Famously, Pope Francis isn’t one for spending a lot of time thinking about doctrinal questions or disputes.

The pontiff often mocks theologians for obsessing over the fine print of things, recycling a quote from Patriarch Athenagoras of Constantinople to Pope Paul VI after an historic 1964 meeting: “We’ll bring about unity between us, and then we’ll put all the theologians on an island so they can think about it!”

Try as Francis might, however, he can’t make doctrinal tussles in Catholicism completely disappear, because Christianity is what’s known as a “creedal” religion, meaning one in which belief matters. In reality, each of the past three years of his papacy has been marked by a defining doctrinal debate, and 2019 may turn out to be more of the same.

The fascinating point about those debates is that each, in one way or another, has centered on the Eucharist - suggesting that in the Pope Francis era, Eucharistic theology may be the defining doctrinal divide.

Of Francis’s personal faith in the Eucharist, there can be no question.

During a general audience in November 2017, for instance, Francis referred to every celebration of the Mass as “a ray of light of the unsetting sun that is the Risen Jesus Christ.” In June 2018, on the traditional Catholic feast of Corpus Christi, Francis said that only the Body and Blood of Jesus Christ, the food of life, can satisfy the hunger of hearts for love.

In August last year, Francis called communion a foretaste of heaven.

“Every time that we participate in the Holy Mass, we hasten heaven on earth in a certain sense because from the Eucharistic food - the body and blood of Christ - we learn what eternal life is,” he said.

Yet despite that ardent Eucharistic emphasis, critics say that Francis has endangered traditional Catholic beliefs about the sacrament.

When the pope issued his document Amoris Laetitia in 2016, it opened a ferocious internal argument over his cautious opening to allowing Catholics who divorce and remarry outside the Church to receive Communion. Although that decision touched on the theology of marriage and other matters, at its core was the question of what the Eucharist is and what the proper conditions are for someone to receive it.

Francis and his advisors insisted that the decision in Amoris didn’t involve any revision at all to Church teaching, while critics lambasted it as a fairly radical repudiation of what had come before. In any event, the point is that disagreements over how to understand the Eucharist were at the heart of the Amoris debates.

In a similar fashion, 2018’s major doctrinal row was centered in Germany, where roughly a two-thirds majority of the country’s bishops favored a set of guidelines opening Communion to the Protestant spouses of baptized Catholics under at least some circumstances.

While a handful of German prelates objected, forcing a Vatican meeting on the subject, Francis essentially left the decision to the discretion of the conference and its members, with the result that there is no uniform national standard right now.

That debate, too, was about the nature of the Eucharist, in part because it raised the question of what it means to be in “communion” with the Catholic faith in especially acute form.

Although 2019 just began, it’s possible that this year’s signature doctrinal controversy could also center on the Eucharist.

Rumors are currently making the rounds that Francis may be getting ready for an ecumenical Communion service with Protestants, in particular Lutherans, the details of which have been entrusted to an informal working group. The idea is that despite whatever nuances may separate Lutheran and Catholic understandings of the Eucharist, they would be judged insufficiently serious to prevent mutual reception of the sacrament, at least under certain circumstances.

Such rumors, by the way, have circulated since Francis traveled to Sweden in October of 2016 to mark the 500th anniversary of the Protestant Reformation, and they may very well be inaccurate or exaggerated. Yet the very fact they circulate at all is revealing, in part because of what that says about people’s perceptions of this pope’s approach to Eucharistic topics.

Why has the Eucharist become the front-and-center doctrinal flashpoint of the Pope Francis era?

Part of the explanation may be that Francis inherited a series of question marks about the Eucharist and was compelled to answer them. In that sense, it may be less a matter of personal choice than the agenda any pope would have been compelled to face.

On the other hand, faith in the Eucharist as the real presence of Christ traditionally has been a cornerstone of Catholic identity, a conviction that sets Catholics apart. Under a pope who seems determined to play down such distinctions in order to emphasize commonalities, perhaps it’s no real surprise that competing visions of the Eucharist, and especially who’s eligible for it, have risen to the surface.

However much Francis may poke fun from time to time at the obtuseness or pedantry of theologians, doctrine is part of the lifeblood of the Catholic Church - and in his era, those theologians seem to have plenty to talk about, beginning with what this pope is teaching in both word and deed about the central sacrament of the faith.