Date: Unknown; possibly mid or late 13th century
Original Language: Arabic
Neither the title of the work nor its full contents have survived. All that is known is that it was written, in Arabic, against Christianity, and probably in response to hostile questions from a monk. It only survives as extracts in al-Qaysī’s early 14th-century Kitāb miftāḥ al-dīn.
In the third, largely autobiographical part of his original Arabic work, al-Qay…