The obstinate post-baptismal denial of some truth which must be believed with divine and catholic faith, or it is likewise an obstinate doubt concerning the same.

Catechism of the Catholic Church, 2089


In the Greek, iconoclasm means "image breaker". This heresy, like its name suggests, has a paranoid fear and rejection of the use of images or icons in religion. With the exception of High Church Anglicanism, most Protestant Churches have a heightened aversion to the use of sacred pictures or objects in their worship services, whose attitude they assumed, ironically enough, from Islam. Other contemporary sects who can be considered iconoclasts include the Mormons and Jehovah's Witnesses.

Although present throughout the Church's history, the most infamous period of iconoclasm occurred in the eighth century. Because of the Islamic incursion in North Africa and Asia minor during this period of history, Emperor Leo III and iconoclastic Eastern bishops sought to sanitize the Faith of images which were offensive to Muslim eyes. In so doing, they believed that conversions to Christianity might be more likely. Through the reigns of Leo III, Constantine V, and Leo IV, iconoclasm was ruthlessly enforced by the systematic destruction of icons, statues, and sacred images. Not until the Second Nicaean Council in 787 A.D., some 60 years later, was the ancient Catholic tradition restored and a distinction made between adoration ("latria") and veneration ("dulia"). The Council re-affirmed the constant custom of venerating religious images and icons while at the same time renouncing "icon worship". Biblical evidence for the Church's position can be found in these passages: Exodus 25:18-22, Exodus 28:33-34, Exodus 37:7-9, Numbers 21:8-9, 1 Kings 6:23-28 1 Kings 7:23-29, 2 Chronicles ch. 3-5.


Arianism is the theological teaching of Arius (c. AD 250-336), who was ruled a heretic by the Christian church at the Council of Nicea.

Arius lived and taught in Alexandria, Egypt in the early 4th century. The most controversial of his teachings dealt with the relationship between God the Father and the person of Jesus, saying that Jesus was not one with the Father, and that he was not fully, although almost, divine in nature. This teaching of Arius conflicted with trinitarian christological positions which were held by the Church. However, 85% of the eastern Church fell into Arianism.

It is historically the largest threat to Christianity since it's beginning and persisted for hundred of years.


Monophysitism (from the Greek monos meaning 'one, alone' and physis meaning 'nature'), or Monophysiticism, is the Christological position that Christ has only one nature (divine), as opposed to the Chalcedonian position which holds that Christ has two natures, one divine and one human. (wikipedia)

We got an email that said:

Acacian schism: “The doctrinal differences that split the Church had to do with a heresy known as "Monophysitism." Monophysites believed that Christ had only one nature: divine. But orthodox belief held that Christ had two natures: both divine and human. This concept had been deliberately expressed at the Council of Chalcedon, an ecumenical council held in 451. Monophysites rejected this Council's decree concerning Christ's dual nature, and were therefore considered heretics by the Catholic Church. The Monophysite heresy was very popular in Syria and Egypt, where anti-imperial feeling was strong, and it took hold in other parts of the Eastern Roman Empire (Byzantium), as well. However, the Patriarch of the church in the Byzantine capital of Constantinople, a leading figure of the Eastern Church, did not support Monophysitism. Up to 476 C.E., both Eastern and Western Churches were united against the Monophysite heresy.”

Your source overlooked the Acacian schism which lasted from c. 484 to 519, when Justinian’s uncle Justin I nullified the Act of Union with the Monophysites and made all the bishops and patriarchs of the Eastern Church seek reunion with orthodox Rome. It was at this time that 2,500 Eastern bishops signed the Libellus Hormisdae, which I quoted in my last email, saying that Rome is infallible because of Matt 16:18-19. During the Acacian schism, the patriarchs of Alexandria, Antioch, Jerusalem, and Constantinople all rejected the Council of Chalcedon and taught that Monophysism was orthodox. ….That is, they denied the reality of Christ’s Incarnation.   

The Council of Chalcedon & the Papacy with respect to the heresy of Monophysitism

by Mark J. Bonocore

Around 448, the aged Byzantine monk Eutyches, who had been a zealous ally of St. Cyril of Alexandria at the Council of Ephesus, became rigid and inflexible on his views regarding the Incarnation. He argued that Christ's Divine nature so absorbed His human nature that His human nature ceased to be -- thus giving birth to the heresy of Monophysitism.

