Purification of the soul is a principle that is central to understanding Islamic spirituality but despite this, relatively little has been written explicitly in the Islamic tradition regarding this discrete method of spiritual purification. This book examines the work of a scholar of this discipline, al-H?rith al-Muh?sib?, who lived and worked during the classical Islamic period under the Abb?sids. Although al-Muh?sib? was well known for his skills in many disciplines, including the Qur'?n, Prophetic narration and scholastic theology, it is his mastery in the field of Islamic spiritu