This is the untold story
of the making of the modern world.
A fresh perspective,
charting the spread of civilization across the globe.
From the dawn of mankind
and the first cities and empires
to the belief in One God.
We follow the flow of civilization
from the Middle East.
An extraordinary place that has been a vital link
between the continents of Asia, Africa and Europe for millennia.
An economic, scientific and cultural center of the world.
This is an epic journey of discovery...
from the east to the west.
Damascus, Syria.
The faithful are called to prayer at the Great Umayyad Mosque.
Allah Akbar! Allah Akbar!
Allah Akbar...
This is a tradition that has marked out the hours of the day
in an unbroken sequence for 1300 years.
...Muhammad rasool Allah.
It is an appeal heard across the globe
by believers in one of the world's great religions, Islam.
It is testament to the enduring power
of the spiritual message of the prophet Muhammad.
But it is also evidence of another tradition in Islam,
its spirit of discovery and rational investigation.
Its embrace of science.
This is the story of the forgotten contribution
of medieval Islam to the history of world civilization.
At the low point of European history,
Muslims brought together the knowledge of the world...
founded great institutions of learning...
and created the foundations of modern science.
The discovery of this knowledge kick-started Europe's emergence
from a Dark Age.
And it formed the basis of the revolution we call the Renaissance.
The Victoria and Albert Museum in London.
Built at the height of Europe's colonial dominance
in the 19th century.
Its Cast Gallery is filled with the ghosts of great European artworks
illustrating the West's own view
of its rise to global cultural supremacy.
These works mark stages in the progress
of what was called “Western Civilization",
portrayed as a humane and rational approach to art and life,
which first flourished under Greece and Home, then died out.
It was rediscovered, according to Western tradition,
by modern Europeans
in the time we call the “rebirth" or the Renaissance.
This story, cherished by the West,
is encapsulated in one of the most iconic images of Renaissance art.
This painting which was done by Raphael for the Vatican originally
encapsulates everything
that the Europeans thought about their Renaissance.
It's called “The School of Athens"
and these are the great philosophers debating the meaning of life.
In this painting, great figures of the Renaissance
masquerade as their ancient Greek forebears.
Raphael himself plays the painter Apelles.
Michelangelo appears as Heraclitus
and in the center, Plato bears the face of Leonardo DaVinci.
One of the stories that this painting tells
is that there was a direct handover of Greek culture
to the European Renaissance.
It is a homage to the intellectual creativity
that flourished for 1000 years under Greece and Home.
But a millennium before Raphael's day
this so-called Classical Age had come crashing to an end.
In the 5th century barbarians from the north
had put an end to the glory of Rome.
Classical civilization in the West
had been consumed by a tide of violence,
plunging Europe into a Dark Age.
The forum, the main square of ancient Rome,
where Cicero and Caesar had addressed the Roman populace,
reverted to agricultural land.
By Raphael's time it was known simply
as the Campo Vaccine, the cow pasture.
With the fall of Home,
Western Europe had lost an entire culture of urban life,
and with it contact with the philosophy of ancient Greece.
The painting illustrates the longing of Raphael's contemporaries
to regain what was lost in that moment.
There is no hint that anything lay between or beyond
these two worlds but ignorance.
But even here there's a clue to another story.
What's fascinating is a rather shadowy figure
almost in the corner leaning over the back of Pythagoras.
Now this man was called Averroes
and he was an Islamic scholar.
And he's one of the very few hints that we get
of how much the Renaissance actually owed
to the Islamic world.
This solitary figure stands for the crucial missing link
between the Classical and Renaissance worlds.
In the Middle East there was no Dark Age.
There the Romans were a blip in a much longer history of civilization.
The Eastern Roman Empire
fell to a dynamic new force that emerged from the Arabian desert.
The invaders brought with them a new religion, Islam.
Within a century the Caliphs in Damascus
had made themselves masters of an empire larger than Rome's.
The new Islamic world stretched from India to the west coast of Spain.
Unlike the tribes that invaded Rome,
these new rulers could not be called unsophisticated barbarians.
In their capital Damascus
the buildings themselves tell the story of an empire
that was more concerned to develop the culture they found
than to destroy it.
In 706 they began work on the first Great Mosque in Islamic history.
