What do we think of Pope Francis? It all seems a bit complicated. One minute he’s telling the US Congress that “we, the people of this continent, are not fearful of foreigners, because most of us were once foreigners” and that they have to take climate change seriously. Speaking in Bolivia in July, he called unfettered capitalism “the dung of the devil.” Since he arrived in America, right-wingers have described him as “anticapitalist pope.”

On the other hand, the Catholic Church still continues to oppose marriage equality at every opportunity. Back in February, Francis compared any account of gender which “does not recognize the order of creation” — such as those which validate the lives of trans people — to the use of nuclear weapons. On Thursday, the pope canonized the missionary Junípero Serra, who oversaw a regime of horrific brutality against Native Americans in California, where colonization and conversion went, as so often, hand in hand.

It was so much easier to have an opinion about Francis’s predecessor — Benedict XVI was simply, everyone could agree, a reactionary, and not even a very effective reactionary. Doing nothing much about such issues as priestly child sex abuse, he seemed much more concerned about reviving the more obscure bits of the papal costume — a fluffy little shawl called the mozetta, a Santa-Claus-style hat called the camauro, and hand-made red leather shoes.

But then Benedict, apparently so orthodox, abdicated — when it wasn’t even clear if the pope could abdicate. The last pope who did so was the disastrous Celestine V, back in 1294 after a short and unhappy reign.

Brief historical digression: medieval popes were big players in European politics, and after Celestine’s predecessor died, two years of Vatican infighting followed without a pope being chosen. Eventually the Vatican received a letter from Celestine, at that time a hermit living on a mountain top, warning that God would punish them if they didn’t get a move on.

They responded by making Celestine himself pope — even though he was completely unsuited for the role, and when informed of the decision tried to run away. He lasted less than six months before being advised by one Cardinal Caetani that he could resign, at which time he did — opening the way for Caetani, no less, to become pope in his place. Poor old Celestine got very bad press for this, turning up later in one of the outer suburbs of Hell in Dante’s Inferno.

Anyway, heedless of the theological niceties and ominous historical precedent, the reactionary Benedict abdicated, and we got the ambiguous Francis. To understand that ambiguity, we could do worse than start with Marx. Everyone knows that Marx called religion “the opium of the people,” but the full quotation (from A Contribution to the Critique of Hegel’s Philosophy of Right) strikes a far less hostile tone:

Religious suffering is, at one and the same time, the expression of real suffering and a protest against real suffering. Religion is the sigh of the oppressed creature, the heart of a heartless world, and the soul of soulless conditions. It is the opium of the people.

The abolition of religion as the illusory happiness of the people is the demand for their real happiness. To call on them to give up their illusions about their condition is to call on them to give up a condition that requires illusions. The criticism of religion is, therefore, in embryo, the criticism of that vale of tears of which religion is the halo.

Criticism has plucked the imaginary flowers on the chain not in order that man shall continue to bear that chain without fantasy or consolation, but so that he shall throw off the chain and pluck the living flower.

Religion is, then, inherently ambivalent. It can reinforce reactionary ideas — as when Republican presidential candidate Ben Carson explains that Darwin developed the theory of evolution because he was inspired by Satan. It can encourage people to reject political activity, because they will get their reward in heaven. But it can also inspire people to a belief in their own dignity, that the powerful of the earth are as mortal and fallible as anyone else and that fighting for justice is one of the best things of which people are capable — as with many, for example, in the Civil Rights Movement of the 1950s and 60s.

This ambiguity — religion as a reactionary influence versus religion as a force for social justice — is exemplified in a story in Joe Bageant’s book about poor white Americans, Deer Hunting with Jesus. Bageant is in a supermarket, and the woman ahead of him in the checkout queue is talking to the woman at the cash register: they’re both born-again Christians. The woman in the queue has had her truck repossessed, but people at her church have done a collection so as to get her another one. The two woman agree, “ain’t it wonderful when the Lord provides.”

On the one hand, it’s a cheering tale of solidarity: on the other, depressing because the women don’t recognize that they and their friends have made a small change in the world through their own actions, but believe that something supernatural has happened.

The mix of supporting reaction and fighting for justice is just as typical of the Catholic Church, including Catholics in America. On the side of reaction and oppression, we have the fact that in the last thirty years, over three thousand legal cases regarding child sexual abuse have been brought against the church.

