things and to measure very precisely. So can I pick up on the device, the machine, as it were? How common, I mean, we don't think of people, because we, so many of us are kind of slaves to the stereotype, I suppose. We don't think of monks in the Middle Ages inventing machines or working with machines, but how common was this?

I mean, did people, was this an age of invention and of kind of tinkering with contraptions and things? Or does that come later in the early modern period more generally? Tinkering is definitely the word. It's an age of kind of innovation, of improvement, of incremental improvement. And they were really very keen on devices. They were keen on gadgets.

And this is the period when we see the first mechanical clocks, you know, first quite basic mechanical clocks and then later more complex mechanical clocks. And that's happening in the monasteries as well because timekeeping was essential to the monastic day. You needed to know when to press. So you say in your book, the mechanical clock was surely the most significant invention of the middle ages

and then shockingly you neglect to mention the clock in salisbury cathedral well i feel like um the sege script alpoisoners have already done an excellent job on publicizing that one um but there are other really important medieval clocks the trouble is actually with medieval clocks is that most of them don't survive because medieval people were really good at recycling. But basically, without timekeeping, without precise timekeeping, we don't have GPS. We don't have, you know, the kind of online delivery slots

that we're all slaves to these days and all the rest of it. So, you know, we couldn't have scheduled this podcast without the innovations of the Middle Ages. So, you know, I suppose what you see in the Middle Ages is not the kind of precise timekeeping that atomic clocks and satellites and all the rest of it. But what you do see is this attention to detail and this attention to precision. People in the Middle Ages were obsessed with calculating things to levels of detail that were completely unobservable. You know, you get them computing the positions of the planets to, you know, billionths of degrees, which they could never have observed in the sky. But the process of computation, of calculation, was something that

they did in an extremely painstaking way. But just on clocks, is this developed by monks specifically because they need it to keep track of the hours for their services or whatever? Is that one of the motivations? That's a great question. And it's one that historians keep arguing about. So there is this practical motivation. But if you look at the clocks that they make, they make them well beyond that capability. And so there is also a sense that when they're making a clock, they are reproducing the cosmos. And they are doing so in order to kind of understand the mind of the creator. We have that sort of metaphor of the clockwork universe that becomes better known later. But even at the time,

in the most popular medieval scientific textbook, the Sphere of John of Sacrobosco starts off by describing the machine of the world. So the world is already seen at this point as a machine. And if the world is a machine, then in order to, and they say that if you can understand the mind of a craftsman by looking at the machine that he makes and therefore you can understand the mind of God

by looking at creation so if you can sort of reproduce the cosmos in a box then you can go some way towards understanding the component parts of it and thereby understanding God so there is a kind of theological motivation for this plus of course there, of course, it's a way of demonstrating your power and your control. And this is where clocks pass quite quickly from their invention around the end of the 13th century. By the 15th century, we're seeing clocks in town halls and in civic buildings, non-religious buildings, where they become a kind of way for local authorities to show their power, to show their control. You know, you put a clock on your town hall in Strasbourg or Burgh.

Where are the clocks invented? Is it Norwich? So, as I say, we don't have the earliest surviving clocks because they were all melted down or recycled or destroyed or replaced. But we have early records of clocks in the 1270s and 80s in many of the cathedrals and abbeys around England, but they were probably also in other parts of Europe as well. And it's tricky because, of course, there were water clocks, there were sundials course there were water clocks there were sundials there were other forms of timekeeping technology and since we only have written records um when they say clock we don't know exactly whether it's a mechanical clock or a water clock or something else uh and the records

are pretty partial so for example we only know that there was a water clock in barry st edmund's abbey in 1198 because they used the water from the water clock to put out a fire so if there hadn't been a fire absolutely i mean it was the nearest source of water so uh so if there hadn't been a fire in barry st edmunds then we wouldn't even know they had a water clock there um so yeah norwich is is one place where we know that they had a clock because we have the accounts uh for when the clock was replaced um and uh and uh in st albans they had really the world's first complex mechanical clock which was designed by the abbot Richard of Wallingford in the late 1320s early 1330s and that did much more than tell the time that that showed you the tides and it maybe even showed you the planets and it computed

eclipses so that really is a model of the universe let's take a break Tom yeah let's take a break you should go and think about the clock in Salisbury. I'm going to reproduce the cosmos in a box. And, and then we'll come back in. And I've got a very good question to come back in with. So stay tuned. Yes. All right. Very exciting. See you back in a minute. I'm Marina Hyde, and I'm Richard Osman. And together we host The Rest Is Entertainment. It's your weekly fix of entertainment news, reviews, splash of showbiz gossip and on our Q&A we pull back the curtain on entertainment and we tell you how it all works. We have just launched our Members Club. If you want ad-free listening, bonus episodes and early access to live tickets, head to therestisentertainment.com. That's therestisentertainment.com. Welcome back to The Rest Is History.

