Western scholars long maintained that the major contribution of Arabian medicine was the preservation of ancient Greek wisdom and that medieval Arabic writers produced nothing original. Because the Arabic manuscripts thought worthy of translation were those that most closely followed the Greek originals (all others being dismissed as corruptions), the original premise—lack of originality—was conﬁrmed. The strange story of Ibn an-Naﬁs (1210–1280; Ala ad-Din Abu al-‘Ala
‘Ali ibn Abi al-Haram al-Qurayshi-ad-Dimashqi Ibn an-Naﬁs) and the pulmonary circulation demonstrates the unsoundness of previous assumptions about the Arabic literature. The writings of Ibn an-Naﬁs were essentially ignored until 1924 when Dr. Muhyi ad-Din at-Tatawi, an Egyptian physician, presented his doctoral thesis to the Medical Faculty of Freiburg, Germany. If a copy of Tatawi’s thesis had not come to the attention of the historian Max Meyerhof, Ibn an-Naﬁs’ dis- covery of the pulmonary circulation might have been forgotten again. Some texts by Ibn an-Naﬁs that were thought to be lost were rediscov- ered in the 1950s.
Honored by his contemporaries as a learned physician, skillful sur- geon, and ingenious investigator, Ibn an-Naﬁs was described as a tire- less writer and a pious man. His writings included the Comprehensive Book on the Art of Medicine, the Well Arranged Book on Ophthalmology, and a Commentary on the Canon of Ibn Sina. According to biographers, while serving as Chief of Physicians in Egypt, Ibn an-Naﬁs became seriously ill. His colleagues advised him to take wine as a medicine, but he refused because he did not wish to meet his Creator with alcohol in his blood.
It is not clear how Ibn an-Naﬁs reached his theory of the pulmo-nary circulation, but he was known to be critical of Galenic dogma. Like Galen, Ibn an-Naﬁs could not conduct human dissection. In his Com- mentary, Ibn an-Naﬁs explained that religious law prohibited human dissection, because mutilation of a cadaver was considered an insult to human dignity. In the pre-Islamic Arab wars, victors sometimes deliber- ately mutilated the bodies of their enemies. Islamic law prohibited this ritualistic mutilation, and orthodox legal experts argued that scientiﬁc dissection was essentially the same violation of the dignity of the human body. It seems quite unlikely that the physician who refused to take wine to save his life would have acted against religious law and the dictates of his own conscience to satisfy scientiﬁc curiosity. During the twentieth century, some Muslim theologians reasserted this prohibition on the mutilation of cadavers in response to advances in organ transplantation. The general population seemed eager to accept organ transplants, but some religious authorities tried to forbid such procedures.
In the midst of a fairly conventional discussion of the structure and function of the heart, Ibn an-Naﬁs departed from the accepted explanation of the movement of the blood. His description of the two ventricles of the heart accepts the Galenic doctrine that the right ven- tricle is ﬁlled with blood and the left ventricle with vital spirit. His next statement, however, boldly contradicted Galen’s teachings on the pores in the septum. Ibn an-Naﬁs insisted that there were no passages, visible or invisible, between the two ventricles and argued that the septum between the two ventricles was thicker than other parts of the heart in order to prevent the harmful and inappropriate passage of blood or spirit between them. Thus, to explain the path taken by the blood, Ibn an-Naﬁs reasoned that after the blood had been reﬁned in the right ventricle, it was transmitted to the lungs where it was rareﬁed and mixed with air. The ﬁnest part of this blood was then clariﬁed and transmitted from the lungs to the left ventricle. Therefore, the blood can only get into the left ventricle by way of the lungs.
Perhaps, some still obscure Arabic, Persian, or Hebrew manuscript contains a commentary on the curious doctrines of Ibn an-Naﬁs, but there is as yet no evidence that later authors were interested in these anti-Galenic speculations. Thus, although Ibn an-Naﬁs did not inﬂu- ence later writers, the fact that his concept was so boldly stated in the thirteenth century should lead us to question our assumptions about progress and originality in the history of science. As only a small percentage of the pertinent manuscripts have been analyzed, the questions may go unanswered for quite some time.
A depiction of human anatomy in an Arabic text.