OPINION: The Pope, Gorbachev and forbidden sex

The Catholic Bishop of Accra, Ghana, Charles Palmer-Buckle, sometimes can't sleep at night. He's tormented by the distance between the Vatican's teaching and his flock's behaviour. Unusually for an African bishop - the continent's Catholic hierarchy is renowned for the strictness of its doctrinal observation - he sways towards accommodating the behavior of the flock.

Describing, in an interview earlier this year, a parishioner married to the same man for 35 years, with children together, but sharing her husband with two other wives, he said: "If I want to apply the law as it is, I must tell her to quit the marriage. But if I do that, she and her children are going to say, 'The Church destroyed my family.' As a bishop, I tell you, I have sleepless nights… If a person is wounded in marriage and is having difficulty, what do you do? That's what the church is struggling with."

Bishop Palmer-Buckle will struggle with this and more three-in-the-morning dilemmas with his brothers-in-Christ in the Vatican's Synod on the Family, which began in Rome last week. It's been billed as the most serious internal debate on sexuality in its various forms that the church has ever had. It may live up to that billing.

One of these brothers (no sisters) will be Cardinal Peter Erdo, from Hungary, who probably doesn't lose sleep over his flock's weaknesses of the flesh, because he knows what to do with people in difficulties: apply the timeless law of the church. In a 7,000 word speech on the synod's first day, Erdo put the hardest of lines under contraception (none), gay marriage (forbidden) and re-admission to the central ceremonies of the church after divorce (never). In the case "of a (consummated) sacramental marriage, after a divorce, a second marriage recognised by the church is impossible." Communion would be denied. The sinner must live with his, or her, sin - unless he or she atoned by renouncing all sexual activity.

As Erdo stands behind and for the conservatives, so does another middle European, Cardinal Walter Kasper of Germany, represent liberals. Kasper insists that the church should allow the divorced to re-enter Catholic rites, constantly raising the issue of homosexuality as a state not to be condemned, but to be understood and accepted.

Sexuality, the force that the priests and cardinals commend for use only in marriage while abstaining from it themselves, now wreaks havoc with the church. Modern secular life - the norm, in Western countries - allows sex ever-larger play, in relationships both deep and casual, in imagery, in entertainment, in education.

Threatened by these storms, the church must either take refuge - as does Erdo - in timeless discipline, the way of the ascetic and the devout, faith strengthened by self-denial. Or it must go the way of Kasper, who said, when asked how to react to the Irish decision to allow same-sex unions, that: "A democratic state has the duty to respect the will of the people. And it seems clear that, if the majority of the people want such homosexual unions, the state has a duty to recognise such rights." He added that same-sex relationships "contain elements of the good."

Before these increasingly stark alternatives, Pope Francis had famously put his position in the form of a question: "If a person is gay and seeks God and has good will, who am I to judge?" The comment to reporters in July 2013 went around the world, underpinning the pope's already burgeoning reputation as a man in tune with modernity, relaxed about sexuality, arms wide to welcome all.

But of course, the rhetorical question did have an answer. It is: "You're the pope! You have to judge!" The Fisherman's ring Francis slipped on his finger at his elevation to the papacy shows the Apostle Peter with the keys to heaven, symbolising papal authority over the Universal Church.

The pope is, by virtue of his office, "the supreme shepherd and teacher of all the faithful" and his definitions "are pronounced with the assistance of the Holy Spirit," according to a pronouncement from the Second Vatican Council in 1964. Vatican II, as it is also known, is famous for updating church rules to allow people to eat meat on Fridays and for Mass to be celebrated in local languages, rather than only in Latin.

In fact, in a less-quoted part of the remarks to the journalists, Francis_ did_ proclaim a "doctrine of faith" - that is, that homosexual acts are sins (though being homosexual, he added, is not). In short, the pope (as far as Catholics are concerned) is the only person in the world with both the authority and the duty to judge on life's supreme issues.

Francis, by stepping down a road towards judgment-free attitudes to forbidden sex, has put himself in the same dangerous position as that taken by Mikhail Gorbachev, the last general-secretary of the Soviet Communist Party, when he subjected the dogmas of communism to ever freer, ever more radical debate. Deserted by the orthodox who tried to depose him, outflanked by the radicals who marked him as irrelevant, the middle ground shrinking to nothing beneath his feet, Gorbachev, at the end of 1991, signed away the Soviet Union into history.

It's unlikely that Francis will live to do the same to the Catholic Church: it's been around much longer than was the Soviet Union, and is unlikely to crumble so easily. But dogma and ideology was and is central to the existence of both. A greater tolerance to the sins of the flesh emboldens the fleshly sinners to ask why they sin.

Once the secular world's relaxed attitude about sexuality enters the calculations of "the supreme shepherd and teacher of all the faithful," the church's leaders must ask ever more awkward questions. One came from Bishop Palmer-Buckle of Accra: When a marriage, or a person, is wounded in an intimate relationship, what do you do?

The greatest of these questions is that which the pope asked himself - "Who are you to judge?" And once he has asked it, what is left?

John Lloyd co-founded the Reuters Institute for the Study of Journalism at the University of Oxford, where he is senior research fellow.