Secrets of the Dead

Narrator: Leonardo da Vinci is one of the worlds greatest artists.

His masterpiece, the "Mona Lisa," is known to everyone.

Millions view it every year.

"The Last Supper" is a landmark of art history.

But Leonardo was more than a painter.

Its in the pages of his notebooks that we find the true Leonardo, the man of science.

He investigated an astounding range of subjects.

Man: Leonardos science cannot be understood without his art, and his art cannot be understood without his science.

Narrator: Leonardo drew everything he saw and everything he imagined.

He pushed science forward in the fields of anatomy, engineering, optics, geology.

Most of these disciplines didnt even have names at the time.

His notebooks contained plans for hundreds of technologies common today: machine guns, diving suits, cranes, robots, flying machines.

His inventions have given him the status of a towering genius, a prophet who anticipated the modern age.

But was he?

As researchers probe Italys 15th-century technical revolution, theyre discovering precedents for many of Leonardos most remarkable innovations.

Some are from Leonardos contemporaries.

Others predate him by a thousand years.

Could it be that Leonardo is not the legendary, isolated genius we take him for, but has, in fact, presented the work of others as his own?

Is Leonardo da Vinci truly an original?

Narrator: At his death in 1519, Leonardo was a famous artist, but his scientific achievements were less well-known.

His notebooks, written in a secretive reverse script, went unpublished for more than 400 years.

They provide insights about the dynamic period in which he lived, but they also raise questions.

Some of his sketches are very similar to those of other inventors.

Did Leonardo steal their ideas?

One of the many inventions attributed to Leonardo is the parachute.

Bartolomeo!

[Both grunting] You must do it.

But, Maestro Leonardo, Im scared!

Ludovico Sforza is down there waiting for us.

Come on!

No, Maestro.

Ask Zoroastro!

da Vinci: No!

You tested it and you have to do it.

No, Maestro!

My dear Bartolomeo, surely once youve tasted flight, you will walk forever with your eyes turned skywards, for there you have been and there you will always long to return.

Narrator: Its not known for certain if Leonardo ever used his parachute.

His written notes are difficult to decipher-- perhaps purposely-- and there are no physical remains of any of his inventions, no way to tell for sure if any of them passed beyond the idea stage.

But in 1482, he was in the service of Ludovico Sforza, the Duke of Milan, a warrior prince interested in any invention with military application, like swooping down on enemies encamped at the foot of a high cliff.

And what did you bring for us today, Maestro Leonardo?

Duke Sforza, my lord.

Today I will demonstrate an ingenious apparatus by which a man can leap from any height without injury.

For instance, it could be used to escape from a tower on fire.

Now!

[Screaming] Look up there!

Whoo hoo!

Sforza: Maestro Leonardo, you always amaze us.

How do you come up with such ideas?

Narrator: But did Leonardo really invent the parachute?

In 1968, researchers examining a trove of drawings discovered sketches from the studio of a 15th-century inventor that were remarkably similar to Leonardos study for a parachute.

The inventor--Mariano di Jacapo, known as Taccola.

[Man speaking Italian] Translator: This drawing, the design for a parachute, is the oldest known to us, and it is very similar to Leonardos.

It was found in a manuscript conserved at the British Library in London.

Leonardo knew manuscripts from the Sienese engineering tradition, and he even refers to Taccolas drawings in his manuscripts.

[Bernardoni speaking Italian] Translator: There are actually two drawings.

The second is a flying man without a parachute, although the subject is similar.

He is holding two sticks with two fabrics, like two wings.

It is a much more primitive design that goes back about 15 years, before Leonardos drawing.

Narrator: Taccola was an engineer of the early Renaissance, 70 years older than Leonardo.

He was among the first to use drawing as a design tool.

Before him, engineers worked out their inventions as they built them, through trial and error.

His manuscripts detail civil and military machines; some original, others copies of ancient inventions.

And just as Leonardo copied him, Taccolas idea is copied from a Muslim inventor, Abbas ibn Firnas, who, the story goes, leapt from the minaret of the Crdoba Mosque in the year 852 and suffered only minor injuries.

