Appositely named Intiṣār—meaning both ‘victory’ and ‘defense’—Abū l-Ḥusayn al-Khayyāṭ’s book is the refutation of a refutation and an angry polemic against much else, including Muslims and non-Muslims, atheists and freethinkers. Above all, it is a demonstration of the dialectic method praised by the Muʿtazili school as the sole correct method of truth-finding in matters relating to God, to physics, to ethics, and to politics. This book priovides an English translation of this work of classical Arabic theology, accompanied by the Arabic text and and an introduction that focuses on the religious and intellectual milieu that informed al-Khayyāṭ’s writing, the sectarian environment where he lived, and the culture of debate in which he participated.