The letter acknowledges that "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."
Nevertheless, the letter asserts, a pope with "heretical views cannot continue as pope." The letter then suggests that the pope could lose office de facto as a result of obstinately holding public heretical views and that the bishops of the Church have an "absolute duty to act in concert to remedy this evil."
The Code of Canon Law explicitly provides for the punishment of Catholics who "make recourse against an act of the Roman Pontiff to an ecumenical council or the college of bishops."
Canon law also defines that both an ecumenical council and the college of bishops can only ever act with and under the authority of the pope.
While the letter makes numerous references to the "canonical delict of heresy," only one of the signatories is listed as having a licentiate in canon law. The letter does not call for a canonical action to be taken against the pope, despite insisting that he has committed the delict of heresy, instead, the authors ask the bishops of the world to "admonish" the pope and cause him to formally "abjure" his alleged heresies.
Among the signatories of the letter are some prominent Catholics, including Professor John Rist,a research professor in philosophy at the Catholic University of America, where he previously held the Father Kurt Pritzl, O.P., Chair in Philosophy.
In a statement to CNA, Catholic University said that Rist does not speak for the university, and underscored his limited role there.
"He is not a teaching professor. His personal views about papal reform do not reflect those of the University," a university spokesperson said.
Dr. Peter Kwasniewski, a professor of philosophy, also signed the letter. Kwasniewski is a Senior Fellow of the St. Paul Center for Biblical Theology in Steubenville, Ohio.
Robert Corzine, vice president of programs at the St. Paul Center, told CNA that Kwasniewski "definitely does not speak for the St. Paul Center in this regard."
Corzine noted that the center had previously published an English language version of a handbook for the pastoral care of the family according to Amoris Laetitia.
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"While the signatories of that letter clearly have their own particular way of interpreting Amoris Laetitia, if anything can be read in continuity with orthodox teaching and tradition it should be – and Amoris laetitia definitely can be," Corzine said.
Petri told CNA that the letter is unconvincing in both its arguments and its rationale.
"Apart from the canonical implications this may have for the signers, the letter itself is a hodgepodge of concerns that prevent it being taken very seriously as a whole," Petri said.
"While I agree there remain questions and concerns about some applications of Amoris laetitia, I cannot see how any of those concerns are necessarily material heresy."