The Muslim theologian al-Ghazali, who was active at the turn of the 12th century in Iran, Iraq, and Syria, was one of the most influential theologians of Islam. In this book, Frank Griffel will present the most comprehensive examination to date of the life and thought of this important figure. The book is divided into two parts. In the first, Griffel gives an account of what it known about al-Ghazali's life, offers brief discussions of his major works, and examines the legacy of his thought by tracing the lineage of his students and followers. In the second part, he provides a systematic exploration of al-Ghazali's theology. He explicates al-Ghazali's views on epistemology, cosmology, physical theory, creation, ethics, theodicy, and a host of other topics. Throughout, he offers a serious revision to traditional views of al-Ghazali, showing that his most important achievement was the creation of a new rationalist theology in which he transformed the Aristotelian views of thinkers such as Avicenna to accord with motives that were well-established within Muslim theological discourse. The result is the most thorough available examination of a major thinker.