The subject of infallibility is one of the most misunderstood subjects among Catholics today. There are two different definitions of infallibility as taught by the Catholic Church; “Infallibility of the Pope” refers to when a pope exercises his office in defining a doctrine on faith and morals, while “Infallibility of the Church” refers to the Catholic Church being divinely kept from the possibility of error in her definitive teaching on matters of faith and morals. It is this latter definition that many Catholics (especially Feeneyites) have a difficult time grasping. If a Catholic doesn't understand how infallibility of the Church works, they will often neglect or even reject some doctrines of the Church that they are supposed to believe. Here we will attempt to explain how infallibility of the Church works for those who do not understand.
The definition of the Infallibility of the Church is described very clearly in "The Catechism Explained" (Spirago-Clarke) under the section, "The Infallibility of the Church", page 237:
"As Christ was not to remain always on earth, He appointed another infallible teacher, His Church, and provided it with the necessary gifts, especially with the assistance of the Holy Spirit. Christ conferred on His Apostles and their successors the teaching office and promised them His divine assistance. Thus He said at His ascension into heaven: "Going, teach ye all nations...and behold I am with you all days, even to the consummation of the world" (Matt, xxviii. 19, 20) ; and at the Last Supper: "I will ask the Father and He shall give you another Paraclete that He may abide with you forever, the Spirit of truth"; (John xiv. 16, 17). To St. Peter He said: "The gates of hell shall not prevail against the Church" (Matt. xvi. 18). Since Christ is the Son of God, His words must be true. If the Church, in the carrying out of her teaching office, could lead man into error, Christ would not have kept His word. Hence St. Paul calls the Church "the pillar and ground of truth" (1 Tim. iii. 15), and the measures decided upon by the apostles in the Council of Jerusalem were introduced with the words: "For it hath seemed good to the Holy Ghost and to us" (Acts xv. 28)."
Considering the definition and quotes above pertaining to the Infallibility of the Church, it is clear that it would be an impossibility for there to remain error in the Church that is not eventually corrected by the guidance of the Holy Ghost.
To elaborate further, on the home page of this website we list a large number of quotes from different sources throughout the history of the Church which teach the threefold baptism. To help explain how infallibility of the Church works, we will choose the teaching on baptism of desire from St. Alphonsus Ligouri in his manual on "Moral Theology”, as an example. The Feeneyites, when shown this quote, will simply say that St. Alphonsus and his manual are “not infallible", implying that they may contain errors. Let's look at the implications of this and how it relates to the infallibility of the Church.
St. Alphonsus openly teaches baptism of desire in his manual on Moral Theology, which was published over 250 years ago. This manual was approved for use in Catholic schools and seminaries after it was reviewed and declared to be free of error at the time it was published. Since this manual was approved for Catholic schools and seminaries, there have been over a dozen popes who were certainly aware of the manual. Certainly if there were heretical teachings found within a manual used in Catholic schools and seminaries, it would have been quickly discovered by those dozen popes, or made known very quickly through the global network of bishops and priests to those popes. While St. Alphonsus wrote the manual, the responsibility for making sure the faithful were not exposed to error after it was published was the Pope at the time, followed by all popes and bishops who used the manual in the years and centuries following. However there are no known objections to this manual since it was published.
In addition, if baptism of desire were indeed heresy, then when St.
Alphonsus’s works were scoured during his beatification, and again
during his canonization, and again when he was made Doctor of the
Church, they would have discovered the heresy, and it would have
impeded each of those processes (if they even got past
beatification). The Church would have had to make a declaration that
his manual contained an error, and the Church would have either
noted what the error was, or if the errors were numerous, possibly
ordered the manual to be added to the Index of forbidden books. None
of this ever happened of course. Yet the Feeneyites will still
boldly claim that they have discovered an error that all popes,
bishops and priests of the Church for the last 250 years have
missed! Clearly based on the definition of the Infallibility of the
Church above, this is impossible.
So while we can rightfully say St. Alphonsus was in himself not infallible, and his manual on Moral Theology was in itself not infallible, we can say that all of the Vicars of Christ and clergy throughout the world that succeeded St. Alphonsus and saw the manual have approved of it, and therefore it became part of the teaching of the Church. Individual teachings become official Church teaching this way; the Church assumes ownership of them when there are no objections to their use. When this is seen, this is the infallibility of the Church in progress. We cannot logically say St. Alphonsus was a heretic and that all of the popes and bishops and priests of the world over the last 250 years didn't notice, as this is a denial of the infallibility of the Church. It would be impossible that a holy, divinely founded Church, with the promise of never being able to fail, would have allowed heresy for centuries without noticing it, as that would certainly indicate a failure of the Church. The Holy Ghost would prevent this to maintain an infallible Church.
The example above can be applied to any of the teachings on baptism of desire on the home page of this website. For instance, Pope Leo XIII approved of the Baltimore Catechism as the standard for schools in the United States in 1885, where it remained the standard for the next century. This catechism contains a blatant teaching on baptism of desire. Why did Pope Leo XIII, and the half a dozen popes that succeeded him, and all the bishops during that century not object if baptism of desire were heresy? To say these popes allowed a heresy for an entire century is to say they poisoned the Church, and that the Holy Ghost failed to prevent it. The Church is Holy, and the Holy Ghost would have seen to it that these popes corrected any errors contained, just as the Church has always done with heresies such as Arianism, Nestorianism, Protestantism, and so many other false teachings throughout the history of the Church.
So what a theologian teaches is also a reflection of all the popes and bishops of the Church. To condemn the theologian’s writing as heretical, you would logically have to also condemn all the popes and bishops after that theologian’s time that continually approved of the writing and failed to warn the faithful of the supposed heresies contained. You would at the same time logically have to conclude that the Church is not infallible, which is impossible since this would be directly opposed to Scripture. If the divinely founded Catholic Church has been teaching error all of these centuries, it has been unfairly sending unsuspecting souls to damnation. It would be to completely deceive the faithful for Scripture to say the Church is the pillar and ground of truth, and mandate that the faithful be members of it and consult it, then have error mixed throughout it. This would be a failure of the Church. We have the promise from Scripture that the Holy Ghost would prevent this.
The Church consists of ordinary everyday teaching and occasional solemn teaching (when the ordinary teaching appears to be going out of bounds). This is how infallibility of the Church works; it tacitly approves of day-to-day ordinary Church teaching, and speaks up (through solemn teaching) when corrections are needed. Just as a mother does not need to verbally approve of every step and action her child takes; she simply speaks up when the child is in danger or has done something wrong. Together, ordinary and solemn teaching form one infallible teaching, as was clearly decreed at the First Vatican Council.
Understanding the “Infallibility of the Church” is crucial for
those who don't understand the threefold baptism, as it puts
everything in perspective. Infallibility of the Church is a dogma of
the Church; it originates in Scripture, and has been mandatory to
believe since the start of the Church. To say all of the quotes on
the home page of this website spanning over 1800 years of the Church
have all been in error throughout the history of the Church, and the
Church never corrected them, is a complete denial of this dogma. We
all know well that the Church has not condemned baptism of desire
and blood because it approves of it.