Pope Pius XII: Lay catechetical teaching must be under the Pope and the Bishops

The Venerable Servant of God, Pope Pius XII

Christ Our Lord entrusted the truth which He had brought from heaven to the Apostles, and through them to their successors. He sent His Apostles, as He had been sent by the Father (Jn. 20:21), to teach all nations everything they had heard from Him (cf. Matt. 28:19 f.). The Apostles are, therefore, by divine right the true doctors and teachers in the Church. Besides the lawful successors of the Apostles, namely the Roman Pontiff for the universal Church and Bishops for the faithful entrusted to their care (cf. can. 1326), there are no other teachers divinely constituted in the Church of Christ... 

As for the laity, it is clear that they can be invited by legitimate teachers and accepted as helpers in the defense of the faith. It is enough to call to mind the thousands of men and women engaged in catechetical work, and other types of lay apostolate, all of which are highly praiseworthy and can be strenuously promoted. But all these lay apostles must be, and remain, under the authority, leadership, and watchfulness of those who by divine institution are set up as teachers of Christ's Church. In matters involving the salvation of souls, there is no teaching authority in the Church not subject to this authority and vigilance.

Recently what is called "lay theology" has sprung up and spread to various places, and a new class of "lay theologian" has emerged, which claims to be sui juris; there are professors of this theology occupying established chairs, courses are given, notes published, seminars held. These professors distinguish their teaching authority from, and in a certain way set it up against, the public Teaching Authority of the Church; at times, in order to justify their position, they appeal to the charismatic gifts of teaching and of interpreting prophecy, which are mentioned more than once in the New Testament, especially in the Pauline Epistles (e.g. Rom. 12:6 f.; I Cor. 12:28-30); they appeal to history, which from the beginning of the Christian religion down to today presents so many names of laymen who for the good of souls have taught the truth of Christ orally and in writing, though not called to this by the Bishops and without having asked or received the sacred teaching authority, led on by their own inward impulse and apostolic zeal. Nevertheless it is necessary to maintain to the contrary that there never has been, there is not now, and there never will be in the Church a legitimate teaching authority of the laity withdrawn by God from the authority, guidance, and watchfulness of the sacred Teaching Authority; in fact, the very denial of submission offers a convincing proof and criterion that laymen who thus speak and act are not guided by the Spirit of God and of Christ. Furthermore, everyone can see how great a danger of confusion and error there is in this "lay theology"; a danger also lest others begin to be taught by men clearly unfitted for the task, or even by deceitful and fraudulent men, whom St. Paul described: "The time will come when men . . ., always itching to hear something fresh, will provide themselves with a continuous succession of new teachers, as the whim takes them, turning a deaf ear to the truth bestowing their attention on fables instead" (cf. II Tim. 4:3 f.).


The full text of Si Diligis can be read here.