How do heresies work?

What is the difference between a legitimate disagreement and heresy?


Heresy is the obstinate denial of a truth or truths revealed by God. Additionally, it can only be committed by a baptized person.

Being innocently mistaken or ignorant is not heresy. Disagreeing about other stuff is not heresy.

1 Like

Well a “heresy” is an obstinate denial of a truth held and taught by the Church since the beginning.
An example The Church teaches that Jesus is fully human and fully GOD.
Not separate. There was an early heresy that denied either the human nature of Jesus or His divine nature and thought that those were somehow separate.
Now what to do you mean by “legitimate disagreement”?

There are some questions that the Church allows different opinions on, because we don’t know the answer 100 percent. Usually the Church still takes a stance on the issue, though, but it’s made clear that it is an opinion and not a teaching.

On other questions the matter has been dealt with, and we do know the correct answer. The Church is therefore more rigorous, and treats the answer dogmatically (because it is true). Disagreeing with a teaching of the Church is called heresy.

Holding a heresy does not make you a heretic, though, it is only when you are aware that the Church teaches differently that you can be blamed for heresy.

1 Like

Thanks for the answers! This has been pretty informative.

So, here’s the interesting thing…

That was factually incorrect from the moment it was first proposed, but… it didn’t become a heresy until the Church declared its doctrine on the nature of Jesus as “fully human and fully God, without admixture…” (etc, etc).

Prior to that time? Not a heresy. Just a bad opinion.

Disagreeing with doctrine or dogma is heresy. If I were to say “I disagree with the Church’s requirement to fast on Good Friday!”, I wouldn’t be a heretic. That’s a different kind of sin… :wink:

1 Like

Material heresy is an opinion which is contrary to Church teaching, but is not known or intended to dispute Church teaching by the person expressing it.

Formal heresy is the same opinion expressed by someone in defiance of the Church. This is where obstinacy comes in, because the heresy becomes formal when a superior formally corrects the errant opinion and the person rejects the correction. The conflict of correction and disagreement is in many ways more important than the technical divergence of opinion.

This is a Catholic view, which can break down in other contexts.

Generally, they don’t.

I am not for sure the “since the beginning” is a needed qualifier. Actually, I think it should not have the qualifier.

1 Like

Very interesting question.

Does this ever change? Like something they once considered to be heresy, should be changed to not be considered heresy?

No… and yes.

Once declared as doctrine, the teaching will not change. So, for a Catholic, being in “obstinate denial” doesn’t just drop away. So… “no”.

But, if you don’t know that you’re in obstinate denial, then you’re not a formal heretic. Over and above that, this only applies to Catholics. So, if you great-great-great-great-great-great grandpa was a Catholic who left the Church during the Reformation, then yeah… he was a heretic. But, if your family has been Protestant, and you’re a Protestant, and you’ve never been a Catholic… then you’re not a material heretic.

(Non-Catholics who look at the anathemae of Trent and say “see! Catholics say I’m damned to hell!” are mistaken: the legal decrees of the Catholic Church do not apply to them, since they’re not Catholic.)

Does that help?

@Gorgias, I wasn’t looking for anything specific, just in general…

If in the past, something they considered heresy then through research realize they were wrong… it should have been considered… considered… what is something considered if it isn’t heresy?

I don’t think they’d ever change what they believe Protestant are, any more then Protestant will ever change what they think Catholic’s are… only the return of Jesus Christ can perform that miracle. :grinning:

I like St Thomas Aquinas’ definition: ‘a species of infidelity in men who, having professed the faith of Christ, corrupt its dogmas’.

This doesn’t happen. Remember, it’s not just any teaching, it’s doctrine. Stuff like “Jesus is God Incarnate” or “Jesus died and resurrected on the third day”. That isn’t something that is “reconsidered” or “realize they were wrong.”

How do heresies work?

Short answer: They don’t. They serve only the malformed conscience of the heretic.*

*This is not to say that God cannot bring good from heresy - it’s just that it is a detour taken while the main road was open.

those who say: … ‘He is of another substance’ (ὑποστάσεως, hypostasis) or ‘essence,’ (οὐσίας, essence)… they are condemned by the holy catholic and apostolic Church

This is one of the Arian positions condemned at Nicea in 325ad.

Ultimately, a few Councils later, they settled on a vocabulary that said Jesus is a different hypostasis(person) from the Father.

After Nicea, saying the Father and Son are different hypostases was heretical. After Constantinople, saying the Father and Son are different hypostases was orthodox.

The difference is that a fuller understanding led to a change in vocabulary. the Father and Son are different hypostases Is still heretical, if by hypostasis you mean they are different substances, and it was always orthodox if you meant persons. The thesis that was condemned is still condemned, but the language changed in a confusing way.

So, imo, this is not a reconsideration of the condemnation at Nicea. But it looks a lot like one, and it would be hard to argue against someone who thinks otherwise.


The primary difference between legitimate differing opinions and heresies is the potential effect that differing opinions present to the unity of the church. Before the Magisterium pronounces its view, there can be no heresy.

Most dogma and doctrine emanate from the Magisterium’s use of its teaching authority to resolve conflicts on matters of faith and morals that threaten the oneness mark of Christ’s true church.

Called under the auspices of Constantine, the Council of Nicea, for instance, sought to address the problem of heresy. When church and state are one so heresy and treason become one, and, left unchecked, heresy threatens the commonwealth. Heresy demands two types of action: first, formal and precise definition of the dogma questioned; and second disciplinary measures to suppress the heresy.

Actually we can differentiate between a heretic and a heresy. Hilaire Belloc described Islam as a Christian heresy. It took
a body of Christian doctrine and added and subtracted some things.

If so, it’s by far the most powerful Christian heresy of all.

This topic was automatically closed 14 days after the last reply. New replies are no longer allowed.

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