But they took as their starting point
a structure that is one of the world's oldest sacred sites.
3000 years ago this is where the mighty god Haddad
was feared and was offered blood sacrifices.
In the 1st century this was small part of the huge Temple of Jupiter
which remained the Temple of Jupiter until the 4th century
when this became the Cathedral of John the Baptist.
And it remained so until the 8th century
when this place became the greatest mosque of the new Islamic empire.
The Umayyad Mosque is testament to the place of Islam
within a much longer story of civilization.
The new mosaics and minarets were built by Christian craftsmen
into the fabric of the old cathedral and pagan temple.
Just as we can see around us in the architectural evidence
that this new empire didn't knock down what was there before it,
but it actually built on it to a new level of sophistication,
it did the same to achieve
its new level of intellectual sophistication that it required.
This new religion had its own reasons
for respecting and developing the knowledge of the past.
In Islam, believers are taught to pray at five specific times a day
and so from the faith's beginning
it was very important to accurately measure the passing of time.
At the top of the minaret of the great Umayyad Mosque in Damascus
we have a beautiful sundial made by lbn Al-Shatir in the 13th century.
Sundials used to adorn the courts and walls of the mosques
because the time of the five daily prayers in Islam
depended on the position of the sun in the sky.
To be able to predict this you need a sundial such as this one.
This sundial works on a system of hours
dividing the time from sunrise till sunset
and the 24 hour system we use today,
as well as indicating the times of the five calls to prayer.
As well as determining the precise time,
Muslims needed to know their exact position on earth.
Also you need to be able to determine the direction to Mecca
because Muslims usually will pray directing themselves towards Mecca
wherever they are on the earth.
So they need to do time-keeping, global positioning,
based on the movements of the sun, planets and moon.
The efforts of the people who positioned this sundial
to understand the universe in scientific terms
were motivated, not discouraged, by their faith in the word of God.
It's motivated not only by its rituals and timekeeping needs,
but also with its intellectual stimulation
because the Koran is full of verses
that actually ask you to look at the sky
and use your rationale to ponder the reason behind the creation,
the reason why there is precise movement
for the celestial bodies.
The reason why there are irregularities,
why there is symmetry, just to think about the reason behind everything
and find out yourself.
There are many passages in the Koran for example,
that tell you to look around at the world and marvel at it,
but also come to understand it better,
because the world is full of signs
that it has been made by a wise and just and merciful creator.
So Muslim scientists in this medieval period,
thought of science as a way of studying
the work of God in the world.
The arrival, two centuries after Rome's fall,
of a new champion of rational inquiry
would breathe new lite into the dormant tradition
of ancient philosophy.
The Arab rulers were very interested
in not only preserving the culture and the learning in particular,
and with a certain emphasis on scientific learning
of the areas that they'd taken over,
but they wanted to gather this information together
beginning with the Abbasids in Baghdad.
In 750 the Abbasid dynasty
founded a new city on the banks of the Tigris.
They called it Madinat as-Salam.
But it was instantly known by its local name, Baghdad.
It was built on a perfectly circular plan
centering on the glorious palace of the Caliph.
Around it grew the greatest city of the age.
If I had to live in the 8th century I'd want to live in Baghdad.
That was the most exciting place, it's where the action was.
It's the center
of the most powerful empire in the world at the time,
and there's a huge amount of money being poured into creating culture,
learning, building a new city.
It must have been fabulously exciting.
That city survives today
only in the buildings it inspired elsewhere,
like the lbn Tulun Mosque in Egypt.
It hints at the opulence of what was once a cosmopolitan metropolis
which drew in talent from around the world.
You have Muslim, Christian, Jewish, Sabaean
and other scholars all working together.
Different schools of thought were able to work together
in an atmosphere of intellectual freedom
which enabled them to produce something new.
Scholars were drawn in from around the empire and beyond
by the desire of the Abbasid dynasty and their courtiers
to create an intellectual culture
that rivaled the empires of the past.
At its epicenter was the royal library known, evocatively,
as the House of Wisdom.
The building itself has long since vanished.
But fortunately evidence for its contents
survives 3000 miles away to the west.
In the archives of the Bodleian Library in Oxford,
manuscripts survive which reveal how the scholars of Baghdad
helped save Greek knowledge from oblivion.
