There are two possible faithful positions on the question as to whether Vatican II could have erred on faith or morals:
1. No errors are possible in any teaching on faith or morals of an Ecumenical Council, so Vatican II contains no errors.
2. Non-infallible teachings of Ecumenical Councils can err only to a limited extent, never to a grave extent; heresy and other grave errors are not possible in the decisions of Ecumenical Councils on faith or morals. This would suggest that some limited errors are possible in Vatican II. The Magisterium has not ruled out this position, as far as I am aware.

My Position

Definitive teachings on faith or morals of any Ecumenical Council approved by the Pope are infallible, including both formal definitions and definitive teachings without a definition. For example, the charism of truth and never failing faith was taught by Vatican I (Pastor Aeternus 4, 7) definitively, and this teaching is supported by other points in the same document, such as the unblemished Apostolic See. But in the Relatio of Vatican I, Bishop Gasser notes that the Council decided not to make a definition of this or other points in PA, apart from the formal definition on Papal Infallibility. This does not mean that Catholics can reject the charism of never failing faith, which has been taught also by Constantinople III and by the perennial teaching of the Church, and so is clearly infallible under the Ordinary Universal Magisterium (OUM).

That definitive teachings on faith and morals of an Ecumenical Council approved by the Pope are infallible is necessarily implied by the fact that the teaching of Christ is infallible, without any formal definitions, and by the fact that the teaching authority of the Church is identical to that of Christ. These are not two different authorities, but rather the Church has been given the authority of Christ. Is Christ required to word His teachings as a formal definition in order for the content to be infallible? Certainly not.

Then, when we examine the teachings of past Councils, we find definitive teachings against heresy, which have always been understood by the Church as dogma, without the form of a definition.

Such a limit on the authority of the Church, to be unable to teach infallibly under Papal Infallibility or Conciliar Infallibility unless the wording is that of a definition, first of all restricts Her authority without reason or benefit to salvation, and secondly, would allow any definition to be rejected on the basis of the wording. Any wording could be questioned and interpreted as not really a definition for almost any teaching. We see such sophistry at work, for example, in the claim that Pope Benedict’s resignation was not valid, even though he called for a new conclave, because of the wording. The Church’s teaching should not be subject to attempted nullifications based not on the content of the teaching, but merely on the incidental form of its exterior expression.

Then we know that the OUM does not require a formal definition in order to teach infallibly, thereby proving that the Church can teach infallibly without that particular form of a definition.

Finally, in the Relatio of Vatican I, Bishop Vincent Gasser rejects the idea that Papal Infallibility requires, beyond the criteria taught by Pastor Aeternus 4, 9, a particular wording or form. The idea of requiring such a form was considered and rejected, and is not part of the teaching on Papal Infallibility. So a Pope can teach infallibly without a particular form, thus suggesting that Popes teach infallibly much more often than commonly thought, as any definitive teaching, that also meets the other criteria, would fully meet the requirements of Papal Infallibility. So why should the same not be true of an Ecumenical Council, whose teachings are never infallible unless confirmed by the Pope? When the successors of the other Apostles gather with the successor of Peter, why should the ability to teach infallibly be more restricted than when the Pope teaches alone? Thus, every definitive teaching of an Ecumenical Council on faith or morals, approved by the Pope (which also meets the other criteria) is infallible.

Here is the explanation of the rejection of a requirement for a particular form for an infallible teaching of the Pope, in the Relatio of Bishop Gasser:

“030. But some will persist and say: there remains, therefore, the duty of the Pontiff – indeed most grave in its kind – of adhering to the means apt for discerning the truth, and, although this matter is not strictly dogmatic, it is, nevertheless, intimately connected with dogma. For we define: the dogmatic judgments of the Roman Pontiff are infallible. Therefore let us also define the form to be used by the Pontiff in such a judgment. It seems to me that this was the mind of some of the most reverend fathers as they spoke from this podium. But, most eminent and reverend fathers, this proposal simply cannot be accepted because we are not dealing with something new here. Already thousands and thousands of dogmatic judgments have gone forth from the Apostolic See; where is the law which prescribed the form to be observed in such judgments?

“031. Perhaps someone will say: if we don’t have a law, let us make one. But let us not do this lest we run up against that already condemned law which said that the council was above the Pope. Furthermore, of what use would be such a law? Would it not be completely useless, since it would never be able to be verified by the faithful and the bishops scattered throughout the world? Even more, it would be a very dangerous thing since it would offer the opportunity for innumerable foolish objections and anxieties. Therefore, let Peter gird himself according to the word of our Lord Jesus Christ, since Peter does not grow old while the world grows old but rather renews his powers like the eagle.” [Relatio of Vatican I]

Now this position presents a certain problem when applied to Vatican II, as Pope Saint Paul VI has clearly implied that some teachings of Vatican II are infallible, but others are non-infallible.

