Rabbi Abraham Ibn Ezra is one of the most important Jewish personalities of all time. Aside from being a Bible commentator of great consequence, his works in Jewish philosophy - though less famous - impacted many of his successors, including Maimonides' Guide for the Perplexed, Nahmanides, and Rabbi Joseph Albo, as well as the Jewish mystics and Kabbalists. The Yesod Mora is one of the first books of Jewish philosophy written in Hebrew, which blazed the trail for philosophy to enter those parts of the Jewish world that were unfamiliar with Arabic. Highlights of Ibn Ezra's Yesod Mora include the claim that we cannot properly understand the Bible and Talmud without studying logic, philosophy, and science; when we are obligated to accept standard rabbinic interpretations of verses, and when we are permitted to draw our own conclusions; the reasons for - and classification of - the commandments in the Torah; the composition of the soul according to Jewish philosophy; how we connect to God by achieving deveikut (communion) with God This edition of Yesod Mora is based on a version originally published in 1995, with additional notes and critical analysis. The original Hebrew text has been supplied as well. Editor, interpreter, and translator H. Norman Strickman is Rabbi emeritus of the Marine Park Jewish Center in Brooklyn and is a Professor emeritus of Jewish Studies at Touro College in New York City. He earned his ordination from Rabbi Dr. Joseph B. Soloveitchik and Rabbi Dr. Samuel Belkin of Yeshiva University. Dr. Strickman received his B.A. and M.H.L. degrees from Yeshiva University, and his Ph.D. from Dropsie University.