I'm looking at a copy of Euclid's Elements.
This is one of the most revolutionary works
in the history of mathematics,
written by Euclid in ancient Greece
around the time of Aristotle and Plato.
If you look through it you can see that it's full of diagrams
being a book about geometry.
And tor other ancient Greek authors and even down to the current day,
the Elements sets out a kind of model of science,
a kind of science where you build up from these first principles.
The interesting thing about this copy of the Elements though
is that it's not in Greek, it's in Arabic.
This is a medieval manuscript
and it's a copy of a translation of Euclid's Elements into Arabic
that was made in the 9th century
as part of a huge translation movement
in which works of Greek science and philosophy
were translated into Arabic in Baghdad
under the Abbasid Caliphs.
Under the patronage of the Abbasid rulers in Baghdad,
a systematic process began
by which the great works of Greek philosophy
were sought out and translated into Arabic.
This was an unprecedented move by one culture to absorb, en masse,
the wisdom of another.
The translation movement of which this copy of the Elements
was such an important part, was absolutely massive.
So it included texts from pretty much every area
of Greek literary endeavor.
Obviously mathematics, but also for example astronomy,
works on music and also of course philosophy.
So if you wanted to read the works
of say Aristotle or Ptolemy or Galen or Euclid in the 9th century,
mostly you could not do it in Europe.
Most of the activity in science and philosophy
was going on in the Arabic-speaking world
and especially in Baghdad at this time.
You have to imagine a fairly diffused
and complex set of groups
spread out across not only Baghdad
but the whole what we would call Middle East.
And all of these groups would have been discussing
what for them were the hot topics of the day
which meant things like Aristotelian metaphysics
and Galen's views on medicine.
The translators of Baghdad were doing nothing less
than creating a new language of world knowledge.
The philosophy of Aristotle,
Galen's revolutionary work on medicine,
Ptolemy's astronomy,
Euclid's Elements,
and Pythagoras' geometry
would now be texts the world read not in Greek but in Arabic.
And Baghdad didn't live on Greek wisdom alone.
Syriac Christians, Zoroastrians from Persia
and even followers of ancient paganism all contributed ideas.
From India the Arabs learned the modern system of numbers,
and new information on the paths of the stars.
The translation movement condensed the knowledge of the globe
into a single language
which could be read and studied from Spain to India.
As time went on, the centralized authority of Baghdad
began to devolve to new centers of power,
each with its own emir or caliph
and with it went this new culture of learning.
In 909, the new Fatimid dynasty came to power in Egypt.
Within a century they had built a new city
on the banks of the Nile.
Quickly Cairo became one of the great cities of the Arab world.
At the heart of this bustling new city,
the Fatimids built the Al-Azhar Mosque.
But this was not just a place of prayer,
this was a purpose-built institution
dedicated to the education of the people.
This is a place that calls itself proudly
the oldest university in the world.
One of the biggest prayer halls in Al-Azhar.
In here people would normally pray during prayer times,
at columns like this for instance.
Throughout the medieval period you'd see professors sitting
and having circles of students around them.
They would explain particular subjects
or give lectures on particular source books.
You would have normally the most advanced students
sitting closest to the professor,
and then the less advanced students,
and all these lectures were open to the public.
Anyone could walk and sit in there and listen to the professor.
At the feet of these columns
sat some of the greatest minds of their time.
Students would choose the professors they want,
who taught different subjects ranging from the law,
Koran, jurisprudence, philosophy, mathematics,
and some of these professors were very popular,
that we have larger crowds coming from the streets
and larger and larger number of students sitting.
They would have to sit on higher places
in order to make themselves heard to all these crowds.
The foundation of Al-Azhar by the new rulers of Egypt
set the tone for a flourishing of rival centers of learning
in the new competing courts of the Muslim world.
This became part of the political competition
between different sovereigns
throughout the Middle East during this period
it's a sort of a pattern that kept repeating
with all these new small kingdoms or principalities or new empires,
where rulers and sovereigns and even rich people and big generals
would build mosques, madrassas
in order to allow for teaching
and for the... and they would host and sponsor scholars
to come and teach in their schools.
Across the Muslim world
madrassas and universities sprang up to rival Al-Azhar.
