Pope Francis is one of the most hated men in the world today. Those who hate him most are not atheists, or protestants, or Muslims, but some of his own followers. Outside the church he is hugely popular as a figure of almost ostentatious modesty and humility. From the moment that Cardinal Jorge Bergoglio became pope in 2013, his gestures caught the world’s imagination: the new pope drove a Fiat, carried his own bags and settled his own bills in hotels; he asked, of gay people, “Who am I to judge?” and washed the feet of Muslim women refugees.

But within the church, Francis has provoked a ferocious backlash from conservatives who fear that this spirit will divide the church, and could even shatter it. This summer, one prominent English priest said to me: “We can’t wait for him to die. It’s unprintable what we say in private. Whenever two priests meet, they talk about how awful Bergoglio is … he’s like Caligula: if he had a horse, he’d make him cardinal.” Of course, after 10 minutes of fluent complaint, he added: “You mustn’t print any of this, or I’ll be sacked.”

This mixture of hatred and fear is common among the pope’s adversaries. Francis, the first non-European pope in modern times, and the first ever Jesuit pope, was elected as an outsider to the Vatican establishment, and expected to make enemies. But no one foresaw just how many he would make. From his swift renunciation of the pomp of the Vatican, which served notice to the church’s 3,000-strong civil service that he meant to be its master, to his support for migrants, his attacks on global capitalism and, most of all, his moves to re-examine the church’s teachings about sex, he has scandalised reactionaries and conservatives. To judge by the voting figures at the last worldwide meeting of bishops, almost a quarter of the college of Cardinals – the most senior clergy in the church – believe that the pope is flirting with heresy.

The crunch point has come in a fight over his views on divorce. Breaking with centuries, if not millennia, of Catholic theory, Pope Francis has tried to encourage Catholic priests to give communion to some divorced and remarried couples, or to families where unmarried parents are cohabiting. His enemies are trying to force him to abandon and renounce this effort.

Since he won’t, and has quietly persevered in the face of mounting discontent, they are now preparing for battle. Last year, one cardinal, backed by a few retired colleagues, raised the possibility of a formal declaration of heresy – the wilful rejection of an established doctrine of the church, a sin punishable by excommunication. Last month, 62 disaffected Catholics, including one retired bishop and a former head of the Vatican bank, published an open letter that accused Francis of seven specific counts of heretical teaching.

To accuse a sitting pope of heresy is the nuclear option in Catholic arguments. Doctrine holds that the pope cannot be wrong when he speaks on the central questions of the faith; so if he is wrong, he can’t be pope. On the other hand, if this pope is right, all his predecessors must have been wrong.

The question is particularly poisonous because it is almost entirely theoretical. In practice, in most of the world, divorced and remarried couples are routinely offered communion. Pope Francis is not proposing a revolution, but the bureaucratic recognition of a system that already exists, and might even be essential to the survival of the church. If the rules were literally applied, no one whose marriage had failed could ever have sex again. This is not a practical way to ensure there are future generations of Catholics.

The newly appointed Pope Francis at the Vatican in 2013. Photograph: Osservatore Romano/Reuters

But Francis’s cautious reforms seem to his opponents to threaten the belief that the church teaches timeless truths. And if the Catholic church does not teach eternal truths, conservatives ask, what is the point of it? The battle over divorce and remarriage has brought to a point two profoundly opposed ideas of what the church is for. The pope’s insignia are two crossed keys. They represent those Jesus is supposed to have given St Peter, which symbolise the powers to bind and to loose: to proclaim what is sin, and what is permitted. But which power is more important, and more urgent now?

The present crisis is the most serious since the liberal reforms of the 1960s spurred a splinter group of hardline conservatives to break away from the church. (Their leader, the French Archbishop Marcel Lefebvre, was later excommunicated.) Over the past few years, conservative writers have repeatedly raised the spectre of schism. In 2015, American journalist Ross Douthat, a convert to Catholicism, wrote a piece for the Atlantic magazine headlined Will Pope Francis Break the Church?; a Spectator blogpost by the English traditionalist Damian Thompson threatened that “Pope Francis is now at war with the Vatican. If he wins, the church could fall apart.” The pope’s views on divorce and homosexuality, according to an Archbishop from Kazakhstan, had allowed “the smoke of Satan” to enter the church.

