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Sedeprivationism Refuted

Within the wake of the Second Vatican Council, there have been various movements, who under the pretext of a great fidelity to the Popes up to Venerable Pius XII, that undermine the legitimacy of Vatican II and the Popes who promulgated it and its subsequent decrees and reforms. There are 3 main branches of these movements: Recognize and Resist, Sedevacantism, and Sedeprivationism. The Recognize and Resist position is the position of the Society of St. Pius X that recognizes the Pope but refuses to follow his orders if they are not traditional. On the other hand, the Sedevacantists not only resist the Pope, but they believe he is not the true Pope, but an Antipope! The Sedevacantists say that the Popes from St. John XXIII to Pope Francis I were manifest heretics prior to their election and could not have been Popes. A final peculiar, but much smaller group of radical traditionalists is Sedeprivationism, a position which I will explain and refute in this brief article.

Founder of the Sedeprivationist Theory

Bishop Guerard des Lauriers, author of the Cassiciacum Thesis

There are without a doubt many conflicting theories in the radical traditional Catholic world, many of them refuting each other’s positions. One not talked about is Sedeprivationism, which is neither Sedevacantism or the Recognize and Resist position, so what is it?

Sedeprivationism, known as the Cassiciacum Thesis, is a proposed theory of former Dominican Catholic theologian Michel-Louis Guerard des Lauriers, who accomplished many feats under Pope Pius XII as a priest including being an advisor for the proclamation of the Assumption of Mary as a dogma. With the abuses running rampant after Vatican II, he was utterly concerned with the situation in the Church and eventually became a professor for one of the seminaries of the Society of St. Pius X in Switzerland. However, he began to doubt that Pope Paul VI was truly Pope and was removed from his position in 1977 by Archbishop Marcel Lefebvre, founder of the SSPX.

Not to long after, the French theologian would officially leave the Catholic Church in 1981 after his illicit consecration as a bishop by the excommunicated Vietnamese Archbishop Pierre Martin Ngo Dinh Thuc, who consecrated various Sedevacantist priests into bishops. After this illegal episcopal consecration, the French theologian was certainly excommunicated from the Catholic Church latae sententiae for the crime of schism. He died in 1988 without reconciling with Pope St. John Paul II, the Pope at the time.

The Cassiciacum Thesis Briefly Explained

Sedeprivationism is a very interesting position. It is a branch of the “non-una-cum” radical traditionalists, namely those who do not pray for the Pope at Mass (“Una cum” means “together with”, the part of the Eucharistic anaphora where we pray for our Pope and Bishop).

Sedeprivationism teaches that the current claimant is materially Pope and not formally Pope. They are waiting for the Pope to recant his “heresies”, and then he will be truly Pope. The Sedevacantists, putting themselves in a dead end, believe the Popes since the Council have 0 claim and are Antipopes. The Recognize and Resist camp believes the Pope is Pope formally, but we must resist his orders.

Sometimes, I believe this Cassiciacum Thesis is between the R&R and the Sedevacantist positions. This is because unlike the Sedevacantist position, they are waiting for the conversion of the Pope, whom they consider only to have a material claim. This is similar in a certain way to the R&R position because the R&R position is waiting for the Pope to “return to Tradition.” On the other hand, they are like the Sedevacantists in that they do not pray for the Pope nor call him Holy Father. As we can clearly see, this radical traditionalist position is schismatic for various reasons.

Vatican I Disproves Cassiciacum Thesis!

Bishop Guerard Des Lauriers concocted this thesis in the early 1980s. This theory is neither traditional, nor catholic, but rather, it is a schismatic position and a doctrinal innovation. On one hand, Sedevacantists claim there are no Cardinals to elect a Pope because they believe the new rites of ordination promulgated in 1968 after Vatican II are invalid and thus prevent an election from happening. They also claim all the Cardinals are heretics and invalidly ordained.

On the other hand, what makes the Sedeprivationist position attractive is that it has a way out because it waits for the “conversion” of the one they claim only holds a material claim to the Papacy so he can get a true claim to the Papacy. They reject everything the Popes since Vatican II decree to escape the inconsistencies of choosing what orders from the Pope they resist yet they escape the dead end of Sedevacantism by claiming that there is a way out of the mess. But alas! This theory, as I will demonstrate is pure fiction.

The First Vatican Council debunks this theory that the Pope can be a material claimant but not possess any legitimate authority. It goes against common sense and against the dogmatic teaching of the First Vatican Council.

If anyone thus speaks, that the Roman Pontiff has only the office of inspection or direction but not the full and supreme power of jurisdiction over the universal Church, not only in things which pertain to faith and morals, but also in those which pertain to discipline and government… let him be anathema” (Sess. 4, Chap. 3, 7/18/1870).

Vatican I clarifies what the Church has always believed about the Papacy, and nowhere in any Church Father, Papal Decree, or writing of the Saints do we here that a Pope can be physically Pope but not formally. Therefore, those who uphold the Cassiciacum Thesis in principle deny the Roman Primacy’s ability to govern the Church with supreme jurisdiction! This position is not only schismatic, but even heretical and can cause people to incur the anathemas of Vatican I.

The position is inconsistent because if a man is Pope, he has supreme authority of the Church. A Pope cannot be separated from his authority. Because Pope Francis is the Pope, we must pledge full obedience to him. We cannot prove that he is not the Supreme Pontiff because to deny the Pope is Pope is a matter of private interpretation, which the Cassiciacum Thesis entails. One cannot say that Pope Francis is the Pope and then say that he possesses no jurisdiction because of an alleged “heresy.” This is merely Protestant private interpretation applied to papal documents. Whereas Protestants privately interpret Holy Scripture and disagree with interpreting the Bible, the radical traditionalist groups have different positions that privately interpret Papal documents and end up debating each other’s theses.

Sedeprivationism and Private Judgment

Finally, Sedeprivationism is a mere theological opinion. It is not true, nor can it be verified as such because it comes from a Sedevacantist bishop who possesses absolutely no authority in the Catholic Church. After the Society of St. Pius X was suppressed in 1975, it had no authority to teach in the Catholic Church, and Father Guerard at the time had no authority in the Catholic Church. This became obviously so when he began to doubt the Supreme Pontiff was actually Pope and was removed from his professorship with the SSPX.

Sedevacantists do not constitute the teaching authority of the Church and do not even claim to have ordinary jurisdiction! Let us recall some of the teachings of the Catechism of St. Pius X.

“49 Q. To whom does the exercise of this power [to teach] belong?
A. The exercise of this power belongs solely to the Hierarchy that is, to the Pope and to the bishops subordinate to him.”

This is very crucial in understanding the Sedeprivationist position. It is private opinion! Bishop des Lauriers may have been a seasoned theologian, but this is merely private interpretation. Sedevacantists have no authority to teach in the Church, nor do they claim ordinary authority. This means they should not calling the Pope a heretic, an Antipope, or a partial claimant. The lawful pastors of the Church are those appointed by the present Pope and not some radical-traditionalists who are just purveyors of illicit Sacraments. Therefore, we must continue to persevere and submit ourselves to the true teaching authority of the Church and not to those who remain outside of it.


As I have demonstrated, the Sedeprivationist position not only contradicts an Ecumenical Council’s anathema, but it also is the result of individual judgment. No Church Father, be it St. Cyprian, St. Gregory the Great, or St. John Chrysostom taught that one can be partially Pope. Just like Sedevacantism, Sedeprivationism is indeed a dead-end position. Let us continue to promote fidelity and obedience to the lawful successor of St. Peter, Pope Francis I.


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