Bartolomeo: Oh, Maestro... Narrator: So why is Leonardo remembered as the inventor of the parachute?

[Man speaking Italian] Translator: In the "Codex Atlanticus" notebook, we find Leonardos parachute, but we know its not really his invention.

Leonardo copied it from Taccola and took inspiration from him.

The most incredible thing is that Leonardo is the first to write about the material needed to make this object-- cloth made of waxed flax-- so that the air doesnt come through and it becomes waterproof, like the feathers of birds.

For the first time, he describes how this object has to be built.

Hes the only one to think about the dimensions.

Theres another interesting thing on this other part of the sheet.

We find a lot more subjects.

Leonardo wrote many pages about how to build a flying machine, and here, we find five or six examples of them.

In these small sketches, Leonardo shows himself as more than an artist or some insane inventor.

For the first time, we see Leonardo da Vinci the scientist, and this is really amazing.

Narrator: Leonardo copied dozens of Taccolas inventions: the screw pump, a device to raise water... ...the life preserver, adapted by Taccola to float armored knights across rivers... ...and the snorkel, though Leonardos version is more developed, with floaters to ensure air flow and valves to counter water pressure.

He relies on science, Taccola on fantasy.

Taccola died the year Leonardo was born, but he cast a long shadow and was a powerful inspiration.

The young Leonardo encountered Taccolas drawings in the course of his artistic apprenticeship, beginning in 1467 at 15 years old.

Man: Leonardo!

Leonardo!

Narrator: Andrea del Verrocchio, master of the greatest of the many artistic workshops in Florence, challenged Leonardo, fired his passion, and began the transformation of this uneducated country boy from the town of Vinci.

Man: A small town or a large village, where nature came right up to your door and your window, so he was immersed in natural forms.

He was immersed in a landscape which one sees repeated over and over in his paintings and drawings.

And I think, perhaps, the most profound legacy of his childhood was his supreme mental independence.

And this independence of mind, um, feeds on into Leonardo as a--a thinker, as a philosopher, as a scientist.

Narrator: Leonardos father paid for his apprenticeship, even though he was born illegitimate.

The idea was to provide him with a trade.

Under Verrocchio, he studied architecture, engineering, and mechanics, as well as painting.

All were considered art in the Renaissance.

Artists were trained as craftsmen, not intellectuals.

He never had a formal education.

[Speaking indistinctly] Uh, the studio of Andrea de Verrocchio was, uh, extraordinarily versatile and varied in its output.

Paintings were certainly one of its major outputs, but only one.

Verrocchio himself was primarily a sculptor, and one has to think, really, of a sort of communal workspace, full of the smells and sounds of light industry.

[Sighs] The workshop of Verrocchio was not only a place where Leonardo learned all kinds of skills, it was also a place of intellectual excitement.

For one thing, the master painters who had left the workshop came back to learn the newest techniques, to discuss the latest about oil painting; uh, people like Botticelli or Ghirlandaio, Perugino, who were master painters, would hang out with Verrocchio, come in the evenings to discuss the newest developments.

So Leonardo had a tremendous inspiration in all kinds of knowledge, and I think his tremendous scientific curiosity also may have been triggered in this workshop culture.

Leonardo.

Maestro.

Nicholl: His interest in machinery would have been considerably quickened in 1471, when he was probably part of the team of Verrochios studio, which was entrusted with the task of putting the copper orb right on the top of the lantern above the dome of Florence Cathedral.

So the technical problems of getting a two-ton ball of copper up 300 meters to the top of Brunelleschis dome required the use of some pretty complex and robust machinery, and it would seem to be at that point that Leonardos interest in the work of Filippo Brunelleschi-- the architect of the dome and the great engineer of the earlier Florentine Renaissance--takes shape.

Narrator: For a long time, Leonardo is credited with inventing the construction machines in his notebooks, but they are actually copies of Brunelleschis, invented 50 years earlier to raise the duomo, and used again by Verrocchio.

