Tools for a Discursive Ontological Method: Muslim Sources in the Hands of a Mozarab Polemicist

ABSTRACT This article examines the use of Islamic sources in a fragmentary text, the Tathlīth al-waḥdāniyya (‘Trebling the Oneness’), written by an anonymous Jewish convert to Christianity. The author’s aim was to demonstrate – using an ontological approach – the inconsistent nature of the arguments employed by his Muslim opponents, and at the same time to highlight the unacceptable practices of Muslims with regard to divorce and adultery. The fragments have survived thanks to their being quoted in a text by a Muslim author, who sought to counter each of the theological views expressed therein.