The mystical and interior current within Islam, devoted to direct experience of God through purification of the self, the remembrance of God, and love. From early ascetics it grew into great orders of master and disciple, produced poets read across the world, carried Islam into Africa and Asia, and remains in long tension with strict scriptural authority.
A man in Baghdad cried out that he was the Truth, and the religious authorities had him killed for it. Later Sufis did not read him as simply claiming to be God. They read the cry as the speech of a self so annihilated that only God remained. His judges heard blasphemy. That paradox sits at the heart of Sufism: a path inside Islam that aims to dissolve the self so completely that only the divine remains.