The Confitendi Ratio is the culmination of a series of tracts published by Luther after the memorable October 31st, 1517, and before his final breach with Rome.[1] In them is clearly traceable the progress that he was making in dealing with the practical problems offered by the confessional, and which had started the mighty conflict in which he was engaged. They open to us an insight into his own conscientious efforts during the period, when, as a penitent, he was himself endeavoring to meet every requirement which the Church imposed, In order to secure the assurance of the forgiveness of sins, as well as to present the questions which as a father confessor and spiritual adviser he asked those who were under his pastoral care. First of all, we find, therefore, tables of duties and sins, reminding us of the lists of cardinal sins and cardinal virtues in which Roman Catholic books abound. The main effort here is to promote the most searching self-examination and the most complete enumeration of the details of sins, since, from the Medieval standpoint, the completeness of the absolution is proportioned to the exhaustiveness of the confession. Although the first of these briefer tracts closes with its note of warning that the value of the confession is not to be estimated by the enumeration of details, but that it rests solely in the resort that is had to the Grace of God and the word of His promise, the transition from the one mode of thought to the other is very apparent. In the Kurze Untetweisung wie man beichten soll of 1519, of which this is a Latin re-elaboration, and, therefore, intended more for the educated man than as a popular presentation, he has advanced so far as to warn against the attempt to make an exhaustive enumeration of sins. He advises that the confession be made in the most general terms, covering sins both known and unknown. "If one would confess all mortal sins, it may be done in the following words; 'Yea, my whole life, and all that I do, act, speak, and think, is such as to be deadly and condemnable.' For if one regard himself as being without mortal sin, this is of all mortal sins the most mortal." [2] According to this maturer view, the purpose of the most searching self-examination is to exhibit the utter impossibility of ever fathoming the depth of corruption that lies beneath the surface. The reader of the Tessaradecas will recall Luther's statement there, that it is of God's great mercy that man is able to see but a very small portion of the sin within him, for were he to see it in its full extent, he would perish at the sight. The physician need not count every pustule on the body to diagnose the disease as small-pox. A glance is enough to determine the case. The sins that are discovered are the symptoms of the one radical sin that lies beneath them all.[3] The cry is no longer "Mea peccata, mea peccata," as though these recognized sins were the exception to a life