To the Editor Zargaran 1 should be congratulated for his recent article in JAMA Cardiology reviewing the history of pulmonary circulation and going so far as the ancient Sassanid era to show that some ideas of pulmonary circulation predated in a thousand years the presentation of the lesser circulation in Miguel Serveto's "Christianismi Restitutio." In the article, Michael Servetus is presented as a "Spanish theologian," 1 and although Servetus is mainly known as a religious reformer with a dramatic end, burned at the stake in Geneva, he was actually a quite versatile writer interested in medicine, mathematics, astrology, and geography. 2 He learned medicine in Paris from Johann Guenther von Andernach, MD, and Jacobus Sylvius, MD, sharing dissection time with Andreas Vesalius, MD. 3 Then, he practiced medicine in Charlieu, France (1539-1541), and Vienne, France (1941-1953, and published a successful medical book, Syruporum Universa Ratio, that went through 6 editions. 2 In this book, he follows the predominant Galenic theory.Michael Servetus was a universal man who believed that all disciplines are deeply interrelated. A good model in our super specialized world!