For years at a time — make that decades — the home of the successor to St. Peter was a house of nasty intrigue, deceit and power put to awful use. Popes fathered wars, and children, had heretics executed or chained to a cell in the belly of Castel Sant’Angelo, the fortress that fronts Vatican City. The Vicar of Christ cut deals with dictators, including a devil’s bargain with Mussolini. With its institutional cover-up of pedophile clerics, the church showed the Mafia a thing or two about organized crime. In matters of sex, it was medieval and hypocritical. It was afraid of science.

Now the pope uses science to shame Trump, who stares down a parade of hurricanes and says, nothing to see there. “Whoever denies it has to go to scientists and ask them,” said Francis last week. “They speak very clearly. Scientists are precise.” Can a statue of Galileo in St. Peter’s Square be far behind?

On Wednesday, a glorious Roman morning with a bite of fall in the air, the pope holds his general audience. The goofy smile is electric. He’s buoyant. The day before, Trump spoke to the United Nations, a tweet dressed up as a speech. He made a very real threat to wipe out a nation of 25 million people. He would, if he has to, “totally destroy North Korea.”

This has always been the implication of having more nukes than the other guy. But diplomacy — another word for Trump to look up — is the art of war by other means. Trump pushed America first, which sounded like “Me, me, me.” He played the petulance card, the grievance card.

As Trump went low, the pope went high. A few days earlier, Francis was asked about a Trump decision that could break up the families of 800,000 Dreamers in the United States. “If he is a good pro-life believer, he must understand that family is the cradle of life and one must defend its unity,” Francis answered.

People who are hung up on doctrinal changes — angels-on-the-head-of-a-pin arguments over whether divorced Catholics can receive communion or not — are missing the big picture. Behold the Francis doctrine: an expansion of “pro-life” to include help for refugees, the poor, the powerless.

Trump doesn’t get it. His nominee to the Vatican is Callista Gingrich, wife of Newt Gingrich. Newt, you must remember, carried on a six-year extramarital affair with her while impeaching a president for having an affair. Her appointment was something the Vatican of old would do — a cynical ploy. The Vatican of today can marvel at how quickly history pivots on a single person.