The Catholic church has spent much of the past century fighting against the sexual revolution, much as it fought against the democratic revolutions of the 19th century, and in this struggle it has been forced into the defence of an untenable absolutist position, whereby all artificial contraception is banned, along with all sex outside one lifelong marriage. As Francis recognises, that’s not how people actually behave. The clergy know this, but are expected to pretend they don’t. The official teaching may not be questioned, but neither can it be obeyed. Something has to give, and when it does, the resulting explosion could fracture the church.

Appropriately enough, the sometimes bitter hatreds within the church – whether over climate change, migration or capitalism – have come to a head in a gigantic struggle over the implications of a single footnote in a document entitled The Joy of Love (or, in its proper, Latin name, Amoris Laetitia). The document, written by Francis, is a summary of the current debate over divorce, and it is in this footnote that he makes an apparently mild assertion that divorced and remarried couples may sometimes receive communion.

With more than a billion followers, the Catholic church is the largest global organisation the world has ever seen, and many of its followers are divorced, or unmarried parents. To carry out its work all over the world, it depends on voluntary labour. If the ordinary worshippers stop believing in what they are doing, the whole thing collapses. Francis knows this. If he cannot reconcile theory and practice, the church might be emptied out everywhere. His opponents also believe the church faces a crisis, but their prescription is the opposite. For them, the gap between theory and practice is exactly what gives the church worth and meaning. If all the church offers people is something they can manage without, Francis’s opponents believe, then it will surely collapse.

No one foresaw this when Francis was elected in 2013. One reason he was chosen by his fellow cardinals was to sort out the sclerotic bureaucracy of the Vatican. This task was long overdue. Cardinal Bergoglio of Buenos Aires was elected as a relative outsider with the ability to clear out some of the blockage at the centre of the church. But that mission soon collided with an even more acrimonious faultline in the church, which is usually described in terms of a battle between “liberals”, like Francis, and “conservatives”, like his enemies. Yet that is a slippery and misleading classification.

The central dispute is between Catholics who believe that the church should set the agenda for the world, and those who think the world must set the agenda for the church. Those are ideal types: in the real world, any Catholic will be a mixture of those orientations, but in most of them, one will predominate.

Francis is a very pure example of the “outer-directed” or extrovert Catholic, especially compared with his immediate predecessors. His opponents are the introverts. Many were first attracted to the church by its distance from the concerns of the world. A surprising number of the most prominent introverts are converts from American Protestantism, some driven by the shallowness of the intellectual resources they were brought up with, but much more by a sense that liberal Protestantism was dying precisely because it no longer offered any alternative to the society around it. They want mystery and romance, not sterile common sense or conventional wisdom. No religion could flourish without that impulse.

But nor can any global religion set itself against the world entirely. In the early 1960s, a three-year gathering of bishops from every part of the church, known as the Second Vatican Council, or Vatican II, “opened the windows to the world”, in the words of Pope John XXIII, who set it in motion, but died before its work had finished.

The council renounced antisemitism, embraced democracy, proclaimed universal human rights and largely abolished the Latin Mass. That last act, in particular, stunned the introverts. The author Evelyn Waugh, for example, never once went to an English Mass after the decision. For men like him, the solemn rituals of a service performed by a priest with his back to the congregation, speaking entirely in Latin, facing God on the altar, were the very heart of the church – a window into eternity enacted at every performance. The ritual had been central to the church in one form or another since its foundation.

The symbolic change brought about by the new liturgy – replacing the introverted priest facing God at the altar with the extroverted figure facing his congregation – was immense. Some conservatives still have not reconciled themselves to the reorientation, among them the Guinean cardinal Robert Sarah, who has been touted by introverts as a possible successor to Francis, and the American cardinal Raymond Burke, who has emerged as Francis’ most public opponent. The current crisis, in the words of the English Catholic journalist Margaret Hebblethwaite – a passionate partisan of Francis – is nothing less than “Vatican II coming back again”.

Cardinal Raymond Burke (centre), one of Pope Francis’s most prominent enemies. Photograph: Franco Origlia/Getty Images

“We need to be inclusive and welcoming to all that is human,” Sarah said at a Vatican gathering last year, in a denunciation of Francis’s proposals, “but what comes from the Enemy cannot and must not be assimilated. You can not join Christ and Belial! What Nazi-Fascism and Communism were in the 20th century, Western homosexual and abortion Ideologies and Islamic Fanaticism are today.”

In the years immediately after the council, nuns discarded their habits, priests discovered women (more than 100,000 left the priesthood to marry) and theologians threw off the shackles of introverted orthodoxy. After 150 years of resisting and repelling the outside world, the church found itself engaging with it everywhere, until it seemed to introverts that the whole edifice would collapse to rubble.

