The well-known writer George Sarton says in his Introduction to the History of Science that “Rhazes was the greatest physician of Islam and the Medieval Ages.” And the Encyclopedia of Islam remarks that “Rhazes remained up to the 17th century the indisputable authority of medicine.” The Bulletin of the World Health Organization (WHO), May 1970, pays tribute to him by stating: “His writings on smallpox and measles show originality and accuracy, and his essay on infectious diseases was the first scientific treatise on the subject.”
Abu Bakr Muhammad Ibn Zakariya Al-Razi was born at the Persian city of Ray near modern Tehran, Iran in c. 864 AD. It is said that early in his life Al-Razi was interested in singing and music besides other professions. Because of his eagerness for knowledge, he became more interested in the study of alchemy and chemistry, philosophy, logic, mathematics and physics. But it was the field of medicine that he spent most of his life, practicing it, studying and writing about it. Due to his fame in medicine he was appointed head of the physicians of the Ray Hospital, and later put in charge of the Baghdad main Hospital during the reign of the Adhud-Daulah.

Al-Razi was an iconoclastic cosmologist, who denied that any man had privileged access to intelligence, whether by nature or from nature. Al-Razi, who, though a theist, rejects prophecy on the ground that reason is sufficient to distinguish between good and evil and also that reason alone can enable us to know Allah. He also denies the miraculousness of the Koran and preferred scientific books to all sacred books.
Al-Razi is considered to have been the greatest physician of the Islamic world. With reference to his Greek predecessors, Al-Razi viewed himself as the Islamic version of Socrates in Philosophy, and Hippocrates in medicine.

Al-Razi was a prolific author, who has left monumental treatises on numerous subjects. He has more than two hundred outstanding scientific contributions to his credit, out of which about half deal with medicine and twenty-one on Alchemy. He also wrote on physics, mathematics, astronomy and optics, but these writings could not be preserved. A number of his other books, including Jami-fi-al-Tib, Maqalah fi al-Hasat fi Kuli wa al-Mathana, Kitab al-Qalb, Kitab-al-Mafasil, Kitab-al-‘Ilaj al-Ghoraba, Bar al-Sa’ah, and al-Taqseem wa al-Takhsir, have been published in various European languages. About 40 of his manuscripts are still extant in the museums and libraries of Iran, Paris, Britain, and Rampur (India). His contribution has greatly influenced the development of science, in general, and medicine in particular.
The greatest medical work of Al-Razi (Rhazes), and perhaps the most extensive ever written by a medical man, is al-Hawi, i.e., the “Comprehensive Book,” which includes indeed Greek, Syrian, and early Arabic medical knowledge in their entirety. Throughout his life Al-Razi must have collected extracts from all the books available to him on medicine. In his last years, he combined these with his medical experience into an enormous twenty volume medical encyclopedia. Al-Hawi was the largest medical encyclopedia composed by then. It was translated into Latin under the auspices of Charles I of Anjou by the Sicilian Jewish physician, Faraj ibn Salim (Farragut) in 1279 and was repeatedly printed from 1488 onwards. Al-Hawi was known as ‘Continens’ in its Latin translation. “By 1542 there had appeared five editions of this vast and costly work, besides many more of various parts of it. Its influence on European medicine was thus very considerable.” (Arnold, T. Pg. 323-5).
Throughout his works he added his own considered judgement and his own medical experience as commentary. His contributions lie mainly in the field of ophthalmology, obstetrics, and gynecology, but he also dealt with diseases like stones in the kidney and bladder. Al-Razi wrote a monograph on children’s diseases – probably the first in the history of pediatrics. A special feature of his medical system was that he greatly favored cure through correct and regulated food. This was combined with his emphasis on the influence of psychological factors on health. He also tried proposed remedies first on animals in order to evaluate in their effects and side effects. Al-Razi was the first person to introduce the use of alcohol (Arabic Al-Kuhl) for medical purposes. He was also an expert surgeon and was the first to use opium for anesthesia. In surgeries, he was ahead of his contemporaries because he treated renal and bladder stones surgically.

