By Daniel Burke, CNN Belief Blog Co-editor

(CNN) - Retired Pope Benedict XVI says he never tried to cover up the sexual abuse of minors by Catholic priests, breaking his post-retirement silence to address one of the greatest threats to his legacy as a church leader.

In a lengthy letter published in La Repubblica, an Italian newspaper, the former pope answered theological and moral arguments from Piergiorgio Odifreddi, an Italian atheist and mathematician who had written about Benedict in 2011.

Earlier this month, La Repubblica also published a letter to its atheist editor from Pope Francis, Benedict's successor.

Since his retirement on February 28, Benedict has mostly stayed out of the public eye, living in a converted monastery behind St. Peter's Basilica and keeping his promise to steer clear - at least publicly - of church business.

Benedict's new letter, coming on the heels of Francis' blockbuster interview published last week, makes for a remarkable week for papal communication. Most modern popes have been fairly inaccessible - to the media, at least.

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In Benedict's letter, published Tuesday, the former pope said: "As far as you mentioning the moral abuse of minors by priests, I can only, as you know, acknowledge it with profound consternation. But I never tried to cover up these things."

Benedict, who now has the title "pope emeritus," also said that even though sociologists have determined that the percentage of priests accused of abusing minors is not markedly higher than other professions, that's "not reassuring" for the church.

Critics answer that it's the not just the crimes but the coverups that made the church's response to sexual abuse so scandalous.

"Over a clerical career that lasted more than six decades, we can’t think of a single child-molesting bishop, priest, nun, brother or seminarian that Benedict ever exposed," said Barbara Dorris of the U.S.-based Survivors Network of those Abused by Priests.

Before he was elected pope, Benedict, formerly known as Cardinal Joseph Ratzinger, headed the Congregation for the Doctrine of the Faith, which assumed responsibility for handling priest abuse cases late in his career.

As pope, he issued revised guidelines in 2010 making it easier to remove abusive priests from the ministry, apologized for the "shame" the scandal brought on the church and met with victims, including in the United States in 2008.

Critics like SNAP dismissed those moves as too little, too late.

In the United States alone, nearly 17,000 people have come forward with abuse claims, and the church has paid $2.6 billion in settlements, therapy bills, lawyers' fees and expenses related to removing priests from the ministry, according to the U.S. Conference of Catholic Bishops.

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In Tuesday's letter, and on past occasions, Benedict has decried the "filth" of sexual abuse in the church. But, the emeritus pope said, it is not "specific to Catholicism." He also chided Odifreddi for neglecting the good the church has done.

"If you do not remain silent about evil in the Church, we must not, however, be silenced even by the great shining path of goodness and purity, which Christian faith has traced through the centuries," Benedict said.

Pope Francis said in April, in one of his first statements as pope, that the church must take "decisive action" regarding cases of child sexual abuse and protecting children.