This heretical doctrine spread throughout the Eastern Church, and forced St. Flavian, Patriarch of Constantinople, to call a local synod to condemn it. However, Eutyches refused to submit to the synod, appealing his case to Pope Leo I. This is what he wrote:

I take refuge, therefore, with you, the defender of religion and abhorrer of such factions. ...I beseech you not to be prejudiced against me by their insidious designs about me, but to pronounce the sentence which shall seem to you right upon the Faith. -- Eutyches to Pope Leo, Ep 21.

Patriarch Flavian also appealed to Rome for a ruling, moving Pope Leo to produced his famous Tome, which totally condemned Monophysitism. And so, responding to Eutyches, St. Peter Chrysologus, Archbishop of Ravenna, writes:

We exhort you, honorable brother, that you obediently listen to what has been written by the blessed Pope of the city of Rome, since blessed Peter, who lives and presides in his own see, offers the truth of faith to those who seek. For we, in our zeal for peace and faith, cannot decide questions of faith apart from consent of the Bishop of Rome. -- Peter Chrysologus of Ravenna to Eutyches, Ep 25

However, Eutyches would not submit. Having the ear of the Eastern Emperor (who, being opposed to the dynasty that supported Nestorius, favored Eutyches' views), the heretical monk persuaded him to call another Council of Ephesus -- the so-called "Robber Council" of 449, in which the Roman teaching was rejected, and Monophysitism declared to be the orthodox doctrine of the Church. At this council, Patriarch Flavian was physically abused; and so writes to Pope Leo in appeal:

When I began to appeal to the throne of the Apostolic See of Peter, the Prince of the Apostles, and to the whole sacred synod, which is obedient to Your Holiness, at once a crowd of soldiers surrounded me and barred my way when I wished to take refuge at the holy altar. ...Therefore, I beseech Your Holiness not to permit these things to be treated with indifference...but to rise up first on behalf of the cause of our orthodox Faith, now destroyed by unlawful acts. ...Further to issue an authoritative that a like faith may everywhere be preached by the assembly of an united synod of fathers, both Eastern and Western. Thus the laws of the fathers may prevail and all that has been done amiss be rendered null and void. Bring healing to this ghastly wound. -- Patriarch Flavian of Constantinople to Pope Leo, 449

At this same "Robber Council" of Ephesus, several other Eastern bishops were deposed from their sees for refusing to embrace Monophysitism. Among them, were Theodoret of Cyrus and Eusebius of Doryleum, both of whom appeal to Pope Leo, saying...

We hasten to your Apostolic See in order to receive from you a cure for the wounds of the Church. For every reason it is fitting for you to hold the first place, inasmuch as your see is adorned with many privileges. I have been condemned without trial. But I await the sentence of your Apostolic See. I beseech and implore Your Holiness to succor me in my appeal to your fair and righteous tribunal. Bid me hasten to you and prove to you that my teaching follows in the footsteps of the Apostles. -- Theodoret to Pope Leo, Ep 113

The Apostolic throne has been wont from the beginning to defend those who are suffering injustice. I entreat Your Blessedness, give me back the dignity of my episcopate and communion with yourself, by letters from you to my lowliness bestowing on me my rank and communion. -- Eusebius of Doryleum to Pope Leo

Thereafter, Pope Leo succeeded in getting both Emperors to call the Council of Chalcedon in 451. At this Council, attended by about 600 bishops (almost all of the Eastern Church), Pope Leo's Tome against Monophysitism and for the orthodox teaching of the two natures of Christ was embraced with the pronouncement:

"This is the faith of the fathers! This is the faith of the Apostles! So we all believe! thus the orthodox believe! Anathema to him who does not thus believe! Peter has spoken thus through Leo! . . . This is the true faith!'" (Acts of the Council, session 2 [A.D. 451]).

Now, many anti-Catholic scholars have tried to chip away at the significance of this statement. However, when compared to other contemporary writings, the meaning of the Council Fathers becomes abundantly clear:

Blessed Peter, preserving in the strength of the Rock, which he has received, has not abandoned the helm of the Church, which he undertook. ...And so if anything is rightly done and rightly decreed by us, if anything is won from the mercy of God by our daily supplications, it is of his work and merits whose power lives and whose authority prevails in his see. To him whom they know to be not only the patron of this see, but also primate of all bishops. When, therefore, believe that he is speaking whose representative we are. -- Pope Leo, Sermon 3:3-4

Now the Lord desired that the dispensing of this gift should be shared as a task by all Apostles, but in such a way that He put the principal charge on the most blessed Peter, the highest of all the Apostles. He wanted His gifts to flow into the entire Body from Peter himself, as it were from the Head. Thus, a man who had dared to separate himself from the solidity of Peter would realize that he no longer shared in the Divine mystery. -- Pope Leo, Ep 10

Similarly, the Acts of the Council of Chalcedon, speak of Leo, saying...

