Emeritus Pope Benedict XVI has denied covering up child sex abuse by priests and called a Richard Dawkins book "science fiction" in a long letter to one of Italy's most well-known atheists.
"I never tried to cover these things up," the former pope says in the letter.
"That the power of evil penetrated so far into the interior world of the faith is a suffering that we must bear, but at the same time we must do everything to prevent it from repeating."
Having mostly stayed out of the public eye since retiring earlier this year and leaving all papal duties to Pope Francis, Benedict's response to child sex abuse allegations were published earlier this week by Italian paper La Repubblica, The Associated Press reported.
The Roman Catholic Church has long been plagued by reports of child sex abuse committed by clergy, and has been criticized for covering up some of the cases in order to protect priests and the Church's image. Both Benedict XVI and Francis have strongly spoken out against such abuse, however, and pledged that they would work hard to combat such crimes.
The former Cardinal Joseph Ratzinger, as he was called before he became Pope, was head of the Vatican office responsible for abuse cases when a series of scandals broke out in 2010 with thousands of people claiming that they had been molested by priests.
Benedit XVI's letter was addressed to Piergiorgio Odifreddi, an Italian atheist and mathematician who in 2011 wrote a book Dear Pope, I'm Writing to You, and accused the Vatican of not doing enough on child abuse.
The Vatican has long stood behind Benedict XVI and insisted that he has done a lot to combat sexual abuse in the Church, but the latest letter is one of the first instances the former pope has addressed claims aimed directly at him.
"Neither is it comforting to know that, according to research, the percentage of priests who commit these crimes isn't any higher than the percentage of other similar professions," the former leader of the Vatican wrote in the 11-page letter. "Regardless, one shouldn't present this deviation as if it were something specific to Catholicism."
Benedict XVI discussed other subjects in the letter, including evolution and the role of God and nature, bringing up The Selfish Gene by Richard Dawkins, the famous atheist and evolutionary biologist who insists evolution was not guided by God and that no God exists.
"There is, moreover, science fiction in a big way just even within the theory of evolution. The Selfish Gene by Richard Dawkins is a classic example of science fiction," the former pope wrote, according to The Independent.
In July, Pope Francis issued a decree that specifically outlined sexual abuse of children as a crime, extending the Church's laws to the Vatican-city state, home to over 800 people.
"As a whole, these normative efforts form part of broader process aimed at modernizing further the Vatican legal system with a view to enhancing its consistency and effectiveness," The Holy See explained the move.