Biography of Ibn Al-Nafis (1213-1288)
He was born in 1213 in Damascus, Syria. He attended the Medical College Hospital (Bimaristan al-Noori) in Damascus. Besides medicine, Ibn al-Nafis was also learned in many other subjects, including Arabic literature, Fiqh (jurisprudence), Kalam (theology) and early Islamic philosophy. He became an expert on the Shafi`i school of jurisprudence and an expert physician.
In 1236, Ibn al-Nafis moved to Cairo, Egypt. He worked at the Al-Nassri Hospital, and subsequently at the Al-Mansouri Hospital, where he became the "Chief of Physicians". In 1242, by which time he was about 29 years old, he published his most famous work, the Commentary on Anatomy in Avicenna's Canon, which contained many new anatomical discoveries, most importantly the pulmonary and coronary circulations. Soon afterwards, he begun work on The Comprehensive Book on Medicine, for which he had already published 43 volumes by 641 AH (1243-1244 CE), by which time he was about 31 years old. Over the next several decades, he would write down notes for 300 volumes, though he was only able to publish 80 volumes before he died. Nevertheless, even in its incomplete state, The Comprehensive Book on Medicine was the largest encyclopedia up until that time, and still remains one of the largest medical encyclopedias to date.
Ibn al-Nafis grew up in a time of political turmoil in Syria and Egypt, during the Crusades and Mongol invasions. After the sack of Baghdad in 1258, Syria was soon temporarily occupied by the Mongol Empire in 1259, who were then subsequently repelled by the Egyptian SultanBaibars at the Battle of Ain Jalut in 1260. Like other traditionalist Muslims in his time, Ibn al-Nafis believed that these invasions may have been a divine punishment from God against Muslims deviating from the Sunnah. Between 1260-1277, he became the personal physician of Sultan Baibars.
Ibn al-Nafis died on 17 December 1288 CE (11 Dhu al-Qi'dah 687 AH), and posthumously donated his house, library and clinic to the Mansuriya Hospital.
Ibn al-Nafis was an orthodox Sunni Muslim and a scholar of the Shafi`i school of FiqhSharia (Islamic law). He wrote a number of works on philosophy, and was particularly interested in reconciling reason with revelation and blurring the line between the two. Unlike some of his contemporaries and predecessors, he made no distinction between philosophy and theology. Ibn al-Nafis adhered to the teachings of the Qur'an and accepted the authority of the hadiths, but required each hadith to be rationally (Islamic jurisprudence) and acceptable.
Ibn al-Nafis, who grew up in a time of political turmoil during the Crusades and Mongol invasions, commented on these conflicts and, like other traditionalist Muslims in his time, believed that these invasions may have been a divine punishment from God against Muslims deviating from the Sunnah. As a result, the falsafa, some of whom held ideas incompatible with the Sunnah, became targets of criticism from a number of traditionalist Muslims. On the other hand, Ibn al-Nafis, who was a traditionalist himself, made an attempt at reconciling reason with revelation in some of his works to show that there is harmony between religion and philosophy. Being a traditionalist, Ibn al-Nafis also disliked the misuse of wine as self-medication, while citing both medical and religious reasons against it, arguing that "I will not meet God, the Most High, with any wine in me." His image as a God-fearing and Sunnah-abiding religious scholar, an intelligent rational philosopher, and an accomplished medical physician, had a positive impression on both traditionalists and rationalists alike. The fact that Ibn al-Nafis' student was Abu Hayyan Al Gharnati, a famous Imam and Hafiz at the time, also appealed to traditionalists such as al-Dhahabi.
The Sharh al-Adwiya al-Murakkaba (Commentary on Compound Drugs) was a commentary on the last part of Avicenna's The Canon of Medicine concerning pharmacopoeia, which was written by Ibn al-Nafis sometime before he wrote his Commentary on Anatomy in Avicenna's Canon in 1242. The Commentary on compound drugs, however, did contain criticisms of Galen's doctrines on the heart and the blood vessels and dealt with the circulatory system to some extent. This work was later translated into Latin by Andrea Alpago of Belluno (d. 1520), who had lived in Syria for about 30 years before returning to Italy with a collection of medical Arabic books. A printed version of his translation was available in Venice from 1547.
Ibn al-Nafis' work on the pulse, where he criticized the Avicennian and Galenic theories and corrected them, was also translated into Latin by Andrea Alpago sometime before 1522 in printed in Venice in 1547.
