Maimonides' main philosophical work was called "The Guide for the Perplexed". He wrote it in Arabic by 1190. It has ideas from Aristotle's writings. "The Guide" influenced Christian Aristotelian theologians, for example, Thomas Aquinas. In 1168, Maimonides finished a commentary to the Mishnah, the written version of traditional Jewish oral law. Maimonides completed these books, called "Mishneh Torah", in about 1178. They are one of the most important collections of Jewish laws. 