Abraham Abulafia

The ecstatic — prophet of "the Kabbalah of Names": letter-permutation, breathing, head-movements, chanting the alphabet into combinatoric trance until the knots of the soul untie. Tried to convert the Pope (Nicholas III died before the meeting; Abulafia narrowly escaped the stake), declared himself Messiah on and off, was banned by the halakhists — and his manuals (Chayei ha-Olam ha-Ba, Or ha-Sekhel) are the most explicit meditation instructions in the entire tradition. Moshe Idel's scholarship restored him from footnote to second pole of all Kabbalah: the theosophic Tree, and Abulafia's ladder of letters.