We have examined a number of ethical issues. We have seen that many accepted practices are open to serious objections. What ought we to do about it? This, too, is an ethical issue.

A week-old baby is not a rational and self-aware being, and there are many nonhuman animals whose rationality, self-awareness, capacity to feel and so on, exceed that of a human baby a week or a month old. If, for the reasons I have given, the fetus does not have the same claim to life as a person, it appears that the newborn baby does not either.

It is interesting, in this context, to think again of our earlier argument that membership of the species Homo sapiens does not entitle a being to better treatment than a being at a similar mental level who is a member of a different species. We could also have said – except that it seemed too obvious to need saying – that membership of the species Homo sapiens is not a reason for giving a being worse treatment than a member of a different species. Yet in respect of euthanasia, this needs to be said. If your dog is ill and in pain with no chance of recovery, the humane thing to do is take her to the vet, who will end her suffering swiftly with a lethal injection. To ‘allow nature to take its course’, withholding treatment while your dog dies slowly and in distress over days, weeks or months, would obviously be wrong. It is only our misplaced respect for the doctrine of the sanctity of human life that prevents us from seeing that what it is obviously wrong to do to a dog, it is equally wrong to do to a human being who has never been able to express a view about such matters.

Voluntary euthanasia occurs only when, to the best of medical knowledge, a person is suffering from an incurable and painful or extremely distressing condition. In these circumstances one cannot say that to choose to die quickly is obviously irrational.

First premise: If we can prevent something bad without sacrificing anything of comparable significance, we ought to do it. Second premise: Extreme poverty is bad. Third premise: There is some extreme poverty we can prevent without sacrificing anything of comparable moral significance. Conclusion: We ought to prevent some extreme poverty.

No doubt we instinctively prefer to help those who are close to us. Few could stand by and watch a child drown; many can ignore the avoidable deaths of children in Africa or India. The question, however, is not what we usually do, but what we ought to do, and it is difficult to see any sound moral justification for the view that distance, or community membership, makes a crucial difference to our obligations.