But three months later another cardinal, Godfried Danneels of Belgium, told a Catholic TV program that if an HIV-positive person insists on having sex, "he has to use a condom. Otherwise he will commit a sin" by risking transmission of a potentially fatal virus.
A third cardinal, Javier Lozano Barragan of Mexico, told The Associated Press recently that condoms could sometimes be condoned — such as when a woman can't refuse her HIV-positive husband's sexual advances — since preserving her life is paramount. "You can defend yourself with any means," he said.
So just what is the Roman Catholic Church's position? It depends on whom you ask. Contrary to what some think, there is no official, authoritative Vatican policy on using condoms to protect against AIDS.
According to several top churchmen and theologians recently interviewed, the issue is being debated within the Vatican and is still far from resolution.
The question isn't just an academic or religious one. In areas such as sub-Saharan Africa, hard-hit by AIDS, it's a matter of life and death, and the Vatican is accused by some of failing to come down on the side of life.
The Rev. Angel Rodriguez Luno, professor of moral theology at the Pontifical University of the Holy Cross in Rome, offers two examples to show how complex the question is.
A Catholic cannot discuss condom use with children in school, because "this is inciting them to use them." But if he were a social worker telling prostitutes they risk getting AIDS unless they make their customers use condoms, "I am not doing anything bad. I am lessening the bad."
"But I can't say this in a school. I can't say this in a newspaper," he said. "I must go to the areas where they are and say to them: 'At least do this. You should stop, but at least do this.'"
Over the years, the church has mapped out its opposition to artificial contraception, most famously in the 1968 encyclical Humanae Vitae, or "Of Human Life," in which Pope Paul VI asserted the inseparable link between the unifying and reproductive dimensions of sexual intercourse for husband and wife.
But that document and others deal with using condoms as contraception, not as protection against a potentially fatal virus. The Vatican hasn't issued its most authoritative type of teaching — an encyclical — specifically about condoms and AIDS, although it has maintained that abstinence is the best protection.
Yet various cardinals and Vatican offices have made their views known in public discussions and documents over the years, perhaps no one more so than Cardinal Lopez Trujillo, who is president of the Pontifical Council for the Family.
In October, Lopez Trujillo repeated to the BBC his claim that condoms don't help because the HIV virus is small enough to "easily pass through" the condom.
The World Health Organization, among others, said the cardinal's message was dangerous and "totally wrong." The U.N. agency said that condoms are 90 percent effective when used correctly and that the other 10 percent fail because they are used incorrectly.
Dr. Joep Lange, professor of medicine at the University of Amsterdam and president of the International AIDS Society, said in an interview that published medical studies had shown that when one partner is HIV-positive, "consistent condom use is associated with non-transmission."
Lopez Trujillo penned a lengthy defense in December, arguing that since condoms don't offer 100 percent protection, it was misleading and dangerous to speak of "safe sex."
"Safe sex" campaigns were actually increasing promiscuity by giving users a false sense of security, he said.
On another side of the debate sits the Rev. Charles Curran, a Catholic professor of human values at Southern Methodist University who was censured by the Vatican in 1986 for his opposition to church teaching on contraception, among other issues, and barred from teaching theology at the Catholic University of America.
For him, the question boils down to the traditional Catholic understanding of advocating the "lesser of two evils" — if someone is contemplating killing his neighbor, one could counsel him to instead burn down his barn since that would be the lesser evil.
Curran cited an example from the 1960s: The Vatican itself condoned giving contraceptive pills to nuns at risk of rape by fighters in the Congo to prevent pregnancy.
If the issue were anything other than condoms and AIDS "they'd have no trouble with the 'lesser of two evils,"' he said in a phone interview. "They're so on the defensive on this that they're unwilling to recognize that traditional Catholic principles would allow this."
Rodriguez Luno is a Spanish adviser to the Vatican's orthodoxy watchdog, the Congregation for the Doctrine of the Faith. He accepts that Curran's argument is supported by church texts dating back 200 years.
He reasons that sex outside marriage is already a sin against the Sixth Commandment, which forbids adultery. "If you transmit a fatal illness, that's also a sin against the Fifth Commandment," which says "Thou shalt not kill."
"If you use a condom, you don't eliminate the danger, but you diminish it, so the offense against the Fifth Commandment is lessened a little. It would diminish more if you stopped this behavior, but if you don't want to, what can you do?"
But he said if the Holy See promoted such an argument it would inevitably provoke the headline "The Vatican says yes to condoms!"'
Yet at a lower level, some bishops' conferences have suggested exceptions to the Vatican rule. In 2001, as it grappled with soaring HIV rates, the Southern African Catholic Bishops' Conference condemned HIV-prevention programs that endorsed condom use. However, it said married couples with the virus could use condoms if they abstained from sex while the woman was ovulating. That way, the condom wouldn't prevent the creation of life.
Bishop Kevin Dowling of Rustenburg, South Africa, who had pressed the bishops' conference to embrace condom usage, says even applying the "lesser of two evils" argument is questionable.
"If one were to use them to promote health — life rather than death — then one is not grudgingly accepting one evil to prevent a greater one but rather is promoting something that in the context is not simply good but a moral imperative," he wrote in U.S. Catholic magazine last November.
Such an argument falls under another tenet of Catholic moral theology — the "double effect." That's the theological argument that an HIV-positive person using a condom isn't doing so for contraception, but for health.
However, Janet E. Smith, head of life ethics at Sacred Heart Major Seminary in Detroit, noted that rape excepted, sex is a voluntary act and there is 100 percent safe alternative: abstinence.
"A question can be raised about why if you love someone, one would want to engage in an action that might transmit a disease," she said in an interview.
The Bush administration is actively promoting "abstinence-only" education, which urges young people to remain chaste until marriage and excludes any mention of condoms except to depict them as unreliable. Major U.S. medical organizations, as well as researchers at the federal Centers for Disease Control and Prevention, have recommended programs that educate young people about condoms and other contraception, as well about abstinence.
With such differing views, the way churchmen handle the issue comes down to nuance, said Bishop Anthony Fisher, founding director of the Australian branch of the John Paul II Institute for Marriage and Family, which the pope established in 1982 to promote his views on family life.
It may sound hypocritical or confusing, he acknowledged, but there are things you can say privately to someone who comes for pastoral counseling that you can't put in a public education campaign.
When Lopez Trujillo speaks, he is the Vatican's voice to the world and has to promote a simple, consistent message, Fisher said in a recent interview.
"Are individual doctors or clinics giving contrary positions? I think that is going to keep happening."