I picked up a book [The Illustrations from the Works of Andreas Vesalius of Brussels ed., Saunders & O'Malley] on Vesalius... [H]e cut the heart... to see the different cavities... in the 1500s. ...[T]he cardiac structure is the first example since Leonardo da Vinci showing the thickness of the walls and the shape of the cavities.

Dr Torrent-Guasp... formalized this description by indicating that the heart looked like a "rope"... [in] three parts: a beginning and an end at the and ; a wraparound loop called a basal loop; and... a helix that he called the apical loop. ...He described a [billion year old] worm... with a vascular tube... like a rope, with a venous and an arterial system. ...[F]ish evolved to show the first generation of a heart, containing a single pumping chamber, and included gills... [Next] the amphibian and the reptile appeared, in which we observe an atrium and a ventricle. Each chamber was separated by an atrial and ventricular septal defect. Human beings developed... [later] and both the atrial defect and the ventricular defect are closed.

There have been, of course, many other insatiable polymaths, and even the Renaissance produced other Renaissance Men. But none painted the Mona Lisa, much less did so at the same time as producing unsurpassed anatomy drawings based on multiple dissections, coming up with schemes to divert rivers, explaining the reflection of light from the earth to the moon, opening the still-beating heart of a butchered pig to show how ventricles work, designing musical instruments, choreographing pageants, using fossils to dispute the biblical account of the deluge, and then drawing the deluge. Leonardo was a genius, but more: he was the epitome of the universal mind, one who sought to understand all of creation, including how we fit into it.

[T]he heart... is, in reality, a that contains an apex. The cardiac helix form... was described in the 1660s by Lower as having an apical , in which the muscle fibers go from outside in, in a clockwise way, and from inside out, in a counterclockwise direction.

While at Windsor Castle looking at the swirling power of the “Deluge drawings” that he made near the end of his life, I asked the curator, Martin Clayton, whether he thought Leonardo had done them as works of art or of science. Even as I spoke, I realized it was a dumb question. “I do not think that Leonardo would have made that distinction,” he replied.

[N]ot only does the fingertip have a spiral, but [there is] the spiral at the tip of your heart. Perhaps the tip of your heart is your apical fingertip. ...The ventricle, which is the beating part of the heart, has a spiral... it goes from inside-out, and outside-in. That spiral is very typical. It goes down to the apex of the heart, the tip of the heart, which is a vortex. The thing that really makes the heart a part of an active way of living.

...the most sublime of oddballs, Leonardo da Vinci

William Harvey... who in England discovered the circulation... wrote this wonderful book called Anatomical Exercises... [S]uddenly he is here with the new idea of the circulation and some other ideas... He contradicted Vesalius who fitted to the Galenic system of ebb and flow concept. That's the twist and suction that the heart always has. Harvey says it didn't happen that way. It didn't dilate and take the shape of cupping glass and suck blood into it. Well, Harvey was a brilliant and wonderful person, but he wasn't perfect, and he was wrong. Because the heart does exactly what he said it didn't do.

Counterclockwise and clockwise spirals exist within our fingertips. ...[T]his harmonic pattern within our fingertips also occurs in our heart, where clockwise and counterclockwise spirals are evident at the apex [lower tip]... shown in 1864 by Pettigrew... [W]e look at the heart anatomically and observe the internal and external spiral loops ...previously called the bulbospiral and sinospiral loops. Their infolding into the heart develops a pathway... similar to those that appear in the Handbook of Physiology and were made by Dr. . Their format characterizes a structural problem... called the of anatomy.

Leonardo was not always a giant. He made mistakes. He went off on tangents, literally, pursuing math problems that became time-sucking diversions. Notoriously, he left many of his paintings unfinished, most notably the Adoration of the Magi, Saint Jerome in the Wilderness, and the Battle of Anghiari. As a result, there exist now at most fifteen paintings fully or mainly attributable to him. Although generally considered by his contemporaries to be friendly and gentle, Leonardo was at times dark and troubled. His notebooks and drawings are a window into his fevered, imaginative, manic, and sometimes elated mind. Had he been a student at the outset of the twenty-first century, he may have been put on a pharmaceutical regimen to alleviate his mood swings and attention-deficit disorder. One need not subscribe to the artist-as-troubled-genius trope to believe we are fortunate that Leonardo was left to his own devices to slay his demons while conjuring up his dragons.

Look longer at the picture. It vibrates with Leonardo’s understanding that no moment is discrete, self-contained, frozen, delineated, just as no boundary in nature is sharply delineated. As with the river that Leonardo described, each moment is part of what just passed and what is about to come. This is one of the essences of Leonardo’s art: from the Adoration of the Magi to Lady with an Ermine to The Last Supper and the Mona Lisa, each moment is not distinct but instead contains connections to a narrative.

In addition to his instinct for discerning patterns across disciplines, Leonardo honed two other traits that aided his scientific pursuits: an omnivorous curiosity, which bordered on the fanatical, and an acute power of observation, which was eerily intense. Like much with Leonardo, these were interconnected. Any person who puts “Describe the tongue of the woodpecker” on his to-do list is overendowed with the combination of curiosity and acuity. His curiosity, like that of Einstein, often was about phenomena that most people over the age of ten no longer puzzle about: Why is the sky blue? How are clouds formed? Why can our eyes see only in a straight line? What is yawning? Einstein said he marveled about questions others found mundane because he was slow in learning to talk as a child. For Leonardo, this talent may have been connected to growing up with a love of nature while not being overly schooled in received wisdom.

To Leonardo a landscape, like a human being, was part of a vast machine, to be understood part by part and, if possible, in the whole. Rocks were not simply decorative silhouettes. They were part of the earth's bones, with an anatomy of their own, caused by some remote seismic upheaval. Clouds were not random curls of the brush, drawn by some celestial artist, but were the congregation of tiny drops formed from the evaporation of the sea, and soon would pour back their rain into the rivers.

Much as Leonardo da Vinci and other Renaissance artists used the revelations of human anatomy to help them depict the body more accurately and compellingly, so, too, many contemporary artists may create new forms of representation in response to revelations about how the brain works.