Mystical movement of Islam that originated in the 8th century. Sufis emphasize the development of spiritual knowledge of God, and believe that deep intuition is the only real guide to knowledge. They follow the Shari’a (law of Islam), but are also trained through meditation and other spiritual practices to concentrate on a direct experience of God. The movement has a strong strain of asceticism (severe self-discipline), rejects material values, and emphasizes humility and kindness. Sufi leaders are called shaikhs. There are a number of groups or brotherhoods within Sufism, each with its own method of meditative practice, one of which is the whirling dance of the dervishes.