One of the earliest pioneers in the history of medicine, Muhammad ibn Zakariya Al-Razi (also known by the Latinized version of his name, Rhazes or Rasis, 865–925 AD, 251–313 AH) was a Muslim Persian polymath, physician, and philosopher. He was born in the city of Rayy, near present-day Tehran, Iran, and spent most of his life between his birthplace and Baghdad, the capital city of the Abbasid caliphate. He taught medicine and was the chief physician in both cities. He made major and lasting contributions to the fields of medicine, music, philosophy, and alchemy and was the author of more than 200 books and treatises. The Secrets of the Medical Profession not only conveys a wealth of medical knowledge, but it also reflects Al-Razi’s own dedication to the profession and to human welfare in general. In the book, he makes available to the public the medical knowledge he acquired from reading the works of earlier physicians, including Hippocrates, as well as his own vast knowledge. He argued that the tendency among the physicians of his time to keep medical treatment secret would harm the spread of learning in general, and that it had turned medicine into a money-making profession, instead of a healing one.