The notion that human life is sacred just because it is human life is medieval.

Of those who die from avoidable, poverty-related causes, nearly 10 million, according to UNICEF, are children under five. They die from diseases such as measles, diarrhoea, and malaria that are easy and inexpensive to treat or prevent.

My view is different from this, only to the extent that if a decision is taken, by the parents and doctors, that it is better that a baby should die, I believe it should be possible to carry out that decision, not only by withholding or withdrawing life-support - which can lead to the baby dying slowly from dehydration or from an infection - but also by taking active steps to end the baby's life swiftly and humanely.

All the particular moral judgments we intuitively make are likely to derive from discarded religious systems, from warped views of sex and bodily functions, or from customs necessary for the survival of the group in social and economic circumstances that now lie in the distant past.

But I think the majority of cows, and even more so chickens and pigs, are leading pretty miserable lives.

The newspapers do little better. Their coverage of nonhuman animals is dominated by "human interest" events like the birth of a baby gorilla at the zoo, or by threats to endangered species; but developments in farming techniques that deprive millions of animals of freedom of movement go unreported.

Becoming a vegan is a sure way of completely avoiding participation in the abuse of farmed animals. Vegans are a living demonstration of the fact that we do not need to exploit animals for food.