Martin Wilkinson, chairman of the xenotransplantation working group of Toi te Taiao: the Bioethics Council, doesn't have any problem separating the cultural, spiritual and ethical aspects of the pig-cell transplant debate from the safety concerns.

But he does acknowledge the debate can't be had without discussing safety issues and without having some view about how effective xenotransplants are likely to be.

"On the other hand, the people who are good at working out safety and efficacy don't have any aptitude for cultural ethical and spiritual aspects."

So how does he, a philosopher specialising in medical ethics, proceed? "By swotting on the safety and efficacy side."

If this is sounding a little circular, that's because it is. Quite how the two strands of the debate come together is unclear, but the ultimate decision rests with the Minster of Health, who will have to absorb the advice from the council and ministry officials.

What follows is a sample of the thorny issues being considered, with selected quotes from the online forum and the council's discussion document.

Individual need v public risk

"From where I am sitting the risk is that we might wipe out the whole human race, which we have never done before (fortunately). This sounds a little facetious, but it is actually a serious and scary thought for many people."

Respecting the position of Maori

"Some may view the transfer of animal organs as mixing the mauri, wairua, mana and whakapapa of different species, therefore disturbing the balance of Maori society."

The Christian viewpoint

"Then God said, 'Let us make man in our image, in our likeness, and let them rule over the fish of the sea and the birds of the air, over the livestock, over all the earth, and over all the creatures that move along the ground'."

The rights and interests of animals

"No one is saying a pig's life is worth more than yours. What I am saying is a pig's life is of value, especially to the pig, and therefore we should not go around killing pigs for fun, food or profit."