Surveillance (Überwachung) is a timely topic. Every day we hear about drones, AI, facial recognition, traffic cameras, digital tracking, and social media monitoring. Our phones record our movements, and we wonder if the cameras on our computers are watching us. High technology has made us suspicious of the modern surveillance state.

Michael Hahn's book about Christian communities during the fourth and fifth centuries is an impressive demonstration that even in the absence of sophisticated technology privacy and secrecy were scarce. With the firm guidance of their bishops, the lay members of Christian congregations were able to enforce norms and regulations through "informal mechanisms" (12) such as accusations, denunciations, ridicule, and snubbing. The slightest of missteps made people vulnerable: "gossip and rumors spread quickly" (57).

Hahn's analysis is based largely on hundreds of sermons by two famous contemporaries. The sermons of Augustine, a priest and then bishop of Hippo during the late fourth and early fifth centuries, offer insights into the dynamics of life in the modest cities of Roman North Africa. The sermons of John Chrysostom, a priest at Antioch and then bishop of Constantinople, reference activities in two of the largest cities in the Greek East. Their extant sermons are representative of the thousands of lost sermons and homilies delivered every week around the empire. In these sermons the preachers were constantly reminding laypeople of all the expectations about proper pious behavior and the many restrictions on their activities.

In three lengthy chapters Hahn details these expectations and restrictions. Violations against sexual norms made up one extensive category, emphasizing abstinence before marriage, fidelity within marriage, and total abstinence for clerics and ascetics (chap. 3). Filling over one-quarter of the book, this chapter is a reminder that the passion for regulating sexual activities is not simply a modern obsession. While concerns about sexual behavior defined the inner dynamics of Christian communities, concerns about other religions looked outward (chap. 4). In Antioch fifteen percent of the population were Jews (285); in North Africa Christian sects fought over the coveted label of "catholic"; Augustine himself had once been a Manichee. These fuzzy borders needed clarification. "The vigilant defense of newly defined boundaries between religious affiliations offered an important opportunity for identification as a self-confident Christian" (313). Another cluster of restrictions highlighted concerns about the public baths and the municipal games (chap. 5). In their sermons preachers emphasized the lurking temptations, such as mixed bathing, nudity, exposure to traditional cult sacrifices, and the potential for aggression and even riots at chariot races. Young men were special targets; as Augustine once warned his audience, "control your sons!" (372).

The punishment of objectionable sexual behavior, prejudices about deviant "Others," the dangers of popular culture: all of this intolerance and bigotry sounds so familiar in our era of culture wars. So does the role of supreme spiritual leaders like bishops and clerics in imposing restrictions. The important innovation of Hahn's discussion is his exposure of the collusion of laypeople in enforcing these regulations on themselves. "In late antiquity the ecclesiastical authorities were dependent on the vigilant assistance of the laity to implement and enforce the norms that they themselves attempted to construct in the congregations by rational exegesis" (394).

This lay enforcement could be violent (chap. 6). During the sectarian conflicts in North Africa one priest was beaten and dragged through a muddy pool - which Hahn cleverly compares to waterboarding (492). This example also illustrates that sometimes laypeople turned on their own clergy, grumbling about bishops who spent too much time with young girls and clerics who seduced married women. Some talked back by deploying their own "Laienexegese" of biblical verses (443). They argued that while bishops and clerics certainly had to observe the prohibitions, "we laypeople" could still attend the games.

Laici religiosi is an exceptional book, interesting, smart, based on a remarkably thorough reading of these sermons and related texts that is the scholarly equivalent of data mining. The most significant outcome is to show that laypeople were not passive conformists, browbeaten into submission to regulations and sanctions. Instead, they were themselves active agents in imposing compliance in their own communities. Laypeople deserve as much credit (or blame) as bishops and clerics for the emergence of a distinctively repressive Christian society in the later Roman empire (7-8, 499).

Hahn concludes his discussion with an apt allusion to Argos, the mythical giant with one hundred eyes who could be always awake and vigilant. In late antiquity the Roman administration, despite the bluster of imperial edicts, never had the capability to monitor provincials and ensure compliance. Distance and time were unforgiving obstacles. But in their small communities bishops might think they could indeed preside over a panopticon. John Chrysostom once claimed that a bishop had to be "perspicacious," by which he meant not just intellectually "insightful," but also "watchful": a bishop needed "ten thousand eyes, everywhere" (475). Laypeople could be the bishop's eyes.

But even as they spied on each other, they also monitored bishops and clerics. In early Christian communities who watched the watchmen? Laypeople.

Raymond Van Dam