In Fez, Morocco,
the Kairaouine University was the first,
and it gave birth to a whole university town,
with smaller institutions of learning,
many of them architectural wonders like the Bou lnania Madrasah.
The madrasa's every surface
bears witness to the intellectual sophistication of those times.
"I am the center of knowledge, so attend it."
"You will be what you want, respected and knowledgeable."
"Order it, endow it, defend it and preserve it."
"Be steadfast in that and be kind to it."
and it continues across the Madrassa,
inside the Mosque, and ends right here.
The Bou lnania Madrasah housed and fed students for free
until as recently as the 1960s.
It was part of an enduring and international culture of scholarship.
The Islamic world in the Middle Ages
represented a massive free trade zone
in which scholars at the courts of different rulers
and the universities they founded,
could exchange and review each others' ideas.
With spectacular results.
This was an environment which did more
than just preserve and pass on the works of ancient philosophy.
The Arab civilization didn't just serve
as a freezer for the Greek civilization.
With their interest in this knowledge
in astronomy and mathematics
they were able to, you know, come up with new things,
they were creative people.
From the beginnings of the translation movement,
the scholars of the Arab world
were generating revolutionary new ideas.
As soon as the scientific works
were being received into the Arabic language,
immediately you find scholars
building on those works and coming up with their own ideas.
So you have mathematicians coming up with new proofs
and proving things that had never been proven before.
You have doctors
immediately going beyond what they found in Hippocrates and Galen
and you have philosophers
who are devising their own philosophical ideas.
The new world of Arab philosophy
would produce a new kind of intellectual,
with a distinctive approach to learning.
These were men whose research was not confined to the library.
One of the men who taught at the columns of Al-Azhar
was lbn Al-Haytham, known to the West as Alhazen.
He is the founding genius of the modern science of optics,
the man who first demonstrated the key properties of light.
I can demonstrate this here differently,
using this glass tube.
We're going to be able to see
that the light travels through this tube in a straight line
and is escaping here and hitting the screen at this point.
This basic truth that light travels in straight lines
was first proven by lbn Al-Haytham.
He also established rules of the process we call reflection.
This tube is reflective
so the ray of light is now reflected
to hit the other side of the tube here again
and again and again, zig-zagging its way out.
Ii I change the angle
you can see the light still traveling in a straight line,
hitting this end here
and then bouncing to hit this edge here
then bounce back again, zig-zagging its way through this tube.
Zig-zagging through this tube is exactly what happens to the light
inside an optical cable.
Ibn Al-Haytham developed his theory of optics
into a holistic vision of how human beings see.
He conducted a brilliant experiment,
to which he gave the name Ibn al-Haytham
which means Dark Room,
or in Latin, Camera Obscura.
We have a beautiful view of a nice church just outside the window here.
Now if I close these blinds
turning this into a dark room
and through this pinhole I created in this blind
I'll be able to capture an image of this church
on this transparent screen.
However, it's an inverted image
as lbn Al-Haytham explained and demonstrated is,
that the light reflected from the bell tower of this church
is going to travel in a straight line diagonally
through the pinhole to hit the bottom of the screen,
whereas the light traveling from the bottom of the church
is going to reflect and travel in a straight line
through the pinhole to hit the top of the screen.
And now if I let this eye look through this pinhole
I'm going to be able to see the image of the church again
inverted back on the retina of this eye.
The brilliance of lbn Al-Haytham
was to see this was the secret to the workings of the human eye.
This was due to his unique methodology.
By positing a theory, testing it with experiments,
then publishing results,
Al-Haytham and his colleagues in the Arab world
had taken what the Greeks called natural philosophy
and changed it into something different,
something that was starting to resemble what we call science.
He carried a huge amount of experiments
to prove the things that many people thought, they're obvious.
He wanted to establish everything experimentally
before moving on to the next stage.
Which is very close to the modern way we practice science.
So he's actually one of the founders of the modern scientific approach.
Ibn Al-Haytham was part of a scientific revolution
that emerged from the mosques and madrasahs of the Islamic world.
Islamic scientists effectively invented modern chemistry
giving us the words alchemy, alembic, alcohol and alkali.
Physicians like lbn Al-Nafis and the great Avicenna
wrote works which remained canonical until the 19th century.
