The pope made the comments in an interview with a German journalist published as a book entitled "Light of the World: The Pope, the Church and the Signs of the Times," which is being released Tuesday. The Vatican newspaper L'Osservatore Romano ran excerpts on Saturday.
Church teaching has long opposed condoms because they are a form of artificial contraception, although the Vatican has never released an explicit policy about condoms and HIV. The Vatican has been harshly criticized for its position.
Benedict said that condoms are not a moral solution to stopping AIDS. But he said in some cases, such as for male prostitutes, their use could represent a first step in assuming moral responsibility "in the intention of reducing the risk of infection."
Benedict made the comment in response to a general question about Africa, where heterosexual HIV spread is rampant.
He used as a specific example male prostitutes, for whom contraception is not usually an issue, but did not mention married couples where one spouse is infected. The Vatican has come under pressure from even church officials to condone condom use for such monogamous married couples to protect the uninfected spouse from transmission.Benedict drew the wrath of the United Nations, European governments and AIDS activists when, en route to Africa in 2009, he told reporters that the AIDS problem on the continent couldn't be resolved by distributing condoms. "On the contrary, it increases the problem," he said then.
Journalist Peter Seewald, who interviewed Benedict over the course of six days this summer, raised the Africa condom comments, asking him if it wasn't "madness" for the Vatican to forbid a high-risk population from using condoms.
"There may be a basis in the case of some individuals, as perhaps when a male prostitute uses a condom, where this can be a first step in the direction of a moralization, a first assumption of responsibility," Benedict said.
Asked if that meant that the church wasn't opposed in principle to condoms, the pope replied: The church "of course does not regard it as a real or moral solution, but in this or that case, there can be nonetheless in the intention of reducing the risk of infection, a first step in a movement toward a different way, a more human way, of living sexuality."
Elsewhere in the book he reaffirmed church teaching opposing artificial contraception.
"How many children are killed who might one day have been geniuses, who could have given humanity something new, who could have given us a new Mozart or some new technical discovery?" he asked rhetorically.
He reiterated the church's position that abstinence and marital fidelity is the only sure way to prevent HIV.
The English publisher of the book, Rev. Joseph Fessio, said the pope was not justifying condom use as a lesser of two evils.
"This is not a justification," he said. Rather, "The intention of protecting the other from disease, of using a condom, may be a sign of an awakening moral responsibility."
However, the Rev. Jim Martin, a Catholic writer, said the comments were certainly a departure, an exception where there had never been an exception before.
"While some bishops and archbishops have spoken in this way, the pope has never affirmed this," Martin said. "And it's interesting that he uses as an example someone who is trying to act morally to someone else by not passing on an infection, which was always the stance of those people who favored condoms in cases of HIV and AIDS. So it does mark a departure."
The English translation of the original German specified "male prostitute." The Italian translation in L'Osservatore Romano, however, used the feminine "prostitute." The discrepancy wasn't immediately clear.
Cardinal Elio Sgreccia, the Vatican's longtime top official on bioethics and sexuality, elaborated on the pontiff's comments, stressing that it was imperative to "make certain that this is the only way to save a life." Sgreccia told the Italian news agency ANSA that that is why the pope on the condom issue "dealt with it in the realm of the exceptional."
The condom question was one that "needed an answer for a long time," Sgreccia said. "If Benedict XVI raised the question of exceptions, this exception must be accepted ... and it must be verified that this is the only way to save life. This must be demonstrated," Sgreccia said.
In the 1960s, the Vatican itself condoned giving contraceptive pills to nuns at risk of rape by fighters in the Congo to prevent pregnancy, arguing that the contraception was a lesser evil than pregnancy.
Archbishop Gregory Aymond of New Orleans said clearly the pope wasn't encouraging condom use.
"I think the pope has been very strong in saying condoms do not solve the problem of morality and do not solve the problem of good sex education. But if a person chooses not to follow the teaching of Christ in the church, they are at least obliged to prevent another person from contracting a disease that is deadly," he said.
In Africa, Benedict's comments drew praise among gays and AIDS activists.
"If he's talking about condoms, it's a step in the right direction," said David Kamau, who heads the nonprofit Kenya Treatment Access Movement. "It's accepting the reality on the ground ... If the Church has failed to get people to follow its moral values and practice abstinence, they should take the next best step and encourage condom use."
John Kitte, a gay Ugandan, said the pope was acting as a good parent.
"He minds about all the people living on earth. What he has suggested is very good and I encourage gays to take his advice seriously."
But an evangelist pastor in the Uganda capital of Kampala, Solomon Male, argued the pope shouldn't be granting any recognition of or encouragement to gays.
"If the Pope is saying so, then he has not read the Bible," he said. "Gay acts are bad. It is abominable and should not take place."
Christian Weisner, of the pro-reform group We Are Church in the pope's native Germany, said the pope's comments were "surprising, and if that's the case one can be happy about the pope's ability to learn."