Marcus Vitruvius Pollio, born around 80 BC, served in the Roman army under Caesar and specialized in the design and construction of artillery machines. His duties took him to what are now Spain and France and as far away as North Africa. Vitruvius later became an architect and worked on a temple, no longer in existence, in the town of Fano in Italy. His most important work was literary, the only surviving book on architecture from classical antiquity: De Architectura, known today as The Ten Books on Architecture.

For many dark centuries, Vitruvius’s work had been forgotten, but in the early 1400s it was one of the many pieces of classical writing, including Lucretius’s epic poem On the Nature of Things and Cicero’s orations, that were rediscovered and collected by the pioneering Italian humanist Poggio Bracciolini. At a monastery in Switzerland, Poggio found an eighth-century copy of Vitruvius’s opus, and he sent it back to Florence. There it became part of the firmament of rediscovered classical works that birthed the Renaissance. Brunelleschi used it as a reference when he traveled to Rome as a young man to measure and study the ruins of classical buildings, and Alberti quoted it extensively in his treatise on architecture. A Latin edition was published in the late 1480s by one of Italy’s new print shops, and Leonardo wrote in a notebook, “Enquire at the stationers about Vitruvius.”

What made Vitruvius’s work appealing to Leonardo was that it gave concrete expression to an analogy that went back to Plato and the ancients, one that had become a defining metaphor of Renaissance humanism: the relationship between the microcosm of man and the macrocosm of the earth.

Leonardo embraced the analogy in both his art and his science. He famously wrote around this time, “The ancients called man a lesser world, and certainly the use of this name is well bestowed, because his body is an analog for the world.”

Applying this analogy to the design of temples, Vitruvius decreed that the layout should reflect the proportions of a human body, as if the body were laid out flat on its back upon the geometric forms of the floor plan. “The design of a temple depends on symmetry,” he wrote at the outset of his third book. “There must be a precise relation between its components, as in the case of those of a well-shaped man.”

Vitruvius described in great detail the proportions of this “well-shaped man” that should inform the design of a temple. The distance from his chin to the top of his forehead should be one-tenth of his whole height, he began, and proceeded with many other such notations. “The length of the foot is one sixth of the height of the body; of the forearm, one fourth; and the breadth of the breast is also one fourth. The other members, too, have their own symmetrical proportions, and it was by employing them that the famous painters and sculptors of antiquity attained to great and endless renown.”

Vitruvius’s descriptions of human proportions would inspire Leonardo, as part of the anatomy studies he had just begun in 1489, to compile a similar set of measurements. More broadly, Vitruvius’s belief that the proportions of man are analogous to those of a well-conceived temple — and to the macrocosm of the world — became central to Leonardo’s worldview.

After detailing human proportions, Vitruvius went on to describe, in a memorable visualization, a way to put a man in a circle and square in order to determine the ideal proportion of a church:

In a temple there ought to be harmony in the symmetrical relations of the different parts to the whole. In the human body, the central point is the navel. If a man is placed flat on his back, with his hands and feet extended, and a compass centered at his navel, his fingers and toes will touch the circumference of a circle thereby described. And just as the human body yields a circular outline, so too a square may be found from it. For if we measure the distance from the soles of the feet to the top of the head, and then apply that measure to the outstretched arms, the breadth will be found to be the same as the height, as in the case of a perfect square.

It was a powerful image. But as far as we know, no one of note had made a serious and precise drawing along these lines in the fifteen centuries since Vitruvius composed his description. Then, around 1490, Leonardo and his friends proceeded to tackle this depiction of man spread-eagle amid a church and the universe.

Francesco di Giorgio’s three Vitruvian Man drawings.

Francesco di Giorgio produced at least three such drawings that were designed to accompany his treatise and translation of Vitruvius. One of them shows a sweet and dreamy image of a man in a circle and a square. It is a suggestive rather than precise drawing. The circle, square, and body do not attempt to show proportions and are instead rendered casually. Two other drawings that Francesco made depict a man more carefully proportioned inside a design of circles and squares in the shape of a church floor plan.

Giacomo Andrea

Around the same time, another dear friend of Leonardo produced a drawing based on Vitruvius’s passage. Giacomo Andrea was part of the collaborative circle of architects and engineers gathered by Ludovico at the court of Milan. Luca Pacioli, a mathematician at the court and another close friend of Leonardo, wrote a dedication to an edition of his book On Divine Proportion that listed the distinguished members of that court. After hailing Leonardo, Pacioli adds, “There was also Giacomo Andrea da Ferrara, as dear to Leonardo as a brother, a keen student of Vitruvius’s works.”

Andrea produced a simple version of a spread-armed man in a circle and a square. Notably, the circle and square are not centered; the circle rises higher than the square, which allows the man’s navel to be in the center of the circle and his genitals to be in the center of the square, like Vitruvius had suggested. The man’s arms are stretched outward, Christ-like, and his feet are close together.

Giacomo Andrea’s Vitruvian Man.

Andrea would end up being killed and brutally quartered by French troops when they captured Milan nine years later. Shortly thereafter, Leonardo would search for and find his manuscript copy of Vitruvius’s work. “Messer Vincenzio Aliprando, who lives near the Inn of the Bear, has Giacomo Andrea’s Vitruvius,” he declared in a notebook entry.

