THE chief object for which this work has been written is to furnish those who wish to lead a solidly devout life in the Ecclesiastical, in the Religious, or in the Secular State, with a manual or text-book containing, in as compendious a form as possible, the' principles' upon which such a life must be built. The sources whence materials for an undertaking of this kind may be drawn are various and numerous; but out of the many at my disposal, two are especially deserving of mention, inasmuch as it has been by the doctrine which I have learnt from them, that I have been guided in much that has been treated of in this book. The first of these are the works of Cassian, to which, as a child of St. Benedict, I felt myself drawn as it were by instinct; for, it was from the world-famed 'Conferences' of this learned ascetic that our holy Father drew much of that spiritual lore which is so conspicuous in the various enactments of his Rule, and to the pages of which he refers his children, for those sublime lessons of spiritual wisdom, which will lead them to the topmost height of Christian perfection. Cassian's teaching, save upon the question of divine grace, is unexceptionally good. His deficiency upon this point may be satisfactorily accounted for, if we bear in mind that in his day various questions which arise out of this most intricate subject had not been thoroughly examined into and set at rest for ever by the infallible decision of the Church. The second is the 'Theologia Mystica' of Father Dominick Schram, O.S.B., in which that erudite Religious has bequeathed to us valuable treasures of Christian asceticism arranged with scientific accuracy, and stored away with scholastic neatness and precision. The plan of which I have made use for reducing to order the mass of material which presented itself to my hands, is a very simple one. It may be stated thus; in the life of every man there is an ultimate end, which is God. But in order to reach that ultimate end, man must comply with certain conditions which have been laid down by God for the attainment of so magnificent a destiny. Therefore, besides his ultimate end, man has also a subordinate end, or object in life. This is to win for himself that measure of perfection which is compatible with his state here below. Perfection, however, is made up of three elements; of charity, of purity of heart, and of humility, all which must be made so to enter the very fibres of his being, as to become part and parcel of himself. To obtain this subordinate end, there are various means at man's disposal, chief among which are, prayer, divine grace, docility to the movements and inspirations of the Holy Spirit, imitation of Christ, and mortification, both internal and external. Upon each of these subjects, and upon the various ramifications into which some of them logically lead, ample instructions have been given. These will, perhaps, prove useful to those who are endeavouring to lead devout lives in the world. For those who wish to enter the Ecclesiastical State, there are chapters devoted to the treatment of subjects which are special to their sacred calling. Finally, for those who, in order to obtain perfection, make their self renunciation perpetual by means of vows in the Religious State, several chapters have been set aside for the explanation of those holy bonds by which they are more closely united to God. Also, an Appendix has been added, in which each chapter has been carefully analysed. These outlines or sketches of the matter which the reader shall have already perused will, it is hoped, enable him to obtain a firmer grasp of it; they will help him to imprint it more deeply upon his mind; and if he should happen to be sealed with the priestly character, and entrusted with the cure of souls, they will furnish him with plans by the aid of which he will be able to use the doctrine contained in this volume for the spiritual training of those committed to his charge.