Church attendance plummeted in the western world, as it did in other denominations. In the US, 55% of Catholics went to mass regularly in 1965; by 2000, only 22% did. In 1965, 1.3m Catholic babies were baptised in the US; in 2016, just 670,000. Whether this was cause or correlation remains fiercely disputed. The introverts blamed it on the abandonment of eternal truths and traditional practices; extraverts felt the church had not changed far or fast enough.

In 1966, a papal committee of 69 members, with seven cardinals and 13 doctors among them, on which laypeople and even some women were also represented, voted overwhelmingly to lift the ban on artificial contraception, but Pope Paul VI overruled them in 1968. He could not admit that his predecessors had been wrong, and the Protestants right. For a generation of Catholics, this dispute came to symbolise resistance to change. In the developing world, the Catholic church was largely overtaken by a huge Pentecostal revival, which offered both showmanship and status to the laity, even to women.

The introverts had their revenge with the election of Pope (now Pope Saint) John Paul II in 1978. His Polish church had been defined by its opposition to the world and its powers since the Nazis and the Communists divided the country in 1939. John Paul II was a man of tremendous energy, willpower and dramatic gifts. He was also profoundly conservative on matters of sexual morality and had, as a cardinal, provided the intellectual justification for the ban on birth control. From the moment of his election, he set about reshaping the church in his image. If he could not impart to it his own dynamism and will, he could, it seemed, purge it of extroversion and once more set it like a rock against the currents of the secular world.

Ross Douthat, the Catholic journalist, was one of the few people in the introvert party who was prepared to talk openly about the current conflict. As a young man, he was one of the converts drawn into the church of Pope John Paul II. He now says: “The church may be a mess, but the important thing is that the centre is sound, and one can always rebuild things from the centre. The point of being Catholic is that you’re guaranteed continuity at the centre, and with that the hope of reconstitution of the Catholic order.”

John Paul II was careful never to repudiate the words of Vatican II, but he worked to empty them of the extrovert spirit. He set about imposing a fierce discipline on the clergy and on theologians. He made it as difficult as possible for priests to leave and marry. His ally in this was the Congregation for the Doctrine of the Faith, or CDF, once known as the Holy Office. The CDF is the most institutionally introverted of all Vatican departments (or “dicasteries”, as they have been known since the days of the Roman empires; it’s a detail that suggests the weight of institutional experience and inertia – if the name was good enough for Constantine, why change it?).

For the CDF, it is axiomatic that the role of the church is to teach the world, and not to learn from it. It has a long history of punishing theologians who disagree: they have been forbidden to publish, or sacked from Catholic universities.

Early in the pontificate of John Paul II, the CDF published Donum Veritatis (The Gift of Truth), a document explaining that all Catholics must practise “submission of the will and intellect” to what the pope teaches, even when it is not infallible; and that theologians, while they may disagree and make their disagreement known to superiors, must never do so in public. This was used as a threat, and occasionally a weapon, against anyone suspected of liberal dissent. Francis, however, has turned these powers against those who had been their most enthusiastic advocates. Catholic priests, bishops and even cardinals all serve at the pleasure of the pope, and can at any moment be sacked. The conservatives were to learn all about this under Francis, who has sacked at least three theologians from the CDF. Jesuits demand discipline.

In 2013, shortly after his election, while he was still surfing a wave of almost universal acclaim for the boldness and simplicity of his gestures – he had moved into a couple of sparsely furnished rooms in the Vatican grounds, rather than the sumptuous state apartments used by his predecessors – Francis purged a small religious order devoted to the practice of the Latin Mass.

The Franciscan Friars of the Immaculate, a group with about 600 members (men and women), had been placed under investigation by a commission in June 2012, under Pope Benedict. They were accused of combining increasingly extreme rightwing politics with a devotion to the Latin Mass. (This mixture, often seen alongside declarations of hatred of “liberalism”, had also been spreading through online outlets in the US and the UK, such as the Daily Telegraph’s Holy Smoke blog, edited by Damian Thompson.)

When the commission reported in July 2013, Francis’s reaction shocked conservatives rigid. He stopped the Friars using the Latin Mass in public, and closed down their seminary. They were still allowed to educate new priests, but not segregated from the rest of the church. What’s more, he did so directly, without going through the Vatican’s internal court system, then run by Cardinal Burke. The next year, Francis sacked Burke from his powerful job in the Vatican’s internal court system. By doing so, he made an implacable enemy.

