Abū ʿAlī al-Ḥusayn ibn ʿAbd Allāh ibn Sīnā, called by the West Avicenna (c.980-1037), was mentioned here in the context of medicine. About 40 of the 240 surviving texts that he wrote (of a total of about 450!) deal with medicine. The encyclopedic Book of Healing and the Canon became standard textbooks for centuries.
The Canon assembled the best known medical knowledge to date, including Galen (129-c.200 CE) and Hippocrates (c.460-c.370 BCE) and adding a great deal of information that seems new to Avicenna. For instance:
The 'Qanun' is an immense encyclopedia of medicine. It contains some of the most illuminating thoughts pertaining to distinction of mediastinitis from pleurisy; contagious nature of phthisis*; distribution of diseases by water and soil; careful description of skin troubles; of sexual diseases and perversions; of nervous ailments. [George Sarton, Introduction to the History of Science]Another reason why Paracelsus would want to burn Avicenna: Paracelsus was advertising hjis reputation as an alchemist, and believed that with salt, sulphur and mercury you should be able to produce anything. Avicenna, however, was completely opposed to the idea of alchemy, rejecting the notion that man could improve on Nature.
One could still work with Nature, however. Besides dealing with disease and injury (such as explaining how to judge how much healthy tissue could be removed during an amputation or the removal of cancerous tumors), Avicenna promoted restoring health, not just treating disease. He believed in the importance of physical exercise, of a good diet, and of a healthful environment.
Among other innovations, he lays the groundwork for modern ophthalmology, even suggesting that the optic nerves cross over each other. He laid out careful ground rules for the preparation, administration, and testing of drugs.
It has been called "one of the most significant intellectual phenomena of all times."** The Canon of Medicine is an essential part of any curriculum that studies the history of medicine.
**Swiss tuberculosis expert, Arnold Klebs