Ibn Rushd was one of the greatest intellectual geniuses in human history. He was acquainted with all the sciences of his time and an authority in several of them-philosophy, jurisprudence, astronomy, and medicine. He became known in Europe under the name of Averroes, in particular for his brilliant commentaries on Aristotle which shaped European thinking throughout the later Medieval and early Renaissance periods. Here, we shall be reflecting mainly on his contribution to the study of human anatomy.
He was born in Cordova in 52OAH (1126) and named after his grandfather Abu al-Walid Muhammad ibn Ahmad ibn Rushd, who died in the same year. His grandfather was the Chief Judge in Cordova and the foremost authority in Maliki jurisprudence. To distinguish him from his illustrious ancestor, Ibn Rushd was later known as Ibn Rushd al-Hafid (the grandson).
Cordova, where Ibn Rushd grew up, was a thriving centre of all the diverse arts of civilization and culture attracting many great scholars from around the then known world to its wonderful libraries. Ibn Rushd studied and memorized the Qur’an and the Muwatta of Imam Malik. He was an excellent student of jurisprudence and quickly qualified to give legal opinions and sit as judge.
Following his work in the sciences of law, language and Hadith, he went on to study mathematics, astronomy and astrology and then medicine. He was a friend to the most prominent thinkers and writers of his age: Ibn al-Tufayl (d. 1186/6), author of the famous allegory Hayy ibn Yaqzan (said to have influenced Robinson Crusoe ); the philosopher, Ibn Bajja (Avempace in the West, d. 1139); the great jurist and judge Abu Bakr ibn al ‘Arabi (d. l148); the famous physician Abu Marwan ‘Abd al-Malik ibn Zuhr (Avenzoar in the West, d. 1161) and his son Abu Bakr (d. 1198).
Ibn Rushd served as a judge in Ishbiliya (Seville) in 1171 and then in Cordova two years later. His reputation for wide knowledge, correctness and fairness in giving verdicts, led to his appointment as Chief Judge. His book Bidayat al-mujtahid wa nihayat al-muqtasid (The reference for the searcher and the resort for the fair) remains an important reference for students of jurisprudence and is still taught in universities to this day. Although he was a Maliki he used the ideas of other schools of thought. Because he had so many activities and interests besides his public duties, Ibn Rushd had to organize his time very fully: he spent his days working as a judge, teaching, and in academic discussion with other scholars; he reserved his nights for reading and writing.
His friend Ibn al-Tufayl wrote to invite him to visit Marrakech, the capital of the Muwahhidun (Almohades) who had established a powerful and stable state in North Africa after they took over from the Murabitun (Almoravides), and were famous for their patronage of scientists, physicians, theologians and philosophers. Ibn Rushd’s intelligence, learning and ideas so impressed the ruler, Abu Yusuf ‘Abd al-Mu’min, that he was appointed to reform the educational system. This he did successfully before returning to Cordova.
When Abu Ya‘qub ibn ‘Abd al-Mu’min came to power, he appointed Ibn Rushd as his personal physician after Ibn Tufayl. Ibn Rushd held this post for a year (1183) when he was appointed as Chief judge. His success provoked court envy and he was falsely accused of heresy, in particular that he adhered too closely to the doctrines of Aristotle. He was indeed a supporter of Aristotle’s doctrines after these were properly reformed and adapted to Islam. Ibn Rushd fell out of favour at the court and was ill-treated. His books on philosophy were burnt, though his works on medicine and theology were not censored. When Abu Ya‘qub discovered he had been misinformed, he tried to invite Ibn Rushd back to apologise to him, but he was too late. Ibn Rushd died on 9th Safar 595AH (December 1198).
