The Bible offers a range of dietary teachings. The Old Testament had placed taboos on consuming a variety of meats. In the New Testament’s Acts of the Apostles, St Peter received a vision indicating that these Jewish rulings no longer applied in the Christian era. But in his letters to the earliest followers of Jesus, St Paul had sought to soothe the conflicts to which these contradictory teachings had apparently given rise. He told the Romans: ‘the kingdom of God is not a matter of eating and drinking, but of righteousness, peace and joy in the Holy Spirit’.

We might assume that the issue was settled with Paul. And yet, throughout ancient and medieval Christianity, food continued to spark controversy. In the Roman Empire’s Christian era, the Emperor Valens (364-78) felt compelled to issue an edict forbidding the slaughter of calves. The rationale: demand for veal had skyrocketed, because too many people had taken to cutting fowl and pigs from their diets in accordance with Jewish custom. The role of food in early Christianity was therefore anything but settled.

The early Christian debate over dietary ethics formed just one aspect of a much larger conversation about the need for personal restraint in the pursuit of an ethical life. These questions may sound esoteric to modern ears, but in the political idiom of the Roman world they became a grammar for debating what kind of community the Church should be. Paul, for instance, had been aware that some of his Roman correspondents were vegetarians (an anachronistic term used here to avoid tedious repetition of the phrase, ‘those who abstained from meats’). Yet as we have seen, his key concern was to stop culinary habits from causing conflict among his readers. If eating meat will upset your vegetarian neighbour, then perhaps don’t eat meat yourself. Equally, he warned that vegetarians shouldn’t judge others for adopting more inclusive diets.

Another biblical letter, 1 Timothy (attributed to Paul in the ancient world, but today considered pseudonymous), struck a harsher note. It foretold that false prophets would one day encourage people to reject marriage and to abstain from certain foods that God had wished humans to enjoy. In early and medieval Christianity, 1 Timothy presented a charter for questioning the ethical credentials of those who practised dietary asceticism. Vegetarianism prompted particular suspicion because of its non-Christian roots. The followers of Pythagoras, for instance, had promoted vegetarianism on the basis of their belief that human and animal souls are recycled and jumbled up when we die, so that, in this logic, eating a pig would be no different from eating a human.

In the earliest Christian centuries, martyrdom was the undisputed gold standard of loyalty to the faith. The conversion of the Emperor Constantine in AD 312 and the formal legalisation of Christianity a year later changed everything. First, clerical office became increasingly desirable, as imperial patronage poured into the Church and new legal privileges were conferred on the clergy. Second, with Christianity on top, martyrdom was no longer a realistic goal. In other words, the stakes of competition within the Church had been significantly raised at the very moment that the most reliable method of achieving perfection had been disabled. In this new context, a whole host of issues relating to bodily ethics – particularly diet and sexual mores – became points of controversy.

In the 380s, these tensions started to boil over. In the city of Rome, the clergy – a class of men who were, at this time, usually married – came under fire from radical Christians who demanded more extreme spiritual practices from their leaders. The highest profile of these critics was St Jerome (died 420), a figure celebrated by posterity for producing the Latin translation of the Bible that held widespread authority across medieval Europe (known as the Vulgate). In his own time, however, Jerome was far from uncontroversial. In a series of letters to the daughters of Rome’s noblest senatorial families, he excoriated the ‘tepid’ faith of the clergy. Writing to the young virgin Eustochium, he accused priests of dressing finely, eating lavishly and cultivating the friendship of wealthy women (the irony of this last charge appears to have been lost on him). He urged the women of his coterie to cultivate ‘a holy arrogance’ through adopting abstemious lifestyles. In doing so, they would prove themselves Rome’s true spiritual elite.

