Epictetus was the sort of figure that only the Roman Empire could have produced. He was born in the Phrygian hills of Anatolia in the middle of the first century. Enslaved and brought to the capital, he served in the household of the freedman Epaphroditos. Epaphroditos, in turn, was in the direct employ of the emperors. Epictetus has told us nothing about his circumstances in these years, but he must have had a close-up view of the swarm of peoples and ideas that passed through the corridors of power. We do not know whether Epictetus noticed, or cared, when in a.d. 64 the emperor Nero fastened blame for the Great Fire on a tiny band of religious eccentrics known as “the people of the anointed one.” We do know that he met the Roman aristocrat and Stoic philosopher Musonius Rufus and fell under the master’s spell. Epictetus earned his freedom and lived out his days, many of them in exile, as a Stoic sage. The former slave from Phrygia was a sensational teacher, sought out by the sons of the gentry from across the empire; he shaped the best minds of a generation.

Epictetus sought to attain the Stoic ideal of “apathy,” a majestic indifference to all things without moral value, including pain and death. For the Stoic, the lover of virtue does his duty—to family, to city—without concern for wealth or status. True freedom, taught the ex-slave, is not a legal condition, but a kind of moral Zen achieved by emancipation from the passions, including the pangs of sexual desire. Musonius Rufus seems to have gone so far as to advise against all sex for the purpose of pleasure, even within marriage. Epictetus, too, reckoned the conquest of physical desire an integral part of the philosopher’s task. But sexual desire claimed no special place of distinction in the wide array of the world’s enticements. “Learn to use wine with refinement,” Epictetus said, “and to hold back from some little lass or a little flatcake.” The precise tone of Stoic advice in sexual matters is nowhere clearer than in his Stoic Handbook. “Remain as pure as you can before marriage with regard to sexual pleasures, and insofar as they are engaged in, let them be lawful. Yet do not become oppressive or reproachful toward those who do indulge, and do not hold forth all the time on your own restraint.”

Of course, when it comes to sex in the ancient world, the moral decency of the imperial Stoics is not what immediately leaps to mind. We are more apt to imagine modern scenes of Roman debauchery (“I’d like a sit-down orgy for forty”) and the naughty pictures on lamps and living room walls dug up in places like Pompeii. But the tame austerity of the philosophers and the ebullient eroticism of the streets coexisted in easy proximity. In fact, they shared a hidden premise. Both presumed that sex was just sex, one instinctual need among others, to be channeled in certain fundamental ways.

For sages and sensualists alike, there were consensus “no-go” zones, where the rules were hard and fast. Expectations of chastity for respectable women, whether maidens or wives, were clear and inflexible. Female purity was heavily guarded. Men were governed by entirely different rules. The code of masculinity abhorred any hint of feminine passivity, in the public square and in the bedchamber alike. The stern threats of public law hovered in the background of these norms. But male sexual restraint was not a prerequisite of dynastic purity, and men were not restrained by the protocols that regulated female chastity. For instance, there is not even a word for “male virgin” in Latin or Greek. It is a little misleading to say that Roman sexual culture had a double standard. There were, very frankly, two entirely different sets of standards of erotic behavior, precisely because sexual morality was determined by the imperatives of reproducing the family and the city, and the bodies of men and women had different roles in that endeavor. The perpetuation of socially honorable households, generation after generation, was the enduring mental frame of public sexual morality. Stoic morality, hard-edged as it might at times be, ran along the grain of this world.

The Roman Empire that nurtured Stoic moralists such as Musonius and Epictetus was really an agglomeration of societies connected by bustling roads and busy sea-lanes. It was a sprawling, polyglot, and agrarian empire. The empire was home to a galaxy of cities—some one thousand of them, most of them smaller than their proud marble ruins might suggest. A grievously poor and unlettered peasantry constituted the silent majority, and some 10 or 15 percent of the empire’s inhabitants had the misfortune of finding themselves in bondage, as chattel slaves whose bodies could as well have been inert matter in the moral imagination of ancient philosophers. Life expectancy at birth was in the mid-twenties. The evanescence of all life turned eros into a divine blessing to be enjoyed in proper season. But the grim realities of Roman life expectancy also made reproduction urgent. Epictetus’s short list of human duties encompassed “citizenship, marriage, child production, piety to God, care of one’s parents.” Sex was a civic duty.

