Pope Francis is firmly upholding church teaching banning contraception, but said Monday that Catholics don’t have to breed “like rabbits” and should instead practice “responsible parenting.”

Speaking to reporters en route home from the Philippines, Francis said there are plenty of church-approved ways to regulate births. But he said most importantly, no outside institution should impose its views on regulating family size, blasting what he called the “ideological colonization” of the developing world.

African bishops, in particular, have long complained about how progressive, Western ideas about birth control and gay rights are increasingly being imposed on the developing world by groups, institutions or individual nations, often as a condition for development aid.

“Every people deserves to conserve its identity without being ideologically colonized,” Francis said.

His comments, taken together with his defense of the Catholic Church’s ban on artificial contraception during the trip, signal that he is increasingly showing his more conservative bent, which has largely been ignored by public opinion or obscured by a media narrative that has tended to highlight his populist persona.

On the trip, he gave his strongest defense yet of the 1968 encyclical Humanae Vitae, which enshrined the church’s opposition to artificial birth control. He warned against “insidious attacks” against the family — a reference to gay marriage proposals — echoing language often used by overwhelmingly conservative U.S. bishops. And he insisted that “openness to life is a condition of the sacrament of matrimony.”

At the same time, however, he said it’s not true that to be a good Catholic “you have to be like rabbits.” On the contrary, he said “responsible parenthood” requires that couples regulate the births of their children, as church teaching allows. He cited the case of a woman he met who was pregnant with her eighth child after seven Cesarean sections.

“That is an irresponsibility!” he said. The woman might argue that she should trust in God. “But God gives you methods to be responsible,” he said.

He said there are many “licit” ways of regulating births that are approved by the church, an apparent reference to the Natural Family Planning method of monitoring a woman’s cycle to avoid intercourse when she is ovulating.

During the Vatican’s recent meeting on the family, African bishops denounced how aid groups and lending institutions often condition their assistance on a country’s compliance with their ideals: allowing health care workers to distribute condoms, or withdrawing assistance if legislation discriminating against gays is passed.

“When imposed conditions come from imperial colonizers, they search to make people lose their own identity and make a sameness,” he said. “This is ideological colonization.”

In other remarks surrounding his Philippines trip:

**For months, Francis has been drafting an encyclical on the environment and global warming which he hopes to release by June or July. Encyclicals are written with the help of a small group of advisers working under strict secrecy. But in a news conference as he traveled last week to the Philippines, Francis gave his strongest signal yet of the direction he’ll take.

He said global warming was “mostly” man-made. And he said he wanted his encyclical out in plenty of time to be absorbed before the next round of U.N. climate change talks in Paris in November after the last round in Lima, Peru, failed to reach an agreement.

**Francis said Monday he wasn’t justifying violence when he said a friend who had cursed his mother could “expect a punch” in return. Rather, he says he was only expressing a very human response to a provocation and that greater prudence was necessary to avoid such offense.

**He also clarified his comments about the limits of freedom of speech made last week in response to the terrorist attack against the French satirical magazine Charlie Hebdo.

Speaking to reporters en route home from the Philippines, Francis said: “In theory we can say a violent reaction to an offense or provocation isn’t a good thing, that one shouldn’t do it. In theory we can say what Gospel says, that we should turn the other cheek.

In theory we can say that we have the freedom to express ourselves,” he said. “But we are human. And there is prudence, which is a virtue of human coexistence. I cannot insult or provoke someone continually because I risk making him angry.”

The “punch” line, and the confusion it caused, was a reflection of how Francis’ informal, and sometimes unpapal, sense of humor can sometime cause confusion or get him in trouble.