The Seeds of Life

by Edward Dolnick

  We assume, for instance, that “new” is a word of praise, almost synonymous with “improved.” But that idea itself is new. Our forebears would have found it bewildering. Since all God’s works were perfect, nearly any change was suspect. We see old ideas as musty and perhaps irrelevant. They saw them as time-tested and stamped with the endorsements of unimpeachable authorities.

  The nearly unquestioned view in the 1500s and 1600s was that the world had declined since Eden, not just spiritually but intellectually as well. The Fall brought not only sin and death into the world but every sort of bad thing, from tiny to momentous. After the Fall, snakes turned venomous, roses sprouted thorns, and human insight dimmed.

  Nearly everyone believed that everything worth knowing had been found long ago. History did not progress but repeated the same cycles, endlessly. Only the names changed. “Again will Achilles go to Troy, rites and religions be reborn, human history repeat itself,” one scholar wrote in 1616. “Nothing exists today that did not exist long ago. What has been, shall be.”

  The very words that early modern scientists used to describe their quest reveal their reverence for the past. “To ‘dis-cover’ was to pull away the covering cloth, disclosing what may have been hidden, overlooked, or lost, but that was in any case already there,” explains the historian Darrin McMahon. “To ‘invent,’ similarly, was to access that inventory of knowledge long ago assembled and put into place: an invention was just a dis-covery, a recovery of an object forgotten.”

  LEONARDO DA VINCI WAS ONE OF THE EARLIEST OF THESE ASTONISHING, ambivalent revolutionaries, split in his own mind between a past he revered and a future he only dimly glimpsed. Starting in about 1490, he set down a series of extraordinary anatomical drawings in his notebooks.

  Sexual anatomy was a compelling part of the story Leonardo wanted to tell, but only a part. Characteristically, he set out to explore everything. His precise, beautiful drawings depicted almost all the muscle groups in the body, and bones and blood vessels and organs, as well as male and female genitals. “Virtually every drawing is the finest depiction of a particular structure to that date,” one scholar notes, “and in some cases for several centuries to come.”

  Leonardo’s sexual studies broke new ground, and at the same time they highlighted how little was known for sure. Even worse, much of what was “known” would later prove false. This is no reflection on Leonardo, who had one of the keenest eyes in world history. The human body is astonishingly complex; it is no wonder that its first explorers occasionally ventured off course. We think of Leonardo as modern, with his helicopters and submarines, but he lived in an age when science and medicine had barely advanced beyond ancient doctrines.

  It was a coincidence—although a coincidence that reflected a change in Europe’s intellectual climate that was destined to shake the world—that Leonardo made his first, revelatory drawings of the human body at almost precisely the same time that Columbus set out to explore a new world of his own. (Columbus’s discoveries—a continent that the ancients had never imagined, teeming with animals and plants they had not heard of—helped undermine the authority of Aristotle and other venerable writers. Every ordinary sailor on Columbus’s voyages, the great English scientist Robert Boyle observed, had seen “an hundred things that they could never have learned by Aristotle’s philosophy.”)

  In the early 1490s, Leonardo was about forty and had already mastered more fields than he could list. A decade earlier he had written a letter to the Duke of Milan seeking an appointment as a military engineer. Leonardo described his ideas for new sorts of cannons, tanks, and catapults. Then he added a kind of P.S.: “Also I can execute sculpture in marble, bronze, and clay. Likewise in painting, I can do everything possible as well as any other, whosoever he may be.”*

  Engineer, inventor, musician, painter, sculptor, Leonardo certainly conveyed the impression that he could do “everything possible.” His appearance was as eye-catching as his résumé. A man of “supernatural” beauty, in the words of one of his earliest biographers, Leonardo was tall and muscular, with long brown hair. He dressed almost entirely in pinks and purples, in satin and silk and velvet, his cloaks, caps, and leggings an exuberant contrast with the somber outfits of other men, and he traveled with a bevy of young, beautiful admirers.

