Pope John Paul has said that human cloning involving the destruction of human embryos is "not morally acceptable even when their proposed goal is good in itself".
Speaking at the 18th International Congress on Transplants in Rome, he said "science itself points to other forms of therapeutic intervention which would not involve cloning or the use of embryonic cells, but rather would make use of stem cells taken from adults."
In this area of medical science too, "the fundamental criterion must be the defence and promotion of the integral good of the human person, in keeping with that unique dignity which is ours by virtue of our humanity," he said.
He described organ donation as "a genuine act of love" but emphasised that "the human body cannot be considered as a mere complex of tissues, organs and functions, rather it is a constitutive part of the person".
Any procedure which tended to commercialise human organs or to consider them as items of exchange or trade "must be considered morally unacceptable, because to use the body as an `object' is to violate the dignity of the human person", he said.
He underlined the importance of organ donors being properly informed in order for their decision to be made freely and conscientiously. Should this prove impossible, then "the consent of relatives has its own ethical validity", he said. But vital organs must only be removed from the body of someone who is "certainly dead", he said.
Dealing with "xenotransplants" - instances where organs are transplants from other animal species into human beings - he recalled the words of his predecessor, Pope Pius XII, who said in 1956 that "in principle for a xenotransplant to be licit, the transplanted organ must not impair the integrity of the psychological or genetic identity of the person receiving it; and there must be a proven biological possibility that the transplant will be successful and will not expose the recipient to inordinate risk".
Pope John Paul expressed the hope that scientific and technological research in the field of transplants would continue. He added, however, that methods which failed to respect the dignity and value of the person must always be avoided.
"I am thinking in particular of attempts at human cloning with a view to obtaining organs for transplants," he said.
Pope John Paul asked Catholics at his regular audience in the Vatican yesterday to pray for peace in Burundi, where more than 200,000 people have been killed in seven years of civil war.
