The Fourth Century: A breakthrough period for the Catholic Church — and an Important Lesson About Its Future

Within the history of Christianity, the fourth century stands out as a crucial turning point — one that forever changed the trajectory of missionary work, Christianity’s role in society, and the Church’s ever evolving ecclesial structure. This paper will explore the combined socio-political, theological, and ecclesiastical factors that formed the blueprint for what is now called Classical Essentialism.

In 313 AD, the Roman Empire instituted an edict that monumentally catapulted Christianity from a community-based network of churches, under an ever-unifying Catholic Church, into the early stages of institutionalism. Known as the Edict of Milan, this document, authorized by Emperor Constantine, gave Christianity the legal license it had desperately needed to quell the occasional, yet furious, persecution that the Romans had inflicted on Christians throughout the second and third centuries (McBrien 65, 66).

As Christians embraced the legal freedom to spread their theological and cultural wings across the vast Roman Empire, they had to adapt to the new responsibilities that the Roman government had expected of them. Largely because of Constantine’s eventual conversion to Christianity in the fourth century, the Church as an institution began to take more shape. Christians who belonged to the Catholic Church had taken on a variety of secular and governmental duties, even having a major role in prosecuting criminals and defending Roman society against foreign enemies (Dulles 204).

Much of this authority rested on Church clergy while it, too, adapted to the freedoms that all Christians were collectively enjoying. The timing of this change also gave clergy a means to expand Church hierarchy into an even more organized ecclesial structure (Tkacik and McGonigle 44). Bishops, presbyters, and deacons had become a triad of authority, serving the foundational role described in The Divine Names, The Celestial Hierarchy, and The Ecclesiastical Hierarchy treatises. In turn, these documents influenced the Church’s transformation into an institutional type of ecclesial structure (Tkacik and McGonigle 84).

The Church had originally understood that these treaties, most likely authored by a Neo-Platonist Syrian Monk in ~500 AD, were written by Dionysius, a Christian whom Paul the Apostle converted. In modern times, these documents are referred to as “Pseudo-Dionysius,” and their contents helped push forward a major shift in how the clergy and laity were to view one other: Ordained clergy now had both the divine and secular authority to govern the laity and oversee civil matters (Tkacik and McGonigle 84, 44).

This type of authority switched the clergy-laity relationship from a broad community of Christians possessing Holy Spirit-infused gifts to serve the Church, to a clergy endowed with the full power of the Holy Spirit, and a laity who were now mostly on the receiving end of this power (Tkacik and McGonigle 84, 89).

Such changes to the clergy’s role in the Church meant reassessing how the sacraments of baptism and the Eucharist were given and managed. Beginning with baptism, this practice was heavily community based until the fourth century. In the first few centuries of Christianity, and per what Paul describes in Romans 6:3-11 and II Corinthians 5:16-62, baptism was not only a rite that bound converts to Jesus’ death and resurrection (and its fundamental meaning of being born into a new life and keeping with Christ’s grace), but it also joined baptized members together as a community devoted to the Church’s mission. In fact, the catechetical process to become baptized was often long and rigorous, allowing the community to be more fully formed believers and serve as loyal missionaries (Tkacik and McGonigle 16, 17).

Then, in the fourth century, with Christianity rapidly spreading because of its legal status and influence on Roman society, Church clergy scrambled to compare their long-standing process for baptizing believers with the droves of people converting to the faith. One of the major decisions by the fourth century Church involved giving clergy additional authority and moving away from a community-driven effort to catechize believers and carry out the sacraments. This included allowing priests to baptize converts more immediately, followed by bishops confirming the baptisms at a later date (Tkacik and McGonigle 17).

These changes also allowed the Church to cut down the catechumenate timeline, including having infants baptized. Yet, although the Church made the conversion process more efficient for the changing circumstances, their reasoning for changing baptism also had to with Augustine’s groundbreaking developments in Christian theology. Augustine, having dealt with multiple heresies that had sprung up in the fourth and fifth centuries, put the tenets of Christian theology back into sharp focus. Using baptism as one of his many talking points, particularly against the Pelagian heresy, Augustine explained baptism as being freed from the consequence of Original Sin. By further clarifying this doctrine, Augustine saw baptism as the means for individual souls to be saved, and not only a spiritual initiation into the greater community. This further meant putting less weight on how the community participated in conversions (Tkacik and McGonigle 17, 18). Moreover, it directly refuted the Pelagian idea that individuals could achieve salvation without any connection to God’s grace.

Like Baptism, the Eucharist was another sacrament that the Church deemed as the clergy’s primary responsibility: As the Church’s liturgy became increasingly ecclesiastical, so did the Eucharist’s place in the liturgy and how the laity were to respond to these changes: The Eucharist had become more ritualized and uniform, which made the liturgy as a whole a standardized experience. Additionally, because the entire liturgy format switched from vernacular languages to Latin, this further divided the laity from the clergy and complicated the laity’s participation in the Eucharist (Tkacik and McGonigle 45).