This was the scene onto which the Christians came loudly striding. The Christian movement’s sexual demands were not just austere or unusual. They were jolting, and deliberately so. The apostolic generation did not pour out of the Levant onto the open roads of the empire with anything like a detailed packet of sexual rules. Paul’s letters show us that Christian sexual morality was settled on the go, adapting the gospel’s searing ethic of radical love and interior purity to the realities of life in the towns of the empire. Paul’s letter to the fledgling Christian community in Corinth provides the clearest example. It is the most direct entrée we have to the confrontation between the nascent Christian Church and the habits and half-articulate expectations that governed sexual life in a Greek or Roman city.

First Corinthians shows that Paul’s message was heard in the most contradictory ways, even by sympathetic ears. Some of the new adherents to the faith had drawn startlingly libertine conclusions from Paul’s language of Christian freedom: “All things are lawful for me.” This was not altogether surprising. In the society from which they came, sexual ethics were not invested with much more significance than dietary guidelines. The desire for some “little lass” and the desire for a “little flatcake” were treated with the same moral gravity. So it stood to reason that just as the Gentile Christians were freed from the magnificently intricate regulations of the Jewish dietary code, so too they might expect a certain laxness in erotic matters.

Paul stops this line of thinking in its tracks. His letter unleashes a barrage of ideas and metaphors that came to define the boundaries of Christian sexual orthodoxy. He could have ruled narrowly—along the lines that sex is a moral category like violence or greed, not a merely ethnic cultic norm like rules about shellfish and the Sabbath. He could have enjoined Gentile Christians to obey the old Jewish codes, which regulated sex in detailed ways. Instead, he offered a conceptual framework that, while drawing some of its language and logic from familiar sources, offered an entirely fresh way of grounding sexual morality. His model of human sexuality flowed from a much grander vision than any we find in pagan antiquity. Sexual morality was part of the proclamation of a half-hidden story of God’s restoration of the created cosmos.

The keystone of Paul’s reaction to the Corinthians was his steadfast opposition to “fornication,” porneia in Greek. The word’s underlying associations are rich and esoteric, and we must approach the term with due caution. Consider that the Latin word for it, fornicatio, seems to have been invented for no other purpose than to capture all the fugitive associations of the original. Fornication in English is a churchy word, with little place in the vernacular. (As I tell my students, it is impossible to imagine “fornication” in a text message or tweet.) The root of the word in Greek is “prostitute,” pornê. In ordinary Greek from the classical period onward, the meaning of porneia was prostitution. Before Jews and Christians took hold of the term, the exclusive meaning of porneia was prostitution in the active sense, from the pimp’s or prostitute’s perspective. Porneia was the business of trading sex for money, not the act of patronizing a brothel—and certainly not premarital or extramarital sex tout court.

Yet Paul has something much broader in mind than running a cathouse when he uses the term in his letters. The generic translation in English, “sexual immorality,” won’t do. The locution is too anodyne and reflects a failure of nerve in the face of the intimidating range of meanings that porneia takes in Paul’s usage. It fails to shed light on what the word meant for Paul and leaves a fog around the origins of a distinctive Christian sexual ethics.

Paul’s use of porneia fuses two very different frames of reference, one biblical and the other drawn from the experience of life in the Greco-Roman towns where the apostle preached. In the Old Testament, prostitution (zenuth in the Hebrew, which became porneia in the Septuagint) became a metaphor for idolatry. It is the visceral image of Israel’s betrayal of her exclusive covenantal relationship with Yahweh, and it appears frequently in the Old Testament. The English “harlotry” may still capture some of the abrasive sound of this evocation of covenant infidelity. Closer still: Idolaters are spiritual sluts. The metaphor is easily reversed, so sexual sin can be considered a form of religious betrayal. The prostitute, especially the non-Israelite harlot, who had many lovers, threatens to lure men into idolatry, the worship of many gods. In the Old Testament, sexual and covenantal infidelity are blurred, and thus the imperative of fidelity also has fused meaning. Religious matters of supreme significance merge with and elevate what the surrounding cultures considered matters of worldly propriety.