[Speaking French] Translator: I think we have to insist on the fact that the Renaissance is also a Renaissance of machines, a technical Renaissance.

For example, in Florence, the Dome of Brunelleschi was first of all a highly technical achievement which involved complex mathematical calculations, and many young students came to Florence so they could study the dome.

Narrator: In Verrocchios studio, Leonardos mind was forged by artists and architects who were transforming the world through their works and through the power of a new intellectual movement, humanism.

[Speaking French] Translator: Humanism is a cultural movement that really takes form and gains power in the first three decades of the 15th century.

Humanists believed in a better future for humankind and the potential for a better man, and perhaps this is the fundamental break with medieval culture which was marked by a sort of fundamental pessimism.

Narrator: Brunelleschis dome is one of the great architectural achievements.

To construct it, he studied the monumental ruins of classical antiquity, reviving long-forgotten building techniques.

The rediscovery of ancient Greece and Rome is the foundation of humanism.

In the Middle Ages, the ruins of imperial Rome seemed a mystery.

Centuries of invasions, plague, and decay had erased the memory of Romes grandeur.

Even Latin had fragmented into regional languages.

The long cultural chain leading from Greece to Rome was broken.

But in the 14th century, Florence saw a new class of merchants and bankers prosper as a result of international trade.

They were drawn to the glories of the classical world, paying fortunes for ancient manuscripts found in isolated monasteries and distant libraries.

In 1439, the most powerful family in Florence, the Medici, played host to the Byzantine emperor and his court.

Thirteen years later, the emperors capital, Constantinople, fell to the Ottoman Turks.

Greek scholars fled to Florence.

Bringing manuscripts from the thousand-year-old Imperial Library, they became teachers and translators.

The encounter between East and West kicked the fledgling Renaissance into high gear.

[Speaking French] Translator: Its at this moment that the concept of the Middle Ages, the Dark Ages is invented.

And at the same time, the concept of Renaissance, "the return of the light," is born.

Its the idea that for decades, wisdom was somehow hidden from humans.

But reading the ancients directly, rediscovered in newly translated texts unknown during the Middle Ages, gives the power to access this treasure of knowledge.

Suddenly, they have direct access to the hidden understanding somehow lost over the last ten centuries.

Narrator: Caught up in the humanist fervor, Cosimo de Medici hired translators and scribes to copy ancient manuscripts.

His goal was to create a universal library containing every written work.

[Speaking French] Translator: Cosimo de Medici invited a group of humanists to settle in his villa outside Florence, Villa Careggi.

Translator: They created what we would call today an academy, a place where humanists would meet to talk, to play the lyre.

It was, at heart, a political program to increase the power of the family.

It starts with Cosimo and will continue with his grandson, Lorenzo the Magnificent.

Narrator: Lorenzo de Medici was just three years older than Leonardo, but he was a product of an elite humanist education.

Like his grandfather Cosimo, he was determined to advance humanism and his familys power and prestige through the patronage of artists and scholars.

[Indistinct chatter] Narrator: But for wealthy patrons and aristocratic humanists, artists and engineers were little more than simple workmen.

A commission usually included a detailed description of the scene, the colors, the size, even the number of angels.

There was little room for creativity.

de Medici!

de Medici!

Its Lorenzo!

Hes here!

Are you sure?

Absolutely sure!

Lets go!

Nicholl: Lorenzo de Medici was a major client of the Verrocchio studio, but the evidence that he supported Leonardo seems to me pretty patchy.

In fact, Id say there was rather some opposite evidence to show that Lorenzo considered Leonardo, uh, a-an unreliable sort of character.

[Artists shouting] Narrator: Already, Leonardo had a reputation as distracted and irresponsible.

He left paintings unfinished and abandoned commissions, even after being paid.

And it only got worse when, after ten years of apprenticeship, he left Verrocchio and set out on his own.

[Laughter] Its a kind of obscure period in the biography and, uh, its slightly clouded by--by a couple of run-ins with the authorities in connection with his homosexuality.

