Opening
A common challenge to Catholic teaching: the doctrine of Mary's Immaculate Conception was defined in 1854. The doctrine of papal infallibility was defined in 1870. The doctrine of the Assumption was defined in 1950. If these doctrines are apostolic, why do they wait 1,800 to 2,000 years to be defined? And if they are not apostolic, where do they come from?
The Catholic answer is the development of doctrine. The doctrines do not change; the Church's articulation of them grows. What was held implicitly comes to be articulated explicitly. The conditions under which it grows, and the markers that distinguish authentic development from corruption, were given canonical articulation in John Henry Newman's Essay on the Development of Christian Doctrine (1845, second edition 1878). Newman wrote the essay as an Anglican; finishing it brought him into the Catholic Church on October 9, 1845.
This article reports the doctrine of development, Newman's seven notes for distinguishing true from false development, and the conciliar acceptance of the principle. LV reports; it does not teach.
1. The basic claim
The deposit of revelation closed with the death of the last Apostle §66 DV §4. No new public revelation has been or will be given. But the Church's understanding of that deposit has grown, is growing, and will continue to grow until the parousia. Dei Verbum teaches:
"This tradition which comes from the Apostles develops in the Church with the help of the Holy Spirit. For there is a growth in the understanding of the realities and the words which have been handed down. This happens through the contemplation and study made by believers, who treasure these things in their hearts, through the intimate understanding of spiritual things they experience, and through the preaching of those who have received through Episcopal succession the sure gift of truth." DV §8
The metaphor is biological. A seed is what an oak is, in potency. The oak does not become a different organism by growing; it actualises what was already in the seed. So with doctrine: the Trinity, defined at Nicaea (325), did not appear at Nicaea; it was the apostolic confession articulated against the Arian challenge. The Hypostatic Union, defined at Chalcedon (451), did not appear at Chalcedon; it was the apostolic confession articulated against Eutyches.
2. Vincent of Lérins's earlier formulation
Newman did not invent the principle. Vincent of Lérins (d. before 450), in the Commonitorium, had already given it.
"But someone will say, 'Will there, then, be no progress of religion in the Church of Christ?' Certainly; all possible progress. For who is so envious of men, so hateful to God, as to try to forbid it? Yet on condition that it be real progress, not alteration of the faith." Vincent of Lérins, Commonitorium 23
Vincent's distinction is progressus (progress, real growth in the same direction) versus permutatio (alteration, change of direction). Real progress preserves the same kind of thing; alteration substitutes one kind for another. He uses the metaphor of bodily growth: the man who develops from a child is the same man, with the same nature; the same body grows in size, articulation, and capacity, but it does not become a different body.
Vincent's three-part canon — quod ubique, quod semper, quod ab omnibus (what is held everywhere, always, by everyone) — is sometimes read as opposed to development. Newman shows that the canon is the test, not the prohibition: a doctrine that is held everywhere, always, by everyone is the apostolic faith; the articulation of that faith may grow, but its substance does not change.
3. Newman's seven notes
Newman's Essay applies the development question to the historical record. Why are some doctrines accepted in 451 (Chalcedon's Hypostatic Union) but the corresponding wide formulations in the same direction (1854, Immaculate Conception; 1950, Assumption) are accepted later? What distinguishes a true development from a corruption that mistakes itself for a development?
He gives seven notes (sometimes also numbered as tests) for distinguishing genuine development from corruption.
- Preservation of type — the doctrine after development is recognisably the same doctrine. The growth has not produced a different organism. The doctrine of the Trinity at Nicaea is recognisably the doctrine of Father, Son, and Holy Spirit named at Matthew 28:19.
- Continuity of principles — the same principles operative in the original deposit are operative in the development. The principle of Theotokos (Mary as Mother of God, Ephesus 431) is the same principle that, eventually, secures the Immaculate Conception (Mary preserved from original sin from the first moment of her conception, 1854) — namely, that what is suitable to the dignity of the Mother of God must be predicated of her if it is consistent with revelation.
- Power of assimilation — a true development can absorb new questions and challenges and integrate them. The doctrine of the Hypostatic Union absorbed the Apollinarian, Nestorian, Monophysite, and Monothelite challenges and emerged with greater articulation, not weakened.
- Logical sequence — the development can be shown to follow logically from earlier articulations. Papal infallibility (1870) is logically presupposed by sixteen centuries of Roman appellate jurisdiction over doctrinal questions; it is the explicit form of what was implicit in the Church's actual practice.