The Arabs invented astronomical instruments
which would eventually guide Europeans to the New World.
And they measured the circumference of the Earth and mapped its surface
with an unprecedented accuracy.
An atmosphere of ideas and invention,
pervaded society from India to the west of Spain.
It was only a matter of time
before it came to the notice of Europeans.
In the year 1000,
Christian Europe was a culture at a crossroads,
a society beginning to emerge from a dark age,
but still centuries from the self-confidence of the Renaissance.
Its scholars remained cloistered in monasteries,
restricted to a very limited intellectual diet.
The work that we have in front of us is what's called in Latin,
De Temporum Ratione, On the Reasoning of Times.
And it is devoted to working out the times of the church festivals,
in particular Easter.
This work represents the cutting edge of European astronomy
at the turn of the millennium,
but compared to what was happening in the Middle East
it was hopelessly limited.
What it doesn't have is anything theoretical.
There's no theoretical astronomy here.
He doesn't tell you about the course of the sun or the moon
through the heavens,
and he doesn't talk about the planets or the fixed stars at all.
The problem for European authors
was the tiny corpus of source material they had to draw on
compared to the libraries of the Islamic world.
We're talking about rather small libraries,
I mean if a cathedral has a library of a 100 books,
that's a large number.
And when you compare this, for example,
with the contemporary library in Cordoba
which, according to reputation, had 80,000 volumes,
this is miniscule, miniscule number of books.
European thought was separated by a vast chasm
from the vibrant world of Islamic science.
It was a gulf that would be spanned in the most unlikely way.
In 1095, Christian knights set out
on the first of centuries of Holy Wars against Islam.
For 200 years, Christianity and Islam were religions at war.
But ironically this new contact
was also bringing the two faiths closer together.
In the wake of the warriors and monks of the First Crusade
came another kind of pilgrim.
It seems as it there were other people joining the Crusades
who were just very fascinated about new avenues,
new opportunities which were being offered on an intellectual level.
Christian scholars came back from the Crusades
with a fascinating glimpse into the wisdom of the Arabs.
But it was not so much in the Holy Land
as in the contested regions of Southern Europe
that first contacts evolved into a steady flow of ideas.
The Crusades were aimed not only at Jerusalem,
but also at Sicily and Spain.
There are a number of different points of contact.
Perhaps the areas where you see the most or the greatest amount
of say transmission of knowledge, transmission of culture,
would be in areas like Sicily or Spain
where first you have a Muslim society
that then is re-conquered or replaced by a Christian authority.
And they absorb a lot of what had been left behind.
In Spain, a world of intricate design,
luxury and sophistication awaited,
which in the 11th century
Christians were only starting to discover.
Its palaces survive as monuments to Islamic wisdom,
that can literally be read like a book.
Each surface bears the trace
of some philosophical idea or geometrical theorem.
But the historical tide was starting to turn.
In 1085 an event occurred that would affect world history forever.
The Christian King Alfonso VI entered the frontier city of Toledo.
This gate was known in Toledo . . .
as the "Puerto Vieha de Bisagra."
and it's also known as the "Puerto de Alfonso VI"
Because, according to tradition,
Alfonso VI, King of Castille and Leon . . .
entered through this gate when he conquered Toledo
This moment marked the beginning of the end for Muslim Spain.
But it signified a new dawn
for the intellectual life of Christian Europe.
When he entered Toledo,
Alfonso found books in quantities that astounded Christian eyes.
When Alfonso VI occupied the town
some Muslims had their own libraries
and there were other books coming here
from other parts of Andalus
Many of them were Arabic translations of classical works,
Greek philosophy and so on.
Tending these books was a literate population
of Jews, Christians and Muslims,
who knew both Arabic and Spanish.
So here in Toledo we have two important elements
Books and people who could read them.
The main thing, is that once they read them,
they could translate them.
After 1085,
Toledo became the center of a massive process
of translation of Arabic works into Latin.
Scholars, frustrated by the restrictions of European learning,
flooded to Toledo
to read for themselves the famed works of the Arab masters.
Daniel of Morley, who knows Adelard's works very well,
he tells of a story of going to Paris
and finding that the scholars there
are exceedingly boring
because all they do is have very big manuscripts in front of them
and they're making little annotations in the margin.
