Before calling someone a ‘heretic’, you might want to check canon law

A statue in Prague of the Czech reformer Jan Hus, convicted of heresy by the Council of Constance and executed in 1415 (PA)

Whenever some kind of controversy, or shall we say “spirited debate”, arises in the Church, one of the most common questions asked of canon lawyers is: “Isn’t this person a heretic because they said this, and doesn’t that mean they are excommunicated?” This is then usually followed by “Why not?”

Heresy is a serious and loaded concept in the life of the Church, and in canon law (as is excommunication for that matter). Quite apart from the risk of weaponising the tone of discourse in short order, its improper use can also severely muddy the waters around what is actually being discussed and, quite often, lead the debate into a poorly informed cul-de-sac about the status of one or more individuals, rather than focusing on the ideas actually being proposed.

To avoid this, it is always helpful to recall that heresy is not a vague term of condemnation but a precise legal concept. It is defined, along with the related crimes of apostasy and schism, by canon 751 of the Code of Canon Law:

“Heresy is the obstinate denial or obstinate doubt, after the reception of baptism, of some truth which is to be believed by divine and Catholic faith [credenda]; apostasy is the total repudiation of the Christian faith; schism is the refusal of submission to the Supreme Pontiff or of communion with the members of the Church subject to him.”

While these concepts are defined within Book III of the Code of Canon Law, concerning the Teaching Office of the Church, they are constituted as delicts, or crimes, by canon 1364 of Book VI on Penal Law which says “An apostate from the faith, a heretic, or a schismatic, incurs a latae sententiae excommunication”.

It is always important to distinguish between the sin and the delict, for while every delict is sinful, not every sin constitutes a canonical delict. In this case, it is important to distinguish between the sin of heresy, that is the violation of the moral law, and the delict of heresy, that is the commission of the canonical crime.

If we parse the provisions of the canon, and the applicable requirements of penal law, we get the following description of the delict of heresy: It is an action committed by a baptised Catholic which is both external and imputable (these criteria are subject to a whole host of canonical standards of which there is not a good common understanding) and which constitutes some ongoing rejection or doubt of a credenda teaching of the Church. This in turn is defined in canon 750 §1 as “All those things contained in the word of God, written or handed on, that is, in the one deposit of faith entrusted to the Church, and at the some time proposed as divinely revealed either by the solemn magisterium of the Church, or by its ordinary and universal magisterium which is manifested by the common adherence of the Christian faithful under the leadership of the sacred magisterium.”

This needs to be distinguished from those teachings that are to be firmly embraced and retained (tenenda). The Code defines these as “each and every thing which is proposed definitively by the magisterium of the Church concerning the doctrine of faith and morals” (c. 750 §2).

So what’s the difference? The Congregation for the Doctrine of the Faith’s commentary of the revised formula for the profession of faith and St John Paul II’s motu proprio Ad Tuendam Fidem give a good steer on what constitutes credenda vs. tenenda teaching. In a nutshell, a credenda teaching is something that is considered to be a divinely revealed truth, and a tenenda teaching is that which is, while definitively taught and not up for discussion, derived from, and dependent upon, a credenda teaching.

Some examples of a credenda teaching would include, without being exhaustive, the following: the articles of faith in the Creed, the various Christological and Marian dogmas; the doctrine of the real presence in the Eucharist; the doctrine on the primacy and infallibility of the Roman Pontiff; the doctrine on the existence of original sin; the doctrine on the grave immorality of direct and voluntary killing of an innocent human being.

It is fairly rare that an external and imputable persistent doubt or denial of a credenda teaching is made and, because of its complicated nature and seriousness, it’s the proper function of the Congregation for the Doctrine of the Faith to declare when it has happened. One could, of course, allege that a person has an interior disposition against such a teaching and has committed the sin of heresy, but I would caution anyone against effectively calling someone a sinner in the internal forum.

This doesn’t mean that those who choose to openly question an infallible, but not necessarily credenda, teaching get a canonical pass. Ad Tuendam Fidem directly addresses those who dispute tenenda teachings and the Code provides that they be punished by a just penalty if they do not retract after a warning, either from the Holy See or their own diocesan bishop (c. 1371).

Vigorous, and at times even contentious, debate is a necessary part of the doctrinal life of the Church. It is to be expected that error and bad arguments may surface from time to time, and it is right that they be opposed and corrected. But misapplying the term of heresy does nobody any favours and further confuses important points already crying out for clarity. In many instances, all sides of a debate could do well to remember: you don’t have to be a heretic to be wrong.