During the nineteenth century the majority of masskilim (Jewish intellectuals) in Germany appreciated only the “enlightened” aspects of Jewish religion. Mysticism was for them an obscure, retarded deviation from Judaism. When, where, how, and why did the rehabilitation of Jewish mysticism take place? This lecture will try to answer these questions. It will show that research of Jewish mysticism did not begin with Martin Buber and Gershom Scholem, and it was not connected with Zionism. A positive change of attitude toward Kabbala, Sabbetaianism, and Hassidism was a process which was taking place in Russia during the last third of the nineteenth century. It was carried out by Jewish scholars and writers of literature who were influenced by Russian modern mystical trends, which at that period were spreading in Russia and in other European countries.