On the indulgences in their relation to the Sacrament of Penance, H, C. Lea, History of Confession and Indulgence, especially Vol. III, Philadelphia, 1896; Brieger, Das Wesen des Ablasses am Ausgang des Mittelalters, Leizig, 1897, and Article Indulgenzen in PRE.3 IX, pp. 76 ff. On the financial aspects of the indulgence-traffic, Schulte, Die Fugger in Rom, 2 vols., Leipzig, 1904.
Brieger knew cases of abstinence without harmful results, but himself thought that no general opinion could be given. Jürgensen said that abstinence in itself is not harmful, but that in some cases intercourse exerts a more beneficial influence.
Tschackert has surmised that even the number of the Theses was determined by the number of the paragraphs in this Instruction. There were 94 of these paragraphs, and of the Theses 94 + 1. Enstehung d. luth. u. ref. Kirchenlehre , p. 16, note 1. The following, based on an unpublished manuscript of Th. Brieger, is an interesting analysis of the contents and subject matter of the Theses.