Although prayerfulness and the remembrance of God suffuse all the formal practices of Islam, there are times when the Muslim simply sits alone with his Lord to repeat formulas drawn from the Qur an and the sayings of the Prophet, seeking remission of his sins and the purification of his heart. The present volume, Book IX of the Revival of the Religious Sciences, is probably the most widely read compendium of such material, popular not only for its comprehensiveness and beauty, but also for the analytical approach of its author, who explores the psychological and spiritual effects of prayer and the celebration of God s name. In this new edition, the Islamic Texts Society has included a trans lation of Imam Ghazali s own to the Revival of the Re ligious Sciences which gives the reasons that caused him to write the work, the structure of the whole of the Revival and places each of the chapters in the context of the others.