When was Petrus Alphonsi born?
Petrus Alphonsi
The Dialogi contra Iudaeos represented a turning point in not only polemical strategy, but also the perception of Judaism. In the Dialogi, Alfonsi argued with himself as his old Jewish self (Moses) and his new converted Christian self (Peter). What made this particular strategy of polemics so influential was the ability to control the argument legitimately without the need of a second party. Since the argument was between Judaism and Christianity, and Alfonsi was once a Jew and then a Christian, he was able to argue both sides with accuracy. By arguing against himself in the Dialogi, he was able to set the parameters of the argument without any unforeseen issues from a second party. Petrus was able to make each side say what he wanted; because of this, it was authoritative, and became a damaging piece to the perception of the Jews.