Pope Benedict XVI will lose his infallibility -- his supreme authority in Church matters -- as soon he steps down on February 28, the Vatican said on Wednesday as it struggles to explain a virtually unprecedented situation.
"These powers go with the office, so they will pass to the next pope.... Whoever renounces no longer has the assistance of the Holy Spirit to guide the Universal Church," Vatican spokesman Federico Lombardi said at a briefing.
The issue is complex for many Catholics who believe the election of a pope is divinely inspired and are accustomed to popes remaining in office until death.
Benedict will be the first pope to resign in more than 700 years and only the second to do so voluntarily in the Catholic Church's 2,000-year history.
Though papal infallibility was only set in stone in 1870, the idea had long been part of Church history and debate, and the notion of the Bishop of Rome as a preserver of apostolic truth was first mooted in the sixth century.
The special power has been used only once by a pope -- in 1950 when Pius XII established the Assumption of Mary as Church dogma -- and is limited to "ex cathedra" statements of doctrine or faith that apply to the whole Church.
While Benedict will have to drop his claim to being right all the time, the Vatican said that as ex-pope he will enjoy a pension of sorts when he retires as planned to a monastery with flower beds and a vegetable garden inside the Vatican walls.
"We will ensure he can live a dignified existence," Lombardi said.