Pope Benedict XVI (search) indicated Saturday he will stick to Pope John Paul II's unwavering stands against abortion and euthanasia, saying pontiffs must resist attempts to "water down" Roman Catholic teaching.
Benedict outlined his vision of his papacy in a homily during a ceremony in which he took his place on a marble-and-mosaic throne in the ancient Roman basilica of St. John in Lateran. The ceremony is the last to formally mark Benedict's assumption of the papacy.
The pope "must not proclaim his own ideas, but ever link himself and the church to obedience to the word of God, when faced with all attempts of adaptation or of watering down, as with all opportunism," Benedict said.
That's what Pope John Paul II (search) did when he "underlined in an unequivocal way the inviolability of human beings, the inviolability of human life from conception to natural death," Benedict said to ringing applause from the congregation.
"Freedom to kill is not a true freedom but a tyranny that reduces the human being into slavery."
In Vatican (search) teaching, the phrase in defense of life "from conception to natural death" refers to its bans on abortion and euthanasia.
"The pope isn't an absolute sovereign, whose thoughts and desires are law," Benedict said. "On the contrary, the ministry of the pope is the guarantor of the obedience toward Christ and his word."
As German Cardinal Joseph Ratzinger, Benedict was in charge for nearly a quarter-century of enforcing doctrinal orthodoxy, and he earned a reputation as a strict interpreter of church teaching who silenced dissident theologians.
An hour earlier, thousands of people cheered as Benedict, standing in an open-topped black sedan, arrived at the Basilica for the ceremony.
Pontiffs must be installed as Bishop of Rome, and that ceremony traditionally takes place at the ancient basilica, which the Vatican describes as the "mother and head of all the churches of the city of Rome and of the world."
Inside the church, cardinals, bishops and other clerics arrayed in several rows applauded vigorously as Benedict took his place on the throne and smiled.
The basilica visit was the last of several ceremonies following Benedict's April 19 election as pope. He was installed at a Mass in St. Peter's Square a few days later.
"Taking possession" of St. John's symbolizes the care that the pope has for all the Roman Catholic churches. Popes lead the entire church in their role as Bishop of Rome and successor to St. Peter, the first pope.
"Dear Romans, now I am your bishop," Benedict said. "Thanks for your generosity, thanks for your sympathy, thanks for your patience."
The first Christian basilica to be erected in Rome, St. John's was founded by the Emperor Constantine. Its original foundations were raised in the early 5th century.
The papal altar contains relics of Saints Peter and Paul, and the bishop's throne is carved out of stone, decorated by mosaics.
Rome Cardinal Camillo Ruini opened the ceremony saying: "Most blessed Father, the church that is in Rome rejoices as you ascend for the first time to your throne, that his the Roman throne of Peter, on which is founded the church."