Pope St Pius V - The Roman Catechism: The Catechism of the Council of Trent for Parish Priests

Such is the nature of the human mind and intellectthat, although by means of diligent and laborious inquiry it has of itselfinvestigated and discovered many other things pertaining to a knowledge ofdivine truths; yet guided by its natural lights it never could have known orperceived most of those things by which is attained eternal salvation, theprincipal end of man's creation and formation to the image and likeness of God.

It is true that the invisible things of Godfrom the creation of the world are, as the Apostle teaches, clearly seen, beingunderstood by the things that are made: his eternal power also, and divinity.But the mystery which hath been hidden from ages and generations so fartranscends the reach of man's understanding, that were it not made manifest byGod to His Saints, to whom He willed to make known by the gift of faith, theriches of the glory of this mystery among the Gentiles, which is Christ, mancould by no effort attain to such wisdom.

But, as faith comes by hearing, it is clearhow necessary at all times for the attainment of eternal salvation has been thelabour and faithful ministry of an authorised teacher; for it is written, howshall they hear, without a preacher? And how shall they preach unless they besent?

And, indeed, never, from the very creation ofthe world, has God, most merciful and benignant, been wanting to His own; butat sundry times and in divers manners spoke to the fathers by the prophets, andpointed out to them in a manner suited to the times and circumstances, a sureand direct path to the happiness of heaven. But, as He had foretold that Hewould give a teacher of justice to be the light of the Gentiles, that Hissalvation might reach even to the ends of the earth, in these last days he hathspoken to us by his Son, whom also by a voice from heaven, from the excellentglory, He has commanded all to hear and to obey. Furthermore, the Son gave someto be apostles, and some prophets, and others pastors and teachers, to announcethe word of life; that we might not be carried about like children tossed toand fro with every wind of doctrine, but holding fast to the firm foundation ofthe faith, we might be built together into an habitation of God in the Spirit.

Lest any should receive the Word of God fromthe ministers of the Church, not as the word of Christ, which it really is, butas the word of man, the same Saviour has ordained that their ministry should beinvested with so great authority that He says to them: He that hears you, hearsme; and he that despises you despises me. These words He spoke not only ofthose to whom His words were addressed, but likewise of all who, by legitimatesuccession, should discharge the ministry of the word, promising to be withthem all days even to the consummation of the world.

But while the preaching of the divine Wordshould never be interrupted in the Church, surely in these, our days, itbecomes necessary to labour with more than ordinary zeal and piety to nourishand strengthen the faithful with sound and wholesome doctrine, as with the foodof life. For false prophets have gone forth into the world, to corrupt theminds of the faithful with various and strange doctrines, of whom the Lord hassaid: I did not send prophets, yet they ran; I spoke not to them, yet theyprophesied.

In this work, to such extremes has theirimpiety, practiced in all the arts of Satan, been carried, that it would seemalmost impossible to confine it within any bounds; and did we not rely on thesplendid promises of the Saviour, who declared that He had built His Church onso solid a foundation that the gates of hell shall not prevail against it, weshould have good reason to fear lest, beset on every side by such a host ofenemies and assailed and attacked by so many machinations, it would, in thesedays, fall to the ground.

For - to say nothing of thoseillustrious States which heretofore professed, in piety and holiness, the trueCatholic faith transmitted to them by their ancestors, but are now gone astraywandering from the paths of truth and openly declaring that their best claimsto piety are founded on a total abandonment of the faith of their fathers -there is no region, however remote, no place, however securely guarded, nocorner of Christendom, into which this pestilence has not sought secretly toinsinuate itself.

For those who intended to corrupt the mindsof the faithful, knowing that they could not hold immediate personalintercourse with all, and thus pour into their ears their poisoned doctrines,adopted another plan which enabled them to disseminate error and impiety moreeasily and extensively. Besides those voluminous works by which they sought thesubversion of the Catholic faith - to guard against which (volumes)required perhaps little labour or circumspection, since their contents wereclearly heretical - they also composed innumerable smaller books, which,veiling their errors under the semblance of piety, deceived with incrediblefacility the unsuspecting minds of simple folk.

The Fathers, therefore, of the GeneralCouncil of Trent, anxious to apply some healing remedy to so great andpernicious an evil, were not satisfied with having decided the more importantpoints of Catholic doctrine against the heresies of our times, but deemed it furthernecessary to issue, for the instruction of the faithful in the very rudimentsof faith, a form and method to be followed in all churches by those to whom arelawfully entrusted the duties of pastor and teacher.

To works of this kind many, it is true, hadalready given their attention, and earned the reputation of great piety andlearning. But the Fathers deemed it of the first importance that a work shouldappear, sanctioned by the authority of the Council, from which pastors and allothers on whom the duty of imparting instruction devolves, may be able to seekand find reliable matter for the edification of the faithful; that, as there isone Lord, one faith, there may also be one standard and prescribed form ofpropounding the dogmas of faith, and instructing Christians in all the dutiesof piety.

As, therefore, the design of the workembraces a variety of matters, it cannot be supposed that the Council intendedthat in one volume all the dogmas of Christianity should be explained with thatminuteness of detail to be found in the works of those who profess to treat theteaching and doctrines of religion in their entirety. Such a task would be oneof almost endless labour, and manifestly ill suited to attain the proposed end.But, having undertaken to instruct pastors and such as have care of souls inthose things that belong peculiarly to the pastoral office and are accommodatedto the capacity of the faithful, the Council intended that such things onlyshould be treated of as might assist the pious zeal of pastors in dischargingthe duty of instruction, should they not be very familiar with the moreabstruse questions of theology.