ROME — When the first Synod of Bishops on the family got underway last October, conservatives concerned with upholding traditional doctrine appeared caught off guard by a progressive push on several fronts, including relaxing the ban on Communion for Catholics who divorce and remarry outside the Church.

The leading symbol of that disorientation was the way Hungarian Cardinal Péter Erdő, ostensibly the man supposed to guide the summit’s work in his role as “General Relator,” appeared to be sidelined by more progressive prelates, especially Italian Archbishop Bruno Forte, in producing a controversial interim report calling for greater openness on divorce, homosexuality, and other hot-button topics.

If the opening day of Synod 2015 is any indication, Erdő has no intention of letting that happen again.

In his 7,000-word opening address on Monday morning, intended to set the tone for the synod’s work, Erdő seemed determined to close a series of doors that many people believed the last synod had left open — beginning with the controversial proposal of German Cardinal Walter Kasper to allow divorced and civilly remarried Catholics to return to Communion.

That Communion ban, Erdő insisted, is not an “arbitrary prohibition” but “intrinsic” to the nature of marriage as a permanent union. Mercy, he said, doesn’t just offer the possibility of forgiveness, it also “demands conversion.”

Erdő argued that exclusion of a divorced and remarried Catholic from Communion isn’t punishment for the failure of their first relationship, but arises from the “objective truth” that living in a second union when the Church regards their first marriage as still valid is a sin.

Not mincing any words, Erdő said the only case in which divorced and remarried believers could be readmitted to Communion is if they “practice continence through the strength of grace,” meaning they renounce any sexual relationship, and only then if allowing them to take Communion doesn’t “provoke scandal.”

“The integration of the divorced and remarried in the life of the ecclesial community can take many forms, [but it] is different from admission to the Eucharist,” he said.

Erdő seemed determined to tackle all the usual arguments advanced for relaxing the Communion ban, such as the so-called “law of graduality,” which holds that people in imperfect life situations can be on a path toward moral growth and should be encouraged rather than excluded.

“Between truth and falsehood, between good and bad, there is no graduality,” he said.

On the equally divisive question of whether the Church should be more positive about homosexuality and same-sex relationships, Erdő threw down another gauntlet.

“There is no basis for comparing or making analogies, even remotely, between homosexual unions and God’s plan for matrimony and the family,” he said, quoting a 2003 document from the Congregation for the Doctrine of the Faith.

Erdő also insisted that international organizations should not tie development assistance for poor nations to their recognition of same-sex marriage, but he also cited official Church teaching to the effect that “unjust discrimination” against gays and lesbians is wrong.

On another front, Erdő issued a ringing defense of the late Pope Paul VI’s controversial 1968 encyclical Humanae Vitae, which reaffirmed the Church’s traditional opposition to birth control.

“This truth seems to have a special relevance today when there are so many technical possibilities for separating procreation from conjugal love,” he said.

Erdő’s speech also included clear denunciations of both abortion, insisting on the “inviolable character of human life,” and euthanasia, insisting on “right of natural death.”

If Erdő projects himself more forcefully as the 2015 synod unfolds, it could have a significant impact on the summit’s direction.

At just 63, he’s destined to be a force in Catholic life for some time to come. He has a strong following among his fellow European prelates, among other things serving as the elected president of the Council of the Bishops Conferences of Europe.

To be sure, this is hardly the first time Erdő has gone on record against the Kasper proposal.

During a news conference at last year’s synod, he said that in the case “of a (consummated) sacramental marriage, after a divorce, a second marriage recognized by the Church is impossible,” which clearly implies that Communion is impossible for someone in that situation.

What was new on Monday, therefore, was not the substance of his position, but rather the determination with which Erdő expressed it and what that might suggest in terms of the role he intends to play.

Erdő opened with a rhetorical move that signaled the broad direction he planned to take.

He acknowledged that many forces negatively affect families in the early 21st century, including poverty, war, and climate change. He then argued that there’s another kind of change that’s equally dangerous: “anthropological change,” meaning moral relativism and individualism, which he said are driving a “flight from institutions” including marriage.

In that context, Erdő called on his brother bishops not to go soft in defending the Church’s teaching.

“If we speak frankly to others about what we believe, we don’t have to worry about not being understood because we, too, are children of our time,” he said. “Even if not everyone accepts what we proclaim, at least our proposal will be comprehensible.”

It remains to be seen if the 270 bishops taking part in the Oct. 4-25 synod will be content to allow Erdő to take issues off the table that some of them believed were still in play. The progressive camp is well-represented, prominently including Kasper and several of his allies, and they may not be willing to go quietly down the path Erdő has set out.

During a news conference after his speech, Erdő was asked if he meant to declare debate over the Kasper proposal closed.

“The synod only begins now,” he said. “Further developments are always possible … we’ll see.”

Erdő also said his remarks were based in part on input received from bishops’ conferences and other sources in the period between last year’s synod and this one.

One thing seems clear, however, from Monday’s opening act: If Erdő’s way of framing the discussion is any indication, the camp concerned with upholding tradition doesn’t simply plan to counter-punch this time around.

Instead, Erdő landed the first blow himself. Now, it remains to be seen whether the “apostolic courage” to which Francis exhorted the prelates on Monday translates into a similar fighting spirit among other participants over the next three weeks.