Paul not only summoned the high-stakes history of porneia in Israel’s Scripture but also deployed it in a way that made the word’s resonance unmistakable. In his usage, prostitution was a synecdoche for the many forms of erotic permissiveness in the culture around him. Moving in a society where it was totally unexceptional—and casually expected—for men to indulge their sexual desires with prostitutes, slaves, and others who lacked social honor, Paul forbade it. Not only that, he proclaimed sexual congress to be a mysterious union of the flesh, something of transcendent significance. The body is a temple, a site of sacred communication. Sexual sin, therefore, is a kind of pollution, as scandalous and disruptive as the desecration of a holy sanctum. We are a long way from the rigorous but pragmatic counsels of Epictetus. The Stoic urged self-control, on the grounds that physical pleasure was a dangerous distraction from the virtuous life. Paul does so because sex implicates us in something with sacred significance.

Paul concedes in his Letter to the Corinthians that marriage is a legitimate safeguard. Because of the lures of the city, the followers of Christ would be allowed to marry. But Paul’s words are hesitant and qualified. Ideally, he writes, followers of Christ would be as he is—in a state of sexual abstinence (possibly but not certainly lifelong celibacy). Marriage is permissible, but only by way of concession, not command. It seems an implicit rejection, or at least a fundamental qualification, of the original imperative “Be fruitful and multiply.” Yet, for Paul, marriage does look back to the original acts of creation. It requires a level of mutual fidelity between partners that mirrors the original congress of God and the human creature. This emphasis on fidelity was alien to the patriarchal culture in which he proclaimed the gospel. With these few words, Paul charted the future course of Christian sexual discipline: Virginity as the highest mode of life and marriage as second best, yet also infused with a divine significance that jealously reserves sexual union for itself.

It is easy enough, and not entirely misleading, to say that Paul’s thought was compressed by the heavy weight of the apocalyptic atmosphere. He wanted his churches to live devotedly toward the coming age, during the small slice of time remaining. But that never led ancient Christians to doubt the larger significance of Paul’s austere counsels. After all, as the time between Christ’s ascension and return lengthened, the entire orthodox tradition in early Christianity chose not to write off Paul’s rigorism as a distortion of his apocalyptic lens; quite the opposite, it tended to accentuate the more extreme and anti-erotic possibilities latent in his thought. The possibility of full-blown Encratism stalked much of early Christian history. (Auden’s “Roman Wall Blues” is about right: “Piso’s a Christian, he worships a fish; / There’d be no kissing if he had his wish.”) In the second century, Clement of Alexandria held fast to the view that within marriage, only sex solely for the purpose of procreation was permissible. Not until the Jovinianist controversy was extinguished in the late fourth century, and Augustine’s tour de force “Of the Good of Marriage” was written, did it become completely clear within Christianity that marriage could be a genuine good and not merely some kind of lesser evil.

Over this same span of centuries, the Church gradually worked out another revolutionary implication of Paul’s message: Sexual morality would require moral agency for all persons, even those whose bodies were beyond the field of vision for ancient thinkers. In today’s terms, Christian sexual morality was inclusive. To be sure, Paul hardly announced the legal emancipation of the unfree. But already (so I have argued, though not all agree) Paul’s ban on porneia restricted one of the slave-owner’s most ordinary prerogatives: sexual access to his slaves. We can trace a dawning awareness in the early Church, unlike anything in pagan antiquity, of the sexual integrity of all persons. By the fifth century, Christian emperors were actually taking proactive (if still, by our standards, limited) measures to protect the bodily integrity of vulnerable women. The heightened place of sexuality in the overarching structure of morality, the respect for the human dignity of all persons, and the insistence on the value of the transcendent and sacred over the secular and the civic—these all went hand in hand in the growth of Christian culture.

