His collected speeches and essays, published as On Kabbalah and its Symbolism (1965), helped to spread knowledge of Jewish mysticism among both Jews and non-Jews.
他在《论卡巴拉及其象征主义》（1965）内所收集的演讲和散文，有助于在犹太人和非犹太人中传播有关犹太神秘主义的知识。