In what ways did al-razi both make use of and advance beyond ancient greek scientific and medical learning?

The Persian physician al-Razi (ca. 865-925), also known Rhazes, prepared compilations that were influential in Western medical for centuries. His monograph on smallpox and measles is still considered a medical classic. During the Middle Ages his most esteemed composition in the West was the concise handbook of medical science that he wrote for a ruler named Mansur, generally believed to be Mansure ibn ishaz, who was appointed governor of Ray in 903. Called by al-Razi the Kitab al Mansuri, the Latin translation was known in Europe as the Lieber de medicina ad Almansorem or Liber Almansoris, and its ninth book in particular formed part of the medical curriculum of almost every European university through the 16th century. Al-Razi's most important medical work, the Kitab al-Hawi, is a compilation of the notes on his thoughts, reading, and practice that he amassed throughout his entire medical life. Perhaps never intended to appear as a single book, it was assembled posthumously by al-Razi's friends and students. In consequence, though the complete title of al-Hawi in Arabic means "System of Medicine", the book lacks the unity of design that only its author could have given it. Because of its immense size, copies of this medical encyclopedia were always rare, and even in the Islamic world it was not until modern times that a complete Arabic text was compiled for publication.

Diet was a fundamental therapeutic procedure in al-Razi's medical methodology. He emphasized the importance of consulting the wishes of the patient concerning food, especially during the period of convalescence. Theoretically, no single factor in the treatment of the sick was more important to al-Razi that was the doctor-patient relationship. He stressed that a physician by a cheerful countenance and encouraging words should instill hopes of recovery in his pateien even ehen the practitioner doubted that the case could terminate successfully.