Here's what it had to say about a Pope falling into heresy:
Could the Pope ever fall into heresy?
The question of whether a Pope can fall into heresy is complex and has been debated throughout Church history. Here's a breakdown of the relevant theological considerations:
Papal Infallibility
Papal infallibility is a dogma of the Catholic Church that states that the Pope is preserved from error when he speaks ex cathedra (i.e., when, as supreme pastor and teacher of all the faithful, he proclaims by a definitive act that a doctrine concerning faith or morals is to be held by the universal Church) 1 2. This infallibility is not a personal attribute of the Pope but a charism given to him for the benefit of the Church 2.
Limits of Infallibility
It is crucial to understand the limits of papal infallibility. The Pope is not infallible in everything he says or does 2. Infallibility applies only to definitive pronouncements on matters of faith and morals when speaking ex cathedra 1 2. His personal opinions, actions, or statements on non-doctrinal matters are not covered by infallibility.
Heresy Defined
Heresy is the "obstinate post-baptismal denial of some truth which must be believed with divine and Catholic faith, or it is likewise an obstinate doubt concerning the same" 3 4. Formal heresy involves a conscious and willful rejection of Church teaching 1.
Can a Pope Be a Heretic?
Theologians have different views on whether a Pope can become a heretic:
Possibility of Private Heresy: Some theologians argue that a Pope, as a private individual, could fall into heresy by holding beliefs contrary to defined doctrines 1 5. However, this would not be an ex cathedra pronouncement and would not bind the Church.
Loss of Papacy: A key question is whether a Pope who becomes a manifest (publicly known) heretic would automatically lose his office. Some theologians throughout history have posited that a Pope who becomes a manifest heretic ceases to be Pope 1. However, there is no definitive Church teaching on this matter.
Deposition of a Pope: Canon law does not provide a mechanism for formally deposing a Pope. Theologians who argue for the possibility of a Pope losing his office due to heresy often suggest that it would be a de facto loss, recognized by the Church, rather than a formal deposition 1.
Guidance of the Holy Spirit: The Church believes that the Holy Spirit guides and protects the Church from error 2. Some argue that God would not allow a Pope to lead the entire Church into heresy through a formal, ex cathedra pronouncement 2.
Pertinacity
Pertinacity, or obstinate adherence to a particular tenet, is required to make heresy formal 1. As long as one remains willing to submit to the Church's decision, they remain a Catholic Christian at heart, and their wrong beliefs are only transient errors and fleeting opinions 1.
Conclusion
In summary, the possibility of a Pope falling into heresy is a complex theological question with no definitive answer in Church teaching. While papal infallibility protects the Church from being bound to error by a Pope's ex cathedra pronouncements on faith and morals, the possibility of a Pope holding heretical views as a private individual remains a topic of debate. The consequences of such a situation, including the potential loss of office, are also subject to differing theological opinions.
References
Catholic Encyclopedia Heresy / The Encyclopedia Press
Catholic Encyclopedia Science and the Church / The Encyclopedia Press
Theology Today: Perspectives, Principles and Criteria 14 / International Theological Commission
CCC 2089
Summa Theologiae II-II, Q. 11, A. 2 / Thomas Aquinas
In short, not a whole lot different than what traditionalists of various stripes argue.