Holy Week began yesterday at churches around the world with the observance of Palm Sunday. Over the next six days, Christians will commemorate Jesus Christ's Last Supper, his tribulation in the Garden of Gethsemane, his arrest and trial before Pontius Pilate, his crucifixion at Calvary, and finally, on Easter morning, his resurrection.

And thanks to a tiny piece of papyrus (it measures 4 by 8 centimeters), at least some of those Christians will be wondering whether Jesus was mourned in death by a spouse whom he considered one of his disciples. When the fragment was unveiled in 2012 by a historian at Harvard Divinity School, many dismissed its authenticity. But now scientific tests appear to show that it isn't a modern forgery.

That doesn't mean that what the papyrus seems to say about Jesus is true. But it does mean that the questions about its veracity will continue to be asked, inflaming the debate about the possibility of women's ordination in the Roman Catholic Church.

Yet reformers would be foolish to suppose that this debate will make a bit of difference to the church and its doctrines with regard to whether women can be priests. The fact is that Catholicism espouses a view of truth that axiomatically discounts the possibility of error in matters of faith and morals — and this much more fundamental doctrine would have to be challenged or rejected before any significant reform would have a chance of taking hold.

Allow me to explain.

Imagine that additional scientific tests eventually demonstrate beyond a reasonable doubt that the scrap of papyrus dates from the 3rd or 4th century. That would show merely that some early Christians may have believed that Jesus was married and approved of allowing women to be apostles (and hence to be ordained as priests).

But early Christians believed all kinds of things about Jesus. Was he a man? Or a divine being? Or some admixture of both? Was he God himself? Or merely like God? Or God's messenger (an angel)? Or a prophet? Or the literal Son of God? And if the last, how are God the Father and God the Son related to each other? And to the Holy Spirit? Is there one God? Or three? Or might God somehow be at once both one and three?

Each of these positions (and many more) was espoused by one Christian faction or another. It was theological chaos.

Which is why in the 4th century the church, newly legalized and empowered by the emperor Constantine the Great, called a series of ecumenical councils to delineate official dogma and doctrine, defining from then on what would be upheld as orthodoxy and what would be denounced as heresy.

According to the form of Trinitarian Christianity that emerged from these councils, Jesus did not marry, did not invite women to be apostles, and did not indicate in any way that women could be ordained. And that's the end of the story.

But wait: Wasn't this outcome no more than a contingency?

That's certainly how modern men and women are inclined to look at it. Various factions at the councils made their cases, people debated, coalitions were formed, deals hatched, positions frozen out, horses traded, compromises struck, and in the end there were winners and losers. It could easily have turned out otherwise. A simple change of detail and the excluded and the marginal could have ended up on top. That's the way politics works.

Except that the Catholic Church explicitly denies that this is what happens when a council or a pope pronounces on fundamental matters of faith. In Matthew 16, Jesus called Peter the rock on which his church would be built, gave Peter the keys to the kingdom of heaven, and declared that "whatever you bind on earth shall be bound in heaven." Which the church claims is proof that whatever dogma or doctrine is authoritatively pronounced by a council or a pope must automatically have God's stamp of approval for all time.

When it comes to the church's fundamental teachings about faith and morals, there is no such thing as a contingent outcome. No possibility of error.

In the case of the papyrus mentioning Jesus' wife and alluding to women's ordination, this means that whichever individuals or groups in the early church believed such things simply must have been wrong. Otherwise, their view would have prevailed in the councils.

Or so the magisterium of the Catholic Church teaches.

As I've argued before, the church is going to face increasing pressure over time to ordain women to the priesthood. Behind the various (extremely weak) arguments against such reform stands the ultimate obstacle — which is that it would require admitting that the church made a mistake on a matter fundamental to the faith. That it feels it cannot do.

That's understandable, since without the church's extraordinary claim about its own infallibility, everything else it teaches would be up for grabs.

The question, then, is how many Catholics actually buy the claim. If it's a lot, the church's opposition to reform is solid. If it's a few, then the dam could burst at any time.

After the doctrine of infallibility falls, then comes the deluge.