In 384, matters came to a head. One of Jerome’s disciples, Blaesilla, died aged 20 after pursuing a programme of extreme fasting. Jerome was driven from Rome in disgrace. During his exile in Bethlehem, a reaction against his teachings took shape. Around 390, Jovinian, a celibate cleric based in Rome, circulated a pamphlet criticising the extreme forms of abstinence that Jerome had promoted in his letters. This original work is lost, but its arguments can be reconstructed using the words of his subsequent detractors. Jovinian’s key claims related to the place of sexuality and culinary restraint in leading an ethical life. He argued that neither virginity nor restrictive diets made a person spiritually superior to those who married and ate a range of foods. Teachers such as Jerome promoted an elitist mentality whose effects on the Christian community were nothing short of corrosive.

In his discussion of food, Jovinian addressed abstinence from meat alongside a set of related practices, such as regular fasting and an unrefined diet. His case was rooted in his reading of the Book of Genesis: God had created all creatures to serve humankind, and while certain animals could be considered useful in non-dietary terms – for example, the ox that pulls the plough – others, such as pigs, served no obvious purpose except for eating. Another key point of reference was 1 Timothy’s prophecy that false prophets would teach dietary abstention. To reject the animals that God had presented for human consumption was to be ensnared by the same vice that had befallen Adam and Eve – pride. In terms that sound oddly familiar to modern ears, Jovinian insinuated that vegetarians were above all self-serving in their motivations. He added that they were no different in this respect from pagans, such as the worshippers of Isis, who adopted similarly unconventional diets.

On the basis of Jerome’s response, it seems that Jovinian also tainted dietary ascetics by associating them with the Manichaeans, a para-Christian sect who believed that two forces (rather than one) had presided over the Creation of the world: one evil, responsible for all things fleshly, and another good, responsible for the soul. Manicheans regarded the renunciation of culinary pleasure and sex as a means of battling against the evil of the body. This line of argument bristled against a strong tradition that placed Jesus’ physical incarnation at the core of Christian doctrine. Jovinian’s appeal to the perfect order of the animal world – and the fundamental goodness of eating animals created for that purpose – was probably intended to position his enemies as crypto-Manichaeans operating in the midst of the Church.

To Jerome, Jovinian’s pamphlet was a charter for spiritual indolence. In his counter-treatise, Against Jovinian, Jerome emphatically reaffirmed the centrality of both sexual and dietary restraint to the Christian life. In his discussion of food, he first set out to prove that there was nothing un-Christian about culinary abstention. He distanced himself from the followers of Pythagoras: his own advocacy of vegetarianism owed nothing to the theory of transmigration of souls that was so unpalatable to Christian notions of salvation. Although some pagan movements had practised dietary restraint, this did not invalidate his case: after all, Satan was a past master at imitating the virtues of the good. Indeed, he noted several biblical exemples to show that many holy people had abstained from the pleasures of the table.

Jerome’s most striking defence, however, spoke specifically to Jovinian’s argument that the avoidance of meat contravened the divine order of nature. Jerome found support for this claim in biblical history, arguing that meat-eating had only come into existence after the Great Flood. The earliest humans had lived as vegetarians. Jerome also appealed to contemporary evidence to bolster his argument. Insisting that ‘no universal law of nature regulates the food of all nations’, he pointed to the range of culinary cultures that existed across the world. The Arabs were thought to consume the milk and meat of camels, and to reject pork. He even posited that some cultures practised cannibalism: the Attacotti, a British tribe that lived beyond Hadrian’s Wall, were said to eat the buttocks of their shepherds and the breasts of their women.

Jerome’s gastro-ethnographies owed much to longstanding Greco-Roman stereotypes about the lifestyles of those who inhabited the earth’s extremities. But his point was an arresting one: when it comes to eating, every nation does things differently and tends to universalise its own norms. Jovinian had said horses were made for riding, but Jerome fired back that the Sarmatians, Quadi and Vandals had been known to eat their mares.

