Rational speculative theology (kalam) in early Islam was represented most distinctly by the theological school of the Mu'tazila. Founded in Basra in the early 8th century, the school soon became predominant in theological scholarship and discourse and remained so until the early 11th century. The Mu'tazila held that the basic truths of theology, such as the existence of God and the nature of His attributes and justice, are entirely subject to rational proof without the benefit of scriptural revelation. Only after these basic truths have been established can the veracity of scripture be proved...

Abū ʿAlī Muḥammad Ibn Khallād al-Baṣrī was a distinguished disciple of the Muʿtazilī theologian and founder of the Bahshamiyya, Abū Hāshim al-Jubbāʾī (d. 321/933). He is reported to have written a theological summa, Kitāb al-Uṣūl, as well as an autocommentary. None of the works of Ibn Khallād has come down to us directly, although substantial portions of his Kitāb al-Uṣūl and/or Sharḥ al-Uṣūl have reached us embedded in the Kitāb Ziyādāt Sharḥ...

Early Ibāḍī Theology presents the critical edition of six Arabic theological texts recently discovered in two manuscripts in Mzāb in Algeria dating from the middle of the 8th century. The texts were sent by their author, the prominent Kūfan Ibāḍī kalām theologian 'Abd Allāh b. Yazīd al-Fazārī to North Africa where he had a large following in the Ibāḍī community later known as the Nukkār. They constitute the earliest extant body of Muslim kalām theology and are vital for the study...

In Ib Texts from the 2nd/8th Century Abdulrahman Al-Salimi and Wilferd Madelung present an edition of fourteen Ib religious texts and explain their contents and extraordinary source value for the early history of Islam. The Ib s constitutes the moderate wing of the Kharijite opposition movement to the Umayyad and Abbasid caliphates. The texts edited are mostly polemical letters to opponents or exhortatory to followers by Abd Allah b. Ibad, Abu l- Ubayda Muslim b. Abi Karima and other Ibadi leaders in Basra, Oman and Hadramawt. An epistle detailing the offences of the...