Peter Singer continues to stir controversy with his radical theories of

MANY people would love to see Peter Singer slip from his moral perch. As the 'father of the animal rights movement' and the world's most famous bioethicist, he attracts scrutiny for defending everything from vegetarianism to issues as controversial as infanticide and euthanasia. Lack of consistency for someone in his position inevitably invites criticism. So does he worry sometimes about putting the wrong foot forward in public? 'Generally it hasn't been a problem because I've never claimed to be perfect,' he says, apparently bemused by the question. Tucking into nuts and chips at the Mandarin Oriental hotel he adds, for example, that he would not send back a bowl of noodles if it came by mistake with bits of meat. 'Morality is not a matter of strict adherence to rules where if you deviate by a hair's breadth it's a tragedy. It's rather a matter of trying to bring about good results.' Some would be relieved to learn of his apparent flexibility while others would probably be enraged. This, after all, is someone who not only says it is wrong to eat meat and expounds on how people should spend their money, but is also trying to convince the world that the sanctity of life is bunk.

The prolific author who in 1999 became the first full-time professor of bioethics at Princeton University in the United States says, for example, that parents of a severely disabled newborn should have the right to kill their baby after consulting doctors. He believes that ending the life of a child with Down's syndrome, for example, may increase the parents' opportunity to have a 'normal' baby and thus the loss of the disabled child is 'outweighed by the gain of a happier life for the second'. He also suggests it may be ethically defensible to use a very retarded human in laboratory experiments rather than a chimpanzee.

Using his definition of the word 'person', which he takes to mean any sentient, rational being conscious of its existence over time (meaning it can conceive of its past and future), Singer says killing a newborn - disabled or not - is not morally equivalent to killing a 'person'. Some humans obviously do not fit this definition while some animals do. It follows then that 'the life of a newborn baby is of less value . . . than the life of a pig, a dog, or a chimpanzee'.

Shouldn't someone who is trying to change the world ethically, however, be practising to the letter what he preaches? Singer obviously believes not, arguing that all he is doing 'is trying to get people to think more consistently and logically about issues'.

But recently critics have pointed to what they say is a contradiction in the 53-year-old Australian philosopher's position: his mother is afflicted with Alzheimer's disease and no longer recognises members of her family. Her condition has deteriorated to the point that he almost cancelled his trip to Hong Kong to take part in the International Conference on Applied Ethics at Chinese University last week. Has her illness made him reconsider his view on the sanctity of life? 'No, but it's certainly made me realise how different people respond emotionally to these things in different ways,' he says. 'It's really not easy to make decisions on behalf of someone who's no longer competent to make them herself.' Those decisions no doubt involve how she wants to be treated and whether or indeed when to end her life. As someone who has lost her ability to reason and is therefore no longer a 'person', would she be a candidate for euthanasia? 'Yes, if she were in pain and distress. But she's not,' he says. 'We would refuse life-prolonging medical treatment on her behalf if we felt it was something that was likely to be invasive or distressing for her.' To accusations that the thousands of dollars he is spending to keep his mother alive could be used to better effect elsewhere, he says: 'I'm not sure why the critics focus on the fact it costs a certain amount to keep my mother looked after and that money no doubt could do more good if it were sent to starving people in a poor part of the world.' Yet he also argues that family ties should not override obligations to strangers. 'If it's a matter of buying your child an expensive Christmas present rather than saving your neighbour's child from starvation then that's carrying the bias in favour of your child too far,' he says.

'I don't condemn family partialism but I think it should be seen as something that is part of a larger moral scheme that requires us to give considerable weight to the interests of strangers.' Says the former Green candidate for the Australian Senate, who donates one-fifth of his income to charity: 'I've never claimed to be completely pure in doing everything I should. I just try to get a bit closer to it.' Despite his laid-back, unantagonistic manner, Singer has ruffled feathers around the world because of what another speaker at the Chinese University conference, Professor Bonnie Steinbock of the State University of New York at Albany, has described as his 'extreme consistency with utilitarianism'. That branch of philosophy, propounded by Jeremy Bentham (1748-1832), says that a morally superior position is that which produces the greatest pleasure (or happiness) for the greatest number of people.