While I agree with the general sentiment of Fr. Edward Oakes’ observations yesterday concerning the invidious or vituperative use of the word heresy , I feel that he is turning into a matter of sentiment what should be a matter of precise definition. If the word heresy is thought of merely as an insult or a taunt, then I agree that it is improper for Catholics to use it of Protestants, or Protestants to use it of Catholics. We should not be attempting to wound one another. Much better to call each other brothers.
The word heresy in Catholic teaching, however, has a very precise technical meaning today. It is not, as Oakes would have it, “explicitly [to] deny key doctrines of the faith.” The word key is not part of the definition of heresy given in the 1983 Code of Canon Law, which reads: “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.”
The Catholic Church says that all things (though not only those things) taught by Ecumenical Councils as revealed truths under pain of anathema are to be believed “by divine and Catholic faith.” There are propositions on justification and other matters that were taught by the Council of Trent under pain of anathema. So, if a baptized person were obstinately to deny one of those propositions, the term heresy , as used technically by the Catholic Church, would apply to him.
When Oakes writes, “I have trouble calling all forms of dissent by the word heresy , sensu stricto ,” he is introducing a red herring. It is quite obvious that not all forms of dissent are heresy in the strict sense. No one except ignoramuses has ever asserted they were. It is clearly possible to dissent on all sorts of doctrinal questions without falling under the definition of heresy, for not all doctrines are proposed by the Catholic Church as having to be believed “by divine and Catholic faith.”
In fact, the Catholic Church does not even say that all things infallibly taught must be received with “divine and Catholic faith,” but only those that are infallibly taught to have been “formally revealed” and thus, at least implicitly, part of the original “deposit of faith.” For example, it is infallibly taught that certain men were true and valid popes and that certain councils were authentic Ecumenical Councils, but these truths obviously could not have been part of the original deposit of faith. Truths of that kind, because they are infallibly taught, must be accepted by the faithful “with definitive assent,” and to fail to do so is to “set oneself against the teaching of the Catholic Church,” according to canon law. And yet, while gravely wrong, it does not make one guilty of heresy in the strict sense. That is why a sedevacantist is a schismatic, but not necessarily a heretic. These technicalities were all clarified in the 1998 motu proprio “Ad Tuendam Fidem” and an accompanying commentary by the Congregation for the Doctrine of the Faith.
It not clear why Fr. Oakes finds it so hard to explain why Lefebvrists are not heretics. He says, “Lefebvrists, for example, are clearly schismatics, and they explicitly dissent from key teachings of Vatican II. But I just don’t feel it’s accurate to call them heretics . . . . I admit, though, I can’t explain why I feel that way.”
With all due respect, this is not a question of how Edward Oakes feels about it. The definition of heresy either fits Lefebvrists or it doesn’t. This is a question of facts and definitions, not sentiment. Nor is it a question of whether something is a “key teaching,” even of an Ecumenical Council. The term key teaching does not name a technical concept in Catholic doctrine or canon law, as far as I am aware. Is there a teaching that Vatican II proposed, to be believed with divine and Catholic faith, that the Lefebvrists deny? That is the only relevant question in deciding whether they are heretics. My understanding is that the answer is no; however, I am not an expert on such things. Yet I do know that it is not a question of feelings.
I agree with my good friend Fr. Oakes that the way the word heresy is apparently tossed about by some people on the Web is not at all helpful. But ecumenical dialogue is also not advanced by muddying the meanings of words and by confusing feeling for clear thought.
Stephen M. Barr is a theoretical particle physicist at the Bartol Research Institute of the University of Delaware and the author of Modern Physics and Ancient Faith 
