Martin Luther (1483-1546) developed the polemicist facet throughout his life. His thorough and precise knowledge of the Bible and his direct, aggressive and disrespectful language, often bordered on insult, made him a fearsome adversary. In The Servant Agency (1525), a work of great theological depth that exposes the doctrine of justification by faith, the Lutheran Reformation is launched in a tromboge against the humanism represented by Erasm of Rotterdam and his defense of free will. The other two writings gathered here, On the Papacy of Rome (1520) and Against Hanswurst (1541), are relevant to understanding the concept of the Church advocated by Luther.