De libero arbitrio diatribe sive collatio

(literally Of free will: Discourses or Comparisons) is the Latin title of a polemical work written by Desiderius Erasmus of Rotterdam in 1524. It is commonly called The Freedom of the Will or On Free Will in English. Background was nominally written to refute a specific teaching of Martin Luther, on the question of free will. Luther had become increasingly aggressive in his attacks on the Roman Catholic Church to well beyond irenical Erasmus' reformist agenda. Luther published in 1520 his Latin Assertio omnium articulorum (itself a response to Pope Leo X's bull Exsurge domine that threatened Luther with excommunication) which included the statement God effects the evil deeds of the impious as part of the Wycliffian claim that everything happens by pure necessity, so denying free will. Bishop John Fisher published a detailed response to the Latin version's arguments as Confutation of the Lutheran Assertion in 1523. (For the popular German version of this work, Luther sanitized his text for Article 36 to remove the arguments that "God is the cause not only of good deeds in man but also of sins, and that there is no natural power of the human will to direct man's actions either for good or for bad.") Erasmus decided necessity/free will was a subject of core disagreement deserving a public airing, and strategized for several years with friends and correspondents on how to respond with proper moderation without making the situation worse for all, especially for the humanist reform agenda..