Despite the Vatican's opposition to the use of condoms as a way to prevent HIV/AIDS transmission, Belgian cardinal Godfried Danneels--seen as a possible successor to the pope--is urging HIV-positive people to use condoms if they have sex. Danneels told the Roman Catholic TV program Kruispunt in the Netherlands Sunday that an HIV-positive person having sex without a condom would be sinning against the Fifth Commandment, which says, "You shall not kill." "When someone is HIV-positive and his partner says 'I want to have [sexual] relations with you,' then he does not have to do it," said the Belgian cardinal. "But if he does, he has to use a condom. Otherwise, he will commit a sin." The Vatican maintains that abstinence is the best HIV prevention method. Danneels, 70, is a leading voice in the European Church and a moderate who has called for more democracy in the Catholic Church.