Talmudic scholar and philosopher; flourished in Yemen about the middle of the twelfth century. He wrote a philosophical work in Judæo-Arabic, called "Bustan al'Uḳul," which he divided into seven parts: (1) the unity of God, (2) man as a microcosm, (3) the necessity of obedience to God, (4) repentance, (5) trust in God, (6) excellencies of the Messiah, (7) the future life. The author quotes Saadia, Baḥya ben Joseph, Solomon ha-Ḳaṭon, and Judah ha-Levi, speaking of the last two as men of his time. R. Gottheil supposes that this Nathanael was the father of R. Jacob b. Nathanael al-Fayyumi, who corresponded with Maimonides about a certain pseudo-Messiah, and to whom Maimonides addressed the "Iggeret Teman"; but Steinsehneider declares this identification doubtful.