It is known that Ibn al-Nafis' Commentary on Anatomy in Avicenna's Canon, which first described the pulmonary and coronary circulations, was also available in Venice as an Arabic manuscript,and it is believed that it may have also been translated into Latin by Andrea Alpago. Along with Latin translations of his Commentary on compound drugs Servetus was himself a Michael Servetus (d. 1553), Realdo Colombo (d. 1559) and William Harveynontrinitarian who is said to have been interested in Islam and familiar with the Qur'an. and his work on the pulse, it may have had an influence on the descriptions of pulmonary circulation given by (1578-1657).
Edward D. Coppola wrote:
"A possible way by which Ibn an-Nafis' theory of the pulmonary circulation could have reached the West [...] Andrea Alpago knew of Ibn an-Nafis, had read his exposition on the Vth canon of Avicenna, his exposition on the book of Samarcandi and was familiar with certain of Ibn an-Nafis' ideas concerning the cardio-vascular system. [...] It is possible that somewhere among the unpublished manuscripts of Andrea Alpago is to be found a rendering of Ibn an-Nafis' description of the lesser circulation. Certainly such manuscripts are extant. [...] It is possible that these and other manuscripts left by Andreas Alpago may yet come to light, and that among them we eventually may find a description of the pulmonary circulation by Ibn an-Nafis."
Joseph Schacht wrote:
"A possible influence of the theory of Ibn al-Nafis on the three sixteenth century authors in the light of what we now know of Andrea Alpago, cannot be ruled out any longer. [...] Servetus shows a specific knowledge of the theory of Ibn al-Nafis on whom he is dependent more than his two contemporaries; he made additions of his own, partly anatomical, partly theoretical, which recur, elaborated and partly modified, in Colombo. [...] Colombo probably had direct knowledge of the theory of Ibn al-Nafis."
During and after his lifetime, Ibn al-Nafis' 80-volume medical encyclopedia, The Comprehensive Book on Medicine, had eventually replaced The Canon of Medicine of Avicenna (Ibn Sina) as a medical authority in the medieval Islamic world. Muslim biographers, historians and reviewers from the 13th century onwards considered Ibn al-Nafis the greatest physician in history, with some referring to him as "the second Ibn Sina" and others considering him even greater than all his predecessors. Al-Dhahabi (d. 1348) and al-Isnawī (d. 1370) considered him "unsurpassed in medicine during his lifetime and unparalleled in his preparation of medicinal treatments and medical inferences", while the biographers Tāj al-Dīn al-Subkī (d. 1370) and Ibn Qadi Shuhba wrote:
"As for medicine, there has never been anyone on this earth like [Ibn al-Nafīs]. Some say that after Ibn Sīnā there has never been one like [Ibn al-Nafīs], while some say that he was better than Ibn Sīnā in practical treatment."
A number of later Arabic commentaries on The Canon of Medicine, including ones by Sadid al-Din Muhammad ibn Mas'ud al-Kazaruni in 1344 and Ali ibn Abdallah Zayn al-Arab al-Misri in 1350, understood and repeated Ibn al-Nafis' descriptions of the pulmonary circulation, suggesting that knowledge of his discovery was fairly widespread among Muslim physicians in the Islamic world.
Shortly after his Commentary on Anatomy in Avicenna's Canon was re-discovered in modern times, George Sarton, the "father of the history of science", wrote the following on the significance of Ibn al-Nafis' discovery of pulmonary circulation to the history of medicine:
"If the authenticity of Ibn al-Nafis' theory is confirmed his importance will increase enormously for he must be considered one of the main forerunners of William Harvey and the greatest physiologist of the Middle Ages."
Commentary on Anatomy in Avicenna's Canon
In 1924, an Egyptian physician, Dr. Muhyo Al-Deen Altawi, discovered a manuscript from 1242, titled Sharh Tashrih al-Qanun Ibn Sina (Commentary on Anatomy in Avicenna's Canon), in the Prussian State Library in Berlin while studying the history of Arab Medicine at the medical faculty of Albert Ludwig's University in Germany. This script is considered one of the best scientific books in which Ibn al-Nafis covers in detail the topics of anatomy, pathology and physiology. In this work, his experimental approach to physiology is evident as he writes:
"...In determining the use of each organ we shall rely necessarily on verified examinations and straightforward research, disregarding whether our opinions will agree or disagree with those of our predecessors."
Based on his anatomical knowledge, Ibn al-Nafis stated that:
"...the blood from the right chamber of the heart must arrive at the left chamber but there is no direct pathway between them. The thick septum of the heart is not perforated and does not have visible pores as some people thought or invisible pores as Galen thought. The blood from the right chamber must flow through the vena arteriosa (pulmonary artery) to the lungs, spread through its substances, be mingled there with air, pass through the arteria venosa (pulmonary vein) to reach the left chamber of the heart and there form the vital spirit..."
