Da Vinci's Ghost (20 page)

Figures 32 and 33.
The human analogy in architecture, from Francesco di Giorgio Martini’s
Treatise
(c. 1481–84).

* * *

V
ITRUVIUS
, A
LBERTI
, F
ILARETE
, Francesco di Giorgio Martini: these were the writers whose works Leonardo would have been exposed to when he began thinking hard about architecture in the mid- to late 1480s. Each in his own way had toyed with the human analogy. No doubt the subject also came up often when Leonardo discussed architectural matters with builders, engineers, scholars, and church deputies, and in his many conversations with Bramante. He and everybody else could even see its physical embodiment right in the center of Milan, in the form of the city’s hulking, unfinished cathedral—which, as one local author put it in 1489,
“seems to outline
the shape of the human body, lying down and spread out.”

It’s not hard to imagine Leonardo in the grips of this idea himself, entering the cathedral to study its form, pondering Brunelleschian ideas for the design of its great dome, and, as he wandered about, gradually finding himself overtaken by the eerie sensation that he was indeed
inside a giant body
. In the late 1480s, as Francesco and Villard had both done before him, he began to make associations between architecture and the human body, but he also discerned something new: specific anatomical correspondences, which in the late 1480s began to creep into his notebook doodlings (
Figure 34
).

Leonardo certainly had the human analogy in mind when he wrote his letter to the deputies of the cathedral of Milan. Like Filarete, he deployed it in the letter as a literary conceit. But privately, in his own investigations, he was also about to take things a step further. If architecture and the human body
were intimately related—as the ancient Greeks and Romans had declared, as so many Christian theologians had insisted, as the medieval master builders had made manifest in stone, and as Taccola, Alberti, Filarete, and Francesco had all demonstrated in their work—then as an artist, an architect, and even a natural philosopher, there was something he would have to do. More thoroughly than anybody had ever done before, he would have to investigate the nature and makeup of the human body, inside and out.

Figure 34.
Neck and skull, column and capital: visual analogies between anatomy and architecture, by Leonardo da Vinci (c. 1487).

A good painter
has two chief objects to paint: man and the intention of his soul. The former is easy, the latter hard.

—Leonardo da Vinci (c. 1490)

T
HE FROG JUST
wouldn’t die.

Gradually, methodically, Leonardo had removed its head, its heart, its intestines, and even its skin, but the animal still showed signs of life.

The year was 1487, and Leonardo’s investigations were proliferating with an almost Malthusian relentlessness. Architecture was on his mind: in his notebooks that year he played with a variety of ideas for the
tiburio
of the cathedral of Milan, and on page after page doodled a dreamy procession of arches and columns, domes and churches, temples and palaces. But he did much more. He roughed out preliminary studies for paintings and statues. He sketched people and animals, landscapes and
plants. He designed an ideal city and drew maps. Incessantly, almost involuntarily, he
invented
things: cannons, ditch diggers, a device for raising and lowering curtains, water pumps, flying machines, musical instruments, a parachute, stage props, underwater breathing devices, submarines. He explored aspects of physics and chemistry, wrestled with geometrical problems, collected observations on the nature of art. He jotted down fables, moral precepts, and jokes. He compiled lists of things to do, books to read, experts to seek out, and questions to ask. Always he sought ways of arriving at first causes—which is why he ended up taking apart that frog. He was interested in the frog’s anatomy for its own sake, of course, but he also had larger concerns. What made it possible for an animal to move? How did it generate warmth? What kept it alive? For that matter, what
was
life?

Leonardo was no stranger to the study of animal anatomy when he began working on his frog. For some time he had been studying the makeup of whatever animals he could get his hands on. Bats, bears, birds, dogs, hares, horses, monkeys, pigs, oxen, even lions: there’s ample evidence in his notebooks that in the late 1480s he dissected them all. He wanted to learn how animals were put together not just to satisfy his natural curiosity but also because he recognized that the better he understood the specifics of their design, the more beautifully and subtly he would be able to reproduce them in his art. Hoping to win the commission for the giant equestrian statue that Ludovico Sforza had long talked of erecting in Milan to honor his late father, for example, he devoted countless hours to the study of the proportions and anatomy of the horse. He scrutinized the anatomy of winged animals, too, but for a different reason:
because of the insights they promised him into the mechanics of flight. And in all of his investigations he sought out information about specific aspects of anatomy and physiology that related to his interests: the nature of the eye, which could shed light on his study of optics; the design of the heart and lungs, which powered hydraulic and pneumatic systems of marvelous efficiency; the layout and function of the various other organs, which worked together as a kind of chemical factory. Animal bodies were living machines, marvels of biological engineering, and Leonardo wanted to learn how the elegant architect of the world—which he tended to define simply as Nature rather than as a bearded, compass-wielding God—had constructed them.