Ibn Rushd was broadly cultured indeed and wrote on many different subjects. Here we can mention only the most famous of his great works. In jurisprudence, as noted above, he wrote Bidayat al-mujtahid wa nihayat al-muqtasid (The reference for the searcher and the resort for the fair). In philosophy, he wrote Tahafut al-tahafut (refutation of the refutation), his response to Imam al-Ghazali’s famous Tahafut al-falsafa (refutation of philosophy). Ibn Rushd combined both philosophy and religion in mainly two books: Fasl al-maqal wa taqrib ma bayna l-shari‘a wa l-hikma min al-ittisal (an authoritative treatise on the convergence between the religious law and philosophy), and Kitab al-kashf ‘an manahij al-adilla fi ‘aqa’id al-milla wa ta‘rif ma waqa‘a fiha bi hasb al-ta‘wil min al-subah al-muzayyifa wa 1-bida‘ al-mudilla (an exposition of the methodology of demonstrating the creeds and description of the confusions and innovations in interpretation which confound truth and lead to error). In medicine, Ibn Rushd wrote the Kitab al-kulliyyat fi al-tibb (a general reference on medicine) which was translated into Latin and Hebrew and European vernaculars. It was a major reference in medicine though it never reached the standard of al-Qanun fi al-Tibb of Ibn Sina (Avicenna, d. 1037) which was used everywhere as simply T he Canon of Medicine.
Ibn Rushd had prepared this book especially for practising physicians and students of medicine. He apologised for the work’s brevity, a limitation he attributed to his preoccupation with commitments to judging, political affairs and philosophy. He advised those who sought greater detail to consult al-Taysir (The simplification) of Abu Marwan ‘Abd Al-Malik ibn Zuhr. Al-Kulliyyat is organized under seven broad headings or chapters:
Ibn Rushd criticized the physicians and students of medicine of his time for neglecting anatomy. His own presentation of the subject is both concise and precise. He divides it into two major areas:
a. Anatomy of ‘simple’ organs such as bones, flesh, and veins.
b. Anatomy of ‘compound’ organs-for example, the arm which comprises bones, flesh, veins, tendons, nerves etc.
His description starts with the bones of the head and the teeth.
There are six bones in the cranium and 14 in the upper jaw (the maxilla) and the ear, and two in the lower jaw (the mandible). All these bones are attached by seams except the two bones of the mandible that are articulately joined. This was later established as untrue-the mandible in fact has a single bone not two. The first to discover this was the physician and linguist ‘Abd al-Latif al-Baghdadi (Ibn al-Labbad). He examined 10,000 cadavers removed from the hills of al-Muqattam, east of Cairo, during the construction of a road. He realized this fact after observing thousands of examples. This was revealed in his wonderful book al-Ifada wa l-i’tibar fi l-umur al-mushahada wa l-ahwal al-mu‘ayana fi ardi Misr, (review and lessons from examinations and experiences in Egypt).
Ibn Rushd wrote of the teeth that there are 16 in each jaw-two central incisors, two lateral incisors and two canines, and five molars and premolars on both right and left sides. There are three or four roots in the maxilla but only two in the mandible, the remaining teeth have only one root.
He also described the large aperture in the back part of the skull, the foramen magnum, and its relation with the seven vertebra of the neck (cervical vertebrae), which have apertures on the sides. The vertebrae of the chest region are twelve; in the lumbar there are five, linked to the sacrum in which he counted three bones (in fact there are five) attached to the bone of the coccyx which is also composed of three attached vertebrae.
Ibn Rushd said that all vertebrae are articulate except the first two from the neck, because the first vertebra is attached to two appendices ramified from the skull.
He also said the bone of the sacrum is attached from the sides of the hips, in each of which is the acetabulum (socket) which contains the ‘head’ of the thigh bone (femur), often referred to as the ‘pomegranate’.
Ibn Rushd described in detail the bones of the front side starting from the clavicles up to the pubic bone, passing by the ribs and the bones of the shoulders. He also described the upper and lower limbs very precisely. What he wrote is not different from what we know today except that, for the bones of the arm, he uses ‘lower’ and ‘upper’ zanad (forearm) to mean the radius and the ulna. He indicated the bones of the leg, nowadays known as the fibula and tibia, in the same terms.
