This work, commonly known simply as al-Irshad, (The Guide) is a major classic of Islamic theology. Its author, Iman al-Haramayn al-Juwayni (d. 478/1085), was the leading Ash'arite (Sunni) theologian of his time but he was more famous for his many important treatises on the principles of law and for having been the teacher of the great al-Ghazzali. Nevertheless, his writings in the field of theology, especially the present book, represent the high point of its development in the Islamic world until then. Here the master sets out systematically what he considered the sure proofs for the principles of any discourse about God and His attributes, about what must be said concerning Him, and how the human being should understand what is possible in respect to God.