In an open letter to the hierarchy, prominent clergy, theologians and scholars have accuse Francis of seven heresies and called for the bishops to take measures to bring about his removal from office. At the end of the 20 page document the authors discuss how the loss of office occurs, and in so doing explicitly reject the sedevacantist' position. They state that the automatic loss of office theory, as it is expounded by the sedevacantists and by Fr. Kramer, is incompatible “with Catholic tradition and theology.” The explanation the clergy and theologians provide for how the loss of office occurs is identical to what Robert Siscoe and John Salza defend in True or False Pope?, as those who have followed the debate over the years will readily see. Here are the pertinent pages.
Canon law and Catholic theology concerning the situation of a heretical pope
The situation of a pope falling into heresy has long been a subject of discussion by Catholic theologians. This situation was brought into prominence after the ecumenical Third Council of Constantinople anathematized the Monothelite heresy in 681, and posthumously anathematized Pope Honorius for his support of this heresy; this condemnation of Honorius as a heretic was repeated by Pope St. Leo II when he ratified the acts of that Council. Since that time, Catholic theologians and canonists have reached a consensus on several essential points concerning the implications of a pope falling into public heresy. We will briefly present these points here.
It is agreed that no pope can uphold heresy when teaching in a way that satisfies the conditions for an infallible magisterial statement. This restriction does not mean that a pope cannot be guilty of heresy, since popes can and do make many public statements that are not infallible; many popes indeed never issue an infallible definition.
It is agreed that the Church does not have jurisdiction over the pope, and hence that the Church cannot remove a pope from office by an exercise of superior authority, even for the crime of heresy.
It is agreed that the evil of a heretical pope is so great that it should not be tolerated for the sake of some allegedly greater good. Suarez expresses this consensus as follows: 'It would be extremely harmful to the Church to have such a pastor and not be able to defend herself from such a grave danger; furthermore it would go against the dignity of the Church to oblige her to remain subject to a heretic Pontiff without being able to expel him from herself; for such as are the prince and the priest, so the people are accustomed to be.' St Robert Bellarmine states: 'Wretched would be the Church’s condition if she were forced to take as her pastor one who manifestly conducts himself as a wolf' (Controversies, 3rd controversy, Bk. 2, cap. 30).
It is agreed that ecclesiastical authorities have a responsibility to act to remedy the evil of a heretical pope. Most theologians hold that the bishops of the Church are the authorities that have an absolute duty to act in concert to remedy this evil.
It is agreed that a pope who is guilty of heresy and remains obstinate in his heretical views cannot continue as pope.Theologians and canonists discuss this question as part of the subject of the loss of papal office. The causes of the loss of papal office that they list always include death, resignation, and heresy. This consensus corresponds to the position of untutored common sense, which says that in order to be pope one must be a Catholic. This position is based on patristic tradition and on fundamental theological principles concerning ecclesiastical office, heresy, and membership of the Church.The Fathers of the Church denied that a heretic could possess ecclesiastical jurisdiction of any kind. Later doctors of the Church understood this teaching as referring to public heresy that is subject to ecclesiastical sanctions, and held that it was based on divine law rather than ecclesiastical positive law. They asserted that a heretic of this kind could not exercise jurisdiction because their heresy separated them from the Church, and no-one expelled from the Church could exercise authority in it.
The canon law of the Church supports this theological consensus. The first canon to give explicit consideration to the possibility of papal heresy is found in the Decretum of Gratian. Distinctio XL, canon 6 of the Decretum states that the pope can be judged by no-one, unless he is found to have deviated from the faith:
Cunctos ipse iudicaturus a nemine est iudicandus, nisi deprehendatur a fide devius (‘he, the one who is to judge all, is to be judged by none, unless he be found straying from the faith.’)
The wording of this statement seems to have been influenced by Cardinal Humbert's De sancta Romana ecclesia (1053), which stated that the pope is immune from judgment by anyone except in questions of faith: ‘a nemine est iudicandus nisi forte deprehendatur a fide devius.’ The claim made in the canon is a development of Pope Gregory the Great’s statement that evil prelates must be tolerated by their subjects if this can be done while saving the faith (Moralia XXV c. 16: ‘Subditi praelatos etiam malos tolerant, si salva fide possint …’).
The canonical assertion that the pope can be judged for heresy came into being as an explication of the canonical principle that the pope is judged by no-one. The statement in this canon is an enunciation of a privilege; its object is to assert that the pope has the widest possible exemption from judgement by others.
This canon was included, along with the rest of the Decretum of Gratian, in the Corpus iuris canonici, which formed the basis of canon law in the Latin Church until 1917. Its authority is supported by papal authority itself, since the canon law of the Church is upheld by papal authority. It was taught by Pope Innocent III, who asserted in his sermon on the consecration of the Supreme Pontiff that "God was his sole judge for other sins, and that he could be judged by the Church only for sins committed against the faith" [“In tantum enim fides mihi necessaria est, ut cum de caeteris peccatis solum Deum iudicium habeam, propter solum peccatum quod in fide committitur possem ab Ecclesia judicari.”]
