His primary interests are in the confluence of intellectual history, theology, and religious ethics in early modern Christianity. His research focuses on challenges to traditions of Christian thought and practice brought about by European expansion, the development of overseas empires, and Christian encounters with others in the Americas and in Asia. His current book project, Holy War, Just War: Rhetoric and Moral Argument in the Conquest of the Americas, explores how arguments over just and unjust wars were applied, reshaped, and transformed by the Spanish conquests of Mexico and Peru in the sixteenth century, particularly as they were appropriated by advocates for a proposal for the conquest of China that emerged from Spanish missionaries in the Philippines.