Uh, the officers of the night, as they were called-- uh, what we might call the vice squad, uh-- received a report about a certain young man and about other young men, or men, who, uh, frequented his company at night for immoral purposes, and Leonardo is on-- one of the men on that list.

Nicholl: I have a feeling that Leonardo is experiencing some uncertainty, some self-doubt.

He realizes the limits of his power, the limits of his, uh, status.

He described himself as "omo sanza lettere," "an unlettered man"; he meant he hadnt had the sophisticated, Latinate schooling.

da Vinci: They say that I, having no literary skill, cannot properly express that which I desire to treat of.

But they do not know that my subjects are to be dealt with by experience rather than by words.

Though I may not, like them, be able to quote other authors, I shall rely on that which is much greater and more worthy-- on experience, the mistress of their masters.

Machiavelli has a line in one of his plays: "If you dont have power in Florence, even the dogs wont bother to bark at you."

And I think theres probably a feeling with Leonardo, a--a sense of exclusion from the more sophisticated, polished, intellectual world.

Narrator: The only way to financial security for an artist was to find a patron, a prince willing to retain his services in his court.

Leonardo knew that Lorenzo de Medici would never support him, so he looked elsewhere, to Milan, where the young duke Ludovico Sforza was assembling artists and scholars to create what he called "a new Athens," and the duke paid well.

Leonardo set out to draft a resum.

da Vinci: My most illustrious lord, I beg leave to present myself to you and to discover to Your Excellence my secrets of war.

I will make covered vehicles, safe and unassailable, which will penetrate the enemy and their artillery, and theres no host of armed men so great that they would not break through it.

I have also types of cannon most convenient and easily portable, with which to hurl small stones almost like a hailstorm, and the smoke from the cannon will instill a great fear in the enemy on account of the grave damage and confusion.

Where the use of the cannon is impracticable, I will install catapults, mangonels, trebuchets, and other instruments of wonderful efficiency not in general use.

[Boom, horse neighs] Narrator: For two centuries, the Italian peninsula had been torn by nearly constant warfare.

Venice, Milan, Florence, Naples, and the Papal States all vied for dominance, sometimes allied with outside powers.

Leonardo had never seen war, but he knew the labor market.

Military engineers were in high demand.

Still, he adds a footnote... da Vinci: Whats more, Im a sculptor.

I can execute figures in bronze, marble, and clay.

Likewise, in painting, I can do everything possible as well as any other man, whosoever he may be.

Im the man you need.

[Taddei speaking Italian] Translator: In the "Codex Atlanticus," there is something very strange.

Its a resum, the first resum in history made by Leonardo da Vinci.

But Leonardo introduces himself as a military engineer who makes secret weapons, incredible submarines, assault bridges.

But the most bizarre and incredible thing is that Leonardo is lying.

Why is he lying?

Hes still young and comes from Verrocchios studio.

How could he be such an expert in military engineering?

Hes not, but here is his genius.

Leonardo is not stupid.

He does what any intelligent person would do.

He studies.

He studies a lot.

This is the famous book of Roberto Valturio, printed just before Leonardo leaves for Milan.

Leonardo uses it as a source.

It is an encyclopedia of military weapons.

We see Leonardos famous scythed chariots taken from this book.

Leonardo is inspired by this book.

He studies every single page and copies all these machines and gives them to the duke as his own inventions.

Here, we see something beautiful, perhaps the ancestor of Leonardos tank.

It is an armored tank with guns.

One can hide cannons inside.

Narrator: In 1472, Valturios "On the Military Arts" was among the first illustrated printed books.

Leonardo turned to it not out of curiosity, but desperation.

He needed to sell himself to the Duke of Milan.

But his improvements on Valturio led to some of his most famous inventions: combat wagons, siege machines, even a machine gun.

Translator: This is a spheroidal machine gun.

Leonardo understood that just having many cannons is not enough.

If your enemy can run fast or even fly, this machine gives you the power to chase him from left to right, but one can also move it like a modern gun.

Thanks to the central sphere inside the gun, one can follow the enemy even if he is moving.

Its a fantastic machine.

It could even work today.