These manuscripts in fact seemed to be works of law.
And so he says “I went to Toledo because I heard
“that they studied the Quadrivium there,
“maths, astronomy, arithmetic, and I was not disappointed."
Obviously it was very exciting for him
and he wrote a book describing his experiences in Toledo
and saying how much more clearly
the Arabs explained things than did the Latins.
An event of historic significance was unfolding in Toledo.
The long forgotten works of the Greek philosophers
and the masterpieces of Arab science
were starting to materialize... in the West.
As scholars returned home from Toledo
they brought with them this priceless wisdom.
The impact was immediate and obvious.
A society which until recently had lain in the Dark Ages
began to construct a grand new culture of its own.
800 miles from Toledo, in the west of England,
traces have been found of the influence of Muslims
on Europe's re-emergence.
In Salisbury Cathedral,
symbols have been discovered
which are blandly familiar to us today.
But in 13th century Europe were a new and exotic Eastern import.
This is a three written on a beam, a roof beam
which we know was put up round about 1240, just after 1240.
As far as we know this is the first use of a Hindu-Arabic numeral
in an architectural context.
And if we look at the neighboring beams
we will see here a two,
and on the next beam there's a four.
And on the other side too
we have one, two, three, four marked,
but with an N after each numeral,
which suggests that those are the north beams.
So these numerals were put up by the carpenters
in order to indicate the order in which the beams should be placed.
This numbering system,
in which nine numerals were complemented by a zero,
which you could add to 1 to create 10, 100
and infinite possibilities beyond,
was invented in India and adopted by the Arabs
in the 8th century.
It's flexibility and ease of use amazed Europeans.
When people became aware
of these Hindu-Arabic numerals and their potential,
the fact that they had place value,
and the fact that there was a single number
for a single meaning, with a single meaning,
it was natural that they should use them
instead of the Roman numerals which were much more cumbersome,
which where you need three or four strokes for each numeral and so on.
These numbers themselves were only the tip of an iceberg of new ideas
which entered Europe at this time,
and allowed Europeans to build cathedrals
of the scale and grandeur of Salisbury.
It's nice to think that they were used
alongside or in conjunction with
much more advanced mathematical techniques,
actually applied to the building
of a gothic cathedral such as Salisbury Cathedral,
which in itself is based
on much more rigorous mathematical planning
than earlier cathedrals.
Cathedrals like Salisbury
tell in themselves the story of Europe's adoption of Islamic wisdom.
They were both the centers of learning
where ideas first penetrated,
and the places where those ideas were turned into stone.
And so we can think of the whole cathedral community,
the architects, the builders, the carpenters,
and the scholars, the teachers, the clerics,
all being part of an intellectual movement
which indeed owes a lot to Arabic science.
Under the influence of the Arabs
scientific thought was starting to infiltrate
Europe's ecclesiastical centers of learning.
In the process, they were starting to evolve into something else.
Across Europe
institutions were founded on the principles of secular learning
inspired by the Arabs.
They were called universities.
Europe was waking up from its intellectual slumbers,
fed by the sheer quantity and range of works
coming in from Toledo.
The works that more than any other would transform European thought,
were the translations from Arabic
of the long lost writings of Aristotle.
The works of the Greek philosopher Aristotle
were fundamentally important to the University movement
because Aristotle dealt with things
like rationale and reason and logic and proof of your argument.
These concepts would form the basis of Western Europe's transformation
into a civilization based on rational inquiry.
But to decipher the works of Aristotle,
Western Europeans would need the guidance
of the people who had done it before.
There's a problem with Aristotle
because actually his works are immensely complicated
and you often need help understanding and interpreting them.
The work that guided Europeans
through their first struggles with Aristotle
was the work of the Muslim philosopher ibn Rushd,
known to the West as Averroes.
What happened at the same time
as these translations were being made in Toledo,
was that Averroes,
not so far away, in Cordova in Islamic Spain,
was writing commentaries on Aristotle's works.
Aristotle was always regarded as being difficult to understand
and very laconic, missing things out.
He needed interpretation.
And Averroes somehow understood Aristotle
better than anybody else.
So ii you'd been in any university in Europe in the Renaissance
then the students would have had Aristotle in one hand
and the commentary of Averroes in the other.
