Heresies & Councils

Apollinarianism

The teaching of Apollinaris that the divine Word replaced the human mind in Christ, denying His full humanity.

Arianism

The heresy of Arius (d. 336) teaching that the Son is a created being, not eternal or of one essence with the Father. Condemned at Nicaea (325).

Chalcedon

The Council of 451, whose formula of “two natures” the Oriental Orthodox did not receive, the parting of the Miaphysite churches from the Chalcedonian.

Chiliasm

Also Millenarianism: the expectation of a literal thousand-year earthly reign of Christ before the end.

Council of Constantinople

The Second Ecumenical Council (381), which completed the Creed and affirmed the divinity of the Holy Spirit.

Council of Ephesus

The Third Ecumenical Council (431), which upheld St. Cyril against Nestorius and confirmed the Virgin as Theotokos (God-bearer).

Council of Nicaea

The First Ecumenical Council (325), which confessed the Son as “of one essence” (homoousios) with the Father and gave the core of the Creed.

Docetism

The claim that Christ only “seemed” (dokein) to have a body and to suffer, denying the reality of the Incarnation.

Donatism

A North African schism holding that sacraments given by unworthy clergy are invalid, and that the Church must be a body of the pure.

Eutychianism

The opposite error to Nestorius: that Christ’s humanity was absorbed into His divinity, leaving one mixed nature. A true “monophysitism,” rejected by the Orthodox.

Gnosticism

A cluster of 2nd-century sects claiming secret saving “knowledge” (gnosis), a lower creator-god, and the evil of matter. The Church’s great early opponent.

Manichaeism

A dualist religion of Mani teaching an eternal struggle of Light and Darkness; Augustine followed it before his conversion.

Marcionism

The 2nd-century sect of Marcion, who rejected the Old Testament and its God as distinct from the Father of Jesus.

Miaphysite

The Coptic Orthodox confession: the one incarnate nature of God the Word, uniting full divinity and full humanity “without mingling, without confusion, without alteration.”

Monophysite

A term (often applied to the non-Chalcedonian churches) for the belief in one nature in Christ. The Coptic Church distinguishes its Miaphysite faith from Eutychian monophysitism.

Montanism

A 2nd-century movement of ecstatic “new prophecy” claiming fresh revelations; drew in Tertullian late in life.

Nestorianism

The teaching associated with Nestorius that Christ is two persons, divine and human, loosely joined, dividing the one Christ. Condemned at Ephesus (431).

Pelagianism

The teaching of Pelagius that the human will can attain righteousness without the necessity of grace. Opposed above all by St. Augustine.

Sabellianism

Also called Modalism: the denial of real distinction among Father, Son, and Spirit, treating them as mere modes of one person.

Subordinationism

Making the Son or Spirit lesser than the Father in being; a tendency in some early writers (e.g. aspects of Origen) later ruled out by Nicene faith.

Where a council has its own page, it is fuller than the line here: the four councils, with what each answered, what it settled, and which of them the Coptic Orthodox Church receives.