What is Heresy, and How Did St. Irenaeus Fight It?

Lucien Bégule (1848–1935), “St. Irenaeus,” in the Church of St. Irenaeus in Lyon, France.
Lucien Bégule (1848–1935), “St. Irenaeus,” in the Church of St. Irenaeus in Lyon, France.

What is a heresy, and who is a heretic?

Father John P. Cush

Rev. John P. Cush is a priest of the Diocese of Brooklyn. He serves as Academic Dean and as a formation advisor at the Pontifical North American College, Vatican City-State. Fr. Cush holds the Doctorate in Sacred Theology (STD) from the Pontifical Gregorian University, where he also teaches as an adjunct professor of Theology and U.S. Catholic Church History. He has served as a parish priest, high school seminary teacher, and as a Censor Librorum for his Diocese, as well as a theological consultant for NET TV. Fr. Cush is a regular contributor to the Brooklyn Tablet and the Albany Evangelist.

I was edified to see that Bishop Kevin Rhodes of Fort Wayne-South Bend, Indiana, called for a recognition of the great Father of the Church, Saint Irenaeus (A.D. 130-202), as a “Doctor of the Church” at the November meeting of United States Conference of Catholic Bishops. Bishop Rhodes described this declaration as “perhaps a way to correct an oversight of history.” The U.S. Bishops all supported this idea, which was begun by Cardinal Philippe Barbarin of Lyon, France.

This plea from the U.S. Bishops Conference will then be communicated to the Vatican and, according to Bishop Rhodes, will have to follow this procedure:

If there is a desire to have the saint named a doctor of the church, the promoter of the cause must do further research and study and reach out to solicit broader consensus across nations that this would be a worthy pursuit. … The congregation has said that the support of entire episcopal conferences is very helpful in discerning these types of petitions.

What I find most interesting is that one of the main reasons that the bishops of the U.S. (along with other episcopal conferences around the world) are promoting this concept is that St. Irenaeus spent much of his ministry in preaching against a particular heresy, one known as Gnosticism. The bishops recognize that Gnosticism, one of the earliest heresies, is alive and well in the world.

In order to understand this, I think it is necessary for us to ask five questions: first, what is a heresy and who is a heretic? Second, what was this particular heresy of Gnosticism? Third, who was St. Irenaeus and what did he do to combat this heresy? Fourth, how is this heresy alive and well in the United States today? And fifth, how can we combat this Gnosticism in our lives and in our world? I hope to explore these themes over my next few articles.

First, what is a heresy and who is a heretic? Teaching first-year seminarians an Introduction to Theological Method seminar (one semester on fundamental theology and the other on dogmatic theology) is great fun for me as a professor. These are very bright, very faithful and very faith-filled young men who have just completed their studies in philosophy and are at the very beginning of their studies in theology. I assign a great deal of reading to them — selections from the Catechism of the Catholic Church, the decrees of the councils and the popes, readings from the Tradition, and even selections from contemporary theologians like Tracey Rowland, Avery Cardinal Dulles and Bishop Robert Barron. It is fascinating to see how the seminarians make the transition from the study of philosophy to the study of theology. In my class, I always emphasize that theology is a sacred science, but it’s also about so much more than just the academic realm — it’s all about learning more and more about someone whom you have fallen in love with, Jesus Christ, and his Mystical Body the Church.

Every so often, it is interesting to see a student slip into “heresy.” Of course, this is not done deliberately. It merely means that he will use imprecise language or fall into some odd interpretation. For example, a student might describe Our Lord, Jesus Christ as “a human person,” when in fact, dogmatically, the Church teaches that the Lord is one Divine Person in two natures, human and divine (CCC 481). Sometimes, a student may fall into an error about the doctrine of the Most Blessed Trinity (something quite easy to do). The 20th-century Canadian philosopher and theologian Bernard Lonergan (1904-1084) is quoted as saying, describing his students’ understanding of the nature of doctrine of the Trinity, as “five notions, four relations, three persons, two processions, one nature, and zero comprehension.”

There is another type of student who appears and, quite remarkably, having never studied theology at all, is able to solemnly declare even such thinkers like Pope Benedict XVI “a little heretical” in some of their writings! After picking my jaw up from the floor of the classroom, I assure the students that they are not reading the works of heretics and that they should be very careful about throwing the H-word around.

With that in mind, what then is a heresy? According to the 1983 Code of Canon Law (No. 751), “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.”

Dr. Alyssa Lyra Pitstick, in a fine article in First Things in which she is in dialogue with the late theologian, Jesuit Father Edward Oakes, offers a clear distinction between the two types of heretics:

Now about this choice, a very simple, accurate, and useful distinction used to be made between a material heretic and a formal heretic: The material heretic errs in his facts, believing something to be true church doctrine which in fact is not. His choice is made in ignorance. If he learns from reliable sources that the Church teaches otherwise, he readily changes his belief, because his concern is to believe what the community of faith believes, since he believes it is Christ’s Church.

In contrast, the formal heretic knows what the Church teaches and believes something else, namely, the object of his choice. His belief is defined over against the Church’s, and his concern is to hold fast to his choice. His choice is made in knowledge. Of course, a formal heretic often enough begins with the innocent error of a material heretic, but the difference is that he clings obstinately to it in the face of new information. Note that formal heresy does not require efforts at official correction by church authorities, nor a declaration on their part. It only requires that the individual know what the Church teaches in essential matters and that he persists in holding something incompatible with that teaching.

Formal heresy also does not require that the heretic abjure his church membership, as Oakes claimed. Indeed, it would be surprising if a heretic did so abjure, since he has convinced himself that his doctrine is the correct one. Implicitly, therefore, he represents the “true (or pure, or original, or whatever) Church”—at least to himself.

With this in mind, we can see that a formal heretic is not merely one who makes a slip of the tongue or who expresses his answer in a wrong manner. It takes a lot of work to be a formal heretic. By learning the teachings of the Church, by adhering to the teachings of the Church, and by living the teachings of the Church, we can avoid all that work!

In my next entry, I hope to continue this theme and describe more on what heresy is, using the thought of the great 20th-century British apologist, Monsignor Ronald Knox (1888-1957), as well as describing what the heresy of Gnosticism was and what the great Father of the Church, St. Irenaeus, did to combat this heresy, which is still present in our world today.