The present dissertation deals with the subject of diocesan faculties as they are directly deducible from the New Code of Canon Law. The study is primarily a theoretical discussion of the basis, nature and extent of exceptional law as implied in the concept of "faculty." However, the highly practical aspect of the subjectmatter is not lost sight of, and not infrequently are the principles and statements of the exceptional law shown in their application to facts and contingencies that come within their scope. Though the matter of the dissertation comes in contact with many questions of a general juridical nature, it is obviously beyond the confines and purpose of the study to enter into a detailed discussion thereof. That must be left to the domain of special treatises. The work is divided into two parts. The first part is a general discussion of the subject of "faculties," the second treats in particular of the diocesan faculties. In the first part, a brief historical survey of the origin and development of faculties prefaces the discussion of the juridical concept of the nature, source and extent of faculties. The constituent elements of the concept expressed by the term "faculty" are submitted to a somewhat lengthy inquiry because of the indefinite meanings frequently associated with this term. The second part of the dissertation submits a list and a discussion of the various concessions that could be placed in the document of diocesan faculties. As indicated above, only those faculties are considered, which, according to the general law, the diocesan priests either possess ex potestate ordinaria or may possess ex potestate delegata, i. e., through the concession of the local Ordinary. Faculties concerning the celebration of Mass and concerning confession receive, for the obvious reasons of their importance and the frequency of their application, a lengthier discussion than others. Faculties, that could be construed on the basis of regional, provincial or diocesan law, are not submitted to discussion in these pages. Such faculties are usually found in the diocesan statutes that frequently embody, at least in outline, the decrees of plenary and provincial councils and of diocesan synods. These particular powers are to follow, of course, the general regulations of the Code, and consequently may be increased, or are to be diminished or, perhaps, even annulled, as the case may require, unless provision to the contrary has been made by peculiar indults or privileges.