Elsewhere in his book, he said: ...
"The heart has only two ventricles ...and between these two there is absolutely no opening. Also dissection gives this lie to what they said, as the septum between these two cavities is much thicker than elsewhere. The benefit of this blood (that is in the right cavity) is to go up to the lungs, mix with what is in the lungs of air, then pass through the arteria venosa to the left cavity of the two cavities of the heart..."
In describing the anatomy of the lungs, Ibn al-Nafis stated:
"The lungs are composed of parts, one of which is the bronchi; the second, the branches of the arteria venosa; and the third, the branches of the vena arteriosa, all of them connected by loose porous flesh."
He then added:
"... the need of the lungs for the vena arteriosa is to transport to it the blood that has been thinned and warmed in the heart, so that what seeps through the pores of the branches of this vessel into the alveoli of the lungs may mix with what there is of air therein and combine with it, the resultant composite becoming fit to be spirit, when this mixing takes place in the left cavity of the heart. The mixture is carried to the left cavity by the arteria venosa."
Ibn al-Nafis' next most important discovery is coronary circulation, the second phase of the circulatory system. He was the first to realize that the nutrition of the heart is extracted from the small blood vessels passing through its wall. He wrote:
"Again his [Avicenna's] statement that the blood that is in the right side is to nourish the heart is not true at all, for the nourishment to the heart is from the blood that goes through the vessels that permeate the body of the heart..."
Ibn al-Nafis discovered a precursor to the "capillary circulation in his assertion that the pulmonary vein receives what comes out of the pulmonary artery, this being the reason for the existence of perceptible passages between the two." Capillary circulation was not known in Europe for several centuries until Marcello Malpighi in 1661.
Ibn al-Nafis rejected the incorrect Galenic theory on the pulse and instead proposed his own accurate theory of pulsation. Galen believed that "every part of an artery pulsates simultaneously" and that the motion of the pulse was due to natural motions (the arteries expanding and contracting naturally) as opposed to foced motions (the heart causing the arteries to either expand or contract). Ibn al-Nafis rejected this view after discovering that pulsation is a result of both natural and forced motions, and that the "forced motion must be the contraction of the arteries caused by the expansion of the heart, and the natural motion must be the expansion of the arteries." He notes that the "arteries and the heart do not expand and contract at the same time, but rather the one contracts while the other expands" and vice versa. He also recognized that the purpose of the pulse is to help disperse the blood from the heart to the rest of the body. Ibn al-Nafis briefly summarizes his new theory of pulsation:
"The primary purpose of the expansion and contraction of the heart is to absorb the cool air and expel the wastes of the spirit and the warm air; however, the ventricle of the heart is wide. Moreover, when it expands it is not possible for it to absorb air until it is full, for that would then ruin the temperament of the spirit, its substance and texture, as well as the temperament of the heart. Thus, the heart is necessarily forced to complete its fill by absorbing the spirit."
He writes several advantages to this theory, such as the following:
"To benefit the spirit by moving towards the heart sometimes, and at other times towards the arteries, and maintain its subtlety and substance, and not get [adversely] affected by ... a lengthy rest in the arteries."
"The heart must be extremely hot in order to generate properly the spirit from the blood and the cool air, and the arteries must be cold in nature ... Thus, if the spirit were to reside always in the heart, it would burn out because of the excessive heat, and if it were to reside always in the arteries, it would become cold and thick."
Other anatomical and physiological discoveries
While the most important discoveries in the Sharh Tashrih al-Qanun Ibn Sina (Commentary on Anatomy in Avicenna's Canon) were the pulmonary and coronary circulations, this work also contains many other discoveries and discredits many erroneous theories advocated in The Canon of Medicine by Avicenna (Ibn Sina) and Galen. Besides the examples given in this article, the Commentary on Anatomy in Avicenna's Canon contains numerous other discoveries, criticisms and corrections on the anatomy and physiology of almost every part of the human body, including the bones, muscles, intestines, sensory organs, bilious canals, esophagus, stomach, etc.
Ibn al-Nafis quotes another error made by Galen, who believed that "blood reaches the brainforebrain through the duramater which divides the vault longitudinally into two equal halves at the sagittal suture." Ibn al-Nafis criticized this theory and corrected it as follows: itself at the section called
"The blood permeates first to the back ventricle (hindbrain) then to the other two ventricles. Dissection confirms this and disproves what they say. The permeation of arteries into the cranium is well known not to be from the front ventricle."
