Martin Luther was one of the most influential men of the last millennium, and the man most responsible for the Reformation that split the Catholic Church in the 16th century. A German theologian, Luther wrote at length criticizing the Church and sparked the Reformation, all while being one of the most read authors on the continent in his lifetime. His teachings included important departures from Church dogma, including the claim that absolution of sin could not be purchased. Today his 99 Theses are among the most famous works in the world. On the Bondage of the Will is Luther’s reply to Erasmus regarding free will, and whether people can choose between good and evil. The argument was crucial to the Reformation and molded the main disagreement over free will vs. predestination.