We rebuilt it for the first time with its original dimensions, just like Leonardo conceived it.

Nicholl: Leonardo arrived in Milan in the spring of 1482.

He found a city much bigger than Florence, much less like a town and more like a metropolis.

Um, he also found a very cosmopolitan city; there were a lot of influences percolating down from across the Alps, lets say, so it was something of a crossroads of trade, and therefore also of ideas and techniques.

Narrator: The spirit of the city was dynamic, entrepreneurial, practical.

Milan suited Leonardo, and though the duke did not immediately hire him as a military engineer, Leonardo set up a studio for painting.

[Music playing] Nicholl: Leonardos first commission by--from the Duke of Milan, Ludovico Sforza, was a portrait of Ludovicos mistress, Cecilia Gallerani, a wonderful portrait known as "The Lady With an Ermine."

Its full of life and movement, full of vitality, full of that wonderful movement of the--of the sitter towards the painter, as if momentarily capturing her, uh, about to speak, that way Leonardo has of capturing women in particular in a moment of suspended or potential animation.

Narrator: In Milan, Leonardo found a fresh atmosphere that sparked his curiosity.

Narrator: And he found new inspiration in the scientific spirit of the universities and booming book trade.

The printing press was invented about the time Leonardo was born.

It was a communications revolution, like the Internet today.

In just 30 years, more books were printed than had been copied in all the Middle Ages.

The cost of a book dropped by 80%.

Books opened a new world for Leonardo; he could read the ancients directly, a source of inspiration that would ignite his scientific impulse.

Capra: These advances of humanist science and philosophy would not have been possible without this tremendous technological breakthrough, the invention of printing.

In fact, there were two inventions that--that contributed.

One was the movable type, typography, and the other one is-- was engraving, where you could present pictures in a way that could be multiplied infinitely without deteriorating, and so this had two consequences.

Dissemination was much more rapid, and it was much more precise.

Would you be interested in this book?

Why, yes, certainly.

[Bell tolling] When he arrived in Milan, he had no books, not a single book, at the age of 30.

Eight years later, he had about 35 books, and another--I dont know-- ten years later, he had about 200 books.

These were books of science and philosophy by, uh--the classical books about mathematics, about botany, astronomy, anatomy, and so on.

So he had the books of a Renaissance scholar, and he actually became a Renaissance scholar.

[Reading aloud in Latin] [Women giggling] Narrator: But the untutored Leonardo needed Latin.

[Women giggling] Narrator: At the age of 35, he began memorizing verbs like a schoolboy.

[All giggle] Narrator: Zoroastro, court mechanic and magician, came from Florence to assist Leonardo, who was finally appointed ducal engineer, responsible for everything from canal-building to staging royal entertainments.

Leonardo found new colleagues attracted to the dynamic city and the free-spending duke, men determined to reinvent themselves and their society: Luca Pacioli, Leonardos tutor in mathematics, whose book "The Divine Proportion" was illustrated by Leonardo... Francesco di Giorgio Martini, the most celebrated military architect of his time and source for some of Leonardos war machines... Donato Bramante, painter turned architect.

He brought the high Renaissance style to Milan and would go on to design Saint Peters in Rome.

His ironic fresco, "Heraclitis and Democritus," is a double portrait of himself and his friend Leonardo, the only image of Leonardo from the period.

Hes an opportunist in many ways, Leonardo.

He learns what he needs to learn for a particular purpose and for a particular situation.

And his situation as sort of, as it were, entertainments manager for the Milanese court, uh, might not seem that congenial put in those terms, but it did enable him to channel all sorts of interests-- technical, scientific, engineering interests-- as well as the pictorial, sort of poetic interests that he has as an artist.

[Music playing] Narrator: For the men and women of the Renaissance, there was little difference between technology and magic.

Seemingly controlled by unknown forces and hidden powers, Leonardos spectacles filled people with curiosity and wonder.

He went so far as to invent a prototype robot just for the dukes entertainment.

[Taddei speaking Italian] Translator: Leonardo is said to have invented the car, but its not a car.