  One of the most famous of his anatomical drawings, from around 1492, is a cutaway drawing of a man and woman having sex. Scattered on other notebook pages are drawings of male and female genitals, some on their own, some locked together, like doodles from the world’s most talented schoolboy. As if in testimony to Leonardo’s varied interests, the genitals share the pages with carefully rendered drawings of cranes, pulleys, and levers. Leonardo’s mirror-writing spills across the paper. (The writing, contrary to legend, is not especially hard to decode and would have been a poor way to record secrets. Apparently Leonardo took up backward writing as a sort of party trick when he was young, and then got in the habit.)

  The most detailed of the sex sketches looks as if Leonardo has somehow, with X-ray vision, drawn a couple making love. That could scarcely be, of course, but the drawing is not even a depiction of what you would see if you could freeze the action, take a scalpel, cut open a man and woman, and record the scene. The drawing shows not what Leonardo saw when he peeked inside the human body—he would not carry out his first human dissections, except in hit-or-miss fashion, until about a decade after this sketch—but what outdated texts told him he would see. His drawing serves less as a depiction of the body at play than as a guide to the medieval mind at work.

  FIGURE 4.2. Leonardo drawing, ca. 1492.

  Leonardo’s depiction of the penis, for example, is a hodgepodge of ancient Greek theories and medieval guesswork. The drawing shows two distinct channels within the penis, though in fact there is only one. As Leonardo drew things, the lower channel carries urine while the upper carries semen and connects with the spinal column. (The role of the testicles in all this was not quite clear.) The spinal connection reflected a Greek belief that, in the words of one ancient writer, “sperm is a drop of brain.”

  Leonardo’s transparent woman has design peculiarities of her own. For a start, she lacks ovaries. As if to make up for that oversight, she has a mysterious tube running from uterus to nipple. This nonexistent pathway, like the imaginary one supposedly running between penis and spinal column, reflected medical dogma. In the case of men, the notion was that sperm was refined from the blood and then made its way to brain, spine, and penis. In the case of women, the refining process transformed menstrual blood into mother’s milk. (The theory, dreamed up by the Greeks, was an attempt to explain why pregnant women and new mothers did not menstruate.)

  It was not all guesswork and misinformation. Leonardo did explain correctly, for the first time in history, how what he called the “soft and feeble” penis grows erect. At last, one of our detectives had happened on an actual clue! The conventional explanation had always been that the erect penis was inflated with air, like a beach ball or one of those New Year’s Eve noisemakers that uncurl to full length when you puff into it. (This belief was so widespread that, as late as 1671, one well-regarded sex and childbirth manual noted that “windy” foods—“beans and Pease and the like”—“will make the Yard stand.”)

  Leonardo contemptuously rejected such notions. “If an adversary says that such a large quantity of flesh has grown through wind causing the enlargement and hardness, as in a ball with which one plays, such wind gives neither weight nor density but makes flesh light and rarified.” But the penis was heavy and clunky, not light and airy. Certainly this odd appendage did not drift aloft like a flimsy and insubstantial balloon.

  Leonardo took up this mystery on several occasions. In the margin of a page that had nothing whatever to do with the genitals—the sheet contains a dazzlingly rendered drawing of the muscles in the lower leg and the tendons in the foot—he jotted down another objection to the standard view. “There would have to be a great wind to enlarge an
d elongate the penis, and make it as dense as wood.… Even if the whole body were full of air, there would not be sufficient.”

  FIGURE 4.3. Hanged man, by Leonardo.

  He had reached a different conclusion, perhaps as early as December 1479, when he witnessed the hanging of a Florentine assassin. Bernardo Baroncelli had thrust a knife into the chest of Giuliano de Medici, the brother of the city’s ruler, Lorenzo the Magnificent. Now he dangled from a rope, hands tied behind his back, while a boisterous crowd looked on. Leonardo sketched the dead man in a few swift lines. Alongside the drawing he jotted down several dispassionate notes: “a tan-colored small cap,” “a blue coat lined with fur of foxes’ breast,” “black hose.”