In the old days, the arteries were called the ‘beating veins’ (dhawarib ), and jugular veins were the ‘non-beating’ veins (ghayr al-dhawarib ). Ibn Rushd made a precise distinction between the two types of veins which remains accurate and valid. He wrote:‘Arteries come out of the heart whereas the jugular veins come back to it.’ He also described the difference precisely, the arteries are more solid and have two similar layers: the fibres of the inner layer are crosswise while the outer layer fibres are length-ways-even by modern standards a very professional anatomical description.
Two arteries of different size come out of the heart, the smaller one goes to the lungs and ramifies into them (pulmonary artery). The other (aorta) is larger, divided into many sections and ramifies into the whole body, one section going up to the head and upper limbs, another going alongside the vertebral column with branches leading to the chest and abdomen; it ends in the lower body and feeds the two lower limbs.
Ibn Rushd’s fascinating description is confirmed as correct and accurate. However, he failed to observe the circulation of the blood accurately. This was not properly described until nearly a hundred years later by Ibn al-Nafis (d. 1288) a Damascus-born physician who worked in hospitals in Cairo, and many centuries before William Harvey (1578-1657).
The nervous system is the most complicated organ in the human body and its anatomy has only gradually become known over recent centuries. Nevertheless, Ibn Rushd was able to describe the brain, its membranes and the cranial nerves. He describes the smelling nerve perfectly, pointing out that it ends with a nipple like that of the breast. He does not consider this nerve as the primary one, giving that distinction to the optical nerve. The first pair of nerves issue from the brain and form the sclera inside the cranium, then come out to the eyes each from its side. This is a wonderfully precise description.
Ibn Rushd then describes the nerves that feed the muscles of the eye. According to modern anatomy, these nerves are the third, fourth and sixth, but Ibn Rushd considers them all as the second pair that ramifies in the muscles of the eyes. He considers the third pair as related to the next (the fourth), and these feed areas of the face, the ear, the palate and the nose-in fact, he was writing about the fifth and seventh pair of nerves according to modern anatomy. As for the fifth, Ibn Rushd says that a part of it leads to the ears and the muscles of the cheeks, whereas this is identified as part of the seventh pair.
Ibn Rushd writes that the sixth nerve feeds the pharynx and the tongue and part of it leads to the muscles near and around the shoulder and another part deviates to the neck and a branch of that goes to the larynx. This is actually the eleventh nerve (the accessory nerve) and there is some confusion in Ibn Rushd’s account with the description of the tenth nerve (vagus; the wandering or confused nerve). Although he attributes many characteristics of the vagus nerve to the accessory one, Ibn Rushd is very accurate in the description of the characteristics themselves. He observes that some of the branches of this nerve lead to the chest and feed the heart, lungs, and esophagus; that it runs through the diaphragm and makes the link with the cardiac and liver membranes, the spleen and the rest of the intestines/bowels.
Ibn Rushd describes the seventh nerve as starting from the back of the brain and ramified in the tongue: he is describing accurately the twelfth nerve (hypo-glossal).
He describes as accurately as modern anatomy does, the nerves that go along the vertebrae. He mentions the eight pairs of cervical nerves, sixteen pairs of dorsal nerves, and five pairs of lumbar nerves.
He misses the correct number of the sacral nerves, they seemed only three to him because they are very closely attached-in fact they are five. Three nerves come from the bone of the coccyx and a single nerve comes out on the sides from the middle. This is absolutely accurate.
Ibn Rushd wrote;
‘The brain has two nipple-shaped appendices that grow from its two advanced abdomens (olfactory bulb). They reach the bone that resembles the cribrium (cribriform plate), which is perforated with many holes [i.e. like a sieve], not smooth but rough with its position in the cranium, where it reaches the end of the nose.’
It would be very hard to improve on the concision or accuracy of this account even today.
About the membranes of the brain, he wrote, again with wonderful, inspiring accuracy:
The brain has two membranes, one is hard and thick (dura mater), and the other is thin (pia mater), they cover the brain very closely and in some locations are completely joined. The thick one is adherent to the cranium. This membrane has many perforations in two places, the first at the canal at the end of the nose (cribriform plate), and the second at the bone of the palate. Under the brain on the thick cover, there is the mysterious net composed of veins that go up to the head.’
