The Ninety-five Theses or Disputation on the Power and Efficacy of Indulgences is a list of propositions for an academic disputation written in 1517 by Martin Luther, then a professor of moral theology at the University of Wittenberg, Germany. The Theses are retrospectively considered to have launched the Protestant Reformation and the birth of Protestantism, despite various quasi- or proto-Protestant groups having existed previously.
The Theses are framed as propositions to be argued in an academic debate rather than necessarily representing Luther's opinions. They aired contemporary theological misgivings about the theory and practice of indulgences and their relation to repentance, penance and papal authority: this was triggered by the scandal of certain Catholic clergy, who were supposedly selling plenary indulgences in Germany, which were certificates supposed to reduce the temporal punishment in purgatory for sins committed by the saved purchasers or their loved ones.