The Book of Lights and Watchtowers: On Jewish Sects and Christianity

Abū Yūsuf Ya‘qūb ibn Isḥāq al-Qirqisānī was a prolific Iraqi Karaite. Little is known about his life, though his name suggests a familial or personal connection to Qarqīsiyā (also known as Circesium), a town on the Euphrates. Al-Qirqisānī’s two major surviving works are the legal and theological The Book of Lights and Watchtowers (Kitāb al-anwār wa-’l-marāqib) and the exegetical The Book of Gardens and Parks (Kitāb al-riyāḍ wa-’l-ḥadā’iq). He reported having composed other theological and exegetical writings, but these are lost. Al-Qirqisānī’s relations with Rabbanites, particularly Se‘adya Ga’on, were polemical but never as bitter as those of some of the Karaite writers in Jerusalem. Al-Qirqisānī frequently recorded earlier views that would otherwise have been lost, making his writings an important historical source. As a theologian, he was most influenced by the Mu‘tazilite version of kalām (rationalist theology).