Kitab al-mu?tamad fi usul al-din

Abu 'l-Husayn al-Basri (d. 436/1044) was the founder of the last theological school of the Mu?tazila and author of, among others, the Kitab tasaffuh al-adilla and Sharh al-usul al-khamsa. None of his theological works survive in full, while his influential Kitab tasaffuh al-adilla, of which only fragments remain, was actually never finished. Al-Basri's teachings were given a new impulse and audience through the writings of Rukn al-Din b. al-Mahmud al-Malahimi (d. 536/1141) of Khurasan, where his ideas also gained support among the Shi?a, including Nasir al-Din Tusi (d. 672/1274). Al-Malahimi's Kitab al-mu?tamad fi usul al-din, in which he relies mostly on al-Basri's Kitab tasaffuh al-adilla, survives only in part. The present volume contains a new edition of this text. Thanks to the discovery of two manuscripts in Yemen it was possible to amend the first edition in places and to add a lot of new material, the text now being double in size.