An Anatomical Essay on the Movement of the Heart

By Jonathan Sawday ~

Originally published in Hidden Treasure: The National Library of Medicine, 2011.

William Harvey’s De motu cordis et sanguinis in animalibus is the single most famous exercise in medical research to have come down to us from the premodern age. In just seventy-two pages of somewhat cumbersome Latin prose, Harvey (1578–1657), the personal physician of King Charles I, dismantled centuries of Galenic medical dogma to present a new image of the body. Drawing on the observation of the still beating hearts of vivisected frogs, fish, dogs, and pigs, together with mathematical calculation and an elegantly simple experiment involving ligatures tied around a human arm, Harvey showed how blood flowed through the arteries and veins via the lungs, propelled by the contractions of the heart in systole. De motu cordis thus represented the triumph of the “new science” of the seventeenth century, a science in which observation and experiment took precedence over classical textual authority, no matter how ancient.

Except that it didn’t quite happen in that way. A conservative by nature, in setting out his ideas on circulation, Harvey was in some respects following well-trodden ground: the view that blood moved through the infamous “invisible pores” of the septum of the heart (a key element in the Galenic system) had been denied by the Paduan anatomist Realdo Colombo (1516–59) in the mid-sixteenth century; the pulmonary transit of the blood had been posited by Arabic authorities in the thirteenth century, and again by the Protestant heretic Michael Servetus (1511?–53) some seventy years before De motu cordis appeared. In fact, what Harvey believed he was doing was reasserting the primacy of Aristotle’s biological views. As explained in the crucial eighth chapter of De motu cordis, Harvey’s own Aristotelian view of the primacy of the heart and of the importance of circular motion rested, in the end, on a metaphorical view of the world, in which Nature (“who does nothing in vain”) endlessly replicates herself. Blood circulates in the body, Harvey claimed, in much the same way that the planetary bodies move in circles, or that moisture, warmed by the sun, circulates in the atmosphere. The heart was much more than a mere pumping mechanism. Instead, its “fiery heat” represented a “store of life…the sun of our microcosm.”

In restoring the heart to this quasi-mystical primacy Harvey, a Royalist, was also implicitly making a political statement. De motu cordis was extravagantly dedicated to King Charles, whom Harvey addressed as “the sun of his microcosm, the heart of the state.” The function of kings, hearts, and the sun was essentially the same: to spread life and succor (“power…and grace”) throughout their respective domains. In 1628, the year in which Harvey’s treatise appeared, the king had already embarked upon his disastrous confrontation with Parliament, which would lead to the eleven years of “personal rule” in which Charles attempted to govern the macrocosm of the state in much the same way that Harvey believed the heart “ruled” the body: in splendid isolation.

Jonathan Sawday is the Walter J. Ong, SJ, Chair in the Humanities in the Department of English at Saint Louis University. His books include The Body Emblazoned: Dissection and the Human Body in Renaissance Culture and Engines of the Imagination: Renaissance Culture and the Rise of the Machine. He is a Fellow of the Royal Historical Society, of the English Association, and of the Royal Society for the Arts.