Another example concerns an incorrect theory on the anatomy of the bilious canals that was supported by Galen and Avicenna, and later repeated by Leonardo da Vinci and even Vesalius during the early modern period. Ibn al-Nafis was the only physician in pre-modern times to prove this theory wrong:
"He [Galen] claims that another canal goes from the gall bladder to the intestinal cavaties. This is completely wrong. We have seen the gall bladder several times and failed to see anything going from it either to the stomach or to the intestines."
Another correction he made concerned the incorrect Galenic and Avicennian theories of bones being present beneath the human heart. Ibn al-Nafis proved them both wrong through his own observations and wrote the following criticism on their theories:
"This is not true. There are absolutely no bones beneath the heart as it is positioned right in the middle of the chest cavity where there are no bones at all. Bones are only found at the chest periphery not where the heart is positioned."
Ibn al-Nafis made the following correction concerning human muscles, where he also briefly refers to his then forthcoming encyclopedia The Comprehensive Book on Medicine:
"The most important muscles of a human body total 529, details of which you will read in a book we are writing on medicine with full investigations into their shapes, functions, tendons, and origins. The forthcoming book will also contain details about proper anatomy since what is said about it here, is short and brief."
Ibn al-Nafis corrects another theory on the nerves stated by Avicenna, who believed that the glossopharyngeal nerve, vagus nerve and accessory nerve arise from the nerve ganglion and that they are attached to the sigmoid and facial nerves through membranous fascia so that these five nerves look like one nerve emerging as three branches from the back foramen lacerum. While examining this theory, Ibn al-Nafis performed the earliest known dissection on the human brain, after he wrote the following criticism on this theory:
"About what he [Ibn Sina] said concerning the sixth nerve being attached to the fifth through membranous facia, I have not so far found a good reason for that attachment, and I have not even verified it. This sixth pair [a confluence of the glossopharyngeal, vagus and accessory nerves] both arises and emerges from behind the fifth, so there is no way it could be attached to it."
Another example was Galen's incorrect theory on the optic nerve, in which he stated that the optic nerve "which comes from the right side of the brain goes to the right eye, and the nerve which comes from the left side goes to the left eye." Ibn al-Nafis also proved this theory wrong and stated:
"In fact it is not like that, [but] each nerve goes to the opposite side."
Embryology and Generation
Ibn al-Nafis criticized previous Aristotelian, Galenic and Avicennian explanations of embryology and proceeds to develop his own theories on embryology and generation. He believed that when a male and female semen mix, and when they create a mixed matter that has an appropriate temperament to receive an animal or human soul, God issues a soul to this matter, which then develops into an embryo that grows and generates organs. He further writes:
"Galen believes that each of the two semen has in it the active faculty to fashion and the passive faculty to be fashioned, however the active faculty is stronger in the male semen while the passive in the female semen. The investigators amongst the falasifa believe that the male semen only has the active faculty, while the female only has the passive faculty. ... As for our opinion on this, and God knows best, neither of the two semen has in it an active faculty to fashion."
He then shows that once the male semen and female semen are brought together in the womb, the female semen quenches the hot fire of the male semen through its own cool and wet nature. Once the two semen are mixed, he says:
"They modify one another’s temperament and [the mixture] obtains a temperament that is prepared for the emanation of the soul from their Supreme Creator."
Philosophy and Psychology
The commentary also dealt with the early Islamic philosophy and Muslim psychology related to Islamic medicine. Ibn al-Nafis developed his own theories on hylomorphic psychology and philosophy, mostly on a theological basis.
In particular, he made a distinction between the soul and the spirit, and he developed his own theory on the soul. He also crtiticized the ideas of Avicenna and Aristotle on the soul originating from the heart. Ibn al-Nafis rejected this idea and instead argued that the soul "is related to the entirety and not to one or a few organs." He further criticized Aristotle's idea that every unique soul requires the existence of a unique source, in this case the heart. Ibn al-Nafis concluded that "the soul is related primarily neither to the spirit nor to any organ, but rather to the entire matter whose temperament is prepared to receive that soul" and he defined the soul as nothing other than "what a human indicates by saying ‘I’."
He also identified the "psychic faculties" with cognition, sensation, imagination, and animal locomotion, and disproved Aristotle's notion that these come from the heart rather than the brain. After Ibn al-Nafis discovered that the brain and nerves are cooler than the heart and arteries, he argued that the psychic faculties come from the brain on this basis. He further wrote that it is the brain which controls sensation, movement and cognition.
