Ramon Llull (1232-1316), born on Majorca, was one of the most remarkable lay intellectuals of the thirteenth century. He devoted much of his life to promoting missions among unbelievers, the reform of Western Christian society, and personal spiritual perfection. He wrote over 200 philosophical and theological works in Catalan, Latin, and Arabic. Many of these expound on his 'Great Universal Art of Finding Truth,' an idiosyncratic dialectical system that he thought capable of proving Catholic beliefs to non-believers. This study offers the first full-length analysis of his theories about rhetoric and preaching, which were central to his evangelizing activities. It explains how Llull attempted to synthesize commonplace advice about courtly speech and techniques of popular sermons into a single program for secular and sacred eloquence that would necessarily promote love of God and neighbor. Llull's work is a remarkable testimony to the diffusion of clerical culture among educated lay-people of his era, and to their enthusiasm for applying that knowledge in pursuit of learning and piety. This book should find a place on the shelf of every scholar of medieval history, religion, and rhetoric.