Al-Razi was the first to give an account of the operation for the extraction of a cataract and also the first scientist to discuss the pupillary reaction or the widening and narrowing of the pupil of the eye. He explained that the reaction was due to the presence of small muscles that act according to the intensity of light. The current understanding on this subject confirms his work.
Kitab al-Mansoori, which was translated into Latin (known by the title ‘Liber Almansoris’) in the 1480s in Milan, comprised ten volumes and dealt exhaustively with Greco-Arab medicine. Some of its volumes have been published separately into German and French. The ninth volume of the translation made by Gerard of Cremona the “Nonus Al-Mansuri,” was a popular text in Europe until the sixteenth century. Al-Razi in Al-Mansoori devoted a whole chapter on anatomy. In it he has presented a detailed description of the various organs of the human body, and sensory and motor parts. He has also given elaborate descriptions of the intervertebral foramina and the spinal chord, and correctly asserted that an injury either to the brain or spinal chord would lead to paralysis of the parts of the organs whose nerve supply was damaged or destroyed.
In his Secret of secrets, he describes the chemical processes and experiments he had performed himself. He also gave in this book a description of a large number of chemical apparatuses. Al-Razi also compounded medicines and took keen interest in experimental and theoretical sciences. It is conjectured that he developed his chemistry independently of Jabir Ibn Hayyan (Geber), meaning all experimentation was in no way influenced by Geber or his conclusion. He has discussed several chemical reactions and also given full descriptions of and designs for about twenty instruments used in chemical investigations. His description of chemical knowledge is in plain and plausible language. One of his books Kitab-al-Asrar deals with the preparation of chemical materials and their utilization. Another one was translated into Latin under the name Liber Experimentorum. He went beyond his predecessors in dividing substances into plants, animals and minerals, thus in a way opening the way for inorganic and organic chemistry. By and large, this classification still holds. As a chemist, he was the first to produce sulfuric acid together with some other acids, and he also prepared alcohol by fermenting sweet products.

His contribution as a philosopher is also well known. The basic elements in his philosophical system are the creator, spirit, matter, space and time. He discusses their characteristics in detail and his concepts of space and time as constituting a continuum is outstanding.
In al-Judari wa al-Hasbah, Rhazes placed great importance in his skill as a medical observer.

The eruption of the smallpox is preceded by a continued fever, pain in the back, itching in the nose and terrors in the sleep. These are the more peculiar symptoms of its approach, especially a pain in the back with fever; then also a pricking which the patient feels all over his body; a fullness of the face, which at times comes and goes; an inflamed color, and vehement redness in both cheeks; a redness of both the eyes, heaviness of the whole body great uneasiness, the symptoms of which are stretching and yawning; a pain in the throat and chest, with slight difficulty in breathing and cough; a dryness of the breath, thick spittle and hoarseness of the voice; pain and heaviness of the head; inquietude, nausea and anxiety; (with this difference that the inquietude, nausea and anxiety are more frequent in the measles than in the smallpox; while on the other hand, the pain in the back is more peculiar to the smallpox than to the measles;) heat of the whole body; an inflamed colon, and shining redness, especially an intense redness of the gums.

The al-Judari wa al-Hasabah was the first treatise on smallpox and measles, and is largely based on Razi’s original contribution. It was first translated into Latin in 1565 and later into several European languages and went into forty editions between 1498 and 1866. It was translated into English by William A. Greenhill, London, 1848. Through his treatise Razi became the first to draw clear comparisons between smallpox and measles. With this European physicians could know easily determine measles from its deadlier counterpart smallpox allowing for easy inoculation
Educational assemblies spread throughout the Islamic world through a methodological system. They were sometimes sponsored by the state but most often by the scientists. This has always been their system. We know that a scientist is known by his assembly, his students, and followers, as well as by the influence he has on the following generations, as each of his pupils reflects him; therefore scientist are always careful to teach pupils in their assemblies in a special way different from other teachers.

Arab physicians’ way of teaching had its characteristics and Abu Bakr Al-Razi, maybe the physicians’ leader and one of the best physicians of his time to preserve for us in their writings the essentials that a physician should know well, and that teachers should engrave in the pupils mind.