Paul’s prohibition on fornication, his highly qualified acceptance of the practical necessity of marriage, and the liberatory movement of Christian individualism form a coherent ethic: For the early Christians, sexual morality was woven inseparably into their whole effort to live rightly in the world. Sex, by its essence, is entangled in the most fundamental questions about the nature of the self and its relation to God. Once launched, the revolution was not easily contained, and when the early Christians tore sexual morality away from the familiar outlines provided by the civic background, the repercussions were not confined to one discrete section of the moral code. Sex came to occupy a place in the foreground of moral instruction in a way that it simply never had in Judaism, or even the most stringent pagan philosophies. The conspicuous austerity of the early Christians caught the eye of early observers, including the Greek doctor Galen. In the competitive marketplace of Roman imperial religion, the way in which Paul loaded questions of sexual morality with dramatic salvific significance gave the moral teaching of this small but vocal movement a particular flavor. The proclamation of the gospel and this strange, spiritualized rigorism were inseparable.

The Christian movement did not come, in the first place, to overthrow the Stoic sages, but rather the folk and civic polytheism that ruled in the hearths and streets of the ancient Mediterranean. Despite the importance of the philosophical schools in shaping literate morality, traditional paganism prevailed. The Roman Empire was not an age of spiritual decadence, as once believed. Christianity did not triumph over a tired or limping polytheism. The old gods confidently ruled. The cities thrummed with their sounds, and the streets were fogged with altar smoke. Later Roman Alexandria, we happen to know, had some 2,500 temples. So it is no accident that the Roman Empire gave birth to the genre of deeply religious literature we call the Greek romance. The romances may be as close as we can get to the warm, earthy spirit of mature paganism in the centuries when Christianity rose to prominence. These long, prose stories of love—of eros, erotic love—start to appear in the first century. They celebrate the idea that two young people, a boy and a girl of high station and uncommon beauty, can fall in love with each other and overcome the obstacles thrown in their way. In the end, all tensions are resolved, as reliably as the stars move across the heavens. The lovers wed and are physically united. Sex is a blessing, the source of all generation and renewal.

These romances proclaim that we belong to the world; we are ordered toward its endless pattern of sexual consummation and new life. The presiding god is Eros, the son of Aphrodite, a god of this world if ever there was one. In Daphnis and Chloe, a second-century pastoral romance that Goethe advised rereading every year, the innocent, natural desire of the two protagonists is likened to the same lush power of nature that impelled the herds of rams and ewes in their season of love. The springs of desire well up from deep inside us and sweep us through life on their raging currents. Sex is an immanent, divine force running through the cycles of time. In these narratives, the whole course of vegetable life—desire, love, marriage, sex, childbirth—constitute who we truly are. We belong here, to the earth, to the benevolent gods, and to the dancing cosmos.

Despite its charms, the romance told Christians exactly what they were not. They did not belong in this world. It is telling that early Christians shaped their imaginations with the diffuse body of legends known as the apocryphal acts of the apostles (whence come such integral stories as the quo vadis and upside-down crucifixion of Peter). These stories are, despite their low literary register, clever anti-romances. In these stories, the Christian apostle often rends a convert away from sex and marriage. Usually, the apostle convinces the beautiful wife of a powerful Roman to believe in Christ, and even to renounce conjugal relations. The Christians in these narratives are ruthlessly hunted by a ruling order that is not benevolent. The assault on physical eros throws ice water in the face of those who walk through life oblivious to the false promises of this world. The stories end not in marriage and the renewal of life but in abstinence and spectacular, sanguinary acts of dying. The renunciation of sex is integral to the apocryphal acts, not as a discrete moral commandment, but as a way of orienting the self in the world. In the early Christian imagination, sexual renunciation turns humanity away from the transient cosmos and toward the eternal reality of divine truth. For the early Christians, a rigorous sexual morality was integral to its spiritual project, which was to move through a world that was always ebbing away and toward the immaterial and transcendent God.

It was not the austere sexual morality itself that set Christians apart from the world so much as its central place within an effort to redefine how humanity ought to live in a created but fallen order. This transforming vision was something new and altogether estranging—in antiquity and ever since. Michel Foucault was neither the first nor the last to look at the rigors of Stoic virtue and see antecedents for Christian austerity. But appearances of continuity are deceptive. However close they were in time, place, and occasionally idiom, what seem like subtle differences between Epictetus and Paul in fact point toward an impassable chasm. The Christian revolution in sexual morality was a departure from, not an acceleration of, Stoic asceticism. And it was a radical break from the warm and earthy pagan eroticism of the kind we find in romance. Christianity put forward a new cosmology, a new ethics, and a new vision of human solidarity, in short, a new view of human destiny that makes sex far more important. Sexual morality is integral to the Christian vision of redemption.

