Abu al-Hasan Ali ibn Sahl Rabban al-Tabari (Persian: علی ابن سهل ربن طبری) (c. 838 – c. 870 CE; also given as 810–855 or 808–864 also 783–858), was a Persian Muslim scholar, physician and psychologist, who produced one of the first encyclopedia of medicine titled Firdous al-Hikmah ("Paradise of wisdom"). Ali ibn Sahl spoke Syriac and Greek, the two sources of the medical tradition of Antiquity which had been lost by medieval Europe, and transcribed in meticulous calligraphy. His famous student Muhammad ibn Zakariya al-Razi has darkened his fame. He wrote the first encyclopedic work on medicine. He lived for over 70 years and interacted with important figures of the time, such as Muslim caliphs, governors, and eminent scholars. Because of his family's religious history, as well as his relig