Tom Holland has indeed been thinking about the clock in Salisbury, and I have indeed made the cosmos in a box which is testimony to my power. Now, Seb Fulk is with us, and he's talking about medieval science. And before the break, we were talking about clocks and tinkering and the extent to which people you know were doing i suppose what we would very loosely now call science my question seb is about progress so obviously so much of our sense of a scientific narrative is based on the idea of progress of standing on the shoulders of giants which we alluded to before and building

something bigger and bigger every time so you have newton and then you have his successors and so on and so on you get to einstein that's the story you know it is a story did they have a sense of something like that do they have any sense of there being a progressive narrative towards greater enlightenment as it were the the short answer is no because uh according to the christian story everything was declined after the Garden of Eden, basically. And so if you asked a Christian scholar, they would say that what they were trying to do was to preserve ancient knowledge and to build on it and to try and redefine it and to try and understand it. But the sense that they had a lot of the time was that they would never be able to reclaim the perfect wisdom of the Garden of Eden. So in that story of the fall, there is a sort of complexity of, well, we couldn't be where we are without it. And yet,

we will never be able to sort of go back to that perfect time. So they didn't have a sense that they were making perfect progress, but that didn't mean that in practical terms, they couldn't learn things and they couldn't discover new things and they couldn't find out what other people knew. But the part of the problem with progress also is that it depends on what you define as progress and what counts as progress.

So they might've thought about progress in moral terms. And, you know, how can we become better people and how can we know God better? And that was something that they could perhaps achieve in their own minds. So I think part of the problem is that we assume that we all agree on what progress is and that humanity must make some sort of linear progression. And that isn't the case in history in the sense of, well, sometimes knowledge has gone backwards. And also we haven't always agreed

on what counts as progress to begin with. But we define progress, don't we, very much as mastery over nature. You know, we can transcend the limits of the natural world. But they presumably didn't have a sense of that in the same way well certainly their nature was one in which god intervened on a daily basis um and so there were limitations to what humans could know and what humans could do and i think it's very important i suppose uh to emphasize that they that they wanted to be modest

about about nature in the sense of, well, in some sense, it wasn't really for humans to try and be gods, essentially, to set themselves up as gods. But they have a spark of the divine reason, don't they? The lux hominem. Yeah. So it is a tension. It is a tension.

I think one of the things that we have to get away from is this idea that medieval people agreed about everything and constantly behaved in a consistent way. Neither of those things are true. So they can say we have to be modest in our ambitions to understand God because we could never understand God and it would be blasphemous even to think that we could. Yet appearing in all of their actions that they spent all of their time trying to understand God

and trying to understand God through nature, which was a very clear principle of something that could be done. So there are contradictions there. And so also, do you think the Christian idea of God is that he's all-powerful, that he's created everything? So there is the sense of the universe as a kind of a coherent entity that perhaps in other ways of understanding the cosmos you don't necessarily get. And on top of that, Christianity has this idea that God

subjects himself to covenants. So he has a covenant with Moses, he kind of signs up to that. And whatever exactly it is the crucifixion, what's going on there, there is a sense that some way, there's some kind of agreement that's being drawn up. So do you think that that implies that both that God is all powerful, but that he is happy to construct laws that perhaps humans can fathom, and that therefore there's a kind of theological framework for what we would now see as, you know, the attempt to work out laws that underpin the running of the universe. Yeah, that's right. There is even a tension there though, right? Because the physicists, you know, followers of Aristotle, try to understand the universe in the terms in which Aristotle put it, and try and explain kind of what is and isn't possible according to the laws

of physics. And that to us makes a lot of sense. isn't possible according to the laws of physics. And that to us makes a lot of sense. But if you talk about the laws of physics, then the theologians might get a little bit tense and antsy about constraining the power of God. So you get these arguments in the 13th century about whether it's possible to have a vacuum in nature. And the consensus was that a vacuum couldn't exist. But the theologians say, well, you can't stop God making a vacuum. Because that's just constraining the power of God.

