Twelfth-century Spain’s polemical writers were mostly converts from Judaism and Islam.

Evidence

This atmosphere produced a number of polemical and apologetical works between Judaism, Christianity, and Islam. At least five Christian writers wrote polemics against Islam in twelfth-century Spain: four of these authors are (or are said to be) converts to Christianity, two from Judaism and two from Islam. All of them show knowledge of Islam, of the Koran, and the Hadîth; all of them know (and continue) the traditions of Eastern Christian anti-Islamic polemics embodied in the Risâlat al-Kindî (a text with which many in Spain were familiar). — John V. Tolan, Saracens, 797