"Wherefore the most holy and blessed Leo, archbishop of the great and elder Rome, through us, and through this present most holy synod together with the thrice-blessed and all-glorious Peter the Apostle, who is the Rock and foundation of the Catholic Church, and the foundation of the orthodox faith, hath stripped him (Dioscorus, Bishop of Alexandria) of his episcopate, and hath alienated from him all hieratic worthiness." -- Acts of Chalcedon, Session 3

In the same way, upon concluding their synod, the Council fathers write to Pope Leo, saying...

You are set as an interpreter to all of the voice of blessed Peter, and to all you impart the blessings of that Faith. -- Chalcedon to Pope Leo, Ep 98

For if where two or three are gathered together in His name He has said that there He is in the midst of them, must He not have been much more particularly present with 520 priests, who preferred the spread of knowledge concerning Him ...Of whom you were Chief, as Head to the members, showing your good will. -- Chalcedon to Pope Leo (Repletum est Gaudio), November 451

Besides all this, he (Dioscorus) extended his fury even against him who had been charged with the custody of the vine by the Savior. We refer to Your Holiness. -- Chalcedon to Pope Leo, Ep 98

You have often extended your Apostolic radiance even to the Church of Constantinople. -- Chalcedon to Pope Leo, Ep 98

Knowing that every success of the children rebounds to the parents, we therefore beg you to honor our decision by your assent, and as we have yielded agreement to the Head in noble things, so may the Head also fulfill what is fitting for the children. -- Chalcedon to Pope Leo, Ep 98

So, the Council of Chalcedon clearly recognized Pope Leo as the successor of Peter and the Head of the Church. However, the Council did have one problem. One of its canons, Canon 28, had given Constantinople primacy in the East. The Canon read:

"...we do also enact and decree the same things concerning the privileges of the most holy Church of Constantinople, which is New Rome. For the Fathers rightly granted privileges to the throne of old Rome, because it was the royal city. And the one hundred fifty most religious Bishops gave equal privileges to the most holy throne of New Rome, justly judging that the city is honored with the Sovereignty and the Senate and enjoys equal privileges with the old imperial Rome...." (Canon 28, Chalcedon)

However, Pope Leo refused to agree to this canon; and employing a kind of "line item veto," ordered it struck from the Council documents. In this, Bishop Anatolius of Constantinople writes to Pope Leo, apologizing and explaining how the canon came to be, saying ...

As for those things which the universal Council of Chalcedon recently ordained in favor of the church of Constantinople, let Your Holiness be sure that there was no fault in me, who from my youth have always loved peace and quiet, keeping myself in humility. It was the most reverend clergy of the church of Constantinople who were eager about it, and they were equally supported by the most reverend priests of those parts, who agreed about it. Even so, the whole force of confirmation of the acts was reserved for the authority of Your Blessedness. Therefore, let Your Holiness know for certain that I did nothing to further the matter, knowing always that I held myself bound to avoid the lusts of pride and covetousness. -- Patriarch Anatolius of Constantinople to Pope Leo, Ep 132 (on the subject of canon 28 of Chalcedon).

So, the matter was settled; and, for the next 6 centuries, all Eastern churches speak of only 27 canons of Chalcedon -- the 28th Canon being rendered null and void by Rome's "line item veto." This is supported by all the Greek historians, such as Theodore the Lector (writing in 551 AD), John Skolastikas (writing in 550 AD), Dionysius Exegius (also around 550 AD); and by Roman Popes like Pope St. Gelasius (c. 495) and Pope Symmachus (c. 500) -- all of whom speak of only 27 Canons of Chalcedon.

