Ibn al-Nafis ابن النفيس

1213–1288 CE

Arab physician (1213–1288 CE) who served as chief physician at al-Mansuri hospital in Cairo and made a defining discovery in the history of medicine: the pulmonary circulation of blood — the passage of blood from the right ventricle of the heart through the lungs for oxygenation before returning to the left ventricle. This discovery, published in his theological-philosophical novel Theologus Autodidactus and his comprehensive medical encyclopedia Sharh Tashrih al-Qanun, overturned Galen's millennium-old model of blood passing through invisible pores in the heart's septum. He was also a prolific author on ophthalmology, dietetics, and other medical subjects, producing a medical encyclopedia intended to supersede Ibn Sina's Canon of Medicine.

Why They Mattered

His discovery of pulmonary circulation was a defining breakthrough in the history of medicine, challenging Galenic orthodoxy that had dominated medical thought for over a millennium. This was not theoretical speculation but a conclusion reached through anatomical reasoning and clinical observation — he recognized that the septum between the heart's ventricles was too thick to allow blood to seep through, as Galen had claimed, and that blood must instead travel through the lungs. His willingness to contradict the ultimate ancient authority in medicine demonstrated the independent empirical spi…

Intellectual Role

Ibn al-Nafis held a crucial role in the field of medicine as a scholar and physician, most notably as the chief physician at the al-Mansuri hospital in Cairo. His approach to medicine was distinguished by his empirical methodology, which set him apart from his contemporaries who adhered more strictly to Galenic principles. In his seminal work 'Theologus Autodidactus', he integrated philosophical discourse with medical inquiry, fostering a holistic understanding of the human body that challenged classical orthodoxies. His emphasis on direct observation and dissection was revolutionary, as he s…

Legacy

A pioneer who placed anatomical observation above classical authority. His description of pulmonary circulation preceded William Harvey's complete description of blood circulation by nearly four centuries, and preceded Michael Servetus and Realdo Colombo's European descriptions of pulmonary circulation by three centuries. Manuscript evidence suggests his work may have been transmitted to European anatomists through Latin translations. His career exemplifies the culture of medical innovation at …