- Anticipation of the future — true developments are anticipated in earlier teaching. The Assumption (1950) is anticipated in the Eastern feast of the Dormition (celebrated for centuries before any Western definition), in patristic homilies on Mary's koimēsis, in the typological reading of the Ark of the Covenant.
- Conservative action upon its past — the development confirms and protects earlier teaching, rather than overturning it. Vatican I's definition of papal primacy is conservative of the constant Catholic teaching on Petrine succession; it does not innovate against it.
- Chronic vigour — the developed doctrine continues to bear fruit in the Christian life. False developments tend to die out; true developments deepen and consolidate.
A teaching that meets all seven is a true development. A teaching that fails some — that breaks the type, contradicts earlier principles, refuses integration with new evidence, lacks anticipation, overturns earlier teaching, or withers — is a corruption.
4. Newman's reception in the Church
Newman published the Essay in 1845. He entered the Catholic Church the same year. The Essay was not initially endorsed magisterially; it was an Anglican's argument for the legitimacy of Catholic doctrinal claims. But its method was substantially absorbed.
Vatican I (1870) drew on Newman's framework in its discussion of doctrinal development 3020. Pope Leo XIII made Newman a Cardinal (1879). Pope Pius X cited Newman approvingly even in Pascendi's anti-modernist context (Pius X, Pascendi Dominici Gregis, 1907).
Vatican II's Dei Verbum §8 (quoted above) gives the principle conciliar form. The Catechism cites the same paragraph §94.
Pope John Paul II beatified Newman; Pope Benedict XVI beatified him personally during his 2010 visit to England; Pope Francis canonised him October 13, 2019. The Magisterium's full reception of Newman is now complete.
5. Examples of development
The Trinity. Homoousios (consubstantial) is not in the New Testament. Yet the doctrine that homoousios expresses — the full divinity of the Son — is the New Testament's teaching at John 1:1, John 20:28, Hebrews 1, Colossians 2. Nicaea (325) gave the technical word; the New Testament gave the substance.
The Hypostatic Union. "One Person, two natures" is not Pauline vocabulary. But Paul teaches at Philippians 2:5-11 that Christ is one subject who, "being in the form of God," took the form of a servant. Chalcedon (451) gave the precise grammar of what Paul presupposed.
The Immaculate Conception. The doctrine — that Mary, by a singular grace and privilege of God, was preserved from original sin from the first moment of her conception — is defined in Ineffabilis Deus (1854). Earlier roots: the Theotokos of Ephesus 431, patristic identification of Mary as the "New Eve" (Justin, Irenaeus, Tertullian), liturgical celebration of Mary's Conception in the Eastern Church from the seventh century, Western liturgical reception in England in the eleventh century.
Papal Infallibility. Defined at Vatican I (1870) 3074. Earlier roots: the bishops of Rome's appellate role in the trinitarian crisis (Leo's Tome, 451), Pope Agatho's letter to Constantinople III (681), the constant practice of Eastern Patriarchs appealing to Rome to settle disputes.
In each case, the substance is apostolic; the articulation develops.
6. What development does not mean
Three precise exclusions.
Development is not novelty. A doctrine that has no apostolic root is not a development; it is a fabrication. The test of Vincent of Lérins applies: held everywhere, always, by everyone — at least implicitly.
Development is not contradiction. The Council that defined the death penalty as in principle just (Trent and earlier tradition) and the CCC §2267 revision (2018, Pope Francis) that calls capital punishment "inadmissible" are an instance of disciplined development on a contingent matter, not a contradiction at the level of definitive doctrine. Articles on the death penalty's development will treat this in detail.
Development is not Hegelian dialectic. Doctrine does not synthesise contradictories. Pope Pius IX teaches in Tuas Libenter (1863) and Pius X in Pascendi (1907) that doctrines are immutable; what develops is not the doctrine but its articulation (Pius X, Pascendi Dominici Gregis, 1907). Modernism's claim that doctrines change in substance with historical consciousness is precisely what Pascendi condemns.
7. What this article does not claim
It does not adjudicate every contested case of putative development (e.g., the death penalty teaching, religious liberty, ecumenical inclusivism). It does not enter the recent ressourcement-vs-traditionalist debates over Vatican II's continuity with prior teaching. It does not engage Anglican and Eastern Orthodox formulations of doctrinal development.
Closing
Catholic doctrine grows; it does not change. The seed is the same as the oak. Newman's seven notes are the markers by which the Church distinguishes the oak from a different tree. Dei Verbum §8 transmits the principle conciliarly: the apostolic deposit is closed, but the Church's understanding of it grows under the Holy Spirit's guidance until the parousia.
— The Editors, LumenVeritatis