In certain respects, this account of culinary diversity seems a remarkably modern argument for tolerating the dietary differences of others. Jerome’s appeal to cultural relativism was strategic, however. He expressed no sympathy for those who indulge their appetites. Although dietary preferences are shaped by the circumstances of one’s birth, he argued that Christians have been born again in the font of baptism, and so are bound to obey its customs. At a stroke, Jerome swept aside the case for tolerating cultural difference within the Church, arguing instead that entry into the community of the faithful demanded the abandonment of all national mores. Although a lax diet might not be sinful in itself, those who ate freely were bound to be undermined in other, more serious, ways. Here Jerome cited medical authorities who had shown that eating and drinking too much would lead to a superabundance of semen.

The life of dietary restraint was not for everyone. Jerome opined that those who labour with their bodies – such as soldiers, miners and slave labourers – needed meat to support themselves. By contrast, those called to the Christian vocation – that is, to worship God – had no need to fortify the body. The Christian way of life was intellectual, rather than physical. Jovinian’s anxiety about spiritual elitism had been well-founded: for Jerome, the Christian movement would only be a narrow stratum set above the great mass of sinners. If we wish to be perfect, we should avoid meat and wine – but not everyone could be perfect.

The orthodox history of the Church relates that Jerome won the argument. In the medieval future that was to come, the religious life of Latin Europe was to be dominated by a monastic class who derived spiritual authority from their pursuit of self-denial. In medieval saints’ lives, the avoidance of meats was often characterised as an especially rigorous form of spiritual athleticism. Jovinian’s democracy of baptised Christians was lost, along with his treatise.

And yet, Christian thinkers after the Fall of Rome shared many of Jovinian’s misgivings. Two hundred years later, Pope Gregory the Great (died 604) – often characterised as the architect of the medieval Church – composed his Pastoral Rule, a guide to Christian leadership. In Book Two, Gregory advised pastors on how to rebuke congregants who slipped into various vices. In discussing gluttony, he stressed that the excessively abstinent should be held accountable no less than the gastronomically lax. Those who fast often do so to enhance their image, rather than to serve the Christian community. Why did they not give some of their spare food to the poor instead of hoarding it? Meanwhile, Gregory advised that those who abstain from meat should be warned against showing contempt for God’s Creation. While dietary ascetics might appear humble, on the inside they cultivate the deadliest of all vices – pride. Despite its well-known celebration of the ascetic life, medieval Christendom never entirely abandoned Jovinian’s suspicions that ‘holy arrogance’ festered beneath the emaciated body of the monastic.

Arguments about the ethics of eating meat are familiar to us today. The current discourse of vegetarianism and veganism tends to focus on the environmental impacts of our diets and the harms that the meat industry inflicts on animals. The early Christian debate was configured along rather different lines. Indeed, Jovinian argued that vegetarians were demonstrating contempt for the natural order by rejecting meat. It is noticeable that Jerome did not make the (apparently obvious) counterargument that avoiding meat was in fact a better way of respecting God’s Creation. It is conspicuous, too, that considerations of animal welfare never entered Jerome’s mind. Most importantly, Jovinian and Jerome’s conception of vegetarianism as one mode of self-mastery among others appears alien to modern sensibilities. For these Christian teachers, the status of vegetarianism was intimately tied to a wider question about the degree of sexual and emotional restraint that should be expected of Christian leaders.

There are traces of similarity between the early Christian controversy and our own that warrant attention. Jerome’s observations about the diversity of culinary cultures (although not carried to their logical conclusion) would undercut claims that any one diet, carnivorous or otherwise, is ‘natural’. This thread of reasoning points towards a less polemical approach to dietary politics. It would serve as a tonic against both the shrill rhetoric of some carnivores and the universalising tendencies of some vegetarian activists. Fairly or unfairly, suspicions of elitism persistently linger around vegetarian and vegan lifestyles. The question of whether a person’s dietary choices can ever truly be individual – or whether they necessarily entail making claims about the lives of others – remains unresolved.