The Course of Instructions contained in this Volume is based upon, or extracted from, the Catechism of the Holy Council of Trent, sometimes called the Roman Catechism.-A Work written by the authority of the same August Assembly, and sanctioned by Pius V, and many of his successors; and meant to be the guide of bishops, priests, and all invested with the Pastoral office, and the store-house whence they are to draw the material for instructing in their Religion the Christian people committed to their care. These Instructions follow the method and mind and spirit of that memorable Work; they are its close and faithful reproduction in a form suitable to be spoken and adapted to the average capacity of those attending Divine service. The form and expression belong to the Author; the substance belongs to the Catechism. The merit of these Instructions, therefore, must be considerable, as there is so little of the Author, and so much of the Catechism-the production of the greatest minds of the Queen of Councils, and which stands alone among all kindred works in ancient or modern times; whose superiority and supremacy is acknowledged even by those who do not employ it, but follow other approved treatises of similar scope. While thus universally celebrated, it is to be regretted that it is not so universally used. The origin and history of the Catechism is familiar to every ecclesiastic. The name of St. Charles Borrorneo can never be separated from its inception, progress and completion. The Council of Trent, anxious to apply remedies to the evils of that period, and to the same evils of all future times, was not content with condemning errors and teaching truths, but sought also to appoint a certain way and rule of instructing the Faithful in the Faith. The Holy Council had this in view from the first; and in its XVIII Session decreed that a book suitable for this purpose should be composed. St. Charles Borromeo, who had conceived the idea, was largely instrumental in bringing this about. As the Council adjourned before the work was finished, it commanded those charged with the task, that the Catechism when completed should be submitted to the Pope that it might be approved and published by His Authority. They labored at it for two years during the Council; on its dissolution they assembled for three years in Rome to prosecute the work. Its different parts were assigned severally to the most distinguished theologians. Before its approval by Pius V, it was subjected to the scrutiny of the most learned scholars and profound theologians appointed by the Pope. He approved it, not once, but many times, and commanded its use by all employed in the preaching of the Word or the instruction of the Faithful. It was also approved by Gregory XIII; St. Charles, in many Synods sanctioned it with his great authority and enforced its use. Since then it has been extolled by innumerable Councils and authorities.