Like many popes before him, Francis has used his bully pulpit to explain world events, contemporary problems and social issues in the light of the Gospel as he reads it. He has promised to issue a document on the environment and climate change. He has spoken passionately on immigration and economics, and recently finalized Vatican recognition of a Palestinian state. He has reached out to Castro’s Cuba, and condemned global inequality as unjust, implying that governments ought to forcibly correct it.

Catholics and non-Catholics alike are confused about how to interpret his statements. As the author of four books explaining Catholic doctrine, I’d like to lay out precisely what the Church claims concerning papal authority — and what it doesn’t. This is not an attempt to defend the Catholic understanding of the pope’s authority, but only to explain it.

Faithful Catholics believe that the core moral teachings dating to the days of the apostles are unchangeable, and each pope has only the power to pass them along and explain them — not alter them. Each papacy and each doctrinal crisis that arises in history is a test of this promise in action. Right now on divorce and remarriage we can watch the experiment in real time.

But what about the myriad questions we cannot answer by simply looking up what the Church has consistently taught in the past? When the pope gives his personal opinion about technical issues of economics, immigration or ecology, are Catholics obliged to agree with him? To piously stay silent? To put the most positive “spin” on statements which in private make us wince?

To answer these questions, and help explain the church’s complex view of papal authority, what follows is a straightforward Q&A. Like my recent Bad Catholic’s Guide to the Catechism, it takes a lighthearted tone. The questions are posed as if by a curious, skeptical friend.

Q: Is the pope infallible?

A: The safe answer is No.

Q: What do you mean by “safe answer”?

A: That if you say No, you will be right some 99.99% of the time. If I asked you, “Are American women in labor right now?” your answer would be the same. But in both cases there would be rare exceptions. A tiny percentage of American women are giving birth as you read this, and an even tinier percentage of statements made by popes throughout history were infallible.

Q: Which ones?

A: We aren’t entirely sure.

Q: You’re kidding, right?

A: No. There are only two statements that popes have made which the Church explicitly labels as infallible. There is a list of six other statements that are probably infallible, and a raft of teachings that some people claim are infallible, while others disagree.

Q: That seems … less than helpful. Which two statements are Catholics sure about?

A: In 1850, Pope Pius IX taught that all Catholics must accept an ancient Christian belief about Mary, the mother of Jesus: that God granted her a kind of baptism at her conception. Since God stands outside of time, he could give her the graces of Christ’s redemption in advance. So when she was born, she was just like Adam and Eve at their creation: free of original sin. She had a blank slate, instead of the toxic inheritance of warped will, blinkered reason and constant temptation to sin that afflicts the rest of us. She was still nothing more than human, and was completely free to sin. But unlike Adam and Eve, she never did. Without this special gift from God, she absolutely would have sinned, just as the rest of us do. So there’s nothing special about Mary in herself; she is simply the most transparent example of God’s saving grace in action.

Q: I don’t buy it, but go ahead. What’s the other one?

A: It’s tied to the first teaching. Because Mary was spared, through the grace of Christ, the stain of original sin, she was also spared one of its consequences: her body dying and rotting in the ground. Instead, at the moment of her death, she was assumed into heaven — in much the same way that the Old Testament teaches Elijah was. Again, this is an ancient Christian belief, which Pope Pius XII declared in 1950 was not just an opinion but fact.

Q: What about the other six, the probably infallible statements?

A: They address complex questions of faith:

• the natures of Christ (He has two—divine and human);
• the two wills of Christ (ditto);
• what happens to your soul after you die (you are judged right away);
• the role of free will in salvation (it’s decisive);
• and the authority of the pope over local bishops, despite the interference of secular monarchs (bishops get their authority from God via Rome, not through politicking).

Q: So is the rest of Christian doctrine and morality up for grabs — er, I meant to say, “left to the individual conscience”?

A: Absolutely not. Almost all of the central teachings that Catholics believe, which most faithful Orthodox and Protestants share, came from teachings at councils of bishops in the early church. The bishop of Rome presided over some of these, played a role in others, and approved still others from a distance. These councils (such as Nicaea and Chalcedon) were the key means the church used to figure out which books to accept as authentic books of the Bible, and how to interpret what they mean. We believe they were protected by the Holy Spirit from error, and hence their statements on faith and morals were infallible.

Q: Okay, so you people believe that these Church councils were universal and could declare infallible teachings?

A: Yes. Our Orthodox brothers argue that there were no such infallible councils after the Eastern and Western churches split, whereas Catholics hold that the councils of the Western churches continued to be infallible. And ever since the next-to-last such council, Vatican I which ended in 1870, we believe that on rare occasions, the pope can act alone with the same authority as a council. This doctrine of papal infallibility was very controversial in its time, and many Catholics opposed the idea. They argued that such a doctrine was unnecessary, divisive and an obstacle to reunion with the Orthodox.

