Moses de Leon Moses , original name Moses Ben Shem Tov (b. 1250, León [Spain]—d. 1305, Arevalo), Jewish Kabbalist and presumably the author of the Sefer ha-Zohar (“Book of Splendour”), the most important work of Jewish mysticism; for a number of centuries its influence among Jews rivaled that of the Old Testament and the Talmud, the rabbinical compendium of law, lore, and commentary. The details of Moses de León’s life, like those of most Jewish mystics, are obscure. Until 1290 he lived in Guadalajara (the Spanish centre of adherents of the Kabbala). He then traveled a great deal and finally settled in Ávila. On a trip to Valladolid, he met a Palestinian Kabbalist, Isaac ben Samuel of Acre; to him (as recorded in Isaac’s diary), Moses confided that he possessed the centuries-old, original manuscript of the Zohar, copies of which he had been circulating since the 1280s. He promised to show it to Isaac at his home in Ávila. Because the authorship of the Zohar was ascribed to the 2nd-century Palestinian rabbinic teacher Simeon ben Yoḥai (a reputed worker of miracles), the original manuscript would have been of incomparable interest and value. Unfortunately, Moses died before he could fulfill his promise, and Isaac subsequently heard rumours that Moses’ wife had denied the existence of this manuscript, claiming rather that Moses himself was the author of the Zohar. The Zohar, written for the most part in a strange, artificial, literary Aramaic, is primarily a series of mystical commentaries on the Pentateuch (the Five Books of Moses), in manner much like the traditional Midrashim, or homilies based on Scripture. Against the backdrop of an imaginary Palestine, Simeon ben Yoḥai and his disciples carry on a series of dialogues. In them, it is revealed that God manifested himself in a series of 10 descending emanations, or sefirot (e.g., “love” of God, “beauty” of God, and “kingdom” of God). In addition to the influence of Neoplatonism, the Zohar also shows evidence of the influence of Joseph Gikatilla, a medieval Spanish Kabbalist thought to have been a friend of Moses de León. Gikatilla’s work Ginnat egoz (“Nut Orchard”) provides some of the Zohar’s key terminology. These influences, although cunningly disguised, were discerned by Gershom Scholem, one of the great 20th-century scholars of Jewish mysticism, and he became convinced that the Zohar was a medieval work. He was able to demonstrate, further, that the Aramaic in which the Zohar is written is, in both vocabulary and idiom, the work of an author whose native language was Hebrew. Finally, by comparing the Zohar with the Hebrew works of Moses de León, Scholem identified León as the Zohar’s author. Scholem theorized that the Zohar was León’s attempt to combat the rise of rationalism among Spanish Jewry and the resultant laxity in religious observance. With the Zohar, according to Scholem, Moses de León attempted to reassert the authority of traditional religion (Kabbala itself means “tradition”) by simultaneously giving its doctrines and rituals a fresh, compelling reinterpretation and ascribing this reinterpretation to an old, mythically revered authority. Many traditional scholars, nevertheless, still hold that Simeon ben Yoḥai wrote the Zohar.