With only one known exception, the animals Leonardo worked on shared a defining characteristic: they were all dead. Only in the case of the frog is he known to have inflicted suffering on a live animal—and in all likelihood he endured considerable moral anguish while doing it. According to Vasari, after all, he was a man who
“took an especial delight
in animals of all sorts, which he treated with wonderful love and patience.” He bought caged birds solely for the pleasure of setting them free, and, bizarrely for his time, adopted vegetarianism as a kind of personal philosophy.
“He would not kill a flea
for any reason whatsoever,” his friend Tommaso Masini would later recall; “he preferred to dress in linen, so as not to wear something dead.” In this respect Leonardo seemed almost Hindu, a thought that occurred explicitly to one Florentine traveler, Andrea Corsali, during a visit to India early in the sixteenth century. The Indians he had spent time with, Corsali reported in a letter home,
“do not feed on anything
that has blood, nor will they allow anyone to hurt any living thing, like our Leonardo da Vinci.”

Nevertheless, in the case of the frog, Leonardo’s curiosity got the better of him. Only by dissecting it alive, he decided, would he have any chance of finding answers to some of his most profound questions about animal vitality. And so, as dispassionately as he could, he proceeded to decapitate, dismember, and disembowel the poor creature.

The results surprised him greatly. “
The frog
,” he observed in his notes, “retains life for some hours.” Only when he pithed it, pricking its spine at the base of its skull, did the animal at last expire, in an involuntary spasm of nerves. “
The frog immediately dies
when its spinal medulla is perforated,” he wrote. “It thus seems that here lies the foundation of motion and life.”

This seemed a momentous discovery to Leonardo. And because he so often thought by analogy, it raised a natural question. If he could make this sort of discovery by studying the simple anatomy of a frog, then what far greater discoveries might he make if he were to venture inside the human body itself? Two years later, in 1489, he would get a chance to find out.

“
H
AVING PLACED IN
the supine position the body of one who has died from beheading or hanging, we must first gain an idea of the whole, and then of the parts.”

So declared the Bolognese physician Raimondo de’ Luzzi—better known as Mundinus—in 1316. The statement,
one of the earliest surviving references
to the practice of medical dissection in Europe, appeared in a brief treatise titled the
Anatomy
, a work that would become the standard textbook in northern Europe until well into the 1500s. By the late 1480s it was
circulating widely in manuscript and print form, and Leonardo knew it well.

Leonardo had been introduced to the superficial study of anatomy much earlier in his career, in Florence. All of the authorities he looked up to as a young apprentice agreed that a working understanding of the human anatomy was essential to the production of fine art. Verrocchio made his students study human proportions and sketch body parts, and sometimes even had his studio models dipped into molten wax in order to create lifelike molds. Alberti, for his part, had encouraged aspiring artists to adopt an inside-out approach.
“Sketch in the bones
,” he wrote in
On Painting
, “then add the sinews and muscles, and, finally, clothe the bones and muscles with flesh and skin.” The famous Florentine sculptor Lorenzo Ghiberti had offered similar advice some fifteen years later in his own influential commentary on art.
“It is necessary
,” he explained, “to have seen dissections, in order that the sculptor, wishing to compose a lifelike statue, knows how many bones are in the human body, and, in a like manner, knows the muscles and all the tendons, and their connections.”

Ghiberti chose his words carefully. What was important in his view was for artists to have
seen
dissections, not that they carry them out—and there’s no hard evidence that any artist before Leonardo actually did conduct any.

Leonardo and many other artists of his day are very likely to have attended dissections. Since the early 1300s, a number of universities in Italy and northern Europe had sponsored public dissections, generally one or two a year, each of which was generally carried out over the course of several days. This was the operating theater in its original sense, and Mundinus’s
Anatomy
often provided the script. Sitting or standing on an elevated podium in front of a large audience, a professor would read ponderously from the works of the great ancient and medieval medical authorities, while below him a lowly barber-surgeon (one of whose other main jobs in life, as a wielder of scissors and knives, was the bleeding of the sick) “illustrated” the lecture by slicing into the body of an executed criminal to reveal the parts of the body under discussion.

Leonardo had ample opportunity to attend public dissections not only in Florence but also in Milan and the nearby town of Pavia, all renowned centers of medical learning and practice. Guidelines established at the University of Tübingen in 1492, just a few years after Leonardo began his anatomical investigations, record how public dissections typically unfolded and make clear that dissection was not the taboo practice in medieval and Renaissance Europe that many authors have argued it was.
“The professor,” declared the guidelines
, “shall read from the writings of the Doctors, especially Mundinus, about the part of the body to be demonstrated. After discussion, each organ shall be shown plainly for inspection.” A memorable image of the scene survives from the same period in
a medical miscellany that Leonardo himself owned
—a work, needless to say, that contained the
Anatomy
of Mundinus (
Figure 35
).

Public dissections probably both fascinated and enraged Leonardo. Here were officially sanctioned opportunities to peer inside an actual human body (which Mundinus, true to medieval custom, identified as the
“microcosm
, that is, the smaller world”), but in Leonardo’s view the professors running the show wasted those opportunities year after year. They didn’t investigate or try to understand anything. Instead, in the pompous,
scholastic manner that so offended Leonardo, they delivered unthinking recitations of traditional learning, reading from the texts of Mundinus and other late medieval authorities, whose works themselves amounted to little more than a rehash of the medical writings of the Arabs and the Greeks, translated crudely into Latin in the twelfth and thirteenth centuries.