The Muʿtazila was not an exclusively Muslim phenomenon, since their teachings were also adopted by medieval Jewish savants. In recent years, a number of Muʿtazilī works were rediscovered or substantially completed by adopting a comparative methodology, which was based on both Muslim and Jewish sources. This article deals with a lost work composed by qāḍī ʿAbd al-Jabbār, entitled al-Jumal wa-l-ʿuqūd. I will give an overview of the sources in Zaydī and Karaite collections that provide us with a more detailed picture of the dissemination of the text. On the basis of quotations by later theologians, I will propose a hypothesis on the content of al-Jumal wa-l-ʿuqūd. I will then discuss a possible relationship between ʿAbd al-Jabbār’s text and a manuscript from the Firkovitch collection in the National Library of Russia, which has recently been identified as a work entitled Taʿlīq al-Jumal wa-l-ʿuqūd.
