Heresy and Excommunication


If a Catholic openly and freely speaks heresy, do they become in danger of being Excommunicated?



Can. 1364 §1. Without prejudice to the prescript of can. 194, §1, n. 2, an apostate from the faith, a heretic, or a schismatic incurs a latae sententiae excommunication; in addition, a cleric can be punished with the penalties mentioned in can. 1336, §1, nn. 1, 2, and 3.(1)

(1) Code of Cannon Law. Canon Law Society of America. Washington, D.C. 1983. Available online at:


Not immediately. They have to be given a warning, and the Church has got to be convinced that they have the intellectual capacity to understand it. However if they persist despite threats of being thrown out, then they will excommunicated as a last resort.


In addition to very correct answers above, we must also consider that in a very important sense, such people excommunicate themselves.


I think there is an underlying assumption that the Church used to excommunicate a lot of people, and of recent - say the last 45 years - has lost the will to do so. I am not convinced at all that a careful reading of history would necessarily prove the point.

Furthe, in reading history, it needs to be kept in mind that subsequent to Constantine, the Church, rightly or wrongly, was at many times and many places intimately involved in the politics of the area in question, and had much more power. Prior to the Reformation and given the areas of the world that were not overseen by the Orthodox Church, a heresy was not only an issue of Church, but also of politics, as a popular heretic could sway political rule.

Some of that started to break down wioth the Reformation, as an short reading of countries which became anti-Catholic will reveal. Then came the French Revolution and Enlightenment, finally leading to the loss of the Papal States, and the Church held much less sway in the political realm.

Fast forward to today, and we find that the issue is a comibination of things; the Church is slow to speak on issues of theology; information moves at warp speed; popular means of disseminating ideas have increased in power, and catechesis has been somewhere between poor and non-existent. The Church could issue all sorts of interdicts and excommunications; but the ultimate question is what truly would they accomplish?

To those who look to the Magisterium for answers, it would provide answers, but would also be “preaching to the choir” as those who truly look tot he Church are not usually lead too far astray. As to everyone else, it would have the reverse effect of making heros; just the opposite of what the Church would want to accomplish.

Hans Kung has been labeled a heretic by many, but not the Church; and he has had at least one personal lunch with the Pope. The likelyhood of him being so labeled?


He has been censured and removed from being able to teach as a Catholic theologian, but not labeled a heretic. To those who follow the Church’s teaching, he is a non-issue; to those who don’t, what could actually be accomplished that hasn’t been already?


I think a person who fundamentally disagreed with the Church on many matters would leave long before excommunication would be imposed. Excommunication seems to be used more on priests or theologians who dissent very fundamentally from the church on some key matter or on a range of matters (and even if so, as in Kung or Boff’s case, they get censured or silenced or dismissed from their posts, rather than excommunicated).

I had a look the other day at some heresy and excommunication trials and people who were excommunicated included:

  1. A woman who was CEO of an abortion clinic
  2. A priest who ordained women and formed a group which effectively split from the Vatican
  3. Bishops who ordained other Bishops without Vatican approval

Excommunication was also threatened in one case by a Bishop against a lay movement who advocated free choice for abortion, but there was no evidence the excommunications were actually carried out. Here in Australia, Cardinals and Bishops asked politicans who voted for Stem Cell research to examine their consciences before taking communion, though most of the papers said the Bishops or Cardinals actually threatened excommunication.

I have asked about this myself a few times and generally a layperson would have to be doing something which would basically be severely damaging to the Church on an ongoing and persistent basis, and would have had to have a lot of prior warnings before this would be used. There are of course other forms of automatic excommunication (for murder or abortion for example) which are automatically imposed under canon law by reason of the act, but how these would actually be implemented in a pastoral situation is complex and would differ in each case.

I like to look at it this way; if you were a Physics Professor who tried to teach that all of Physics past Newton and established firmly by experiment and observation was utterly wrong, without foundation, you would be dismissed. If you were a lawyer who perjured himself under oath or stole trust money, you are struck off the register. If you are an incompetent doctor, you get de-registered. If you were teaching Biology and rejected all of 20th and 21st century biology in favour of Linnaeus’s theory, you would lose your post.

All human organisations have certain laws and rules. The CC is basically the same. Excommunication is basically there to protect the Church from being torn apart. From the outside, one could debate the fairness or warrant for an ecclesial penalty, just as say in debating a criminal case in civil law, one could debate the justice of a sentence a judge places on a criminal. But in the end the judge who is appointed to his post has the legitimate power and right, by virtue of his office, to do certain things, including sentence those found guilty of a crime to a certain penalty allowed under law, or to make a definitive ruling on a certain matter, or to make an authoritative and final judgement in a case and not to be over-ruled. It is similar in the Church and its canon laws, in that certain structures of power exist, and people can legitimately use power within that framework to discipline or even expel people who break the rules of the church persistently and in a highly damaging manner. Likewise, judges in the church by virtue of their office, have the right to impose certain penalties on people for reasons they deem valid, given their powers and discretion.


They do not Excommunicate themselves, I don’t believe, but do subject themselves to possible Excomunication by the authority of the Church.



closed #9

DISCLAIMER: The views and opinions expressed in these forums do not necessarily reflect those of Catholic Answers. For official apologetics resources please visit