The Comprehensive Book on Medicine
The most voluminous of his books is Al-Shamil fi al-Tibb (The Comprehensive Book on Medicine), a medical encyclopedia which Ibn al-Nafis begun immediately after he completed his Commentary on Anatomy in Avicenna's Canon in 1242. He had already published 43 volumes by 641 AH (1243-1244 CE). Over the next several decades, he would wrote down notes for 300 volumes, though he was only able to publish 80 volumes before he died in 1288. Even in its incomplete state, however, The Comprehensive Book on Medicine is one of the largest known medical encyclopedias in history, and was much larger than the more famous The Canon of Medicine by Avicenna. However, only several volumes of The Comprehensive Book on Medicine have survived.
To date, three surviving manuscripts comprising volumes 33, 42 and 43 of The Comprehensive Book on Medicine have been found in Damascus and at the Lane Medical Library of Stanford University. One of the three surviving manuscripts (MS Z 276) of The Comprehensive Book on Medicine is dedicated to surgery, and is divided into three talim. The first talim is twenty chapters in length and deals with the "general and absolute principles of surgery", the second talim deals with surgical instruments, and the third examines every type of surgical operation known to him. Only the first five chapters of the first talim has been translated into English and their contents are listed as follows:
- "On the role of the physician during the time of presentation, the time of operative
- "On the different stages of surgical operations, and the role of the patient in each stage"
- treatment, and the time of preservation"
- "On a detailed discussion of the role of the physician during the time of presentation"
- "On relating the things to which the physician should pay attention during the time of operative treatment"
- "On the patient's posture during surgical treatment"
Ibn al-Nafis states that in order for a surgical operation to be successful, full attention needs to be given to three stages of the operation. The first stage is the pre-operation period which he calls the "time of presentation" when the surgeon carries out a diagnosis on the affected area of the patient's body. The second stage is the acutal operation which he calls the "time of operative treatment" when the surgeon repairs the affected organs of the patient. The third stage is the post-operation period which he calls the "time of preservation" when the patient needs to take care of himself and be taken care of by nurses and doctors until he recovers "by the will of God". For each stage, he gives detailed descriptions on the roles of the surgeon, patient and nurse, and the manipulation and maintenance of the surgical instruments being used. The Comprehensive Book on Medicine was also the earliest book dealing with the decubitus of a patient.
Sections of the book also dealt with urology, including the issues of sexual dysfunction and erectile dysfunction. Ibn al-Nafis was one of the first to prescribe clinically tested drugs as medication for the treatment of these problems. His treatments were mainly oral drugs, though a few patients were also treated through topical or transurethral means.
Al-Risalah al-Kamiliyyah fil Siera al-Nabawiyyah (The Treatise of Kamil on the Prophet's Biography), also known as Risālat Fād il ibn Nātiq (The Book of Fādil ibn Nātiq), was the first theological novel, written by Ibn al-Nafis and later translated in the West as Theologus Autodidactus. This work is one of the first Arabic novels, the first science fiction novel, and the earliest example of a desert island story and coming of age story. This novel was written sometime between 1268 and 1277 CE.
The plot of this novel was the earliest example of a desert island story, a coming of age story, and a science fiction story. The protagonist of the story is Kamil, an autodidactic adolescent feral child who is spontaneously generated in a cave and living in seclusion on a deserted island. He eventually comes in contact with the outside world after the arrival of castaways who get shipwrecked and stranded on the island, and later take him back to the civilized world with them. The plot gradually develops into a coming-of-age story and then becomes the earliest example of a science fiction novel when it eventually reaches its climax with a catastrophic doomsday apocalypse.
knowledge of Ibn al-Nafis uses the plot to express many of his own religious, philosophical and scientific themes on a wide variety of subjects, including biology, cosmology, empiricism, epistemology, experimentation, futurology, geology, Islamic eschatology, natural philosophy, the philosophy of history and sociology, the philosophy of religion, physiology, psychology, and teleology. Ibn al-Nafis was thus an early pioneer of the philosophical novel. Through the story of Kamil, Ibn al-Nafis attempted to establish that the human mind is capable of deducing the natural, philosophical and religious truths of the universe through reasoning and logical thinking. The "truths" presented in the story include the necessity of God's existence, the life and teachings of the prophets of Islam, and an analysis of the past, present, and future, including the origins of the Homo Sapien species and a general prediction of the future on the basis of historicism and historical determinism. The final two chapters of the story resemble a science fiction plot, where the end of the world, doomsday, resurrection and afterlife are predicted and scientifically explained using his own empiricalbiology, astronomy, cosmology and geology. One of the main purposes behind Theologus Autodidactus was to explain Islamic religious teachings in terms of science and philosophy through the use of a fictional narrative, hence this was an attempt at reconciling reason with revelation and blurring the line between the two.
