Dominicans attacked Judaism and Islam by turning their own scriptures against them

Evidence

Most of Martí’s missionary efforts were directed toward Jews, and he shows the same strategy in his works of polemic against both religions: he attempts to attack the religion at its base by showing how its own scriptures invalidate its precepts. This line of attack was not new: Petrus Alfonsi, for example, ridiculed the Koran and the Talmud, showing supposed contradictions in them. Yet the Dominican missionaries pursued this tactic with a zeal and perseverance never seen before: they schooled themselves in Hebrew, Aramaic, and Arabic, pored over the Talmud and Koran, produced massive tracts for the use of their missionaries, and (with the aid of King Jaume) forced Jewish and Muslim scholars to debate with them. — John V. Tolan, Saracens, 1185

Categorization

• XREF: Connects to the pattern of interfaith disputation and conversion-by-debate seen in other medieval polemical works; also parallels the logocentric ‘scripture-invalidates-scripture’ strategy used in anti-Islamic polemic.