He studied in Verrocchios studio, where, in addition to paintings and sculptures, they made theatrical objects, and this is probably a magical theatrical device-- Leonardos robot.

Why a robot?

Because it is programmable.

Leonardo invented these systems.

These simple rods already existed, but Leonardo conceived them as something new.

If I put these rods in this position-- one, none, or many-- these two levers will touch the pedals from time to time, and the cart will move from right to left.

[Taddei speaking Italian] Translator: For the first time, he creates a robot with its own internal energy, a robot that does what Leonardo wants it to do.

[Wheels creaking] [People murmur] [Applause continues] [Applause abates] [Taddei speaking Italian] Translator: This is a dream that takes us back to Leonardos predecessors; people like Heron of Alexandria, who created magical objects for the fun and wonder of making things that never existed before.

Narrator: Leonardos robots copy inventions made a thousand years earlier, during a Greek scientific revolution in Alexandria.

There, the first-century engineer Heron compiled a book of temple magic... the worlds first vending machine for holy water, and a self-propelled cart.

Leonardo had a summary of Heron in his library.

The 12th-century Arab Golden Age preserved and advanced the science of Alexandria.

Inventor and engineer Ibn al-Jazari updated Heron with Indian and Chinese technologies encountered with the spread of Islam.

His ingenious clockworks and automatons used control devices like those in Leonardos cart.

Advanced Arabic works on mechanics, astronomy, mathematics, and optics made their way to Europe through Muslim Spain or through Medicis agents, sent to Persia and Syria in search of manuscripts.

Man: Leonardo had actually referred to the "Book of Optics," Alhazen, Ibn al-Haytham.

Now, he is a guy who had come-- faced two philosophical, two theoretical explanations of how we see, and what he did is he carried out experiments to verify what he thought how we see and developed what we call the dark room or dark box, which became the pinhole camera and then we refer to as the camera obscura.

Now, he says that you should always doubt what you read, even if you have to doubt yourself, but you must prove things by experiment, so experimentation began to take, uh, a lot of, uh, interest in that society.

Narrator: Leonardos notes show he was familiar with al-Haythams "Optics," written in 1021.

Its the source of his interest in the camera obscura, where a small hole acts as a lens to project a brightly lit exterior on the opposite wall in a darkened room.

Narrator: Leonardo was not a prophet of the future.

He discovered a distant past, where a much more advanced technology had existed, lost to the West with the fall of Rome.

Ibn al-Haytham arranged three candles in a row in a dark room.

He put a screen with a small hole between the candles on the wall and noted that images were formed.

Capra: Leonardo certainly was very influenced by, uh, Arabic scholars.

His experimental method, his empirical method, uh, somehow came from his reading of these texts because these, uh, uh, Arab scholars were not bound by-- by religious doctrine.

Uh, Islam left them complete freedom to--to do the science, the philosophy, their reinterpretations of Aristotle.

Narrator: In reinventing an ancient technology, Leonardo also reinvented something that had been lost for centuries-- the scientific experiment.

His detailed observations and carefully drawn results paved the way for modern research methods.

Books start to mean something to him, and its hard to know exactly what this change of attitude, uh, signals, but I suppose its the desire to-- it--it goes with that newly encyclopedic idea that Leonardo has for himself, that all branches of knowledge are within his reach, and that he--as what he calls the painter/philosopher--must acquire knowledge of all sorts.

And indeed, there is a sort of bewildering multiplication of his interests around about the same time as he starts to acquire and collect books.

[Insects chirping] Although nature begins with reason and ends with experience, we must do the opposite-- to begin with experience, and from this, to investigate the reason.

Narrator: In 1482, a translation of Ptolemy was printed from a newly discovered Greek manuscript.

The second-century mathematician created the Earth-centered model of the universe held by Alexandria, Islam, and Europe for over 1,200 years.

Leonardo turned his attention to the geometry of the night.

Ptolemy held that the moon and planets shine with their own light.

As a test, Leonardo embarked on an imaginary voyage.

He placed himself outside the earth.