Ibn al-Nafis described the book as a defense of "the system of Islam and the Muslims' doctrines on the missions of Prophets, the religious laws, the resurrection of the body, and the transitoriness of the world." He presents rational arguments for bodily resurrection and the immortality of the human soul, using both demonstrative reasoning and material from the hadith corpus to prove his case. The novel also includes references to his new physiology and his theories of pulmonary circulation and pulsation, which he uses to justify bodily resurrection. Some have thus argued that it was his attempts at attempting to prove bodily resurrection that led him to his discovery of the pulmonary circulation. Later Islamic scholars viewed this work as a response to Avicenna's metaphysical claim that bodily resurrection cannot be proven through reason, a view that was earlier criticized by al-Ghazali.
The plot of Theologus Autodidactus was intended to be a response to Ibn Tufail (Abubacer), who wrote the first fictional Arabic novel Hayy ibn Yaqdhan (Philosophus Autodidactus) which was itself a response to al-Ghazali's The Incoherence of the Philosophers. Ibn al-Nafis thus wrote the narrative of Theologus Autodidactus as a rebuttal of Abubacer's arguments in Philosophus Autodidactus. Both of these narratives had protagonists (Hayy in Philosophus Autodidactus and Kamil in Theologus Autodidactus) who were autodidactic individuals spontaneously generated in a cave and living in seclusion on a desert island, both being the earliest examples of a desert island story. However, while Hayy lives alone with animals on a desert island for the rest of the story in Philosophus Autodidactus, the story of Kamil extends beyond the desert island setting in Theologus Autodidactus, developing into a coming-of-age plot and eventually becoming the first example of a science fiction novel. The purpose behind this changing story structure in Theologus Autodidactus was to refute Abubacer's argument that autodidacticism can lead to the same religious truths as revelation, whereas Ibn al-Nafis believed that religious truths can only be attained through revelation, which is represented through Kamil's interactions with other humans.
Theologus Autodidactus also contains some passages that are of significance to medicine, particularly physiology and biology, such as the following statement:
"Both the body and its parts are in a continuous state of dissolution and nourishment, so they are inevitably undergoing permanent change."
This is seen as the first example of the concept of metabolism, which is comprised of catabolism, where living matter is broken down into simple substances, and anabolism, where food builds up into living matter.
Theologus Autodidactus also criticizes the idea of wine being used as self-medication, an idea believed by ancient Greek physicians as well as some unorthodox Muslim physicians in his time, despite the Islamic prohibition of alcohol. The novel further argues that the consumption of alcohol, along with the prevalence of homosexuality among a small minority of Muslims at the time, were the cause of the Mongol invasions into Islamic lands as a divine punishment.
The novel also contains a reference to the pulmonary circulation which Ibn al-Nafis had previously described in his Commentary on Anatomy in Avicenna's Canon, which is briefly described by the character Kamil when he observes the heart:
"[Its] right ventricle is filled with blood and its left ventricle is filled with spirit."
Another passage has a reference to Ibn al-Nafis' theory of pulsation:
"Its left ventricle is filled with spirit, and this ventricle contracts, thereby sending this spirit in the arteries to the organs. Then it expands, and this spirit returns to it."
Ibn al-Nafis makes use of his new systems of anatomy, physiology and psychology which he had developed in his previous works in order to defend his views on bodily resurrection in Theologus Autodidactus. This may have been one of the reasons that initially motivated his discovery of the pulmonary circulation.
A Short Account of the Methodology of Hadith
Ibn al-Nafis wrote Al-Mukhtasar fi Ilm Usoulil Hadith (A Short Account of the Methodology of Hadith), a treatise on the science of hadith. The work is notable for its use of ijtihad (reason) in the evaluation of a hadith (narration or report) and its isnad (chain of transmission), unlike other contemporary hadith scholars, notably Ibn al-Salāh, who relied on traditional methods of classifying a hadith and its isnad. Ibn al-Nafis, on the other hand, sought to demonstrate the use of rationality and logic to classify the hadiths and to find whether there are any contradictions within them. Later traditionalists, however, disagreed with the use of reason in the science of hadith, including the hadith scholar al-Dhahabi and the polymath Ibn Khaldun, who argued that "there is no place for the intellect in them, save that the intellect may be used in connection with them to relate problems of detail with basic principles."