Paul VI: “Again, you cannot appeal to the distinction between what is dogmatic and what is pastoral to accept certain texts of this Council and to refuse others. Indeed, not everything in the Council requires an assent of the same nature: only what is affirmed by definitive acts as an object of faith or as a truth related to faith requires an assent of faith. But the rest also forms part of the solemn magisterium of the Church to which each member of the faithful owes a confident acceptance and a sincere application.” [Letter of Pope Saint Paul VI to archbishop Marcel Lefebvre]

Some texts of Vatican II are “affirmed by definitive acts as an object of faith” and therefore require the full assent of faith given to infallible teachings. But Saint Paul VI does not say that only definitions require this assent. Instead, he says that any definitive acts (with the other criteria) are infallible. And while Vatican I says “he defines” in its definition of Papal Infallibility, Vatican II says “by a definitive act, he proclaims”.

Since Pope Saint Paul VI says that “the rest” is part of the solemn magisterium which, as he phrases it, requires a lesser and different type of assent (religious assent), this implies these other teachings are non-infallible. However, non-infallible teachings do not necessarily err; most happen to contain no error. So it is nevertheless possible for the non-infallible teachings of Vatican II to contain no error.

The other issue, which I believe is decisive in the Vatican II question, is that since the Council the body of Bishops dispersed in the world and the successive Popes have never ceased to teach the teachings of Vatican II, very frequently, each teaching as one position definitively to be held (LG 25), making these teachings, even if non-infallible when issued, now infallible under the OUM.

One can hardly find a substantial teaching document of the Church since Vatican II that does not cite the Council, most often repeatedly or even profusely. Such use of Vatican II by the Magisterium implies, but the indefectibility of the Church, that the Council contains — as a matter of absolute certitude — no grave errors on doctrine or discipline. For the Church is not the blind leading the blind, like the schismatics and heretics of any age. What She affirms as truth again and again, Pope after Pope, and throughout the body of Bishops, must be truth.

A Pope or Council in the future could declare that all teachings of Vatican II on faith or morals (or more broadly all teachings of all Ecumenical Councils to-day on faith or morals) is now infallible, if not by Conciliar infallibility, then by the ordinary universal magisterium. For the Church has never found any teaching of any Ecumenical Council to be in error in the least.

Such a formal infallible declaration by a Pope or Council would end these constant attacks on the Council, which have persisted for over 50 years. If so, then from that point forward, anyone who rejects Vatican II on any teaching would be a heretic and schismatic.

Can a Council refrain from teaching definitively? Trent refrained from teaching on the Immaculate Conception, but reaffirmed the feast of the same for the Church. So only definitive teachings, with the other criteria, would be infallible.

What about future Councils? If a future Council teaches non-infallibly (non-definitively) then can such teachings err? No Ecumenical Council approved by the Pope has ever been known to err at all. But even if errors in what is non-infallible are theoretically possible (and that is for the Magisterium to decide), no grave errors on doctrine or discipline are possible in the teaching of any Pope or Council, under the dogma of the OUM that the Apostolic See is unblemished.

Those who accuse Vatican II of heresy or other grave error are therefore already heretics and schismatics, even before the Magisterium decides the question discussed in this article. For they accuse the Church of defecting, contrary to the dogma of indefectibility. And this aspect of their accusations against Popes and Councils has become very clear over time. As they continue to accuse Vatican II, Pope Francis, and other Popes and Councils, their rejection of indefectibility has become so clear that they are manifest heretics and schismatics who accuse multiple Popes and Councils of grave errors that they admit would gravely harm the Church (if these really were errors). God does not permit the one holy catholic and apostolic Church to defect.

Thus, it is already dogma that Vatican II, like every other general Council, contains no grave errors on doctrine or discipline. And it is easily explained and defended that no errors at all on faith or morals are found in any past Council’s teaching, including Vatican II.

Bellarmine: “A general Council represents the universal Church, and hence has the consensus of the universal Church; therefore, if the Church cannot err, neither can a legitimate and approved Ecumenical Council err.”

Bellarmine: “It must be held with Catholic faith that general Councils confirmed by the Supreme Pontiff can neither err in faith nor morals.”

Ludwig Ott, in The Fundamentals of Catholic Dogma: “It has been the constant teaching of the Catholic Church from the earliest times that the teachings of the General Councils are infallible.” [Ott, The Fundamentals of Catholic Dogma Revised and Updated Edition (London: Baronius Press, 2018), p. 321.]

Ronald L Conte Jr