In 1517, Luther was deeply concerned with the widespread understanding and practice of indulgences, but he was still not quite clear what indulgences and their power might be. Thus, he invited colleagues to discuss the 95 Theses on indulgences that he had written, in order to discern the truth about them. Only the first four of the ninety-five did Luther himself claim to be entirely true. All the other theses were considered matters for debate; he was not making a truth claim about them.