He realized that moonlight is really reflected sunlight, and that the dim light that makes the body of the moon just visible at crescent is reflected from the earth-- earthshine.

Anyone standing on the moon when it and the sun are both beneath us would see our earth and the element of water upon it, just as we see the moon, and the earth would light it, as the moon lights us.

The earth is not the center of the suns orbit, nor at the center of the universe, but in the center of its companion elements and united with them.

Narrator: "The sun does not move."

His cryptic phrase was written a hundred years before Galileo, but never developed further in his notebooks.

A theory of the heavens?

Notes for a spectacle?

Impossible to say.

Leonardo believed that the same force that moved the heavens moved the body; as above, so below.

The form of the cosmos was reflected in the human form.

And just as the map of the heavens went unchanged for centuries, so too did the map of the body.

Doctors relied on illustrations inherited from ancient Greece and Persia.

Leonardo would conduct his own medical examinations.

First sign of Leonardos, uh, actual practical involvement in anatomy and dissection is some wonderful, slightly eerie drawings of a skull, uh, dateable to about 1489.

One of the drawings makes it clear that at least one of his interests is to establish by a sort of grid-referencing the particular location of the sensus communis, which is an Aristotelian concept, the communal sense, where all the sensory impressions go into the brain and was where a mans soul could be found.

Narrator: Leonardos first dissections were in search of the soul.

Narrator: His guide, a newly published manual of anatomy by Mondino de Liuzzi, would remain the authority for 250 years.

Capra: Even though he was a mechanical genius, he never treated the body as a machine.

He said that nature has given the body or has given animals mechanical instruments, but the source of the movement comes from the soul-- which is not mechanical, which is spiritual-- and by that, he meant immaterial, and he actually traced back the sensory nerves to the center of the brain, which he considered to be the seat of the soul.

Narrator: In the center of the brain, he found three small cavities-- the ventricles-- the site, he was certain, of Aristotles sensus communis.

[Zoroastro reading aloud in Italian] The soul appears to reside in the judicial part, and the judicial part seems to be the place where all the senses come together, the sensus communis, and the sensus communis is the seat of the soul.

[Zoroastro continues reading] Narrator: While Leonardos proof of Aristotles theories has not stood the test of time, his anatomical drawings have never been surpassed.

Sequential views suggest a cinematic animation, and views from multiple angles provide a true three-dimensional understanding of the bodys form.

His images are never static, but animated by a dynamic energy and seem just on the verge of moving on their own.

Leonardos illustrations, as precise as his technical drawings of machines, were unequaled in accuracy until the photographic techniques of the 19th century, but they were never published in his lifetime.

They remained unknown and unpublished for more than 300 years.

Leonardo, like his fellow humanists, was very eager to read classical texts, but there was a big difference.

He would examine them in the light of his observation of nature, in the light of his own experience, and he would never hesitate to correct the classical texts, even of the greatest authorities.

When he made progress in one area, he immediately applied it to a related area so that you can actually see his progress as a kind of spiral that-- that goes higher and higher but always touches several fields.

Capra: Dealing with a problem or understanding a phenomenon, for him, meant to see how it is related to other phenomena.

In this way, I think he generated what we now call the scientific method, and he singlehandedly created the scientific method.

Narrator: Leonardo wanted to understand underlying principles.

Just his study of spirals in water, flights of birds, plant growth, even hair patterns, led him to explore the fields of geology, botany, topology, and more.

For him, everything was deeply connected, a great system in continual movement, with human beings at its center.

And there is an image that seems to summarize all of his work-- the "Vitruvian Man."

Man: Everybody knows this picture.

Its become a kind of icon, even, like an emblem of the human spirit.

Leonardo drew it in about 1490, um, and he did it as a kind of answer to a riddle.

Um, the architect, uh, Vitruvius, from ancient Rome, had proposed a man could fit inside a square and inside a circle, and for centuries after that, people had wondered about how that might work at a literal and at a metaphorical level.

The height of a man equals four cubits.

Narrator: Vitruvius book, printed in 1486, stated that to achieve harmony, buildings must reflect ideal human proportions.

