Abu Hamid Muhammad al-Ghazzali (1058-1111) is one of the most important religious figures in Islamic history. He is particularly noted for his brilliant synthesis of mysticism and traditional Sunni Islam. Ghazzali's "The Alchemy of Happiness", written toward the end of his life, provides a succinct introduction to both the theory and practice of Sufism (Islamic mysticism). It thus offers many insights into traditional Muslim society. This translation is fully annotated for readers unfamiliar with Ghazzali and includes an introduction to his life and historical milieu.