Includes bibliographical references and index.; The Umayyad period. The beginnings of sectarianism ; The Khārijites ; The Shīʻtes ; The Murjiʼites and other moderates -- The first wave of Hellenism 750-950. The historical background ; The translators and the first philosophers ; The expansion of Shīʻism ; The Muʻtazilites ; The consolidation of Sunnism ; Al-Ashʻarī -- The second wave of Hellenism 950-1258. The historical background ;The flowering of philosophy ; The vicissitudes of Shīʻism ; The progress of Sunnite theology ; Al-Ghazālī ; Sunnite theology from 1100 to 1250 ; Theology and philosophy in the Islamic west -- The period of darkness. The historical background ; The sclerosis of philosophical theology ; The vitality of the Ḥanbalites ; The transformation of Shīʻism -- The new dawn. The prospect for theology.;