Rejection of the canon in the Decretum would undermine the canonical foundation for papal primacy itself, since this canon forms part of the legal basis for the principle that the Pope is judged by no-one.
The canon was universally accepted by the Church after the compilation and publication of the Decretum. The heresy referred to in this canon is understood by virtually all authors to mean externally manifested heresy (the thesis that a pope loses his office for purely internal heresy was advanced by Juan de Torquemada O.P., but it has been conclusively refuted and has been rejected by all canonists and theologians ever since.) Neither the 1917 Code of Canon Law nor the 1983 Code of Canon Law abrogate the principle that a heretical pope loses the papal office. This is agreed by all commentators on these codes, who state that this principle is correct.
The early canonical tradition generally requires that in the specific case of papal heresy, the pope must be admonished several times before being treated as a heretic. The Summa of Rufinus, the Summa antiquitate et tempore (after 1170), and the Summa of Johannes Faventius (after 1171) all assert that the pope must be warned a second and third time to desist from heresy before he can be judged to be a heretic. The Summa of Huguccio states that before the pope can be judged a heretic, he must be admonished to abandon heresy and must contumaciously defend his error in response to such admonition.
Sedevacantist authors have argued that a pope automatically loses the papal office as the result of public heresy, with no intervention by the Church being required or permissible. This opinion is not compatible with Catholic tradition and theology, and is to be rejected. Its acceptance would throw the Church into chaos in the event of a pope embracing heresy, as many theologians have observed. It would leave each individual Catholic to decide whether and when the pope could be said to be a heretic and to have lost his office. It should instead be accepted that the pope cannot fall from office without action by the bishops of the Church.Such action must include adjuring the pope more than once to reject any heresies that he has embraced, and declaring to the faithful that he has become guilty of heresy if he refuses to renounce these heresies. The incompatibility between heresy and membership of the Church is what leads to the loss of the papal office by a heretical pope. The Church's determining that a pope is a heretic, and the announcement of his heresy by the bishops of the Church, is what makes the pope's heresy a juridical fact, a fact from which his loss of office ensues. There are some lesser differences of opinion between Catholic theologians concerning the measures that the Church must take in dealing with a heretical pope. The school of Cajetan and John of St. Thomas asserts that in order for the papal office to be lost, the Church, after ascertaining and pronouncing that the pope is a heretic, must also command the faithful to avoid him for his heresy. The school of St. Robert Bellarmine does not reject the step of commanding the faithful to avoid the pope as a heretic, but it does not consider it a necessary precondition for the pope's losing office for heresy. Both these schools have adherents, up to and including the present day. We do not take a position on these disputed questions, whose resolution is a matter for the bishops of the Church. Full document here. See e.g. Thomas de Vio Cajetan, De Comparatione auctoritatis papae et concilii cum Apologia eiusdem tractatus (Rome: Angelicum, 1936); Melchior Cano, De Locis theologicis, book 6, chapter 8; Bañez, In IIaIIae q. 1 a. 10; John of St. Thomas, Cursus theologici II-II, De auctoritate Summi Pontificis, d. 8, ad. 3, De depositione papae; Suarez, De fide, disp. 10; St. Robert Bellarmine, De Romano Pontifice, book 2 ; Billuart, Cursus theologiae, Pars II-II ; St. Alphonsus Liguori, Vindiciae pro suprema Pontificis potestate adversus Iustinum Febronium; Cardinal Charles Journet, L'Église du Verbe Incarné, vol. 1: l'hiérarchie apostolique (Éditions Saint-Augustin, 1998), pp. 980-83 See e.g. St. Augustine, Sermon 181; Pope Pius IX, Bull 'Ineffabilis' defining the doctrine of the Immaculate Conception. This principle is applied to the loss of the papal office for heresy by St Robert Bellarmine, De Romano Pontifice, Book 2, Chapter 30. Later authors have qualified this assertion by accepting that heretical clerics can exercise jurisdiction in certain extraordinary circumstances, because it is supplied to them by the Church. None of these authors have however accepted that a pope whose heresy is manifest and established can possess or exercise papal jurisdiction. The Church cannot grant papal jurisdiction, and a heretical pope cannot grant this jurisdiction to himself. See e.g. Jus Canonicum ad Codicis Normam Exactum, Franciscus Wernz and Petrus Vidal (Gregorianum, 1924-1949), II (1928), n. 453; Introductio in Codicem, 3rd ed., Udalricus Beste, (Collegeville: St John’s Abbey Press, 1946), Canon 221; New Commentary on the Code of Canon Law, John P. Beal, James A. Coriden, and Thomas J. Green eds. (New York: Paulist, 2000), p. 1618.We do not reject the possibility that a pope who publicly rejected the Catholic faith and publicly converted to a non Catholic religion could thereby lose the papal office; but this hypothetical case does not resemble the current situation.