The history of medical science is a testament to the gradual evolution of knowledge, where countless scholars contribute to theories that shape our understanding of the human body. One such ground breaking discovery—the pulmonary circulation—remained shrouded in misconceptions for centuries before its true mechanism was elucidated. While many names, including Galen, Michael Servetus, Realdus Columbus, and William Harvey, have been associated with this discovery, modern historical research confirms that Ibn al-Nafis (1213–1288), an Arab physician, was the first to accurately describe pulmonary circulation—three centuries before his European counterparts.
Let’s examine why Ibn al-Nafis deserves recognition as the true pioneer of pulmonary circulation.
The Historical Context: From Galen to Harvey
For over a millennium, the anatomical and physiological teachings of Galen, the Greco-Roman physician of the 2nd century AD, held almost undisputed sway across both Eastern and Western medicine. Galen’s schema, while pioneering for its time, contained significant inaccuracies, particularly regarding the movement of blood. He posited that blood was formed in the liver, then moved to the right ventricle, from where a portion seeped through “invisible pores” in the interventricular septum directly into the left ventricle. The remaining blood was believed to nourish the lungs via the pulmonary artery. This notion of invisible septal pores was a critical, yet unsubstantiated, pillar of his theory, necessary to explain how blood reached the left side of the heart without a clear understanding of its passage through the lungs. Galen’s model, while influential, lacked a coherent explanation for the full journey of blood, instead suggesting a perpetual “ebb and flow” rather than a true circulatory path, and importantly, failed to grasp the heart’s pumping action. This intellectual stasis persisted for centuries, a testament to Galen’s profound authority.
It was against this backdrop of established, yet flawed, wisdom that Ala ad-Din Abu al-Hasan Ali Ibn Abi-Hazm al-Qarshi, known to history as Ibn Nafis, emerged in the 13th century. Born near Damascus in 1213, Ibn Nafis developed into a physician of extraordinary caliber, eventually becoming chief of physicians at Cairo’s Al-Mansouri Hospital and the Sultan’s personal doctor. Yet, his most earth-shattering contribution lay largely forgotten until 1924, when his manuscript No. 62243, “Sharh Tashrih Al Qanun (Commentary on the Anatomy in Al-Qanun)”, was rediscovered in a Prussian state library. This manuscript unveiled a description of pulmonary circulation that pre-dated Western accounts by nearly 300 years, prompting historians like Aldo Mieli and Max Mayrhoff to unequivocally credit him as the true discoverer.
Galen’s Misconceptions (129-200 AD)
Galen, the Greco-Roman physician whose theories dominated medicine for over a millennium, proposed that blood moved from the right ventricle to the left through ‘invisible pores’ in the interventricular septum. He believed:
– The liver produced blood, which then travelled to the heart.
– The lungs merely cooled the blood.
– Blood seeped passively through tissues rather than circulating.
His model, though flawed, remained unchallenged for centuries.
The Islamic Golden Age and Ibn al-Nafis (1213-1288)
During the Islamic Golden Age (8th-16th centuries), scholars in the Arab world made significant scientific advancements, among them, Ibn al-Nafis, a Syrian-Egyptian polymath, emerged as a revolutionary thinker. In his Sharh Tashrih Al Qanun (Commentary on the Anatomy in Al-Qanun) (1242), [that was translated into Latin by the Italian physician Andrea Alpago in 1520] he refuted Galen’s theory and proposed:
- No Pores in the Septum:
– “The septum is thick and impermeable; there are no passages, visible or invisible.”
– This directly contradicted Galen’s claim that blood passed through the heart’s wall.
- Pulmonary Transit of Blood:
– Blood from the right ventricle must travel to the lungs via the pulmonary artery, mix with air, and return to the left ventricle via the pulmonary vein.
– “The blood is refined in the lungs before reaching the left ventricle.”
- Prediction of Capillaries:
– He theorized small passages (manafidhمنافذ – ) between pulmonary vessels—anticipating the discovery of capillaries by Malpighi (1661).
European Rediscovery: Servetus, Columbus, and Harvey
Centuries later, European scholars independently reached similar conclusions:
– Michael Servetus (1553) described pulmonary circulation in a theological work but was executed for heresy.
– Realdus Columbus (1559) and Andreas Vesalius also rejected Galen’s pores.
– William Harvey (1628) is often credited with discovering “systemic circulation”, but he himself acknowledged earlier influences.
Yet, none matched Ibn al-Nafis’s precision—his work was lost to Europe until 1924, when his manuscript was rediscovered in Prussian state library, Berlin.
Why Ibn al-Nafis Deserves Primary Credit?
- First Accurate Description
Ibn al-Nafis was the first to systematically dismantle Galen’s errors and propose a complete pulmonary circuit—long before Servetus or Harvey.
- Scientific Rigor
Unlike Galen, who relied on philosophical reasoning, Ibn al-Nafis used anatomical observations to justify his claims.
