Abū Bakr al-Rāzī (full name: أبو بکر محمد بن زکریاء الرازي, Abū Bakr Muḥammad ibn Zakariyyāʾ al-Rāzī),[a] c. 864 or 865–925 or 935 CE,[b] often known as (al-)Razi or by his Latin name Rhazes, also rendered Rhasis, was a Persian physician, philosopher and alchemist who lived during the Islamic Golden Age. He is widely regarded as one of the most important figures in the history of medicine, and also wrote on logic, astronomy and grammar. He is also known for his criticism of religion, es