Building on recent revisionist scholarship, this book offers a new overview of the last two decades of the life of the seminal eleventh-century Islamic thinker Abu Hamid al-Ghazali (d. 1111). It focuses on his masterpiece, the Revival of the Religious Sciences, and argues that al-Ghazali was the first Muslim thinker to self-consciously marshal the rhetoric of revival to promote his new vision of the Islamic religious sciences. The "Science of the Hereafter" that is the subject of the Revival draws on Islamic law, Sufism, and the philosophy al-Ghazali is understood to have refuted. While his autobiography suggests that his masterpiece grew out of a radical break with his earlier thought, a reading of his earlier work shows that its major theses were present before his famous spiritual crisis. Al-Ghazali's letters show him actively promoting his revivalist agenda in the final decade and a half of his life. This book contextualizes al-Ghazali's famous autobiography and explains what led him to reconstruct a controversy of the Revival, thereby giving such a misleading account of his life and thought.