A Guide to Papal Infallibility

Is the Pope always right? Many non-Catholics and even Catholics misunderstand the meaning of Papal Infallibility.
They read the word “infallible” without any context and assume it means that the Pope can never be wrong. If falsely understood this way, it can be an off-putting concept for some.
The Catechism of the Catholic Church defines Papal Infallibility as follows:
“The Roman Pontiff, head of the college of bishops, enjoys this infallibility in virtue of his office, when, as supreme pastor and teacher of all the faithful – who confirms his brethren in the faith he proclaims by a definitive act a doctrine pertaining to faith or morals… (CCC: 891).”
If we break the Church’s definition of Papal infallibility down, it’s apparent that the Pope is only infallible when he clearly and willingly proclaims something relating to faith and morals. That means he cannot be expected to make a correct World Series prediction every year. Nor does it mean that he cannot make private mistakes or act immorally, which many popes have done throughout history.
In fact, to be infallible, the Pope must literally speak ex cathedra, or from the seat and office of the first Pope, St. Peter. Such public proclamations are so rare, that it has only formally happened once when, in 1950, Pope Pius XII declared the Assumption of Mary to be official doctrine. So, infallibility is not something the popes have taken lightly, and they only invoke it when the Holy Spirit is speaking through them.
Why is the Pope Infallible?
Now that we know what Papal infallibility is, let’s explore why it exists.
In Matthew 16:18, Jesus tells Simon, “I also say to you that you are Peter, and upon this rock I will build My church; and the gates of Hades will not overpower it.”
When Jesus says this, he is not pointing to a literal rock. He is giving Simon the name of Peter, which means “stone” in the original Biblical language. Peter thus becomes the first Pope, the foundation upon which Jesus builds His Church.
The fact that the Church is built upon Peter takes nothing away from Jesus’ role as head of the Church. Peter, and the popes who succeed him, become stewards of Christ’s Church on earth. In fact, the very next verse explains Jesus’ intention:
“I will give you the keys of the kingdom of heaven, and whatever you bind on earth shall be bound in heaven, and whatever you loose on earth shall be loosed in heaven” (Matthew 16:19).

Jesus is handing Peter the keys to His kingdom. Peter and all the popes are gatekeepers to the faith, but only because the Holy Spirit guides them. Indeed, Jesus tells His Apostles:
“…when He, the Spirit of truth, comes, He will guide you into all the truth; for He will not speak on His own initiative, but whatever He hears, He will speak; and He will disclose to you what is to come (John 16:13).”
Since the Holy Spirit guides the Pope, who is Peter’s successor, it is impossible that the Pope can make a mistake when it comes to faith and morals, which is why he is infallible in that regard. However, when it comes to matters of personal morality or private opinions, the Pope is as human as the rest of us.
Papal Infallibility: The Bottom Line
The Catholic Church has had more than 2,000 years’ worth of popes. Although the doctrine of Papal infallibility was only officially declared in the nineteenth century, in practice, it had been recognized since the early Church.
In all that time, Papal Infallibility has never been abused, not even by the worst popes. As mentioned, it was only used once in modern times, and that was 70 years ago. The only way that such a clean track record is possible is with the help of the Holy Spirit, which always guides the Church, never allowing the gates of Hades to triumph against her.