LEONARD LEWISOHN is Lecturer in Persian and Iran Heritage Foundation Fellow in Classical Persian and Sufi Literature at the University of Exeter, UK. His previous books include The Angels Knocking on the Tavern Door: Thirty Poems of Hafez (2008, translated with Robert Bly), Attar and the Persian Sufi Tradition: The Art of Spiritual Flight (I.B.Tauris, 2006, edited with Christopher Shackle), The Heritage of Sufism, vols 1-3 (1999) and Beyond Faith and Infidelity: The Sufi Poetry and Teachings of Mahmud Shabistari (1995).