Hai Gaon

Hai ben Sherira (Hai Gaon) was a theologian, scholar and the last of the Babylonian Geonim. He received his rabbinical training from his father, Sherira ben Hanina, who appointed him to be his successor as the Gaon (head) of the Yeshiva of Pumbedita. Prior to his appointment he also served with his father in the capacity of av bet din, jointly issuing rulings on halachic questions received from all corners of the Jewish world. He is credited with over 800 responsa, containing explanations of halachot and aggadata. He was familiar with the works of Plato and Aristotle as well as the Quran and the Hadit, but he strongly advised against the study of general philosophy.