|The 4th century AH was a time of fresh developments in the history of Imami theology. The period also witnessed the appearance of a large corpus of works by Imami theologians on the subject of imamate. However, the decisive development of the period was the appearance of the theological school founded by Nubakhti family, headed by Abu Sahl Nubakhti who managed to construct a comprehensive theological system capable of responding to the criticisms leveled against the Imamis by their opponents. The titles of Abu Sahl’s works indicate that apart from topics relating to the subject of imamate he was in general agreement with the Mu`tazilites.
From the days of Abu Sahl until the later years of the 4th century AH one encounters the names of Imami theologians throughout Islamic lands, from Khurasan all the way to Egypt. They included the likes of Ibn Qubbah Razi, Muhammad b. Bahr Rahani, Ibn Rustam Tabari, Abu al-Ahwas Misri, Ibn `Aqil `Umani and Abu al-Tayyib Razi who concentrated the bulk of their efforts on issues relating to imamate and its disputed topics. On the other hand, others such as Hasan b. Musa Nubakhti, with his rational method, and Abu al-Qasim Kufi, with his Ghali tendencies, devoted their works to the discussion of a wide range of theological topics. It should be noted that some of the theologians of the period such as Ibn `Abdak and Abu Mansur Sarram were closer than others to Mu`tazilite positions. For instance, they both believed in the doctrine of wa`id.
Finally, mention should be made of a group of Imami scholars who may not be characterized as theologians, but whose Traditionalist discussion of theological issues left a lasting imprint on the development of Imami theology in the coming centuries. Examples of such works include the chapters on the principles of faith contained in Kulayni’s Kitab al-kafi and the books of Tawhid and I`tiqadat by Ibn Babawayh. Shaykh Mufid (d. 413 AH) has discussed the views of this group of Imami scholars whom he characterizes as “Imami Traditionalists” or the like. His Tashih al-i`tiqad, devoted to a critical analysis of the views of Ibn Babawayh, is the ultimate example of the encounter between these two tendencies.
Shaykh Mufid, the well known Baghdadi scholar, must be considered as the reviver of Imami theology after a long period of stagnation. In addition to possessing a deep knowledge of the views of past Imami theologians, he was well versed in the works of Mu`tazilites, especially those of Abu al-Qasim Balkhi, the leader of the school of Baghdad. In fact, he made extensive use of Mu`tazilite views and methods. A comparison of his views with those of the Mu`tazilites indicates that he held similar opinions with regards to the subjects of divine unity and justice, while he differed with them on imamate and wa`id.
The movement set in motion by Shaykh Mufid was carried on by his eminent students, such as Sayyid Murtada and Shaykh Tusi, who created a large corpus of, at times, extensive works on Imami theology based on the same set of principles. Examples of these works include Sayyid Murtada’s al-Dhakhirah, Abu Salih Halabi’s Taqrib al-ma`arif, and Shaykh Tusi’s Tamhid al-usul. Among the Imami theologians of the 6th century AH mention should be made of Sadid al-Din Hamasi, the Razi scholar who flourished in the second half the century. His surviving al-Munqidh min al-taqlid is based on the method of Baghdadi theologians, both in terms of formulation of problems and in terms of theological foundations. In this work he lashes out at blind imitation in matters relating to the articles of faith and advocates rational reasoning.