However, when canon 28 was first rejected by Rome, the Monophysites tried to exploit the situation claiming that Leo had rejected the authority of the entire Council. So, at the urging of the Eastern Emperor, Pope Leo drafted a letter to the bishops, explaining how Chalcedon was doctrinally sound:

I have willingly complied, therefore, with what the most clement emperor thought necessary by sending a letter (Ep 114) to all brothers who were present at the Council of Chalcedon to show thereby that the decisions taken by our holy brothers concerning the tenets of the Faith were pleasing to me. My doing so was naturally on account of those who want the decisions of the council to appear weak and dubious, as an occasion for cloaking their own perfidy, on the grounds that decisions were not ratified by assenting opinion of mine (canon 28), whereas I did dispatch a letter. -- Pope Leo, Ep 117


Marcionism is derived from its architect, Marcion, who was a wealthy ship-owner and the son of a bishop. The heresy attacked the Christian teaching of monotheism, God's inherent goodness throughout the ages, and the compatibility between the Law of the Old Testament and the Gospel of the New Testament. While other heresies fomented within the Church, Marcionism, because of Marcion's personality and organizational skills, constructed itself as a full-fledged schismatic body.

Marcion believed that there were two Gods. The God of the Old Testament was cruel and vengeful while the New Testament God was loving and merciful. He believed that the God who created the world was therefore tyrannical. As his dualistic heresy spread, he was called before the Church at Rome in 144 and summarily excommunicated, even though his heresy survived in some forms for the next three centuries.

Marcion was a true heretic insofar as he picked and chose which books of the bible he accepted as canonical. Since he rejected Judaism completely, he ended up purging all of the Old Testament and most of the New Testament from his canon! He kept the Pauline letters and most of the Gospel of St. Luke.

Some other his heresies included:

  • Rejection of the Resurrection
  • Denial of the Incarnation
  • Rejection of the Second Coming
  • Rejection of Marriage

Marcion was opposed by some of the greatest giants of Christian orthodoxy, including Justin Martyr, Irenaeus, Hippolytus, and Tertullian. Their treatises, especially Tertullian's Against Marcion, spawned some of the greatest defenses of Christianity teachings on monotheism, the Trinity, and the holiness of marriage.

Marcionism also had an influence on Martin Luther. As Marcion held to the incompatability of the Law and the Gospel, Luther did as well. Current battles within Evangelicalism over the necessity to keep the Old Testament's moral law is also a leftover from Marcion's heresy.


In response to the Jesuits' greater stress of man's free will as represented by the writings of theologian Luis de Molina, Cornelius Otto Jansen, bishop of Ypres in France, completed his work entitled Augustinus which sought to re-affirm the efficacy of God's grace in human affairs. After his death, his multi-volume work, Augustinus, was condemned by the Holy Office in 1641, and then again by Pope Urban VIII's encyclical In Eminenti in 1643. Its principal errors included denying the necessity of free will, affirming the irresistablity of grace, and affirming that such grace was only for the "elect". In short, this heresy was simply a repeat performance of the Reformers' errors.

Jansenism did not begin to challenge the Church until Jansen was dead, and it was more famous for its political dimensions than it was for its theological questions. By practicing a rigorous moral lifestyle, the Jansenists began to gain momentum against the Jesuits until it reached the pinnacle of political powerplay between the Church and the State. After French Cardinal Jules Mazarin was able to secure Pope Innocent X's condemnation of the heresy (Bull Cum Occasione, 1653), this only cemented the Jansenists resolve to continue the struggle. By a series of pamphlets called the Provinciales, they were able to gain widespread support among the populous and the secular clergy. King Louis XIV, anxious to squash a perceived Jansenism's challenge to royal power, sought to silence the group. After a truce was negotiated by Pope Clement IX in 1667, tension remained for the next few decades until Pope Clement XI condemned the work of a prominent Jansenist, Pasquier Quesnel. After the Bull Unigenitus Dei Filius was issued in 1713, and although the proponents of the heresy still refused to accept Rome's decision, the movement died out by the mid-1700s.

Because of the resistance of the Pope's authority by some of the French bishops, Jansenism, as all heresies frequently do, led many into accepting yet another heresy. The refusal of Papal authority on the question resulted in the heresy of Gallicanism raising its ugly head. Gallicanism proposed that the Pope is subject to ecumenical councils. Gallicanism was dealt its final death blow in 1870 at the First Vatican Council which defined Papal Infallibility.


Ebionism found its roots in a Jewish Christian named "Ebion". The influence of the heresy spread not because of him, however, but rather as a popular and broad movement among Jewish Christians. The heresy began in the first century and the New Testament has many recorded teachings which oppose it. It lasted until the fifth century. Its principal errors were:

  • the necessity of circumcision of all Christians;
  • a denial of the deity of Jesus, claiming instead that he was an angel or man;
  • a rejection of most of the New Testament, especially the Epistles of Paul.

