Hasidism or Chasidism was a 17th-20th century Eastern European Jewish movement emphasizing feeling over intellect (compared to normative, legalistic Judaism). There were, however, earlier movements called Hasidic in Western Europe (i.e. Germany) sometimes referred to as Ashkenazi Hasidism. The movement in question, however, was started by the Baal Shem Tov (acronym = Besht) or Master of the Good Name. There are many magical tales about the Besht and his disciples (see books by Martin Buber, Aryeh Kaplan, and Elie Wiesel). Moshe Idel is a fine writer. His most famous work (taking issue with Scholem in a number of issues) is "Kabbalah: New Perspectives." Idel has no problem creating his own ideas and innovations. He has also written an impressive trilogy of works about the great ecstatic Kabbalistic master, Abraham Abulafia ("Language, Torah, and Hermaneutics in Abraham Abulafia," "The Mystical Experience in Abraham Abulafia," and "Studies in Ecstatic Kabbalah"). They are worth reading--especially the last one. Thus, Idel has delved deeply into ecstatic mysticism. This work might serve as an introduction into his works on Abulafia, but only to a degree. Those are much deeper, more difficult texts. This one could be read by the beginner or someone interested in Hasidism. My favorite quote in this book is: [referring to the Maggid of Koznitz who presented himself "as a servant that is standing before God ready to be sent"]"...consistent with the view of R. Levi Yizhoq, mainly that by annihilation one expands his capacity to receive the influx even more than before he annihilates himself" on page 317 (N106). This is reminiscent of both Eliade's "Shamanism" and Machik's "Chod" practices in Tibetan Buddhism (Vajrayana). As Jung reported in "Man and his Symbols," on page 102, when a Rabbi is asked, why no one sees God anymore, he replies - `no one can stoop so low.' Also quoted by Barbara Hannah in "Encounters with the Soul: Active Imagination" page 9 Sigo Press, Santa Monica, CA 1981