While traditional hadith scholars identified hadiths into three categories; sahih (sound), hasan (fair) and da'if (weak); Ibn al-Nafis instead classified them into four logical categories: decidedly true (maclūm al-sidq), probably true (yuz annu bihi'l-sidq), probably false (yuz annu bihi'l-kadhb) and decidedly false (maclūm al-kadhb). He used reason and logic to judge the veracity or falsity of a report:
"As for the report whose truthfulness is certain but not on account of the veracity of the reporter, [it is of the following types]: it may be congruous to a report known to be true. For example, if one reports something that is in agreement witha report of God, or the Prophet, or is something that [all] Muslims agree upon... Likewise, what is reported may be known to be true on account of its agreement with fact. The knowledge of that may be self-evident, for example if it is said that two is half of four, or that the whole is greater than the parts. Or it may not be self-evident, for example when one says that since we have a creator, the world must be created. As for the report that is known to be false, it may be due to knowing the truth about another report that contradicts it, either by being its opposite or by being incompatible with it. For example, if one reported something that contradicted the saying of God, or his Prophet or the saying of the consensus of Muslims. It may also be false if it is known to contradict facts. Knowledge of that kind could be theoretical speculation such as the reports that the innovators disseminate in texts on anthropomorphism... or it could be self-evidently false, for example if one were to say, ‘The part is greater than the whole!‘"
According to traditional hadith scholars of his time, all sahih hadiths, especially those reported in the canonical Sahih Bukhari and Sahih Muslim hadith collections, should instantly be classified as definitely true on the basis of a reliable isnad (chain of transmission). Ibn al-Nafis disagreed and instead classified most of those same sahih hadiths as "probably true" instead of "decidedly true", as he denied the absolute and unconditional validity of the sahih hadiths that was becoming the norm during his time. He argues thad, while a report emanating from Muhammad is always "decidedly true", most hadiths do not reach them directly from Muhamamd and so they can only be classified as "probably true" or "probably false" based on their isnad. He states that the only hadiths that are "decidedly true" are the multiply transmitted mutawatir (consecutive) hadiths. Since most sahih hadiths do not meet the criteria of mutawatir, he rejects the absolute soundness of the Sahih Bukhari and Sahih Muslim collections, placing a strong emphasis on mutawatir hadiths:
"As for the reports that are at our disposal now, most of what we adhere to are only highly probable [ghālib al-zann] and not indubitable knowledge [al-cilm al-muh aqqaq], contrary to [the majority of] people who say: “Everything that Muslim and Bukhārī agree upon is decidedly certain because the scholars agree on the soundness of these two books.” But the truth is that that is not the case! For the agreement is only over the permissible actions that are found in these two [texts], but that does not preclude what is in these two from being suspect in its soundness."
This was a view that was held by a majority of ulema (legal scholars) in his time, but this view was not shared by traditional hadith scholars in his time who did not differentiate between hadiths that were "sahih" and "mutawatir". Ibn al-Nafis further classified the da'if (weak) hadiths as "probably false", and the only hadiths he classified as "decidedly false" were the ones where there was a known liar among the chain of transmission, the ones contradicting a "definitely true" hadith, and the ones dealing with anthropomorphism:
"As for lies in the meaning of a hadīth, that is as if one said: “The messenger of God said such-and-such,” when the messenger of God actually said, “I do not say that.” Likewise, when something transmitted on the authority of the messenger of God seems absurd rationally [caqlan] or through law [sharcan], then it is permissible to interpret it and reduce it to a likely meaning."
With his emphasis on reason throughout the text, he wished to highlight the importance of ilm al-dirāya (content analysis) which was practiced by the early hadith scholars but was absent from the hadith scholarship of his time who put far more emphasis on isnad instead. He disagreed with their definition of a sahih hadith as a hadith from the canonical sahih collections, but instead he defined a sahih hadith as a "decidedly true" hadith that is "free from being challenged on account of its transmitters [rijālihi], its content [matnihi] and its meaning [macnāhi], while having a continuous chain of transmitters" and without any anthropomorphic content.
So far, the titles of at least 37 of his works are known, which add up to at least more than a hundred volumes in total, though only a fraction of his works have survived (or yet to be discovered) and even fewer have been printed (or translated).
A Summary of Medicine
Ibn al-Nafis' Al-Mujaz fi al-Tibb (A Summary of Medicine) was a 500-page book on medicine. Parts of the book dealt with otolaryngology, and one chapter in particular first described the ear infections otitis media and otitis externa. He described the latter as an "outer ear canal infection" where the "ear was painful and tender, slightly swollen and producing a smelly coloured discharge" and with a "degree of hearing impairment." It was here that he introduced the concept of dividing a condition into an early acute stage and a later chronic stage, which remains similar to modern classifications of ear diseases. In some of the preparations and remedies he described for their treatment, he introduced the use of vinegar, which is still used for ear infections in modern times.
