This book presents a comprehensive critical survey of all the logical doctrines of the well-known but little understood Catalan philosopher and theologian, Ramon Llull (1232-1316). The highly idiosyncratic character of Llull's writings has long frustrated the efforts of general medieval historians to define his contribution to later scholastic culture, and has resisted attempts by specialists to explain exactly how his methods and procedures worked. This new study--the first book-length treatment in English of Llull's philosophy to appear in over fifty years--seeks to resolve both of these difficulties. The author argues that Llull's peculiar logical doctrines result from his reinterpretation of the use of commonplace scholastic teachings according to his own preferred ethical and spiritual ideals.