Burke, a bulky American given to lace-embroidered robes and (on formal occasions) a ceremonial scarlet cape so long it needs pageboys to carry its trailing end, was one of the most conspicuous reactionaries in the Vatican. In manner and in doctrine, he represents a long tradition of heavyweight American power brokers of white ethnic Catholicism. The hieratic, patriarchal and embattled church of the Latin Mass is his ideal, to which it seemed that the church under John Paul II and Benedict was slowly returning – until Francis started work.

Cardinal Burke’s combination of anti-communism, ethnic pride and hatred of feminism has nurtured a succession of prominent rightwing lay figures in the US, from Pat Buchanan through Bill O’Reilly and Steve Bannon, alongside lesser-known Catholic intellectuals such as Michael Novak, who have shilled untiringly for US wars in the Middle East and the Republican understanding of free markets.

It was Cardinal Burke who invited Bannon, then already the animating spirit of Breitbart News, to address a conference in the Vatican, via video link from California, in 2014. Bannon’s speech was apocalyptic, incoherent and historically eccentric. But there was no mistaking the urgency of his summons to a holy war: the second world war, he said, had really been “the Judeo-Christian west versus atheists”, and now civilisation was “at the beginning stages of a global war against Islamic fascism … a very brutal and bloody conflict … that will completely eradicate everything that we’ve been bequeathed over the last 2,000, 2,500 years … if the people in this room, the people in the church, do not … fight for our beliefs against this new barbarity that’s starting.”

Everything in that speech is anathema to Francis. His first official visit outside Rome, in 2013, was to the island of Lampedusa, which had become the arrival point for tens of thousands of desperate migrants from north Africa. Like both his predecessors, he is firmly opposed to wars in the Middle East, although the Vatican gave reluctant support to the extirpation of the Islamic State caliphate. He opposes the death penalty. He loathes and condemns American capitalism: after marking his support for migrants and gay people, the first big policy statement of his time in office was an encyclical, or teaching document, addressed to the whole church, that fiercely condemned the workings of global markets.

Francis (then still Cardinal Bergoglio) washing drug addicts’ feet in Buenos Aires in 2008. Photograph: AP

“Some people continue to defend trickle-down theories which assume that economic growth, encouraged by a free market, will inevitably succeed in bringing about greater justice and inclusiveness in the world. This opinion, which has never been confirmed by the facts, expresses a crude and naive trust in the goodness of those wielding economic power and in the sacralized workings of the prevailing economic system. Meanwhile, the excluded are still waiting.”

Above all, Francis is on the side of the immigrants – or the emigrants, as he sees them – driven from their homes by a boundlessly rapacious and destructive capitalism, which has set catastrophic climate change in motion. This is a racialised, as well as a deeply politicised, question in the US. The evangelicals who voted for Trump and his wall are overwhelmingly white. So is the leadership of the American Catholic church. But the laity is around a third Hispanic, and this proportion is growing. Last month Bannon claimed, in an interview on CBS’s 60 Minutes, that American bishops were in favour of mass immigration only because it kept their congregations going – although this goes further than even the most rightwing bishops would publicly say.

When Trump first announced that he would build a wall to keep out migrants, Francis came very close to denying that the then candidate could be a Christian. In Francis’s vision of the dangers to the family, transgender lavatories are not the most urgent problem, as some culture warriors claim. What destroys families, he has written, is an economic system that forces millions of poor families apart in their search for work.

As well as tackling the old-school practitioners of Latin Mass, Francis started a wide-ranging offensive against the old guard inside the Vatican. Five days after his election in 2013, he summoned the Honduran cardinal Óscar Rodríguez Maradiaga, and told him that he was to be the co-ordinator of a group of nine cardinals from around the world whose mission was to clean the place up. All had been chosen for their energy, and for the fact that they had in the past been at loggerheads with the Vatican. It was a popular move everywhere outside Rome.

John Paul II had spent the last decade of his life increasingly crippled by Parkinson’s disease, and such energies as he had left were not spent on bureaucratic struggles. The curia, as the Vatican bureaucracy is known, grew more powerful, stagnant and corrupt. Very little action was taken against bishops who sheltered child-abusing priests. The Vatican bank was infamous for the services it offered to money-launderers. The process of making saints – something John Paul II had done at an unprecedented rate – had become an enormously expensive racket. (The Italian journalist Gianluigi Nuzzi estimated the going rate for a canonisation at €500,000 per halo.) The finances of the Vatican itself were a horrendous mess. Francis himself referred to “a stream of corruption” in the curia.

