Death by burning at the stake has been a popular method of execution in the history of mankind, so the case of Spanish theologian Miguel Servet (29 September 1511 – 27 October 1553) would not be unusual beyond the prominence of the historical figure—the discoverer of pulmonary blood circulation. However, Servetus is a notable case for something else: his ideas were so persecuted that he was burned not once, but three times.
About this tragic figure there is much that is unknown, beginning with his origin and even his actual name. Rather than a historical fact, the proposed date for his birth is because September 29 is the day of Saint Michael, and it is a Catholic tradition to choose the name of newborns according to the saints. Historians argue about whether he was born in Villanueva de Sigena (Aragón) or in Tudela (Navarra), and if his change of name to Miguel de Villanueva after his first persecution was a return to his real surname or a tribute to his land. In other words, it’s not clear if the man persecuted was Miguel de Villanueva, alias Servet, born in Tudela; or if he was Miguel Servet, and wanted to mark his origin in Villanueva de Sigena.
The trajectory of his life was also peculiar. At the age of just 15 he left Spain to study law in France, where he would live most of his life. He travelled through Europe thanks to his work as secretary of the Franciscan friar Juan de Quintana, who became confessor and advisor to the Emperor Charles V. It was then, shocked by the luxury and corruption of the papacy, that he embraced the Protestant Reformation led by Luther.
However, he went much further in his propositions to what the Reformation tolerated. He studied the Bible in Hebrew and Greek, coming to the conviction that the official translation in Latin had distorted the doctrine. In 1531, he published his first book, whose title did not hide his intentions: in De Trinitatis Erroribus he challenged the dogma of the Trinity, which set both Catholics and Protestants against him. After changing his last name he went to Paris, where he studied medicine while teaching mathematics and astronomy.
The first one to understand respiration
In Paris, Servet inherited from the famous anatomist Andreas Vesalio the position of assistant in the dissections. His knowledge of the work of Galen—the Greco-Roman physician and philosopher whose theories prevailed at the time—was unrivalled. But once again he became entangled in problems: after a dispute with the university authorities, he emigrated again and settled in Vienne (in the southeast of France), where he worked as a doctor and proofreader.
At that time he entered into correspondence with Calvin, who led the Protestant Reformation in Geneva. However, the relationship was soon cut short; Servetus’ ideas so exasperated Calvin that he decided to ignore him, but in 1546 he wrote in a letter to a friend: “If [Servetus] comes here, if my authority is worth anything, I will never permit him to depart alive.”
Finally, in 1553, Servet published his most famous work, Christianismi Restitutio, a treatise on theology that nevertheless contained his investigations into medicine, since for him physiology revealed the divine connection of the human being. “He who really understands what is involved in the breathing of man has already sensed the breath of God and thereby saved his soul,” he wrote.
And indeed, Servetus was the first author in the West to understand respiration. Until then Galan’s theory had prevailed, according to which air travelled to the heart through the pulmonary vein to mix with blood, which then crossed from one ventricle to another through pores to be distributed throughout the organism. Servetus proposed instead that the pulmonary artery carried the blood to the lungs not only to nourish these organs, but also to collect air through capillaries, and the blood then returned through the pulmonary vein to the heart. In other words, there was no communication between the ventricles; the blood passed from one to another just prior to circulation through the lungs for aeration.
Condemned for his theological doctrine
Servetus’ theory, which proved correct, was received with deafening silence, not so his theological doctrine. Condemned by the Inquisition, he fled Vienne, where they had to settle for burning his effigy along with some blank books. But for some unfathomable reason, on the way to southern Italy he decided to stop in Geneva. There he was recognised, accused and sentenced to burn at the stake.
Calvin himself tried to commute his penalty to a more pious decapitation, but it was in vain: on 27 October 1553 Servetus was burned alive with a copy of his work tied to his arm.
Servetus would be burned still one more time: in 1942, the French collaborationist government under the Nazi occupation considered that the sculpture dedicated to him in Annemasse, next to Geneva, was a monument to free thought. The statue was removed and melted down by fire. It was restored in 1960, finally in more tolerant times.