Critics accused him of trying to shift blame away from the Church.
In a rare essay, Benedict, who for 23 years headed the Vatican doctrinal office that has been widely criticized for its handling of sexual abuse cases, argues that the sexual revolution led some to believe that paedophilia and pornography were acceptable.
The 91-year-old, who in 2013 became the first pope in six centuries to resign, also bemoaned that some Catholic seminaries had an openly gay culture and thus failed to train priests properly.
“It could be said that in the 20 years from 1960 to 1980, the previously normative standards regarding sexuality collapsed entirely, and a new normalcy arose that has by now been the subject of laborious attempts at disruption,” Benedict wrote.
Benedict was head of the doctrinal office before he became pope in 2005. He was in charge in 2002, when the first-wave abuse cases were exposed in Boston.
Abuse scandals in Ireland, Chile, Australia, France, the United States, Poland, Germany and elsewhere have since led the Church to pay out billions of dollars in damages to victims and forced it to close parishes. Many cases date back decades before the 1960s.
Revelations that predatory priests were often moved from parish to parish rather than expelled or criminally prosecuted as bishops covered up the abuse have shaken the church globally and undermined its authority.
Late last year, Australian Cardinal George Pell became the most senior Catholic to be convicted for child sex offences. His role as a former top adviser to Pope Francis brought the scandal to the heart of the papal administration.
Benedict offered his evaluations in a long essay in Klerusblatt, a monthly Church magazine in his native Bavaria region of Germany. A Vatican official confirmed it was authentic.
The former pope, who lives secluded in a former convent on the Vatican grounds, said he wanted to “contribute one or two remarks to assist in this difficult hour”.
The impetus for the essay, titled “The Church and the Scandal of Sexual Abuse”, was a summit of senior bishops that Francis held in February to discuss the crisis, he said.
“Among the freedoms that the Revolution of 1968 sought to fight for was this all-out sexual freedom, one which no longer conceded any norms,” he wrote, according to an English translation published by several Catholic websites.
He said the spread of explicit sex education for young schoolchildren and nudity in advertising had contributed to a loosening of moral bearings.
Some theologians took to Twitter to criticize Benedict.
“This is an embarrassing letter,” said Brian Flanagan, professor of theology at Marymount University in Virginia.
“The idea that ecclesial abuse of children was a result of the 1960s, a supposed collapse of moral theology, and “conciliarity” (the Church after the 1962-65 Second Vatican Council) is an embarrassingly wrong explanation for the systemic abuse of children and its cover up.”
Massimo Faggioli, professor of theology at Villanova University, called it “a caricature” of the Church in the post-Vatican II period, “with all its ingenuities and some tragic mistakes”.
Benedict wrote that after the Second Vatican Council there was a “far reaching breakdown” of the traditional methods of priestly formation that coincided with a dissolution of the Christian concept of morality.
“In various seminaries homosexual cliques were established, which acted more or less openly and significantly changed the climate in the seminaries,” he writes.
Benedict, who has appeared in public only a handful of times since his resignation, said the situation in Catholic seminaries has since “greatly improved.”
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