- Influence on Later Scholars
While direct transmission of his ideas to Europe remains debated, historians like Aldo Mieli and Max Meyerhof argue that his work likely influenced Renaissance anatomists through Arabic-Latin translations.
- A Forgotten Genius of the Islamic Golden Age
His contributions were overshadowed by Europe’s scientific Renaissance, but modern scholarship has restored his rightful place in medical history.
Restoring Ibn al-Nafis to His Rightful Place
Modern historians, with the benefit of rediscovering Ibn Nafis’s seminal work, have largely revised the narrative of discovery. Aldo Mieli proclaimed it “fair to attribute the discovery of the pulmonary circulation to Ibn Nafis,” recognizing him as a “distant precursor.” Max Meyrhoff noted that Ibn Nafis had “already noticed visible passages between the two types of pulmonary vessels” three centuries before Columbus. Edward Coppola underscored that Ibn Nafis’s theory “was not forgotten and that centuries after his death it may have influenced the direction of the anatomical investigations of Colombo and Valverde.” Dr. Abdul Rehman, among others, has unequivocally stated that “In 1242 Ibn Nafis was the first to describe human blood circulation and pulmonary circulation.”
The discovery of pulmonary circulation was not a sudden revelation but a cumulative effort across civilizations. While William Harvey’s work on systemic circulation was monumental, Ibn al-Nafis’s accurate description of pulmonary blood flow three centuries earlier marks him as the true pioneer.
His story also highlights the Islamic Golden Age’s contributions to science, often overlooked in Western narratives. By acknowledging Ibn al-Nafis’s genius, we honor not just a man, but an era where Muslim scholars preserved and advanced human knowledge.
Ibn al-Nafis’s Other Books:
Ibn al-Nafis was a prolific author. He had an outstanding memory and had written his books from memory without reference to other textbooks or compendia. His works can be divided into several categories:
Original contributions
- Kitab Al-Shamil fi al-Sina’a al-Tibbiyya (Comprehensive Book on the Art of Medicine).
- Kitab Al-Mukhtar Min al-Aghdiyah (Book of Selection of Nutrients).
- Al Muhadhab fi al-Kohl (The Polished Book on Ophthalmology).
- Bughyat al-Talibin wa Hujjat al-Mutatabbibin (Reference Book for Physicians).
Commentaries on Greek works
- Sharh Fusul Al Buqrat (Commentary on Hippocratic Aphorism).
- Ibidimiya li Buqrat wa tafsiruhu li al Amrad al Wafideh (Commentary on the Epidemiology of Disease by Hippocrates)
- Sharh Taqdimat Al-Ma’rifah (Commentary on Hippocratic Prognostics).
- Sharh Tabi’at al-Insan li Buqrat (Commentary on Hippocrates book “De Natura Hominis’ or Nature of Man).
Commentaries on Islamic medical works
- Kitab Mujaz al-Qanun (Commentary on Al Qanun fi al Tibb by Ibn Sina).
- Sharh Tashrih Al Qanun (Commentary on the Anatomy in Al-Qanun). In this book, he gives the earliest description of the pulmonary circulation.
- Sharh Mufrada Al Qanun (Commentary on Simple Medicines in Al Qanun).
- Sharh Masai’l Hunain (Commentary on Questions of Hunain Ibn Ishaq).
While the progression of scientific understanding is invariably a cumulative process, credit for foundational insights must be accurately attributed. The rediscovery of Ibn Nafis’s “Commentary on Anatomy in Avicenna’s Canon ” leaves little doubt. His categorical refutation of Galen’s septal pores, his logical deduction of the pulmonary transit of blood, and his astonishing prediction of capillaries, all articulated with remarkable clarity in the 13th century, establish him as the true and primary discoverer of the pulmonary circulation. The subsequent independent findings in Europe, while significant in their own right, served to re-establish and, in Harvey’s case, experimentally prove a truth that had been brilliantly conceived and meticulously documented by a forgotten genius of the Islamic Golden Age. Ibn Nafis stands as a powerful reminder that the torch of scientific inquiry has been carried across diverse cultures and eras, often by unsung heroes whose brilliance only much later receives its rightful recognition.
As historian Edward Coppola stated:
“Ibn al-Nafis was the first to describe pulmonary circulation—a fact now beyond dispute.”
Thus, history must remember that ‘The real discoverer of pulmonary circulation was Ibn al-Nafis’.
Thank you,
Ahmad Suhaib Nadvi
[Email: Laahoot.Media@gmail.com]
Laahoot Digest
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References:
– Meyerhof, M. (1935). Ibn al-Nafis and His Theory of the Pulmonary Circulation
– Haddad, S. I. (1936). A Forgotten Chapter in the History of Circulation.
– West, J. B. (2008). Ibn al-Nafis, the Pulmonary Circulation, and the Islamic Golden Age
– Sharh Tashrih Al Qanun (Commentary on the Anatomy in Al-Qanun) – Prussian state library, Berlin.
