In my world of the people who study war and defense issues, we simply did not talk about robotics. We do not talk about it because it's seen as mere science fiction. It's cold, hard, metallic reality.

The new freedom of expression brought by the Internet goes far beyond politics. People relate to each other in new ways, posing questions about how we should respond to people when all that we know about them is what we have learned through a medium that permits all kinds of anonymity and deception.

What you could say, and what I do argue in the book, is that he doesn't have as much concern for the lives of Iraqis as he does for the lives of Americans, or even frozen American embryos.

My major concern about leaving enhancement to the marketplace is that then the rich will be able to buy themselves genetically superior children and the poor will not - sharpening the class divisions we have now. That problem could be overcome if, genetic enhancement were available to all, subsidized by the state - and that would, over time, have benefits for society as well.

We don't usually think of what we eat as a matter of ethics. Stealing, lying, hurting people - these acts are obviously relevant to our moral character. In ancient Greece and Rome, ethical choices about food were considered at least as significant as ethical choices about sex.

We may feel the pain of falling back from a level of affluence to which we have grown accustomed, but most people in developed countries are still, by historical standards, extraordinarily well off.

There is no humane slaughter requirement for wild fish caught and killed at sea, nor, in most places, for farmed fish.