The putrid state of the curia was widely known, but never talked about in public. Within nine months of taking office, Francis told a group of nuns that “in the curia, there are also holy people, really, there are holy people” – the revelation being that he assumed his audience of nuns would be shocked to discover this.

The curia, he said “sees and looks after the interests of the Vatican, which are still, for the most part, temporal interests. This Vatican-centric view neglects the world around us. I do not share this view, and I’ll do everything I can to change it.” He said to the Italian newspaper La Repubblica: “Heads of the church have often been narcissists, flattered and thrilled by their courtiers. The court is the leprosy of the papacy.”

“The Pope has never said anything nice about priests,” said the priest who can’t wait for him to die. “He’s an anti-clerical Jesuit. I remember that from the 70s. They’d say: ‘Don’t call me Father, call me Gerry’ – that crap – and we, the downtrodden parish clergy, feel the ground has been cut from under our feet.”

In December 2015, Francis gave his traditional Christmas address to the curia, and he pulled no punches: He accused them of arrogance, “spiritual Alzheimer’s”, “hypocrisy that is typical of the mediocre and a progressive spiritual emptiness that academic degrees cannot fill”, as well as empty materialism and an addiction to gossip and backbiting – not the sort of thing you want to hear from the boss at the office party.

Yet four years into his papacy, the passive resistance of the Vatican seems to have triumphed over Francis’ energy. In February this year, posters appeared overnight in the streets of Rome asking, “Francis, where’s your mercy?”, attacking him for his treatment of Cardinal Burke. These can only have come from disaffected elements in the Vatican, and are outward signs of a stubborn refusal to yield power or privilege to the reformers.

This battle, though, has been overshadowed, as have all the others, by the infighting over sexual morality. The struggle over divorce and remarriage centres on two facts. First, that the doctrine of the Catholic church has not changed in nearly two millennia – marriage is for life and indissoluble; that’s absolutely clear. But so is the second fact: Catholics actually get divorced and remarried at about the same rate as the surrounding population, and when they do so, they see nothing unforgivable in their actions. So the churches of the western world are full of divorced and remarried couples who take communion with everyone else, even though they and their priests know perfectly well it is not allowed.

The rich and powerful have always exploited loopholes. When they want to shuck off a wife and remarry, a good lawyer will find some way to prove the first marriage was a mistake, not something entered into in the spirit the church demands, and so it can be wiped from the record – in the jargon, annulled. This applies especially to conservatives: Steve Bannon has managed to divorce all three of his wives, but perhaps the most scandalous contemporary example is that of Newt Gingrich, who led the Republican takeover of Congress in the 1990s and has since reinvented himself as a Trump ally. Gingrich broke up with his first wife while she was being treated for cancer, and while married to his second wife had an eight-year affair with Callista Bisek, a devout Catholic, before marrying her in church. She is about to take up the post of Donald Trump’s new ambassador to the Vatican.

The teaching on remarriage after divorce is not the only way Catholic sexual teaching denies reality as laypeople experience it, but it is the most damaging. The ban on artificial contraception is ignored by everyone wherever it is legal. The hostility to gay people is undermined by the generally acknowledged fact that a large proportion of the priesthood in the west is gay, and some of them are well-adjusted celibates. The rejection of abortion is not an issue where abortion is legal, and is in any case not particular to the Catholic church. But the refusal to recognise second marriages, unless the couple promise never to have sex, highlights the absurdities of a caste of celibate men regulating women’s lives.

Pope Francis at the Vatican on Good Friday this year. Photograph: Alberto Pizzoli/EPA

In 2015 and 2016, Francis convened two large conferences (or synods) of bishops from all around the world to discuss all this. He knew he could not move without broad agreement. He kept silent himself, and encouraged the bishops to wrangle. But it was soon apparent that he favoured a considerable loosening of the discipline around communion after remarriage. Since this is what goes on in practice anyway, it is difficult for an outsider to understand the passions it arouses.

“What I care about is the theory,” said the English priest who confessed his hatred of Francis. “In my parish there are lots of divorced and remarried couples, but many of them, if they heard the first spouse had died, would rush to get a church wedding. I know lots of homosexuals who are doing all sorts of things that are wrong, but they know they should not be. We’re all sinners. But we’ve got to maintain the intellectual integrity of the Catholic faith.”

