Rabbi Saadiah ben Yosef Gaon was a man of immense knowledge—and immense opinions.
Born in Egypt in the 10th century, the Saadiah Gaon was the first Jew to write extensively in Arabic, becoming the founder of Judeo-Arabic lit. In fact, his Arabic translation of the Torah is a relic of vast historical significance, not simply because it helped infuse Jewishness with Arabic culture, but also due to the Gaon’s pluralistic translation: the Arabic was clear and uncomplicated, meant to be understood by people of all classes.
But the Gaon’s most important contribution was his 933 C.E. treatise: Emunoth v’Deoth, or “The Book of Beliefs and Opinions.” This loftily titled tome was the Gaon’s defense of Rabbinic Judaism against Karaite dissenters. To the Karaite Jews, the only legal authority in Jewish law was the Tanakh itself—no Mishna, no Talmud, no Oral Law of any kind. They were, in a sense, literalists. The Book was a hit, becoming the first systematic integration of Jewish theology and Greek philosophy.
The Gaon’s proclamations didn’t simply rebuff the Karaites. He believed in reincarnation as essential to Judaism, believed the world was created for human benefit, and not just because God was bored, and believed that all animals killed for food would be rewarded in the World to Come, which is a super easy way to justify eating hamburgers.