Ibn Rushd’s ability and competence as an anatomist is most clearly demonstrated in his description of the eye and its layers, which compares most favorably with what is known today except some minor differences in terminology. Ibn Rushd had even established the original development of the layers of the eye in the fetus, and discovered that they appear to imitate the layers of the brain and its membranes. Ibn Rushd combined accurate observation with brilliant exposition, sight with insight, presenting the structures of the eye as well as any twentieth-century expert could, and did so many centuries ahead of any physician in Europe.
The eye is composed of seven layers and three liquid areas. The first, from the side of the cranium, is a membranous layer that develops from the thick layer (sclera). The next layer from outside develops from the thinner membrane of the brain; it is called al-mashima (choroid). The next is a layer similar to the net (retina). It grows from the same nerve that comes out of the brain. In the middle of this layer, there is a soft and liquid area called al-rutuba al-zujajiyya (vitreous humour). Inside it, there is another spherical body but with some minor flatness. It is as clear as the ice and called al-rutuba al-jalidiyya , and we call it nowadays al- ‘adasa (lens).’
Ibn Rushd continues this wonderful description, by mentioning al-rutuba al-ma’iyya al-amamiyya (aqueous humour), he also called it al-rutuba al-baydhiyya because its liquid is similar to the soft liquid egg-white:
‘On the outside of this liquid appears a soft body whose inner texture is velvet-like, that follows the al-rutuba of baydhiyya (aqueous humour); smooth from the outside its colour is different from the body of the other, it can be very black or less dark or even blue.’ This is an extremely precise description of the iris (quzahiyyatu al-‘ayn) and the ciliary body (al-jism al-hudhabi).
‘Inside the ciliary body, next to the lens, a hole that widens and narrows depending on the extent of darkness that it needs, the hole is called hadaqa (pupil) and the membrane itself is called the inabiyya (grape- like) layer.
‘Next to this layer, a cover that has a hard and clear white and thin plate which is called al-qarniyya (cornea). It takes the colour of the layer below it. On the top of this rises a white body called al-multahim (conjunctiva).’
Ibn Rushd also wrote about the physiology of sight:
‘The sight is not a thing that comes out of the eye as Galinius used to think. The eye receives the colours through the reflecting objects in which they are held, in the same way as a mirror does. Once the colours are reflected in the eye, the object is then conceived by the visioning power.
‘This could well be proved in natural science (physics). That is why any of those parts of the eye is able to reflect the colours because of its very glossy surface. So that body is the special tool to the lens and the advantage of the qarniyya (cornea) is . . . [that] it is made clear and thin so that it does not prevent the ice-like liquid (lens) from receiving the images.’
This is an accurate description of the eye and the physiology of sight that does not differ much from what we know today.
From this brief dip into a chapter of al-Kulliyyat fi al-Tibb , we realize the importance of the work of Ibn Rushd-jurist, philosopher, physician. He was an expert in each of these fields and the most distinguished scholar in Spain and North Africa. He neither experienced nor discovered any contradiction between his religion and his science; rather, his quest for knowledge and excellence, his wonderful curiosity, enlightened and improved his faith. His famous observation- who practises autopsy, his faith in God increases -should silence the false allegation that Muslims never practised anatomy and that they are against applied sciences. What has been written by so many Muslims in all fields of knowledge refutes this allegations. Medicine and the other applied sciences are a necessary and essential contribution to the well-being of humankind. Therefore, to work in them is fard kifaya , a collective obligation upon the community of Muslims as a whole, an obligation which some members of the community must undertake on behalf of the others who cannot.
Islam is the guide for those who seek true and sound knowledge in every subject. All sciences, so long as they are directed to God and not to merely worldly ends or personal glory, bring their students closer to God and make easier the way to approach and please Him: Those who fear God, amongst his servants, are those who have knowledge. And God is the Guide to the straight path.