Pope Pius IX, however, thought that infallibility was essential to shore up the authority of the pope in an age when nationalism was sweeping through the West, including the church, pitting French cardinals against Germans, and Catholics were becoming more loyal to their nation-states than to the church. Of course, as we’d see in 1914, such bishops on both sides of the war would bless the armies marching to the trenches, and speak of the war as a holy crusade. So Pius IX had a point: It would be very hard to run the church via councils of bishops after that.

Pius IX had rather inflated ideas of what that infallibility would mean. Had Pius had his way, Vatican I might well have made virtually every papal statement on any important subject binding on every Catholic — enshrining the pope as a kind of oracle. But the Holy Spirit does guide ecumenical councils, and what Vatican I approved was much more modest. It taught that in a narrow set of very special circumstances, when the pope explicitly announces that his statement is infallible, then Christ will grant him protection from error.

Q: So on those occasions what he says is considered divinely inspired, almost prophetic?

A: No. We don’t think that of councils either. Catholics believe that God wouldn’t let a council or a pope solemnly teach heresy. He’d simply prevent it, as he prevented the Church from accepting forged documents as Gospels. Think of it as a divine veto power, which might take the form of a still, small voice in a pontiff’s heart. Or maybe a sudden heart attack (see video below):

Q: What about when the pope writes or speaks on politics and economics?

A: Most of the time, those topics involve specific disputes about how to apply moral principles, statements of fact or arguments over what’s prudent. Infallibility can’t apply to any of those. When he’s writing on those subjects, the pope is just an ordinary man — although in most cases a wise and learned one, whose ideas we should take seriously. For instance, when Pope Paul VI wrote in Populorum Progressio that the right way for rich countries to help poor ones was to tax their citizens and send money to Third World governments, that was a suggestion worth considering. But faithful Catholics can disagree. Many have noted that there is now an extensive track record of such foreign aid, and all too often it ends up in Swiss bank accounts or being spent to prop up corrupt regimes. Pope Paul VI made a prudential judgment, and faithful Catholics are perfectly free to reject it. The same applies if a pope speaks out on immigration policies, welfare programs or Middle Eastern politics.

Q: A lot of Catholics seem to disagree with what you just said. They suggest that the Holy Spirit picks who’s elected pope, then protects his everyday statements and policies from error.

A: The Church has never said any such thing — out of deference to the First Commandment, and perhaps to avoid becoming the laughingstock of even Catholic historians.

If the Holy Spirit directly picked the popes without human agency, we’d have to ask why He picked so many illegitimate children of previous popes; so many cardinals who bribed their way to the throne; or — my favorite example — the pope who so hated his predecessor that he dug up the old pope’s corpse and tried it for heresy, before dumping it in the river. We’ve done much better with choosing popes since the Council of Trent, but the process never became magical. Sometimes the cardinals pick a weakling, a coward or a bully. Popes do have original sin. The Holy Spirit oversees the process, of course, but allows a lot of room for human freedom and folly.

The pope can’t infallibly predict the weather, draw up the U.S. budget or tell us which wars are just or unjust. Think of the five “crusades” which Pope Martin V launched against cities full of Christians for “heresy.” Popes misused their authority so often and so egregiously that it helped cause the Reformation.

Q: What about when the pope does teach about faith and morals, but doesn’t invoke the divine-infallibility veto you’ve spoken of?

A: Catholics view every other papal pronouncement in context — the context of previous solemn church teaching on an issue. So if a pope reiterates some previous teaching, with roots in the Bible and the councils of the church, we defer to his interpretation. If he says something that seems new, we judge it against those previous teachings and are free to disagree — respectfully, of course. You shouldn’t mock the nakedness of your father. But you don’t have to bring him another skin full of wine.

If one pope contradicts another, or either contradicts a council, you can rest assured that none of the statements is infallible, and the issue is still open for debate.

Q: Are there examples of popes speaking fallibly at cross-purposes with one another?

A: Lots of them. I’m sure that I’ve already tested your ecumenical patience, but if you’re really interested, read this piece. In it, I explore conflicting papal statements on slavery, lending at interest, torture and religious freedom.

Q: Those aren’t petty issues.

A: No, they aren’t. But the Church has never pretended that Jesus made each pope a magical fountain of new divine revelations and brilliant policy ideas. We do the church no favors by inflating the papacy’s claims like a balloon. Our history is full of needles which could pop it.