The Holy Father opened his remarks with praise for the various institutions exploring and promoting research on adult stem cells. Adult stem cells hold great possibilities healing chronic degenerative illnesses by repairing damaged tissue and restoring its capacity for regeneration. These therapies, the Pope said, would be a great advancement for medical science as well as bring hope to many people who suffer and their families.
“For this reason, the Church naturally offers her encouragement to those who are engaged in conducting and supporting research of this kind, always with the proviso that it be carried out with due regard for the integral good of the human person and the common good of society.”
Man is both the “agent of scientific research,” and also “the object of that research,” the Pope noted. However, the “transcendent dignity” of man “entitles him always to remain the ultimate beneficiary of scientific research and never to be reduced to its instrument.” This, of course, is the problem with embryonic stem cell research. Embryos are human beings in the earliest stages of development and research using embryonic stem cells always involves the destruction of these nascent human lives.
“The destruction of even one human life can never be justified in terms of the benefit that it might conceivably bring to another.”
Science and ethics must be in dialogue with one another “to ensure that medical advances are never made at unacceptable human cost.” By calling for respect for the ethical limits of biomedical research, the pope said, the church does not seek to impede scientific progress, but to “guide it in a direction that is truly fruitful and beneficial to humanity.”
The conference Pope Benedict was speaking at was part of the Vatican’s $1 million dollar collaboration  with US based biopharmaceutical company NeoStem’s Stem For Life Foundation  to support research and increase public awareness of treatment using adult stem cells.
The pope concluded his address with a prayer that adult stem cell research “will bring great blessings for the future of man and genuine enrichment to his culture.”
Full text of the pope’s speech can be found here .