Born in Berlin in the heart of an assimilated Jewish family, he studied mathematics, philosophy and oriental languages ​​before his doctorate from the University of Berlin with a thesis on the translation and commentary of a cabalistic text. He emigrated to Palestine, became part of the Hebrew University of Jerusalem from 1923 and there, from 1933 until his retirement in 1965, he devoted his education to Jewish mysticism and the Kabbalah. Considered the greatest twentieth-century scholar of Kabbalah, its history and its symbolism, was president of the Academy of Sciences and Humanities Israel. His works include titles like The Kabbalah and Its Symbolism (1985), Major trends in Jewish mysticism (1996), Basics of Judaism. God, Creation, Revelation, Tradition, Salvation (2000), "... it's cabal." Dialogue with Jörg Drews (2001), The secret names of Walter Benjamin (2004) and There's a mystery in the world (2006), the last four published in this same Publisher.