By Josephine Quintavalle
Founder, Comment on Reproductive Ethics (CORE)
As the fiercely controversial debate over embryonic stem cell therapy gathers pace, two personal and opposing accounts argue the case for and against.
Josephine Quintavalle sets out her views below.
An estimated 56 diseases have been treated with the use of adult, human stem cells.
Ms Quintavalle: "We have a duty to protect human subjects from abuse"
But there are no recorded cases of treatment using stem cells derived from a human embryo.
Worldwide a huge debate rages about the ethics of stem cell research.
One side argues that no moral boundaries should be in place in this field beyond basic issues of safety.
Others, including Comment on Reproductive Ethics (CORE), insist that science must always function within an ethical framework, even if this may lead to prohibitions.
This is not a war of absolutes, however. Both sides are in favour of stem cell therapy.
The debate centres not around stem cells themselves, but about their provenance.
IF... CLONING COULD CURE US
Thursday, 16 December, 2004
Where stem cells are harvested from the embryo and foetus - as opposed to the umbilical cord blood or placenta of the newborn, or the adult - existing life has to be sacrificed.
This is a trade-off which CORE simply cannot accept.
We believe we have a duty to protect human subjects from abuse, and this duty must inform all medical ethics.
Regardless of potential benefit, we must reject outright any research which results in the deliberate destruction of human life.
A blind woman's sight was restored this October, in the US, using stem cells. These particular cells had come not from an embryo (up to eight weeks old) but from aborted foetal tissues.
We believe that such cures should never depend on the killing of an unborn child.
Indeed, some patients have had their sight restored through corneal transplants created from their own, adult, stem cells.
This is the kind of stem cell therapy we welcome wholeheartedly and which makes up the 56 types of treatment highlighted in the opening paragraph.
It is "no" to embryo and foetal stem cells, but a huge vote of confidence in cord blood, placental and adult stem cells.
Some scientists are prepared to accord the embryo and foetus some special status and would be happier to explore ethical alternatives if these were indeed available.
But others support their destruction regardless of the alternatives.
It is, therefore, important to be scrupulously objective when weighing up the relevant scientific evidence.
There is far too much inaccurate or inadequate information in circulation, particularly in relationship to the potential of embryonic stem cells.
One rarely hears of the dangers associated with this kind of cell: how they can run out of control, become unstoppable and form tumours.
It is sometimes claimed that the embryos used in this research will be simply "discards" from assisted fertility treatments.
In fact, "quality" human embryos will sometimes be created deliberately for this research.
Moreover, in order to avoid problems of tissue rejection in the sick patient, some embryos will be cloned - something that many people object to very strongly.
With the therapeutic reality of adult stem cells increasing by the week, it is very difficult to justify the unfettered enthusiasm for embryo research which dominates UK science.
Even if embryonic and foetal stem cells were to prove safe and effective in forthcoming decades, the fact remains that they can only be harvested at the cost of destroying early human life.
Such cures can never be morally acceptable.
Josephine Quintavalle was a contributor to BBC Two's If... Cloning Could Cure Us, broadcast on Thursday, 16 December 2004, at 2100 GMT.