“You should not finish your priestly life involved in an open and scandalous rebellion that inflicts a very painful wound” on the church, he wrote.

Archbishop Viganò’s initial letter was a remarkable broadside against the Vatican hierarchy. Francis has essentially said he would not dignify the accusations with a response. But Cardinal Ouellet did, and he answered in kind.

Cardinal Ouellet offered personal testimony based on his own interactions and the congregation’s archives. He said that there was no written record of punishment against Archbishop McCarrick, though he acknowledged that the American had been “strongly exhorted” to live a discreet life of prayer, without travel or public appearances, because of the sexual misconduct rumors.

“We come to the facts of the matter,” Cardinal Ouellet wrote to Archbishop Viganò, whom Benedict XVI sent to Washington as the papal envoy in 2011, after his involvement in a scandal in Rome that revealed his frustration at not being made a cardinal.

“How is it possible,” Cardinal Ouellet wrote, that Archbishop McCarrick was promoted to the “high offices of archbishop of Washington and cardinal?”

A professor in a New Jersey seminary sent warnings to the Vatican of the sexual misconduct allegations, in 2000, when Archbishop McCarrick was made archbishop of Washington.

Pope John Paul II, who was accused of allowing sexual abuse to fester in the church, made him a cardinal in 2001. Other accusations have recently surfaced, including from men who say they were abused as young teenagers.

In his letter, Cardinal Ouellet treads carefully on the fact that the American’s ascent took place under John Paul, while making clear that Francis had nothing to do with Archbishop McCarrick’s promotions from New York to New Jersey to Washington.

“Without getting into the details,” he wrote, decisions are made by the popes based on the information available at the time, and the judgments “are not infallible.”

Coming to the defense of John Paul II, who is beloved by Archbishop Viganò and his conservative allies, Cardinal Ouellet, a Canadian, said it seemed unfair to call the decision makers corrupt, even if “some indications supplied by witnesses should have been examined further.”

He said that Archbishop McCarrick showed great ability in defending himself, and, in response to Archbishop Viganò’s ad hominem attacks on Vatican officials for being homosexual or supporting homosexuals within the church, he wrote that “the fact” that in the Vatican there could be people who practice or support sexual behavior “contrary to the values of the gospel” was not reason to generalize and declare “unworthy and complicit” a broad swath of people, “even the Holy Father.”

To do so, he said, was only “slander and defamation.”

He acknowledges that Archbishop McCarrick, who retired in May 2006, was strongly urged “not to travel and not to appear in public, so as not to provoke more hearsay about him,” but he said it was false to present those measures taken against him as punishments decreed by Pope Benedict XVI and then lifted by Francis.