  Years later he recorded another observation, perhaps from this early scene or perhaps from another execution. The dead man had an erection. “Many die thus, especially those hanged,” Leonardo wrote. Why were the hanged hung? Leonardo sorted that out. Postmortem dissections of newly executed criminals resolved the mystery. “I have seen the anatomy [of these penises],” Leonardo wrote in a notebook, “all of them having great density and hardness, and being quite filled by a large quantity of blood.” Blood, not air. Case closed.

  This was a genuine advance, but Leonardo quickly passed onto other matters. Perhaps so straightforward a bit of engineering as male hydraulics held less intrigue than did flying machines and diving suits. Nor did the contemplation of sex speak to Leonardo’s aesthetic side. “The act of coitus and the parts employed therein are so repulsive,” he wrote in a notebook, “that if it were not for the beauty of the faces and the adornments of the actors and frenetic state of mind, nature would lose the human species.”*

  Leonardo’s professed disgust with humankind’s sexual apparatus may have been a bit one-sided. At times he described the penis with fond indulgence, as if he were speaking of an eager but exasperating employee. “It remains obstinate and goes its own way,” he wrote. “… Often a man is asleep and it is awake, and many times a man is awake and it is asleep. Many times a man wants to use it, and it does not want to; many times it wants to and a man forbids it.”

  As Leonardo described things, this was an organ that seemed more like a living animal. Moreover, “it appears that this animal often has a soul and intellect separate from a man; and it appears that a man who is ashamed to name or show it is in the wrong, always being anxious to cover up and hide what he ought to adorn and show with solemnity.”

  FOR ANATOMISTS IN LEONARDO’S DAY, THE FIRST PROBLEM WAS finding a body. Newly executed criminals were the usual subjects, but there were not enough of them to go around. Animals were easier to come by. Leonardo dissected whole menageries. Around 1490 he made a meticulous drawing of the muscles and tendons in a bear’s paw, for instance, as well as anatomical drawings of dogs and monkeys. At about this time, he managed to acquire a human leg, which he dissected and drew. He found a human skull, too, sawed it open, and produced a careful series of sketches.

  More than a decade would pass before Leonardo finally had a reliable supply of human bodies to dissect, from hospital patients who had died and whose bodies had gone unclaimed. On one winter’s day in the early 1500s, he sat at the bedside of an ancient, frail man in a hospital for the poor in Florence. “This old man, a few hours before his death, told me that he was over a hundred years old, and that he felt nothing wrong with his body other than weakness. And thus, while sitting on a bed in the hospital of Santa Maria Nuova in Florence, without any movement or other sign of any mishap, he passed from this life.”

  In the very next sentence, Leonardo noted coolly that “I dissected him to see the cause of so sweet a death.” (He found two problems, hardening of the arteries and cirrhosis of the liver. Neither had ever been described before.) In the same entry in his notebook, and in the same matter-of-fact tone, Leonardo recorded “the dissection of a child of two years, in which I found everything contrary to that of the old man.” Over the course of the next several years, now with both executed criminals and hospital patients to study, Leonardo plunged ahead. He would soon boast that he had dissected “more than thirty” corpses.

  At the best of times, dissection is a messy business. The 1500s were not the best of times. In an era before refrigeration and before the development of embalming techniques, this was, in the words of Leonardo’s first biographer, “inhuman and disgusting work.” A note that Leonardo wrote to himself before a trip in 1510 gives some hint of what his dissections involved and, incidentally, of his difficulty in confining himself to one project at a time. He reminded himself to pack forceps, a bone saw, and a scalpel (as well as “boots, stockings, comb, towel, shirts”), and he jotted down a few specific tasks. “Get hold of a skull.” For best results, “break the jaw from the side.” “Describe the tongue of the woodpecker and the jaw of a crocodile.”

  Unlike Leonardo’s sex drawings, which he made early in his career and which illustrated theories that other men had proposed, Leonardo’s later anatomical sketches rely on observations that he made himself. Presumably he took notes while he worked, but working in the dissecting room would have been more like drawing at a crime scene than in an artist’s studio. The grime-smeared first drafts vanished long ago. We have only the finished drawings, crowded but so clean and precise that we can hardly imagine Leonardo standing next to his wet, slick subjects and sketching by the light of a flickering candle.

