[Abū-l Ḥasan Alī ibn Ismāīl ul-Asharī]. Arabian theologian, born of pure Arab stock at Baṣra, but spent the greater part of his life at Bagdad. Although belonging to an orthodox family, he became a pupil of the great Mutazalite teacher al-Jubbāī, and himself remained a Mutazalite until his fortieth year. In 912 he returned to the faith of his fathers and became its most distinguished champion, using the philosophical methods he had learned in the school of heresy. His theology, which occupied a mediate position between the extreme views on most points, became dominant among the Shafiites. He is said to have written over a hundred works, of which only four or five are known to be extant.
See W. Spitta, Zur Geschichte Abu l-Hasan al Ašaris (Leipzig, 1876); A. F. Mehren, Exposé de la reforme de lIslamisme commencée par Abou l-Hasan Ali el-Ashari (Leiden, 1878); and D. B. Macdonalds Muslim Theology (London, 1903), especially the creed of Ashari in Appendix iii.