 Arguably the most important German thinker of fifteenth century, Nicholas of Cusa (1401–1464) was also an ecclesiastical reformer, administrator and cardinal. His life-long effort was to reform and unite the universal and Roman Church, whether as canon law expert at the Council of Basel and after, as legate to Constantinople and later to German dioceses and houses of religion, as bishop in his own diocese of Brixen, and as advisor in the papal curia. His active life as a Church administrator and bishop found written expression in several hundred Latin sermons and more theoretical background in his writings on ecclesiology, ecumenism, mathematics, philosophy and theology. Cusanus had an open and curious mind. He was learned and steeped in the Neoplatonic tradition, well aware of both humanist and scholastic learning, yet mostly self-taught in philosophy and theology. Nicholas anticipated many later ideas in mathematics, cosmology, astronomy and experimental science while constructing his own original version of systematic Neoplatonism. A whole range of earlier medieval writers, such as Thierry of Chartre, Ramon Llull and Albert the Great, influenced Nicholas, but his important intellectual roots are in Proclus and Dionysius the Areopagite. In spite of his significance few later thinkers, apart from Giordano Bruno, understood or were influenced by him until the late nineteenth century.