  The very years in which Leonardo spent his days and nights manipulating lifeless flesh were also those when he painted images whose beauty would make them immortal. In Leonardo’s mind, at least, the anatomical drawings and the soft, subtle portraits bore a close connection. At the same time he was painting the Mona Lisa, for instance, Leonardo was cutting open the faces of corpses and dissecting the muscles of the mouth and lips, to sort out the secrets of the smile. “These I intend to describe and illustrate in full,” he wrote, “proving these movements by means of my mathematical principles.”

  Nor was that all. “It is noteworthy,” writes Kenneth Keele, a renowned Leonardo scholar and a physician as well, “that at about the same time as Leonardo was painting the Mona Lisa he was making his dissections of the pregnant uterus.” That dissection yielded perhaps the most famous of all Leonardo’s anatomical drawings. The sketch, based on Leonardo’s dissection of a woman who died when she was about five months pregnant, depicts a curled-up fetus in profile, with all ten toes carefully rendered, and a big, domed head and a tiny ear and a winding umbilical cord.

  FIGURE 4.4. Leonardo drawing, ca. 1510.

  We peek inside the opened-up womb as if at a stage set where, a moment before, the curtains have been pulled back. Keele believes that, at just this period, Leonardo’s various interests converged. “My interpretation of the smile of Mona Lisa,” he writes, “is that it subtly expresses the secret, which she has successfully kept for so long, that she is pregnant.”

  The stunning ink and red chalk drawing of an infant in the womb was one of hundreds of anatomical sketches that Leonardo made in a few intense years around 1510. The “notebooks” that include these drawings were really loose pages that were assembled years later. If Leonardo had a particular order or arrangement in mind, scholars have never been able to guess it. Most sheets are covered on both sides with beautifully rendered drawings and careful notes.

  Leonardo described his accomplishment proudly. “You who say it would be better to watch an anatomical demonstration than to see these drawings would be right,” he challenged, “if it were possible to see all the things the drawings demonstrate in the dissection of a single body.” But no single dissection could show the different levels of organization that Leonardo drew, with his cutaways, close-ups, and multiple vantage points.

  After Leonardo’s death in 1519, his anatomical sketches and notes disappeared from view. (Leonardo was a master of the art of procrastination, along with every other art.) He had enormous difficulty finishing projects, and though he had grand ambitions for a book on anatomy, he never publish
ed one, or anything at all, during his lifetime. He bequeathed countless manuscripts and artworks, including his anatomical drawings, to a young painter and protégé named Francesco Melzi. Over the course of fifty years, Melzi struggled to impose some order on this ingenious shambles. He paid little heed to the anatomical work. In time Melzi’s son inherited his father’s Leonardo collection and sold it.

  The anatomical sketches passed to an Italian sculptor. Eventually they wound their way to England. They landed at a suitably grand location, Charles II’s royal library. Even so, they lay neglected through the centuries, not only unpublished but seldom even glanced at. Not until 1796, almost three hundred years after Leonardo’s death, would the world see what he had found so long before.

  In the meantime, other anatomists had joined the quest. They did not have Leonardo’s discoveries to learn from, and they did not know that, when it came to the mysteries of sex and conception, this supremely confident thinker had struck an uncharacteristically modest note. “There is much that is mysterious,” Leonardo conceded briskly, and then he hurried on to more congenial topics.

  FIVE

  “DOUBLE, DOUBLE TOIL AND TROUBLE”

  LONG AFTER LEONARDO’S DEATH, ANATOMISTS CONTINUED TO have trouble finding human subjects to dissect. For centuries they relied on newly executed criminals for most of their raw material. This was mainly a matter of practicality—doctors needed bodies to study, and criminals, many of them isolated and friendless, had no say about whether they wanted their last act to play out on a dissecting table. Partly the story was even darker. Dissection was a fearful prospect, widely seen as too harsh an end to the life of an ordinary man or woman but a fitting finale to a criminal’s career of sin. (In England, in 1752, Parliament would make this reasoning official. The newly passed Murder Act decreed that a condemned murderer be dissected as well as hanged, in order “that some further terror and peculiar Mark of Infamy be added to the Punishment of Death.”)*