So it's not that God has made a vacuum or that God is going to make a vacuum, but that if God feels like making a vacuum, he can now walk out. It's a strange thing to do with your day, right? Yeah, but he's gone. Yeah, I guess so. He moves in mysterious ways. But Seb, you mentioned Aristotle. And kind of on the idea of progress, I guess one of the ways in which people in medieval Europe do feel a sense of progress

is actually that they're kind of fathoming this ancient wisdom that you talked about. Because they live in a world where Aristotle for much of the early Middle Ages is not really known. And then through Byzantium, through the Islamic Spain, they get the opportunity to discover Aristotle. And you're brilliant in your book at talking about what a kind of bombshell effect this is. So can you just try and explain why Aristotle kind of has this impact? Because, you know, I mean, he's not a Christian, he's a Greek philosopher. What is the way that he kind of impacts on the Christian world in medieval Europe? So Aristotle was the ultimate polymath. I mean, he observed animals, so he would creep up on sea urchins to see if they behaved differently when they thought they were being watched from

when they didn't think they were. And he understood the fundamental laws of physics and tried to bring time and motion together in a single law. And so for medieval people, the scale of his ambition was tremendously daunting. But his texts were very hard to get into, because not only were they not really written to be read, they were really notes from lectures, but also they'd been translated through Syriac and Arabic and often Castilian Spanish, and so they were extremely hard to understand. So medieval people spent a huge amount of time just trying to get their heads around the works of Aristotle. But to them there was a kind of a sense that there was hidden knowledge here, and there was a kind of deeper level of explanation than they'd ever encountered before and part of the problem is is that aristotle

says that that everything has always existed and so there's no kind of genesis right so i mean that's a that's a pretty firm statement that he makes that is very hard for christians to get around and simply uh that's that's one that they can dismiss because, you know, yes, Aristotle says the universe is eternal, but that clearly conflicts with the principle of biblical creation. And so Christians simply have to say, no, Aristotle is wrong about that. So they're not, you know, they're not averse to saying that Aristotle is wrong about something. I think sometimes it's a cliche about the Middle Ages that the scholastics are slaves to Aristotle and just spend all of their time reading Aristotle and studying Aristotle and never go anywhere beyond Aristotle, which of course it is possible to do. But that's not the case because they do point out places in which

he is, according to them, clearly mistaken. But in general, they spend a lot of time working through his ideas and understanding the implications of him. And famously, he's called the philosopher because he is the ultimate authority in that sense to them. Seb, you mentioned translations from Arabic and so on, and when you were talking about Aristotle and the transmission of Aristotle. And we had a question about this from Diogo Morgado, who I have to say has been on fire in recent weeks with this question. He really is, isn't he, singing?

He says, shouldn't we be talking about medieval Islamic science? Because that's where the most advanced research was conducted at the time. Cordoba and Baghdad were so much more ahead than anywhere else, right? Well, is that right? And should we be talking about medieval Islamic science rather than Christians necessarily? Yeah, well, yes. It's undoubtedly the case that in the high Middle Ages,

the Islamic world was a centre for science. And that's basically because science proceeds ultimately through processes of communication. And the Islamic world was, in a sense, at the centre of the civilised world. So they took ideas from ancient Greece and translated them into Arabic. They took ideas from India. And you get scholars from Central Asia coming to Baghdad, the center of the Abbasid Caliphate in the 8th and 9th centuries, translating all these ideas, studying them, copying huge numbers of books, and developing these ideas. And the Islamic world gives us scholars like Al-Kindi,

