That's why I've suggested putting a clear boundary on the time within which it is justifiable to kill a severely disabled infant. At one point, I suggested a 28-day boundary. But I no longer think that will work. It's too arbitrary. I don't think you would get people to recognize that there's a big difference in the wrongfulness of killing a being at 27 or 29 days. So what do you do? I think you need to look at it on a case-by-case basis, given the seriousness of the problems, and balance that against the age of the child.

Have you ever received letters from parents of children born with severe disabilities who had to make difficult decisions about their care?
I've had letters from people who were worried about whether they did the right thing. I've also received letters, including some just recently, from parents who have read my work and are now more angry than they were before at what the doctors did in keeping their children alive. Some parents said the doctors basically had given them no choice about whether to operate on their child. The parents used language like, "They got to play with their toys"--meaning their medical equipment--"and left us with a child who has a terrible life."

You've said that the U.S. seems to be a less caring society than every other economically developed society in the world. Why do you think that?

It may be that the American tradition makes people think in terms of their rights, rather than their responsibilities or obligations to others. And that makes the community a more individualistic one. The clearest figures are the foreign-aid figures where the U.S. is at the absolute bottom of economically developed countries in terms of what it gives as a percentage of gross national product.

In terms of the lack of care for American citizens, the figures are a little harder to pick out. I guess I'm aware of two things: most obviously, that there is no national health insurance, and that you see more homeless people sleeping rough in New York City than you do in any Australian city, for example. So something is going on here.

What are your observations about people in the U.S. and our treatment of animals?

America is really falling behind the rest of the civilized world in its care of animals. Europe is now moving forward in eliminating the most confining forms of factory farming. They're phasing out the battery cages for hens, which means that European hens will be able to stretch their wings, walk around freely, lay their eggs in a nest. American hens will still be trapped in little wire cages, unable even to stretch their wings.

Why do you think we're behind the mark on the care of animals?

The American political system is unresponsive to concerns like this that do not have a lot of money behind them and that face politically influential groups such as agribusiness that have billion-dollar corporations with millions of dollars to spend on congressional lobbyists.

Would you like to clarify any of your views that you feel have been misrepresented?

There was a letter in a recent Princeton Alumni Weekly that again quoted this line about "defective infants." It's the emphasis on "defective" that I find really unfair because the letter writer is quoting from a book published in 1979. If the writer bothered to look at the 1993 edition of "Practical Ethics," he would find the language has changed to "disabled." It's a little like accusing someone of having a negative attitude to African-Americans because they used "Negro," quoting a speech from the 1950s. Martin Luther King Jr. used that word. The fashions change in terms of the language you use.

"Religion has a major impact--basically in stopping people from thinking."

Another important point is that people sometimes say that I have more compassion for animals than I do for humans. I have an essentially unified position: I am opposed to unnecessary suffering, whether it's a human or an animal. A lot of the suffering we inflict on nonhuman animals is unnecessary and in some cases pointless. And I want to put a stop to that. The same is true in regard to human beings.

Have you ever been faced with making a life-and-death decision for a loved one?

My mother has Alzheimer's. I guess it's reaching the point where I have to think about what treatment I would provide for her if she were to become physically ill and in need of life support.

Do you see any conflict between your spending considerable money on the care of your mother and your principle of spreading out wealth to help the most people?