In the 1980s, Andrea’s drawing was rediscovered. Architectural historian Claudio Sgarbi found a heavily illustrated manuscript copy of Vitruvius’s tome that was languishing in an archive in Ferrara, Italy. He determined that manuscript had been compiled by Andrea. Among its 127 illustrations was Andrea’s version of Vitruvian Man.

Leonardo’s Version

There are two key differences that distinguish Leonardo’s version of Vitruvian Man from those done around the same time by his two friends, Francesco di Giorgio and Giacomo Andrea. In both scientific precision and artistic distinction, Leonardo’s is in an entirely different realm.

Rarely on display, because prolonged exposure to light would cause it to fade, it is kept in a locked room on the fourth floor of the Gallerie dell’Accademia in Venice. When a curator brought it out and placed it before me on a table, I was struck by the indentations made by the stylus of Leonardo’s metalpoint pen and the twelve pricks made by the point of his compass. I had the eerie and intimate sensation of seeing the hand of the master at work more than five centuries earlier.

Unlike those of his friends, Leonardo’s drawing is meticulously done. His lines are not sketchy and tentative. Instead, he dug hard with his stylus, carving the lines confidently into the page as if he were making an etching. He had planned this drawing very carefully and knew precisely what he was doing.

Image: Getty

Before he began, he had determined exactly how the circle would rest on the base of the square but extend out higher and wider. Using a compass and a set square, he drew the circle and the square, then allowed the man’s feet to rest comfortably on them. As a result, per Vitruvius’s description, the man’s navel is in the precise center of the circle, and his genitals are at the center of the square.

In one of the notes below the drawing, Leonardo described additional aspects of the positioning: “If you open your legs enough that your head is lowered by one-fourteenth of your height and raise your hands enough that your extended fingers touch the line of the top of your head, know that the center of the extended limbs will be the navel, and the space between the legs will be an equilateral triangle.”

Other notes on the page provide more detailed measurements and proportions, which he attributed to Vitruvius:

Vitruvius, architect, writes in his work on architecture that the measurements of man are distributed in this manner:

The length of the outspread arms is equal to the height of a man.
From the hairline to the bottom of the chin is one-tenth of the height of a man.
From below the chin to the top of the head is one-eighth of the height of a man.
From above the chest to the top of the head is one-sixth of the height of a man.
From above the chest to the hairline is one-seventh of the height of a man.
The maximum width of the shoulders is a quarter of the height of a man.
From the breasts to the top of the head is a quarter of the height of a man.
From the elbow to the tip of the hand is a quarter of the height of a man.
From the elbow to the armpit is one-eighth of the height of a man.
The length of the hand is one-tenth of the height of a man.
The root of the penis [Il membro virile] is at half the height of a man.
The foot is one-seventh of the height of a man.

Despite what he stated, instead of accepting what Vitruvius had written, Leonardo relied on his own experience and experiments, as per his creed. Fewer than half of the twenty-two measurements that Leonardo cited are the ones Vitruvius handed down. The rest reflect the studies on anatomy and human proportion that Leonardo had begun recording in his notebooks. For example, Vitruvius puts the height of a man at six times the length of his foot, but Leonardo records it as seven times.

In order to make his drawing an informative work of science, Leonardo could have used a simplified figure of a man. Instead, he used delicate lines and careful shading to create a body of remarkable and unnecessary beauty. With its intense but intimate stare and the curls of hair that Leonardo loved to draw, his masterpiece weaves together the human and the divine.

The man seems to be in motion, vibrant and energetic, just like the four-winged dragonflies that Leonardo studied. Leonardo has made us sense, almost see, one leg and then the other being pushed out and pulled back, the arms flapping as if in flight. There is nothing static except the calm torso, with subtle crosshatch shadings behind it. Yet despite the sense of motion, there is a natural and comfortable feel to the man. The only slightly awkward positioning is of his left foot, which is twisted outward to provide a measurement guide.

To what extent might Vitruvian Man be a self-portrait? Leonardo was thirty-eight when he drew it, about the age of the man in the picture. Contemporary descriptions emphasize his “beautiful curling hair” and “well-proportioned” body. Vitruvian Man echoes features seen in many assumed portraits of him, especially Bramante’s depiction of Heraclitus, which shows Leonardo still beardless at about that age. Leonardo once warned against falling prey to the axiom “Every painter paints himself,” but in a section in his proposed treatise on painting called “How Figures Often Resemble Their Masters,” he accepted that it was natural to do so.

The stare of Vitruvian Man is as intense as someone looking in a mirror, perhaps literally. According to Toby Lester, who wrote a book about the drawing, “It’s an idealized self-portrait in which Leonardo, stripped down to his essence, takes his own measure, and in doing so embodies a timeless human hope: that we just might have the power of mind to figure out how we fit into the grand scheme of things. Think of the picture as an act of speculation, a kind of metaphysical self-portrait in which Leonardo — as an artist, a natural philosopher, and a stand-in for all of humanity — peers at himself with furrowed brow and tries to grasp the secrets of his own nature.”

Leonardo’s Vitruvian Man embodies a moment when art and science combined to allow mortal minds to probe timeless questions about who we are and how we fit into the grand order of the universe. It also symbolizes an ideal of humanism that celebrates the dignity, value, and rational agency of humans as individuals. Inside the square and the circle we can see the essence of Leonardo da Vinci, and the essence of ourselves, standing naked at the intersection of the earthly and the cosmic.