The Catholic Church continues to teach this doctrine. The Compendium of the Catechism of the Catholic Church says infallibility is exercised when the Roman Pontiff, as supreme pastor, or the college of bishops in union with him, proclaims by a definitive act a doctrine pertaining to faith or morals. It also says the faithful must adhere to such teaching with the obedience of faith. Vatican II’s Lumen Gentium repeats the same basic teaching, saying that papal definitions are irreformable when the Pope, as supreme shepherd and teacher of all the faithful, proclaims by a definitive act a doctrine of faith or morals. Vatican II also clarifies that the infallibility of the Church resides in the body of bishops when they exercise the supreme magisterium with the successor of Peter.
The Catholic case rests heavily on the belief that Christ gave Peter a unique pastoral role among the apostles. Catholics commonly cite Matthew 16:18–19, where Peter receives the keys of the kingdom and the power of binding and loosing; Luke 22:31–32, where Christ prays that Peter’s faith may not fail and commands him to strengthen his brethren; and John 21:15–17, where the risen Christ tells Peter to feed and shepherd His sheep. Pastor aeternus explicitly uses these Petrine texts in support of the Roman doctrine of primacy and infallible teaching authority.
From a Catholic perspective, papal infallibility is not supposed to be a personal privilege for the Pope’s glory. It is presented as a charism of service: a protection given for the unity and doctrinal stability of the Church. Vatican I also says the Holy Spirit was not promised to Peter’s successors so they could reveal new doctrine, but so they could guard and faithfully expound the apostolic deposit of faith. That distinction matters because Catholic theology does not claim that the Pope can invent new revelation. It claims that, under specific conditions, he can definitively clarify what belongs to the faith handed down from the apostles.
The Orthodox objection is not usually that the Church can never speak definitively. Orthodoxy affirms the authority of the ecumenical councils and the Spirit-guided life of the Church. The objection is that Rome locates a unique, irreformable teaching authority in one bishop in a way Orthodoxy believes is foreign to the first millennium. The Orthodox Church in America states plainly that Orthodoxy does not believe in the infallibility of the Pope of Rome, or of any individual, but upholds that the Church gathered together in council under the Holy Spirit is guided in making correct decisions and proclaiming truth.
This is why Acts 15 is important in the debate. In the Jerusalem Council, the apostles and elders gather to address the Gentile question. The decision is conciliar: “it seemed good to the Holy Spirit and to us” (Acts 15:28). Critics argue that this biblical pattern is closer to Orthodox conciliarity than to a later Roman model in which one bishop may issue an irreformable definition for the whole Church. The same argument is made from the first four ecumenical councils: Nicaea I, Constantinople I, Ephesus, and Chalcedon defined doctrine for the universal Church through councils, not by one bishop acting alone.
The most famous historical case raised against papal infallibility is Pope Honorius I, who reigned from AD 625 to 638 during the Monothelite controversy. Monothelitism taught, in effect, that Christ had only one will, whereas orthodox dyothelite Christology confesses two natural wills in Christ, divine and human, corresponding to His two natures. The Third Council of Constantinople, held in 680–681 and later received as the sixth ecumenical council, condemned Monothelitism and included Honorius among those anathematized. The council’s text says Honorius was anathematized because he followed Sergius and confirmed impious doctrines.
The Honorius case is not simple. Catholic defenders argue that Honorius did not define a doctrine ex cathedra. Therefore, they say, his case does not technically refute the 1870 definition. Some Catholic treatments also stress that Pope Leo II confirmed the condemnation while emphasizing Honorius’s failure to guard and set forth the apostolic faith rather than treating him as having issued an infallible heretical definition.
Critics respond that this still creates a major historical problem. If a pope could be condemned by an ecumenical council and that condemnation could be confirmed by another pope, then later claims about Roman doctrinal indefectibility appear more complicated than simple slogans suggest. The issue is not merely whether Honorius technically met Vatican I’s later criteria. The deeper question is whether Vatican I represents faithful clarification of the ancient Church’s faith or a later development beyond the first-millennium pattern.
The debate, then, is not really about whether popes can be intelligent, holy, or useful in preserving unity. Nor is it merely about whether Rome had ancient honor or primacy. Many Orthodox Christians can affirm that Rome held a place of honor in the early Church while rejecting universal jurisdiction and papal infallibility as later exaggerations. The real controversy is ecclesiological: where did Christ locate final doctrinal authority in His Church? In the Pope alone under rare conditions? In the bishops united with the Pope? Or in the whole Church gathered, tested, and received through council, worship, and the Holy Spirit’s guidance?
From a historic Orthodox critique, papal infallibility is difficult to square with the conciliar pattern of the first millennium, the lived authority of ecumenical councils, and the Honorius case. From the Catholic side, the doctrine is defended as a narrowly defined protection of the Church’s faith, not a claim that popes are personally flawless or constantly inspired. That distinction should be kept clear, because the strongest critique is not a caricature: it is whether Vatican I’s definition truly reflects the ancient apostolic Church or represents a later Roman development.
Primary / official Catholic sources
Vatican I, Pastor aeternus, English translation hosted by EWTN:
https://www.ewtn.com/catholicism/teachings/vatican-is-dogmatic-constitution-pastor-aeternus-on-the-church-of-christ-243
Vatican II, Lumen Gentium, especially section 25:
https://www.vatican.va/archive/hist_councils/ii_vatican_council/documents/vat-ii_const_19641121_lumen-gentium_en.html
Compendium of the Catechism of the Catholic Church, especially questions 182 and 185:
https://www.vatican.va/archive/compendium_ccc/documents/archive_2005_compendium-ccc_en.html
CDF, “The Primacy of the Successor of Peter in the Mystery of the Church” (1998):
https://www.vatican.va/roman_curia/congregations/cfaith/documents/rc_con_cfaith_doc_19981031_primato-successore-pietro_en.html
Orthodox sources
Orthodox Church in America, “Infallibility”:
https://www.oca.org/questions/romancatholicism/infallibility
Orthodox Church in America, “Roman Catholicism” — nineteenth-century Church history section:
https://www.oca.org/orthodoxy/the-orthodox-faith/church-history/nineteenth-century/roman-catholicism
Council / historical sources
Third Council of Constantinople, text hosted at New Advent:
https://www.newadvent.org/fathers/3813.htm
Catholic Encyclopedia, “Third Council of Constantinople”:
https://www.newadvent.org/cathen/04310a.htm
Scripture references
Matthew 16:18–19
Luke 22:31–32
John 21:15–17
Acts 15, especially Acts 15:28
1 Timothy 3:15
Jude 3