pope, St. Peter, when he denied Christ three times just before the Crucifixion (Matthew 26:69–75).
Everything the sacred authors wrote in the Bible is inspired, but not everything every pope says or writes is infallible. Infallibility means that if the pope attempts to teach a false doctrine on faith or morals, the Holy Spirit prevents him (even by death) from imposing such an error on the faithful. So, for example, no pope can declare, “As of today, the number of commandments is nine instead of ten.” Nor can he declare, “Jesus was not a man” or “Jesus was not the Son of God.”
Infallibility also doesn’t mean perfection. Infallible statements aren’t perfect statements, so they can be improved so that subsequent popes can use better or more accurate language. Yet infallible statements can never be contradicted, rejected, or refuted. So according to Catholicism, an immoral pope (you’ll find several in Church history) can sin like any man and will answer to God for his evil deeds. But as head of the Church, the pope retains his infallibility on matters of faith and morals as long as he remains pope.
No pope in 2,000 years has formally and officially taught an error of faith or morals to the universal Church. Individually, some may have been poor or inadequate theologians or philosophers, and some may have had erroneous ideas about science. That has nothing to do with papal infallibility, however, because the main objective is to preserve the integrity of Catholic faith for all the members at all times and in all places.
The pope can exercise his papal infallibility in two ways. One is called the Extraordinary Magisterium, and the other is called Ordinary Magisterium. The word magisterium is from the Latin word magister meaning “teacher,” so the Magisterium is the teaching authority of the Church, which is manifested by the pope alone and or the pope along with the bishops all over the world.
The Extraordinary Magisterium
Extraordinary means just that: out of the ordinary. When an Ecumenical (General) Council is convened, presided over, and approved by the pope, and he issues definitive decrees, they’re considered infallible because they come from the Extraordinary Magisterium. The Church has held an all-time total of only 21 councils. These are gatherings of the world’s bishops and cardinals. Sometimes priests, deacons, and laity are invited to observe, but only bishops and the pope can discuss and vote. The culmination of these councils is a written letter that explains the faith, interprets Scripture, or settles disputed topics of faith and morals. They never contradict the Bible but apply biblical truths to contemporary concerns and problems, as well as giving more understanding to essential core beliefs. The names and years of the councils throughout Church history are as follows:
1 Nicea (325)
2 Constantinople I (381)
3 Ephesus (431)
4 Chalcedon (451)
5 Constantinople II (553)
6 Constantinople III (680–81)
7 Nicea II (787)
8 Constantinople IV (869–70)
9 Lateran I (1123)
10 Lateran II (1139)
11 Lateran III (1179)
12 Lateran IV (1215)
13 Lyons I (1245)
14 Lyons II (1274)
15 Vienne (1311–12)
16 Constance (1414–18)
17 Basel-Ferrara-Florence (1431–45)
18 Lateran V (1512–17)
19 Trent (1545–63)
20 Vatican I (1869–70)
21 Vatican II (1962–65)
The Ecumenical Councils have defined doctrines such as the divinity of Christ (Nicea); the title of Mary as the Mother of God (Ephesus); the two natures of Christ, human and divine, being united in the one divine person (Chalcedon); transubstantiation (see Chapter 10) to describe how the bread and wine are changed at Mass into the Body and Blood of Christ (Lateran IV); the seven sacraments, Sacred Scripture and Sacred Tradition (see Chapter 2), and other responses to the Reformation (Trent); and papal infallibility (Vatican I). These conciliar decrees and ex cathedra papal pronouncements form the Extraordinary Magisterium.
Ex cathedra (Latin for “from the chair”) pronouncements from the pope are considered infallible teachings. The only two ex cathedra pronouncements in 2,000 years have been the dogmas of the Immaculate Conception (1854) and the Assumption (1950). When the pope teaches ex cathedra, he’s exercising his universal authority as Supreme Teacher of a doctrine on faith or morals, and he’s incapable of error. Catholics consider the Assumption of Mary and the Immaculate Conception infallible teachings because they involve the solemn, full, and universal papal authority. (See Chapter 17 for more information on Mary, the Immaculate Conception, and the Assumption.)
Unlike governments that separate their executive, legislative, and judicial branches, in the Catholic Church, the pope is all three rolled into one. He’s the chief judge, the chief lawmaker, and the commander in chief all at the same time. That’s why the triple crown (also known as a tiara or triregnum) was used in papal coronations — to symbolize his three-fold authority and that he’s higher in dignity and authority than a king (one crown) or even an emperor (double crown). (Pope St. Paul VI was the last pope to wear the tiara. It’s a matter of personal choice and preference now.)
The Ordinary Magisterium
The second way that an infallible teaching is taught to Catholics is through the Ordinary Magisterium, which is the more common and typical manner, hence the reason why it’s called ordinary. This teaching of the popes is consistent, constant, and universal through their various documents, letters, papal encyclicals, decrees, and so on. It’s never a new doctrine but rather one that has been taught ubique, semper et ab omnibus (Latin for “everywhere, always and by all”). In other words, when the pope reinforces, reiterates, or restates the consistent teaching of his predecessors and of the bishops united with him around the world, that’s considered the Ordinary Magisterium and should be treated as infallible doctrine.
When popes write papal documents (anything authored by a pope), the title they use to refer to themselves the most is Servant of the Servants of God (Servus Servorum Dei in Latin). St. Gregory the Great (590–604) was the first pope to use this title. Check out the different types of papal documents from the most solemn on down:
Papal Bulls
Papal
