Martin Lings provides an excellent and authoritative introduction to the mystical movement of the Sufis based on his lifelong interest in Islamic culture. His explanation derives from a profound understanding of Sufism, and extends to many aspects which are usually neglected. His illuminating answer to 'What is Sufism?' gives a taste of the very subject matter itself. What do Sufis believe? What do they aim at? What do they do? Unlike other writers...