These teachings were not just theoretical, but they came out of experience and practice, Abu Bakr Al-Razi was the best clinical physician, had no competitor in this field, beside being a good teacher of medicine and its writing. His book (The Guide or al-Fusul) is a good example. During his teaching sessions pupils crowded around him in circles according to the precedence of their joining these sessions. He used to present them patients and let them ask about the illness and try to diagnose it; if they failed he would intervene and give the final decision (Nagi, K. Pg. 30, 35).

Al-Razi’s educational assembly was of two kinds, one for theoretical teaching the other for the practical one (Nagi K. Pg. 25). Theoretical teaching took the form of debates between three groups of students; the group in the circle nearest to him were the more advance in learning and practice. Next came the second group of those with less experience and last came the third circle in which new students were grouped. He read to them, explained, argued and listened to their debates answering their queries. Whenever he detected an intelligent pupil he moved him to a circle nearer to him in which he had to spend three years. So he spent one year in each circle. During this period he was taught anatomy, physiology or organ properties and pathology.

As for the practical teachings, like during his theoretical ones, students placed hemselves in circles around the patient’s bed in the hospital. He explained to them rare cases one after the other. In this way Al-Razi used the patient as a book to be read daily and continuously to be able to understand the symptoms of his illness (Al-Samarai, K. Pg. 19).

The most important thing in this matter, is that the teacher explained to his pupils in the assemblies each case he examined and noted his questions and his observations in a special page. He started by asking the patient, and the pupils around him, asking his name, age, country of origin, trips and his illness, the date it started, place of pain and symptoms. He assured that the patient was the best person to explain the extent of what he feels. He also asked the patient about his family and its members, and whether they felt the same symptoms. (Ibn Abi Usabiah Pg. 732).

Muslim physicians were concerned with referring to experiment because it is the best witness to the correctness of an opinion. That is why Al-Razi mentioned in his book (The Characteristics of Things) many texts on experiment, “we add what we know by experiment and people know that we do not give our confidence to anything except after its test and experimentation”. Meaning Muslim physician were always sure that their proposed treatments were effective. (Olman, M. Pg. 125).

Al-Razi believes also that the skilled physician must have two characteristics together “one, he should be skilled in the scientific art of medicine and the other, he must have at the same time a lot of experiences” (Olman M. Pg. 126).

From this point of view, we find that Al-Razi was committed always to experiment as it is considered the principal criterion in judging things. As long as experiment is the criterion that the physician always resorts to “to distinguish between the truth and the falsehood in what concerns these characteristics that might be submitted to the denial of those who could not understand the aims of science” (Galal, M. Pg. 128).

Like other great scholars of Islamic history, Razi’s erudition was all embracing and his scientific work remarkable. The foregoing description represents only a part of the great legacy left by Al-Razi. He died in c. 930 AD. Razi’s portrait adorns the great hall of the Faculty of Medicine in the University of Paris.
Al- Razi was without a doubt the single most influential medical pioneer of medieval time. To this day many of his contribution (such anesthetics, Alcohol for sterilization and the removal of bladder stones surgically.) are still I use today. He procured man conclusions concerning the human body that only recently have been proven to be correct. He influence almost every part of medicine, as we know it.

(1) Nagi, K Al-Razi the Pioneer of Clinical Medicine P. 30, 35
(2) ibid. P 25
(3) Al-Samarai, K Who is Abu Bakr Al-Razi?, P. 19
(4) Ibn Abi Usaibiah, op.cit. P. 732
(5) Olman, M., Islamic Medicine., Arabic Translation by Y. Al-Kilani, Kuwait,P.125
(6) Ibid. P. 126
(7) Galal, M., The Arab Methodology of Scientific Research in Natural andCosmological Sciences, The Lebanese Publishing House, Beirut,
1972, P. 128.

(8) Max Mayerhof, “Science and Medicine”, in The Legacy of Islam by T. Arnold, The Arabic translation by Gorgeis Fathallah, Dar al-Taleia,
Beirut, 1972, P.423.