The topic of Jewish mysticism is of increasing interest to the Russian-speaking readership, but, unfortunately, almost no reliable and scientifically based books on Kabbalah have appeared in Russian. The first complete Russian-language edition of the fundamental scientific work on the history and phenomenology of Kabbalah “The Main Currents in Jewish Mysticism” by Gershom Gerhard Scholem opens a new series of our publishing house: אΛΕΦ research in Jewish mysticism.” As part of the אΛΕΦ series, we plan to introduce the reader to Kabbalistic sources, as well as the most important scientific works of researchers from around the world. Hence the name of the series: the letter א Aleph, the first letter of the Hebrew alphabet, does not represent any sound, but potentially contains all twenty-two letters. According to many great mystics, it is in this letter, symbolizing silence, that the very essence of the Sinai Revelation is contained. We would like to thank all those who provided invaluable assistance in the preparation of this book: Prof. Moshe Idel and Prof. Yehudu Libesa from the Hebrew University of Jerusalem, as well as Prof. Havivu Pdaya from the University. Ben-Gurion in the Negev, whose consultations and advice accompanied us throughout the work on the book; Dr. Aryeh Samet from the Hebrew University of Jerusalem, who provided unique illustrations for this publication; Konstantin Burmistrova from the Russian State University for the Humanities, who took the trouble to review the manuscript and made a number of valuable comments.