These warnings are repeated in the Theses. The preaching of indulgences has concealed the true nature of repentance; the first thing to consider is what "our Lord and Master Jesus Christ means," when He says, "Repent." [32] Without denying the pope's right to the power of the keys, Luther wishes to come into the clear about the extent of the pope's jurisdiction, which does not reach as far as purgatory. He believes that the pope has the right to remit "penalties," but these penalties are of the same sort as those which were imposed in the early Church as a condition precedent to the absolution; they are ecclesiastical penalties merely, and do not extend beyond the grave; the true penalty of sin is hatred of self, which continues until entrance into the kingdom of heaven.[33] The Theses are formulated with continual reference to the statements of the indulgence-preachers, and of the Instruction to the Commissaries issued under the name of the Archbishop of Mainz. [34] For this reason there is little logical sequence in the arrangement of the Theses, and none of the attempts to discover a plan or scheme underlying them has been successful.[35] In a general way it may be said that for the positive views of Luther on the subjects discussed, Theses 30-37 and 41-51 are the most vital, while Theses 92-95 are sufficient evidence of the motive which led Luther to make his protest. 5. Conclusion—The editors of this Translation present herewith a new translation of the Theses, together with three letters, which will help the reader to understand the mind of Luther at the time of their composition and his motive in preparing them. The first of these letters is that which was sent, with a copy of the Theses, to Albrecht of Mainz. The second and third are addressed respectively to Staupitz and Leo X., and were written to accompany the "Resolutions," [36] an exhaustive explanation and defense of the Theses, published in 1518, after the controversy had become bitter. 6. Literature—(a) Sources. The source material for history of indulgences is naturally widely scattered. The most convenient collection is found in Koehler, Dokumente zum Ablassstreit, Tübingen, 1900. For the indulgences against which Luther protested, see, beside the Editions of Luther's Works, Kapp, Schauplatz des Tetselischen Ablass-Krams, Leipzig, 1720; Sammlung einiger zum päbstlichen Ablass gehörigen Schriften, Leipzig, 1721; Kleine Nachlese zur Erläuterung der Reformationsgeschicte, Leipzig, 1730 and 1733; also Loescher, Vollständige Reformationsacta, I, Leipzig, 1720 (b) Secondary Works. Beside the general works in Church History and History of Doctrine, see the Lives of Luther, in German especially those of Köstlin-Kawerau, Kolde, Berger and Hausrath; in English those of Beard, Jacobs, Lindsay, Smith and McGiffert; also Boehmer, Luther im Lichte der neueren Forschung, ad ed., Leipzig, 1910.