The Choice of Foodstuffs
Another famous book, embodying a number of original contributions, was on the effects of diet on health, entitled Kitab al-Mukhtar fi al-Aghdhiya (The Choice of Foodstuffs). His approach to health placed a greater emphasis on diet, nutrition, and controlling the food consumed by a patient, rather than the prescriptions of drugs.
The Polished Book on Experimental Ophthalmology
Ibn al-Nafis wrote a large textbook on ophthalmology called The Polished Book on Experimental Ophthalmology in which he made a number of original contributions to the field. The book is divided into two sections: "On the Theory of Ophthalmology" and "Simple and Compounded Ophthalmic Drugs".
Ibn al-Nafis discovered that the muscle behind the eyeball does not support the ophthalmic nerve, that they do not get in contact with it, and that the optic nerves transect but do not get in touch with each other. He also discovered many new treatments for glaucoma and the weakness of vision in one eye when the other eye is affected by disease.
The most famous known work of Ibn al-Nafis is his 20-volume commentary on Avicenna's The Canon of Medicine, in which Ibn al-Nafis "elucidated the scientific problems, pointed out the logical conclusions, and explained the medical difficulties" in the text according to the biographers Umarī and al-Safadī. The most famous part of his commentary is the Sharh Tashrih al-Qanun Ibn Sina (Commentary on Anatomy in Avicenna's Canon), in which Ibn al-Nafis made his discovery of pulmonary circulation and coronary circulation. The other four surviving volumes of the commentary are called A Commentary on Generalities, A Commentary on Materia Medica and Compund Drugs, A Commentary on Head-to-Toe Diseases, and A Commentary on Diseases Which Are Not Specific to Certain Organs. In the first of these volumes, A Commentary on Generalities, he repeats his account of the pulmonary circulation.
He also wrote the Kitab al-Mujiz or Mujiz al-Qanun (Epitome of the Kitab al-Qanun), another work based on the Canon, but rather than a commentary, this was an edited version of the original Canon for medical students. The sections on anatomy and physiology, however, were removed from the text due to the inaccuracy of those segments, and he also did not include his own commentaries in this work, hence it has no mention of his descriptions on the pulmonary or coronary circulations. This work was popular in the Islamic world and was translated into several other languages, including Turkish and Hebrew, and several commentaries were written on his edited version of the Canon.
He also wrote a number of commentaries on the topic of medicine. His commentaries include one on Hippocrates' book, and several volumes on Ibn Sina's Qanun Fil Tibb (The Canon of Medicine). Additionally, he wrote a commentary on Hunayn ibn Ishaq's book. In his commentaries on Avicenna and his commentary on Hippocrates, entitled Sharh Fusul BuqratCommentary on Hippocrates' Aphorisms), he wrote an introductory note on them, making obvious his rebellious nature against established authorities as he states that he has decided to:
"throw light on and stand by true opinions, and forsake those which are false and erase their traces..."
Other medical writings
His other medical works include the Risalat al-A'ada'a (An Essay on Organs) and Al-Shamel fi al-Tibb (Reference Book for Physicians).
Ibn al-Nafis wrote a treatise on environmental science, which covered a number of subjects related to pollution, such as air pollution, water pollution, soil contamination, municipal solid waste mishandling, and environmental impact assessments of certain localities.
Fiqh jurisprudence and Sharia law
Ibn al-Nafis wrote several books dealing with Fiqh jurisprudence and Sharia law, including the Theologus Autodidactus and a commentary on Abu Ishaq al-Shirazi's Al-TanbeehExhortation).
One of his most famous books on law is Mujaz al-Qanun (The Summary of Law). He also wrote a number of other commentaries on the topic of law.
Ibn al-Nafis wrote two books on Arabic linguistics. One was his original work, Tareeq al-FasahaRoad to Eloquence), while the other was a commentary on the linguist Said bin al-Hassan al-Rab'i al-Baghdadi's Al-Fusous (The Segments)
Ibn al-Nafis wrote two books on logic in Islamic philosophy. One of these works deals with Avicennian logic as a commentary of Avicenna's Al-Isharat (The Signs) and Al-Hidayah (The Guidance). His other work on logic, Al-Wurayqat (The Little Papers), deals with Aristotelian logic as a commentary on Aristotle's Organon and Rhetoric.
His Theologus Autodidactus and A Short Account of the Methodology of Hadith also deal with the use of logic in Islamic theology.