There were essentially three kinds of Ebionites during New Testament times:

  • 1) Judaizers - which proposed a strict view of Gentile circumcision;

    2) Nazarenes - which proposed that all Jewish Christians must be circumcised;

    3) Gnostic Jews - which insisted on keeping the Law but also added pagan elements.

The Book of Acts recounts Peter's revelation from God which abolished the necessity of the ceremonial precepts of the Law. Up until that time, however, the Church viewed itself as a branch of Judaism, and therefore the Mosaic Law and all its ceremonial prescriptions still had to be fulfilled. In Acts 10, however, Peter was instructed that such a requirement was no longer binding on any Christian - Jew or Gentile. In Acts 15, the controversy came to a climax when the Judaizers were insisting that the Gentiles be circumcised according the Law of Moses. As we learn in this chapter, their insistence was rejected by the Apostles at the first Ecumenical Council in Jerusalem. In addition to the book of Acts, there are many other places in the New Testament where not only the strict view of circumcizing Gentiles was rejected, but also the necessity of circumcising Jews (Cf. Gal. 2:11, 1 Cor 9:20-21, Col. 2:13-17, Rom. 6: 14-15, 7:1-6). Today, there are Christian sects which still hold to some parts of the Mosaic ceremonial law, including Messianic Jews and Seventh Day Adventists.


Donatism is a heresy which denies the intrinsic efficacy of the sacraments by conditioning their power on the worthiness of the minister of the sacrament. Hence, if a minister was in a state of mortal sin, the sacrament would not be valid. The Catholic teaching, of course, does not tie the validity of a sacrament to the moral state of the minister. A corrupt minister can still dispense a sacrament's grace.

Donatism, flourishing in the fourth century, was skilfully promoted by Donatus, the bishop of Carthage, and later opposed by St. Augustine. It drew its popularity and power by pitting various regional ethnic groups against Roman imperialism which came to be associated with the Church in Rome. Its main propagation came from the brutal persecution of Diocletian (ending in 305) which caused many Christians to either suffer martyrdom or abandon their faith. Those who survived the persecution became infuriated with those who renounced Christ but were later readmitted into the Church's communion after they had confessed their sin. This led to a sort of puritanical theology in regards to the sacraments. In this climate and with Donatus' deft organizational and rhetorical abilities, he and his supporters were also able to paint a picture of Roman primacy as foreign intervention and suppression. Church historian Frederick van der Meer observed: "Donatism was from its inception a popular movement poor in original ideas, but nevertheless full of people who were easily inflamed and drawing from its principle strength."

Donatism has certain parallels to Protestantism. Luther and his aristorcratic backers attempted (and succeeded) in selling the idea that Rome was a "foreign power". The Church's corruption during the Reformation along with Luther's just anger over it fuelled the Reformation just like the re-admission of apostates (rightly so however) caused the Donatist schism and heresy.


Many anti-Catholics accuse Catholics of worshipping Mary. Of course, there is no basis for this because the Church explicity forbids the worship of anyone other than God. However, back in the early Church, there was group who did in fact worship Mary; they were known as "Collyridians". Their excessive Marian devotion developed into a full blown worship of the Holy Virgin. The heresy lasted about 100 years, existing between 350 and 450 A.D.

The great opponent of the Collyridian sect was Epiphanius, bishop of Salamis and a close colleague of St. Jerome. One of his most outstanding contributions in defeating the Collyridians was his apologetic Panarion (Medicine Box). In his refutation, he addressed both extremes of Marian heresies: Collyridianism (the super-exhaltation of Mary) and Antidicomarianitism (an Arabian movement which demoted and debased Mary's importance).

The Collyridian sect was comprised of mostly women who combined Catholic and Pagan rituals and beliefs and fused them into a new religion - not unlike, it should be observed, many pseudo Catholic nuns who do the same today. Epiphanius considered this blasphemous, writing "certain women there in Arabia have introduced this absurd teaching from Thracia: how they offer up a sacrifice of bread rolls in the Name of the ever-Virgin Mary, and all partake of this bread."

Heresy floats outside of the boundaries of the true faith. One extreme exaggerates a truth; the other extreme denies it. In the case of Collyridianism, we see a perfect example of the former: where there should be a veneration and devotion to Mary, there is an adoration of her instead.


  • Catholic Encyclopedia (1908)
  • This Rock Magazine
  • Fundamentals of Catholic Dogma, Ott

Mark Bonocore

Edited by Hugh