The experience of the early Church might suggest that there have always been, and will always be, uneasy fault lines between the Church and the culture around it. These fault lines have become more visible and dramatic in recent decades. In A Secular Age, Charles Taylor describes the 1960s as the “hinge moment” in the longer arc of modern secularization. The triumph of the secular, by Taylor’s account, does not mean the simple abolition or erasure of the divine from the modern world. Instead, it is a change in the background conditions of all beliefs. The self is no longer imagined as journeying toward final redemption. Human existence is pictured within an indifferent and infinite universe made up of what T. S. Eliot called the “vacant interstellar spaces.”

In this model, sex was, and is, the crux of secularization. According to Taylor, the 1960s saw the sensibility of romanticism broadened into a mass phenomenon. By romanticism he does not mean the dynamic of the ancient Greek romances, a fusion of erotic desire with a fecund, living cosmos. Modern romanticism is more anthropocentric. Romanticism in this sense means an ethic of individual expressivism in accord with codes of authenticity and freedom. Unable to recover eros as worldly god—and unmoored from a shared, public culture whose picture of the universe has a measure of enchantment and meaning—we are left with eros as a private prerogative.

Secularization is not just the scraping away of a religious crust and the return to a pristine condition. (Indeed, it is worth observing that the social assumptions of pre-Christian sexual morality, such as the casual exploitation of the bodies of non-persons, seem incomprehensible precisely because the Christian revolution so completely swept away that old order.) The dethroning of a broadly Christian public morality in the last generations has seen the revival of eros, but not a return to a pre-Christian framework. Eros is no longer a god that weaves us mysteriously into the fabric of an enchanted cosmos. The Christians killed that god dead. Nor does modern sexuality bear any trace of the Stoic sensibility, in which the needs of the city provide moral order to the desires of the individual subject. The power of eros simply is.

Thus, the modern Church finds itself in an odd position. It is surrounded by a culture that bears some of its own values, but they are shorn of their enchanted origins and presented as neutral axioms of the universe. Ironically, some of the most unabashedly secular models of human sexuality also share with Christianity a belief in the central place of the erotic within the architecture of morality. This is utterly alien to Epictetus, and for that matter to most religions outside the Christian (and to some extent the Jewish) tradition. An avowed secularist is as likely as a Christian activist to proclaim the universal dignity of all individuals and insist upon the individual’s freedom. And yet, however moralized the domain of sex might be, the vast, vacant universe seems to have left only authenticity and consent as the shared, public principles of sexual morality. These axioms derive from a picture of the universe different from the one imagined by Paul, who always envisioned the individual—including the sexual self—within the larger story of the gospel and its picture of a created cosmos in the throes of restoration.

And so we live in a fractured culture, with a shared background of meaning that is as thin as gossamer and yet whose values bear the ghostly presence of ancient religious revolutions. The friction between old codes and new ones is not about restraint versus liberty, repression versus authenticity, any more than the difference between Stoic sexual morality and the Pauline view can be described in terms of strict versus lax. In our secular age, just as in the early years of Christianity, differences in sexual morality are really about the clash between different pictures of the universe and the place of the individual within it.

The modern sexual revolution, Taylor writes, has “a tremendous impact on churches whose stance in recent centuries has laid so much stress on these issues [sexual ethics], and where piety has often been identified with a very stringent sexual code.” That is putting it delicately. For stance, read core. For recent centuries, all the way back. For piety, orthodoxy. In the early Church, sexual morality was not baggage, afterthought, or accident. It was the plane on which Christians tried to live in the world, but not of it. Which is why adapting this sexual morality to the modern age has proven as simple as extricating a taut thread from a spider’s web

Kyle Harper is professor of classics and letters and provost at the University of Oklahoma. His new book, The Fate of Rome: Climate, Disease, and the End of an Empire, has just been published.

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