Avicenna, Ibn al-Haytham, some names that are famous and other names that deserve to be better known. So yes, absolutely, the Islamic world was at the centre of things. I mean, amazing detail from your book about John of Westwick, who begins, I think, have I got this right, that he begins his text, in the name of God, pittus and merciful, which is obviously the bismillah, the Islamic formula referring to God, that you've got that echo coming all the way through, presumably, I guess, through Spain up into St. Albans. And that's kind of an amazing tribute to what an international project this is. Yeah, absolutely. And of course, you know, there are many words, many modern scientific words that go back to Arabic and Arabic culture. Algorithm famously comes from al-Khwarizmi,

the man who brought the Hindu Arabic numerals from India to the Arabic speaking world. And, you know, things like algebra and so on. So Arabic culture is infused in our science even today. What's interesting about that quotation from John Westwick is that early readers of that manuscript thought that this was evidence that he was translating an original Arabic text. And it's possible that's true, but I suspect it's actually because it's a kind of literary flourish. He thinks scientific texts start with Bismillahirrahmanirrahim. That's how they begin. Yes, that's just what you do. So I'm going to do the same. And he does it in Middle English, which is unusual. And astrolabes, do they come to the medieval world, to the European world through Spain as well?

Yes. Well, yes. So the principles of the astrolabe were what is an astrolabe that's that's it's a kind of it's a it shows you the workings of the universe basically uh I mean the word means kind of star finder um I've got one here I shall wave it at my microphone so listeners can at least hear it even if they can't see it good sound effects podcasting yeah absolutely um and it's a brass disc it fits in the palm of your hand it's multifunctional uh so in some senses it's like a medieval smartphone in that it looks cool um you can make people jealous with it but you can also do a bunch of really interesting things with it uh such as tell the time work out the hard to work out the height of a building

so when abelard and eloise call their their son uhrolabe, it's kind of like calling it iPhone. Yeah, pretty much. Yeah. Wow. I mean, you know, it's nothing that Elon Musk couldn't beat. So, yeah, it's a sort of multifunctional device. And basically it's anything. It's a model of the universe.

So you can tell the time with it. You can work out when a certain star is going to rise or you can work out which way is north all of these sorts of things with an astrolabe and it's a piece of design it's a it's a kind of beautiful object and a status symbol um so those the principles of of projection essentially putting the spherical universe onto a flat disc are laid out by Ptolemy the ancient Greek astronomer in Alexandria in the second century AD. But we don't know for sure whether he ever made one. And then we get late ancient Greek texts from people like Theon of Alexandria later on saying, you know, this is how you make an astrolabe in practice. But the earliest astrolabes that we have are from the Islamic world.

And as you say, they come into medieval Europe through Muslim Spain, where they are kind of refined and adapted and made to suit Christian purposes. So the designs are adapted and shifted, but the basic principles are unchanged. Coming to an end and kind of drawing on that sense of a vast hinterland of knowledge that people in Europe are drawing on, but also the way in which perhaps the medieval becomes the early modern.

Could we just look at Copernicus who in your book you cast as someone who is drawing on what a kind of central Asian tradition of thinking about the the earth as being at the center sorry the sun being the center of the universe and the earth going around the sun and this is and is that sense I mean is that a radical break with what's gone before or is it an expression of continuity, do you think? I'd say it's probably more an expression of continuity. Certainly Copernicus is concerned to present it in those terms, in the preface that he writes as a form of a letter to the Pope.

So he's in the 16th century, isn't he? And he's drawing on stuff from Central Asia. I mean, has that got that right? Well, yes and no so uh the the ideas that the earth might be um going around the sun rather than the reverse um is is found in uh ancient european sources is found in um roman and greek sources it's suggested uh and copernicus goes back to those a true renaissance man that he's going back to the classical sources to try to find other people who have thought what he thinks in the past as a kind of support for his assumptions. So in that sense he's a true medieval, he's trying to look for

authorities to back up his ideas. The geometry that he uses to make it work, that comes from the Islamic world, that comes from Central Asia And so he draws on a bunch of scholars, most notably At-Tusi, who was Persian in the 14th century. Oh, Ali Ansari would be thrilled to hear that. It's all Persian. Well, there's a whole bunch of them, Al-Urdiya, Shirazi, you know, from across the Islamic world. And it's argued still by historians

how much Copernicus depends on them versus independently discovering these geometrical models. But he basically has to make it work geometrically. He starts with this idea where he thinks that actually it's the sun that's at the centre of the universe, not the earth. He sticks to the idea of perfect circles. So he can't make it work because the universe doesn't operate in perfect circles but Copernicus maintains this basic principle that motion in the heavens should be in in perfect circles and so he ends up with a system that is basically just as complicated as the one that he started with but replaces isn't it I mean it's it's not just as complicated but it's also as unprovable yeah and there are clear

objections to Copernicus's theories most obviously the fact that if we're moving through the universe at thousands of miles an hour, why do we not feel the wind rushing past our ears? And if we are moving thousands of miles in the course of a year, why do we not observe any parallax in the stars? And those questions weren't resolved for a long time after Copernicus was writing in the early 16th century. So there were objections to him at the time.

