There was no mention of any Vatican responsibility in the scandal and no specific punishments doled out for bishops blamed by victims and Irish government-ordered investigations for having covered up years of abuse.
In a pastoral letter to the Irish faithful, Benedict said: "I am truly sorry" for the harm done to generations of Irish Catholics who suffered "sinful and criminal" abuse at the hands of priests, brothers and nuns.
"It is understandable that you find it hard to forgive or be reconciled with the church," he said. "In her name, I openly express the shame and remorse that we all feel."
Benedict used his harshest words for the abusers themselves, saying they had betrayed the trust of the faithful, brought shame on the church and now must answer before God and civil authorities.
"Conceal nothing," he exhorted them. "Openly acknowledge your guilt, submit yourselves to the demands of justice, but do not despair of God's mercy."
Benedict faulted their superiors, the Irish bishops, for having failed "sometimes grievously" to apply the church's own law which calls for harsh punishments for child abusers, including defrocking them.
But he didn't rebuke them specifically for having failed to report cases of abuse to police, saying only that serious mistakes were made and that now they must "continue to cooperate with civil authorities."
"I recognize how difficult it was to grasp the extent and complexity of the problem, to obtain reliable information and to make the right decisions in the light of conflicting expert advice," Benedict wrote.
"Nevertheless, it must be admitted that grave errors of judgment were made and failures of leadership occurred. And this has seriously undermined your credibility and effectiveness."
While the letter doled out no punishment for the bishops, the pope did order a Vatican investigation into some diocese, seminaries and religious orders. Such a move is undertaken only when Rome considers a local church unable to deal with a problem on its own. The Vatican ordered such an "apostolic visitation" into U.S. seminaries after the U.S. clerical sex abuse scandal exploded in 2002.
The results of the Irish investigation could lead to further action.
In the letter, the pope said merely that while bishops committed errors in the past, the church's leadership had already begun to remedy past mistakes.
Victims have been demanding that bishops resign, and three Irish bishops have offered to step down. Benedict hasn't accepted the resignations.
Asked why there were no punitive provisions contained in the letter, Vatican spokesman the Rev. Federico Lombardi noted that the letter was pastoral, not administrative or disciplinary in nature, and that any further measures concerning resignations would be taken by the competent Vatican offices.
Three Irish government-ordered investigations published from 2005 to 2009 have documented how thousands of Irish children suffered rape, molestation and other abuse by priests in their parishes and by nuns and brothers in boarding schools and orphanages. Irish bishops did not report a single case to police until 1996 after victims began to sue the church.