The Sufi Orders in Islam - Paperbackby J. Spencer Trimingham (Author), John O. Voll (Foreword by) Sufism, the name given to Islamic mysticism, has been the subject of many studies, but the orders through which the organizational aspect of the Sufi spirit was expressed has been neglected. The Sufi Orders in Islam is one of the earliest modern examinations of the historical development of Sufism and is considered a classic work in numerous sources of Islamic studies today. Here, author J.