Catechismus Romanus ad Parochos (Catecismo del Concilio de Trento)

For those who intended to corrupt the minds of the faithful, knowing that they could not hold immediate personal intercourse with all, and thus pour into their ears their poisoned doctrines, adopted another plan which enabled them to disseminate error and impiety more easily and extensively. Besides those voluminous works by which they sought the subversion of the Catholic faith - to guard against which (volumes) required perhaps little labour or circumspection, since their contents were clearly heretical - they also composed innumerable smaller books, which, veiling their errors under the semblance of piety, deceived with incredible facility the unsuspecting minds of simple folk. The Nature of this Work The Fathers, therefore, of the General Council of Trent, anxious to apply some healing remedy to so great and pernicious an evil, were not satisfied with having decided the more important points of Catholic doctrine against the heresies of our times, but deemed it further necessary to issue, for the instruction of the faithful in the very rudiments of faith, a form and method to be followed in all churches by those to whom are lawfully entrusted the duties of pastor and teacher. To works of this kind many, it is true, had already given their attention, and earned the reputation of great piety and learning. But the Fathers deemed it of the first importance that a work should appear, sanctioned by the authority of the Council, from which pastors and all others on whom the duty of imparting instruction devolves, may be able to seek and find reliable matter for the edification of the faithful; that, as there is one Lord, one faith, there may also be one standard and prescribed form of propounding the dogmas of faith, and instructing Christians in all the duties of piety.…