Before scientific standards, all measurements were taken from the body-- the foot, the digit, the step.

But to build something, the proportions must be known: how many thumbs in a palm, how many palms to a step.

Architects hoped to find the answer in Vitruvius ideal proportions, to unlock secrets of ancient buildings.

Forty at the dial and... 19 at the rod.

Narrator: But the book wasnt illustrated.

How could a human body fit proportionally inside a circle and a square?

The image of a human at the center of a circle is an ancient way of relating individual existence to the infinite universe.

It proposes a linking between the two.

The individual is a microcosm, a miniature reflection in all its parts of the universe, or macrocosm; as above, so below.

Vitruvius square represents the material world.

His figure has a dual nature, inscribed in both the heavens and the earth.

His idea was appealing to humanists values, but without illustrations, the question of how to fit the body in a square and a circle without distorting its proportions became an obsession for architects.

Those who tried failed.

Narrator: Leonardo was fascinated with proportion.

During the Renaissance, the goal of art was the expression of harmony, and harmony is a matter of proportion.

Vitruvius gave complex measurements for the ideal body, but Leonardo needed to verify everything for himself, and then he too undertook the quest for "Vitruvian Man."

[Speaking Italian] Its a matter of proportions.

Come.

I want to show you my work.

Narrator: In 1490, Leonardo met a young architect, also hard at work on the "Vitruvius" problem.

Lester: Discovery recently suggests that there was another person who also drew a "Vitruvian Man."

It comes in a manuscript by an architect named Giacomo Andrea, who was from Ferrara, but who worked in Milan at the time that Leonardo was there, and it turns out the two of them were good friends.

Look at this.

"I have all measures inside me, "the divine ones, as well as the ones coming from earth and hell."

You see... the man is called "Little World," who contains in himself all the general perfections of the entire world.

Lester: If you look at this manuscript of Giacomo Andreas, which seems to date to around 1490 as well, possibly a little bit earlier, youll find in it a--a vision of "Vitruvian Man" that is eerily like Leonardos and seems to be a predecessor.

Its a tentative effort that you can see erasures on.

You can superimpose them and get almost an identical image.

Again, Leonardos image doesnt appear out of the blue.

Uh, its part of a progression, and it may have been part of a very close collaboration with Giacomo Andrea.

Narrator: Giacomo Andrea de-centered the circle in the square.

The spiritual realm of the circle is centered on the navel, the earthly realm of the square on the genitals.

No one else had thought to do that.

The same solution is found in Leonardos famous drawing, but as always, he takes it much further.

Andreas figure is almost Christ-like, a throwback to the Middle Ages.

Leonardos is unquestionably human, bold and ambitious.

"Vitruvian Man" is a pure expression of the Renaissance, a secular, almost carnal figure whose reach extends to the very limit of the cosmos and whose face, staring out with absolute confidence, might be that of Leonardo himself, 38 years old and at the height of his powers.

There might seem to be some arrogance in the idea that he is putting his own face into this, uh, central, iconic sort of a figure.

I think its appropriate, though, because who better to encapsulate this knowledge that he is imparting than the painter, philosopher, anatomist Leonardo da Vinci, who finds all these different avenues to his knowledge of the human condition, of what it is to be a man?

Narrator: Leonardos great dream was to write a series of books which would unify and transmit the vision he developed over years of research.

That, for him, would cement his posterity in a way his fragile paintings could not; he would join the timeless human chorus of the book.

There would be a manual of painting, a detailed book of anatomy, a book of mathematics, astronomy, geometry, but he never really seemed able to stop and look backwards.

New subjects called to him: the movement of water, the flight of birds.

This project, like so many, went unrealized.

Leonardo was the perfect man for his time, and his time was perfect for him.

Leonardo was opposed to any kind of imitation.

If he copied the work of others, it was to learn from it, transform it, enhance it, and send it forward to us as a great gift.

Human ingenuity will never discover an invention more beautiful, easier, or more economical than natures because in her inventions, nothing is wanting and nothing is superfluous.