Those objections were voiced very clearly by scholars who were equally, if not more eminent than him. And other models were proposed, most notably that of Tycho Brahe in Denmark, who proposed that essentially all the planets went around the sun except the earth. The sun goes around the earth. So that also, in fact, that explains the phenomena that we observe better than Copernicus's model. So what we see in the 16th century is this constant argument, this back and forth, and that is the basis of science, really. It's the argument, not this idea of some great person coming up with the right answer and everybody else immediately falls into line. Seb, is this the point where medieval science as it were is coming to an end

and we're moving into some new phase so obviously you know our sense of time is much as we like to complicate it we do divide it into kind of blocks is this the sort of 15th century Copernicus and then getting into the the sort of early period. Is that a definite shift, as you see it, in our scientific history? Well, there definitely is a change that takes place, but it's very gradual. And most people would sort of put it in the 17th century, sometime between Galileo and Kepler and the end of Newton's career at the beginning of the 18th century. What we see in Copernicus is definitely a shift because he's taking advantage of the new medium of printing to exchange ideas. But he also, as I already said, in his kind of looking back to earlier authorities, is a real Renaissance man. And his

De Revolutionibus, his book in which he presents his heliocentric theory, is modelled very closely on Ptolemy's Almagest. So he is self-consciously presenting himself in some sense as medieval. But that's a sensible way to promote your ideas, really, because if you want people to take something controversial and understand it, you have to present it in terms that they're going to accept. What we see later is a whole shift in ideas. And part of that is a kind of valorization of the new and original, which some people have associated with the European discovery of what they call the new world, as a kind of way of proving that actually something new, we can know something new that the ancients didn't know about. But also there's a kind of increase in experimentation, an increase in inductive

knowledge, observing nature and not worrying too much about whether your observations were the same as what somebody else might observe, which was always a stumbling block in the Middle Ages, this idea that our senses were fallible and therefore we couldn't rely too much on our own observations but you could say couldn't you that you know this process of experimentation that some of the areas that we now regard as as absolutely not science of astrology or alchemy or whatever that that is you know testing to find out whether they work or not is a process of experimentation and that in a sense the kind of line that becomes by the 19th century, what we would now call science. I mean, we arrive at that through a process

of testing other approaches to knowledge. Yeah, it's all about how systematic it is, right? Because experimentum in Latin just means experience. It just means something that happens to you. And so this process of experiment morphing into something that is a discrete moment in time, into something that you design, something that you carry out and you might do multiple times in order to check it, that's something that happens gradually over time from this medieval idea that experiment is just an experience that you had

that maybe happened to you rather than something that you did. So we can't really ever say one person invented experiment it's an idea that evolved over time but basically we could say i mean just to kind of draw a line under it we could say monks yay for monks well they're not the baddies i mean the whole point the whole point about uh copernicus right is that he is a sort of symptom of an increase in knowledge that the universe is not operating as we want it to to do and so astronomers over centuries noticed that the models of Ptolemy didn't quite match up to reality it was just a kind of question of how content they were with the imperfection and it's it's an increase in in experience it's an increase in calculation it's

an increase in all the things that medieval people did that allows them to say, no, this isn't good enough. We need a better system. So it relies on that medieval practice, even if it takes a little bit longer for somebody to come up with an alternative that works better.

Brilliant. Well, thanks so much. And your book, The Light Ages, is great. I read it in proof and then I read it again yesterday to prepare for this and I enjoyed it just as much the second time as the first. So, rush out and

buy it, guys, because it bears definitely a second reading. Thanks so much, Seb. Thanks, everyone, to listening. We will be back soon with... What are we going to be doing? We don't know. We haven't decided yet. Something. Something. Experimental process. Yeah, we need to

work that out. Thanks very much for listening. See you all soon. Something. Experimental process. Yeah, we need to work that out. Thanks very much for listening. See you all soon. Bye. Thanks for listening to The Rest Is History. For bonus episodes, early access, ad-free listening, and access to our chat community, please sign up at restishistorypod.com. That's restishistorypod.com.