A literary dialogue between a Christian and a Muslim, maintaining the superiority of Christianity: this volume presents a critical Latin text and the first ever English translation, annotated, of this important but hitherto largely overlooked document among sources in Christian – Muslim relations. Some of Vives’s criticisms of Muhammad and Islam are based on scripture or reason; many others rely on lampoon of Arab or Islamic folk tales. Still, he censures Muslim followers only narrowly, far less for moral failings or hatred of Christians than for gullibility in accepting Islam. Book Four provides valuable evidence of the reach and the limits of Vives’s humanistic tolerance as applied to religious conflict.