Abū al-Hasan possessed extraordinary acuity and a profound command of the sciences; he was endowed with many commendable traits, and his numerous writings testify to the vastness of his learning.

Among the leading scholars who studied under him were: Abū al-Hasan al-Bāhilī (1), Abū al-Hasan al-Kirmānī, Abū Zayd al-Marwazī, Abū ʿAbd Allāh ibn Mujāhid al-Baṣrī, Bundār ibn al-Ḥusayn al-Shīrāzī, Abū Muḥammad al-ʿIrāqī, Zāhir ibn Aḥmad al-Sarakhsī, Abū Sahl al-Ṣuʿlūkī, and Abū Naṣr al-Kawwāz (2) al-Shīrāzī (3).

Abū al-Hasan al-Ashʿarī says in his work al-ʿUmad fī al-Ruʾya: “I have authored al-Fuṣūl fī al-Radd ʿalā al-Mulḥidīn (Chapters in Refutation of the Atheists), consisting of twelve books; Kitāb al-Mūjaz (The Concise Compendium); Kitāb Khalq al-Aʿmāl (The Creation of Deeds); Kitāb al-Ṣifāt (The Divine Attributes)—a large volume in which we addressed the various sects of the Muʿtazilah and the Jahmiyyah; Kitāb al-Ruʾya bil-Abṣār (The Beatific Vision with the Eyes); Kitāb al-Khāṣ wa al-ʿĀm (The Particular and the Universal); Kitāb al-Radd ʿalā al-Mujassimah (Refutation of the Corporealists); Kitāb Īḍāḥ al-Burhān (Clarifying the Proof); Kitāb al-Lumaʿ fī al-Radd ʿalā Ahl al-Bidʿah (The Flashes: A Rebuttal of the People of Innovation); Kitāb al-Sharḥ wa al-Tafsīl (Explanation and Elaboration); Kitāb al-Naqd ʿalā al-Jubbāʾī (4) (Critique of al-Jubbāʾī); Kitāb al-Naqd ʿalā al-Balkhī (5) (Critique of al-Balkhī); Kitāb Jumal Maqālāt al-Mulḥidīn (A Compendium of the Doctrines of the Atheists); and yet another work (6) on the Divine Attributes—our largest composition—in which we refuted what we had previously written in support of the Muʿtazilite doctrine,