As regards working for social justice, I remember time I spent about ten years ago with an American nun. I had gone to Philadelphia to take part in a conference about how charities use computers, and before the event we were each assigned to a local project, to help sort out their IT problems. I was told that I would be meeting a “sister,” and in my ignorance (I was raised in the vague but respectable pieties of the Church of England) I expected someone looking like the Mother Superior in The Sound of Music. In fact, when I arrived at a run-down building in a working-class area, I met a lively woman wearing a polyester dress like the ones my gran favored, running a community center and trying to turn a small neglected park into a facility for local people.

Now, this isn’t unusual when it comes to American nuns, the majority of whom work in the community. Most of them — around forty thousand — are members of a body called the Leadership Conference of Women Religious (LCWR). When Occupy was active in 2011, the LCWR called on its members to get involved. In a newsletter headed “We are the 99%” it encouraged them to read Naomi Klein’s Shock Doctrine.

The Vatican was unimpressed and called LCWR’s president, who had spent fifteen years working with refugees in Latin America, to the Vatican to meet with the Congregation for the Doctrine of the Faith — the body previously known as the Inquisition. In response, fifty thousand American Catholics signed a petition condemning the Vatican. Class struggle, it appears, takes place even within a Catholic Church that includes both the rich and the poor, both cardinals and bishops at the top of the hierarchy and ordinary churchgoers at the bottom.

The fact that Catholic Church has this more radical side, of course, doesn’t absolve religion of its many reactionary crimes. I don’t mean for a moment to excuse the role the Orthodox Church plays in Russia, for example, or the support of the Catholic hierarchy for fascism in the Spanish Civil War. The sexual abuse committed by Catholic priests, the horrors of the Magdalene laundries, the bodies of some eight hundred babies discovered at a home for unwed Irish mothers in Tuam — all this is deeply disgusting, and only the tip of an iceberg. Many people reading this will have suffered deep hurt, in one way or another, from religion, including from the Catholic Church.

Yet these horrors are not the totality of the Catholic Church, or of its thinking. It’s an organization of over a billion people, in most parts of the world, some rich, many poor. The ambivalence which Marx detects in religion is built into its ideas. We are told that gay sex is a terrible sin, but also that we must not condemn others (“Judge not, that ye be not judged,” commands Christ) and we can decide where to strike the balance — Francis’s “Who am I to judge?” as regards gay people is a shift in emphasis, but entirely compatible with the teaching of the church. Loving the sinner and hating the sin, after all, leaves quite a lot of what White House staffers in The West Wing used to call “wiggle room.”

That’s even more the case when an organization has existed for almost two thousand years, which surely is only possible if you build a certain amount of flexibility into your ideas, all the while maintaining that nothing has changed really — and that long history gives you a wide range of tactics which can be reused in new ways across the centuries.

Divorce, for example, remains impossible in the eyes of the church, so divorced people can’t remarry. For a church keen on the family, when in many countries divorce is commonplace, this is a problem. If a Catholic goes to church with her second husband, how will the family be received?

Earlier this month, Francis announced that annulment of marriages was about to be made easier. Annulment resembles divorce: A is no longer married to B, and can now marry C. The difference, in the eyes of the church, is that divorce ends a marriage. An annulment, on the other hand, is granted when you can convince the church that you didn’t take the wedding vows quite seriously enough in the first place — and so the vows are invalid and you were never married at all.

Annulment has a long history. You hear it said that Henry VIII wanted a divorce from Catherine of Aragon, but what he actually wanted was an annulment, in this case on the grounds that the marriage was invalid because she had previously been married to his brother Arthur, now deceased. Annulments came in handy when aristocratic wives failed to bear children who could inherit the family name and property — a tradition still alive, remarkably, in 1992, when Princess Caroline of Monaco got an annulment on the grounds that she and her husband hadn’t had any children.

Altogether, then, Francis is neither radical nor reactionary. In theological, ideological, or PR terms, he presents a papacy with something for everyone, one that can appeal to Catholics be they French fascists campaigning against gay marriage or a working-class American nun running a community center.

In many ways, he is a far more typical religious leader — and a far better one — than uncomplicated reactionaries like Benedict and John Paul II. In a multimedia age — and he has surely appeared more on television than any pope so far — we want to see a contradictory human personality, not a carefully styled politician with a position tested in focus groups. As a White House aide remarked of Francis, “we don’t know what he’s going to say until he says it.”

The ambiguities of religion, described by Marx and typified in Catholicism, lie at the heart of Francis’s considerable appeal.