Marvels of the Heart is thought to be the key volume of the 40-book Ihya' 'Ulum-Al Din-Revival of the Religious Sciences-, the most read work in the Muslim world after the Qur€an, and considered by many to be the Summa Theologica of Islam. These traditional teaching stories, which use the theme of the heart as a mirror, illustrate key tenets of Islam on the requirements of religion, living in society, and the inner life of the soul.