Still, the remarkable changes to the sacraments were mainly a consequence of the Church’s ecclesiastical and theological evolution: The Church had abundant authority in the fourth century and did not take that lightly at all. What’s more, the Church had already spent its first 300 years trying to be a well-respected, unified, ecclesial authority in the ancient world: Having moved away from the primitive, first century version of the monarchical episcopate, the Church hierarchy in the second century grew into a proper definition of monarchical episcopate. Then, by the fourth century, bishops had an all-encompassing, commanding authority over their local churches and the civil power structures in Roman society. This helped Church clergy continue to uphold apostolic succession and defend the Petrine Primacy (Tkacik and McGonigle 107).

At the same time, as the Church evolved into an ecclesiastical powerhouse, its theology had significantly evolved too. As mentioned earlier, Augustine was a central contributor to Christian belief and the Church’s role as both a visible and invisible force for God’s kingdom. But this was not without the dizzying array of challenges that Augustine and the Church overall faced in the fourth, and into the fifth, centuries. With the Donatist, Arian, and Pelagian schisms waging spiritual and ecclesiastical warfare against the Catholic Church, its clergy had to be fully equipped with the theological, social, and political backing to remain a unified entity (McBrien 64, 65).

McBrien breaks down Augustine’s contributions into several categories, including The Church and the Holy Spirit, The Visible and Invisible Churches, the Catholicity of the Church, the Church and the Eucharist, and the Bishop of Rome. Some of these categories not only reinforce the Church’s theology, but also explain how Augustine refuted Donatist and Pelagian heresies (McBrien 68-70)

For instance, in Augustine’s teachings on the Holy Spirit, he refutes the Donatist claim that the Holy Spirit is essentially only present in their version of the Church; he does this by using Acts, as well as Paul’s letters to the Ephesians and Corinthians, to show that the Body of Christ is not about whatever way an institution or believer wants to define it, or that one part of the Body can be exclusively claimed. Rather, the Body of Christ “gives life to all the parts” (McBrien 68, 69).

While Augustine’s arguments against the Donatists were necessary to cementing the Church’s theology and its Catholicity in the world, they also helped the ecclesiastical structure. In addition, Augustine, as with prior Church Fathers and ecclesiastical writers, supported Peter’s role in apostolic succession. McBrien sums up Augustine’s view of bishops by quoting from Epistle 53.2: all are “united with Peter who is one with Christ, and with the bishop of Rome who succeeded Peter” (McBrien 70, 71).

Keeping the wide range of fourth century theological, socio-political, and ecclesiastical matters in mind, the rise of monasticism added yet another bold layer to the Church’s development: Christians who were enamored with the religious life had created an organized system of piety, asceticism, and service.  Chastity, poverty, self-denial, and service to others grew into staples of strict discipline, all guided by monks who were rapidly influencing the culture. The monastic movement was so wide-sweeping, that just about every part of culture — even literature, art, and music — was enriched by it (Dulles 204; McBrien 66, 67).

This same influence captured the Church as well and would be a blueprint for how Church customs and missionary work developed during the Medieval Era. Monastic attire, the vow of celibacy, and the emphasis on detaching from worldly desires all became standard components of living the religious life. So much so, that Church bishops, presbyters, and deacons ended up adopting these standards. And lastly, like ordained clergy, monks took on several ministerial duties, including overseeing the liturgy and caring for the poor.

All in all, the myriad of angles to Christianity’s growth in the fourth century feature a Church that grew from communal living to ecclesiastical positioning. With its ramped-up authority and unity through the Roman Empire, the Church experienced its first real taste of wielding a double-edged sword of power over the next several centuries.

Considering alone that the Church was able to suppress or eliminate powerfully heretical movements with their own churches and large numbers of adherents, this speaks volumes about the Church’s influence over the outcomes. It also says a lot about the ecclesial structure, having been more divided between clergy and laity.

Unfortunately, this divide would open wide enough to let corruption roll on in and cause political, social, and ecclesiastical strife among the clergy and with various political powers.  And hence why, a thousand years later, the Reformation was a whistleblower reaction to Church corruption; and then close to 500 years after the Reformation, Vatican II identified the entire period as Classical Essentialism.

Works Cited

Dulles, S.J., Avery. Models of the Church, expanded edition. New York: Doubleday, 2002.

McBrien, Richard P. The Church. New York: HarperCollins Publishers, 2008.

Tkacik, Michael J., and Thomas M. McGonigle, O.P. Pneumatic Correctives: What is the Spirit Saying to the Church of the 21st Century? Lanham: University Press of America, 2007.