In fact he wasn't called Averroes often,
he was known simply as “The Commentator...
Averroes was only the greatest of a pantheon of Islamic scholars
to whom the Europeans turned to understand the new sciences
they were beginning to study.
Under their influence,
Europe was becoming a different kind of place.
As the 12th became the 13th then 14th century,
Europe discovered a new curiosity and dynamism.
The reconquest of Spain
was completed just as Europe discovered a new world
across the Atlantic.
The world's center of gravity was moving west.
The place that symbolizes this era more than any,
still has the power to astound.
Millions of people visit Florence to celebrate a city
where European civilization finally came of age.
This was the city of Dante and Petrarch,
of Leonardo DaVinci and Machiavelli.
A place where new ideas were being forged
that would take Europe out of the Middle Ages.
Traditionally the inspiration for this
is thought to have come from ancient Greece and Rome,
but even at this defining moment
the Renaissance masters were still standing on the shoulders
of the giants of Muslim philosophy.
This debt to Muslim learning
extended even to the greatest scientific discovery of the era.
Nicolaus Copernicus is the man to whom we owe the idea
that the Earth is not the center of the universe.
In this book,
Copernicus believed that the Sun is at the center
and all the planets, but the Moon, orbit the Sun.
His theory rested on a particular diagram
which explained why planets sometimes seemed to move not in circles
but in straight lines.
There is a first circle,
and a second circle
which center is moving around the first one,
and the planet is moving on the circumference of the second circle.
And the combination is motion
along the diameter of this device.
This diagram explains what is essentially an optical illusion,
that one circle moving within another circle
appears to be moving up and down a straight line.
Copernicus believed this is what we saw when we observed the planets.
So this is a mathematical, geometrical device,
that Copernicus uses several times inside the book
for explain the possession of the equinoxes for instance
but also for explain part of the model of Mercury.
The diagram showing the movement of Mercury
was only one of many times Copernicus used this device
to explain the solar system.
But extraordinarily
it appears that this utterly crucial idea was not Copernicus' own.
It already existed in the Muslim world.
This is the so-called Al-Tusi couple,
because it was already conceived
by an astronomer in the 13th century
that was an Arabic astronomer that was called Al-Tusi.
Al-Tusi was an Islamic astronomer based in Iran.
If you put his diagram side by side with that of Copernicus
the debt of the European scientist to Al-Tusi becomes clear.
It is an open question if Copernicus
knew something about the Islamic astronomer or not,
but what is certain is that his models of the planets
are very similar to those of the Arabic astronomer,
just changing the position of the Earth and the Sun.
This discovery reveals that our modern vision of the solar system
owes a crucial debt to centuries of astronomical work
by Islamic scientists.
It is only one of a host of Islamic ideas
on which the European Renaissance was based.
It was not just the substance of science
that the Renaissance learned from Muslims.
It was the philosophy that lay behind it.
Copernicus' discovery was immediately controversial
as it contradicted the teachings of the church
that the Earth was the center of the universe.
The clashes that followed
have come to define a conception of secular rationalism
that the West regards as peculiarly its own.
But this too had an Islamic precedent.
There had been famous debates in Europe
about the validity of secular and religious thought
and whether those two could run along together,
whether you could have scientific and philosophical exploration
and also believe in God.
But actually these were already arguments
that had been played out in the Islamic world.
Averroes was not only a commentator on Aristotle,
he was also the man who taught Western science
how to face down conservative opposition.
He said there are two paths to real knowledge.
One through rational thought and one through divine revelation.
And he met quite a bit of resistance from the Muslim authorities.
Averroes' arguments in his defense
were used by the scholars of the first European universities
to justify the study of natural philosophy.
Averroes' argument is very simple.
He says that philosophy is the search tor the truth,
and that if God is true the two can exist side by side.
Now his ideas were immensely influential in the West
for centuries after,
and they were used when people were trying to justify
religious and secular learning existing side by side.
The Europeans of the Middle Ages
had discovered in the philosophers of the Muslim world
pioneers of an idea that still shapes the modern world
that the universe can be understood through reason,
without harm to religion.
Perhaps the opponents of Averroes
should have listened to the words of one Christian translator...
“Of course God rules the universe.
“But we may and should inquire into the natural world.
“The Arabs teach us that."