Abu Bakr al-Razi

Abū Bakr al-Rāzī, also known as Rhazes, 864 or 865 – 925 or 935 CE, 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, especially with regard to the concepts of prophethood and revelation. However, the religio-philosophical aspects of his thought, which also included a belief in five "eternal principles", are fragmentary and only reported by authors who were often hostile to him.