With this mindset, the fact that the world rejects your teaching merely proves how right it is. “The Catholic Church ought to be countercultural in the wake of the sexual revolution,” says Ross Douthat. “The Catholic church is the last remaining place in the western world that says divorce is bad.”

For Francis and his supporters, all this is irrelevant. The church, says Francis, should be a hospital, or a first-aid station. People who have been divorced don’t need to be told it’s a bad thing. They need to recover and to piece their lives together again. The church should stand beside them, and show mercy.

At the first synod of the bishops in 2015, this was still a minority view. A liberal document was prepared, but rejected by a majority. A year later, the conservatives were in a clear minority, but a very determined one. Francis himself wrote a summary of the deliberations in The Joy of Love. It is a long, reflective and carefully ambiguous document. The dynamite is buried in footnote 351 of chapter eight, and has taken on immense importance in the subsequent convulsions.

The footnote appends a passage worth quoting both for what it says and how it says it. What it says is clear: some people living in second marriages (or civil partnerships) “can be living in God’s grace, can love and can also grow in the life of grace and charity, while receiving the Church’s help to this end”.

Even the footnote, which says that such couples may receive communion if they have confessed their sins, approaches the matter with circumspection: “In certain cases, this can include the help of the sacraments.” Hence, “I want to remind priests that the confessional must not be a torture chamber, but rather an encounter with the Lord’s mercy.” And: “I would also point out that the Eucharist ‘is not a prize for the perfect, but a powerful medicine and nourishment for the weak’.”

“By thinking that everything is black and white,” Francis adds, “we sometimes close off the way of grace and growth.”

It is this tiny passage that has united all the other rebellions against his authority. No one has consulted laypeople to find out what they think about it, and in any case their opinions are of no interest to the introvert party. But among the bishops, between a quarter and a third are passively resisting the change, and a small minority are doing so actively.

The leader of that faction is Francis’s great enemy, Cardinal Burke. Sacked first from his position on the Vatican court, and then from the liturgy commission, he ended up on the supervisory board of the Knights of Malta – a charitable body run by the old Catholic aristocracies of Europe. In Autumn 2016, he sacked the head of the order for supposedly allowing nuns to distribute condoms in Burma. This is something that nuns do quite widely in the developing world to protect vulnerable women. The man who had been sacked appealed to the pope.

The outcome was that Francis reinstated the man Burke had sacked, and appointed another man to take over most of Burke’s duties. This was punishment for Burke’s quite untrue claim that the pope had been on his side in the original row.

Meanwhile, Burke had opened a new front, which came as close as he could to accusing the pope of heresy. Along with three other cardinals, two of whom have since died, Burke produced a list of four questions designed to establish whether or not Amoris Laetitia contravened previous teaching. These were sent as a formal letter to Francis, who ignored it. After he was sacked, Burke made the questions public, and said he was prepared to issue a formal declaration that the pope was a heretic if he would not answer them to Burke’s satisfaction.

Of course, Amoris Laetitia does represent a break with previous teaching. It is an example of the church learning from experience. But that is hard for conservatives to assimilate: historically, these bursts of learning have only happened in convulsions, centuries apart. This one has come only 60 years after the last burst of extroversion, with Vatican II, and only 16 years after John Paul II reiterated the old, hard line.

“What does it mean for a pope to contradict a previous pope?” asks Douthat. “It is remarkable how close Francis has come to arguing with his immediate predecessors. It was only 30 years ago that John Paul II laid down in Veritatis Splendor the line which it seems that Amoris Laetitia is contradicting.”

Pope Francis is deliberately contradicting a man who he himself proclaimed a saint. That will hardly trouble him. But mortality might. The more Francis changes his predecessors’ line, the easier it becomes for a successor to reverse his. Although Catholic teaching does of course change, it relies for its force on the illusion that it doesn’t. The feet may be dancing under the cassock, but the robe itself must never move. However, this also means changes that had taken place can be rolled back without any official movement. That is how John Paul II struck back against Vatican II.

To guarantee Francis’ changes will last, the church has to accept them. That is a question that will not be answered in his lifetime. He is 80 now, and only has one lung. His opponents may be praying for his death, but no one can know whether his successor will attempt to contradict him – and on that question, the future of the Catholic church now hangs.

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• This article was amended on 27 October and 3 November 2017. An earlier version said Robert Sarah was Ghanaian. This has been corrected to Guinean. This article was further amended because CDF is the Congregation for the Doctrine of the Faith, not the Congregation for the Defence of the Faith, as an earlier version had it.

