Focused on the work of the renegade missionary 'Ali Quli Jadid al-Islam (d. 1734), this book contributes to ongoing debates on the nature of confessionalism, interreligious encounters and cultural translation in early modern Muslim empires. By disentangling the connections between polemics and other forms of Islamic learning and by emphasising the Shi'i character of the case in question, Alberto Tiburcio accounts for the dynamism of polemics as an ever-evolving genre capable of adapting to different historical contexts.