Pandemics can influence and radically alter habits and practices of entire populations. Billions of people have personally tested this phenomenon during the current Coronavirus Disease 2019 (COVID-19) crisis. History knows numerous signs of behavioral practice changes that can be attributed to pandemics, such as the bubonic plague that devastated medieval Europe in the mid-14th century, upsetting many sectors of civil life, or the pestilence that ravaged the Byzantine Empire during the reign of Justinian (mid-sixth century C.E.), even forcing the Goths and the Byzantines to suspend the war fought on the Apennine Peninsula.
Like other catastrophes, pandemics can be critical and polarizing events that generate societal changes beyond the immediate, health-centered issues. Some historical pandemics also had considerable religious consequences: They fueled religious radicalism, encouraged reform movements, and inspired theological discourse. One ancient pandemic even helped to establish the Christian rite of baptism administered to little children and infants—a practice not attested in early Christian communities until the late second century.1
Sometime during 165 C.E., under Emperor Marcus Aurelius (r. 161–180), the Roman Empire was struck by the first documented devastating outbreak of an infectious disease.a Known as the Antonine Plague, it probably was the first appearance of smallpox in the Mediterranean and Europe. The origin of this pandemic was probably in the city of Seleucia, near present-day Baghdad. According to the most widely accepted hypothesis, the Roman soldiers sent to invade Parthia returned in 165, spreading the plague all the way back to Rome, where, according to some modern estimates, smallpox at its apex killed approximately 5,000 people per day.
Mortality was so high it was not unusual to see caravans of fully loaded chariots carrying dead bodies from cities. The scourge reportedly wiped out more than 90 percent of the population in limited areas of Egypt and probably more than 20 percent of the Roman Empire’s total population.2
Christians likely managed to face and overcome the epidemic with greater success than pagans. It can be assumed that the organization of the Christian communities and the care that individual members showed toward the sick may have reduced their mortality rate. However, smallpox tends to cause a high mortality among children, and Christians certainly were not exempt.
The pandemic generated a religious response in the highest echelons of Roman society. Marcus Aurelius restored temples and shrines, summoned priests, and called for every form of prayer to calm the divine anger that he believed was at the origin of the plague. These unusual religious manifestations probably began around 166.3
So what kind of impact did the Antonine Plague have on Christian communities?
One might imagine that the sense of fear and impotence felt by the population along with the revival of religious sensitivities may have contributed to the growth and rapid spread of Christianity throughout the empire.b However, it is plausible that Christian communities were first reorganized internally, including on a theological level.
There hasn’t ever been a Christian community that, at any time, would not request baptism for those who wanted to be part of it. The practice of the rite generated heated debate in the 1950s and 1960s concerning the legitimacy of administering baptism to children and infants. If today the tone of the debate has somewhat dampened, it is due more to a certain fatigue than to a consensus.
The first mention of child baptism comes from the bishop Irenaeus and dates to c. 180 C.E. (Adversus haereses 2.22.4). But we must wait another 20 years to find a clear statement on the baptism of children, put in writing by the prolific author Tertullian, in c. 200 C.E. (De baptismo 18.1.4–5). Tertullian opposed baptizing children, who do not fully understand the significance of the rite. However, it is equally clear that by the end of the second century child baptism was already a reality. About 15 years later, the theologian Hippolytus in his Apostolic Tradition provides a palpable liturgical formulation of the baptism of children (21).
To what factor do we owe the rapid establishment of this habit within the Christian community between 180 and 200 C.E.? The growing number of those who were born into Christian families (as opposed to adult converts) meant an increasing presence of children within the Christian community. When we consider the high infant mortality rate, we can see how an emergency practice of administering the salvific baptism to infants eventually became a normal practice—even more so under the circumstances of a cruel pandemic. Once the emergency of the epidemic was over, in 180 C.E., Irenaeus and other Christian theologians developed a theology of infant baptism and spread the teaching in the following 20 years, so much so that Tertullian, at the dawn of the third century, speaks of it as a commonly accepted practice.
The problem with this scenario is that the connection between the beginnings of infant baptism and the Antonine Plague is purely hypothetical, because no literary source explicitly expresses it. Intriguingly, not only is the link between the plague and infant baptism missing, but also any type of generic mention of the plague in the writings of contemporary Christian authors. We can assume that in the middle of the Antonine Plague every learned debate was silenced by the emergency of the epidemic. The plausible demands for seriously ill children by their Christian parents, who wanted to ensure their salvation through baptism, needed immediate action. It was only when the calamity ended that the first references to the baptism of children began to appear, while the silence of the sources on the plague itself persisted.
So why this silence even after 180 C.E.?
The majority pagan population considered the epidemic a sign of the gods’ disfavor, putting the blame on Christians. Christianity, still living in the imminence of Christ’s return, interpreted this event in a similar manner—as God’s disapproval of the world’s immorality, despite Christians’ presence. The Antonine Plague was the first devastating demographic catastrophe that struck the church. Apologists had to face a sort of theological disorientation: how to justify this “divine punishment.” Is it possible that this disorientation resulted in the puzzling silence of literary sources?
Throughout the subapostolic period, there is no explicit reference to the baptism of children. Every time the topic is tackled, children are considered pure regardless. This was orthodoxy up to the time of the Christian theologian Justin (in 150 C.E.), who was the last apologist to write about baptism before the Antonine Plague struck the Roman Empire (First Apology 61.9–10). Thirty years later, with Irenaeus, the situation seems to have changed, and, after 20 more years, we learn from Tertullian that the practice of infant baptism was implemented unreservedly.
Between 150 and 180 C.E. something must have happened that would justify such an important and unprecedented change. The Antonine Plague fits perfectly in the history of baptismal theology, presenting itself as a crucial event on the world stage.
Francesco Arduini is an author and independent researcher in biblical studies and the history of Christianity. He wrote the book Il battesimo dei bambini (2010).
1. For more, see Francesco Arduini, Il battesimo dei bambini (Rome: Aracne Editrice, 2010).
2. Elio Lo Cascio, “Fra equilibrio e crisi,” in Storia di Roma, vol. 2.2 (Turin: Einaudi, 1991), p. 710.
3. Christer Bruun, “La mancanza di prove di un effetto catastrofico della ‘peste antonina’ (dal 166 d.C. in poi),” in E. Lo Cascio, ed., L’Impatto della “Peste Antonina” (Bari: Edipuglia, 2012), p. 133.
b. Sarah K. Yeomans, Classical Corner: “The Antonine Plague and the Spread of Christianity,” BAR, March/April 2017.
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