Abu Ali al-Husayn ibn Abd Allah ibn Sina, known in the West as Avicenna, wasa highly respected Persian physician whose medical treatise, the Canon ofMedicine, influenced medical practice for centuries. He was born near Bukhara, then the capital of the Persian Samanid dynasty and the intellectual center of Islam. Avicenna's father hired tutors to teach him the Koran and literature, and sent him to the greengrocer to learn arithmetic. So bright that his teachers soon had nothing left to impart to him, Avicenna continued his education on his own, instructing himself in astronomy, mathematics, philosophy, and medicine. At 16 he already had a reputation as an authority in legal and medical matters.

When the Samanid ruler Nuh ibn Mansur fell ill, Avicenna was asked to consultwith the court doctors. The ruler recovered, and Avicenna was offered a position at court as a physician, which gave him access to the royal library. Avicenna wrote his first book, a work on philosophy, when he was 21.

Following the death of his father, Avicenna acquired a government post. But in the wake of impending Samanid defeat at the hands of the Turks, Avicenna left Bukhara. He took up a series of court appointments in a variety of cities,working as a lawyer, physician, and administrator. He treated the Majd al-Dawla for depression, and the Buyid prince Shams al-Dawla for a bowel disorder.Employed by Shams al-Dawla as a physician and vizier, or high executive officer, Avicenna devoted his days to his prince and his nights to discussion sessions with his students that were often also occasions for musical performances and general merriment. Political intrigue shadowed Avicenna. For a time hewas forced into hiding, and once he was jailed.

Avicenna began his Canon of Medicine in 1012, and completed it a little more than a decade later, in 1023, in Hamadhan, in west-central Iran. His purpose in writing it was put together a clear, concise compendium of Greco-Roman scientific medicine. The Canon was translated into Latin by Gerardof Cremona (c.1114-1187) between 1150 and 1187. It became the standard European medical textbook for the duration of the Middle Ages.

The first part of the Canon defines the nature of the human body, health, illness, and medical treatment, and the causes and symptoms of disease. Disease is caused by humoral imbalance, bodily malformation, or dysfunction such as obstruction. Urine and pulse are a guide to the inner state of the body, and therapies include drugs, bleeding, and cauterization. Part two of the Canon deals with medicinal plants and the conditions they treat. Diseases of individual organs or systems are covered in the third part of the Canon. Part four deals with fevers. It also teachers minor surgery, and treatment of tumors, dislocations, poisons, and skin conditions, among other afflictions. The fifth and final part of the Canon is a guide to preparing medicinal compounds.

Critics of the Canon point out that also it was a reliable reference tool for answering certain questions, it did not represent genuine progress. The material on physiology and anatomy was not as well organized as the partson specific treatments and preparation of pharmaceuticals. In writing his compendium, Avicenna hoped to bring together the best of the ancient texts whilecorrecting their shortcomings, and to provide a working manual that would spare practitioners the need to do original research in physical science. But in discouraging investigation, the Canon held back medical progress. And some consider it outdated even at the time of its composition. All the same, Avicenna distinguished between diseases and their causes -- a major conceptual leap--and he knew that diseases are spread by water and soil, not only by"bad air." The Canon's materia medica (medical remedies) listed over760 drugs.

In 1023, the city of Hamadhan was attacked, and Avicenna fled to Isfahan. Lodged and welcomed by the ruler, Ala al-Dawla, Avicenna would spend the last 14years of his life there in relative peace. He continued his research in practice in medicine, noting that ice compresses effectively relieved headaches,and that sugar-rose preserves cured a woman of her tuberculosis. In January 1030, Isfahan fell to the Ghaznavids, and Ala al-Dawla and Avicenna evacuatedthe city. While on a campaign with al-Dawla, Avicenna suffered an acute abdominal attack and died. He was 57 years old.