Human decision-making is complex. On our own, our tendency to yield to short-term temptations, and even to addictions, may be too strong for our rational, long-term planning.

I think ethics is always there; it's not always a very thoughtful or reflective ethics.

If we compare a severely defective human infant with a nonhuman animal, a dog or a pig, for example, we will often find the nonhuman to have superior capacities, both actual and potential, for rationality, self-consciousness, communication and anything else that can plausibly be considered morally significant.

We need to learn how to capture and kill wild fish humanely - or, if that is not possible, to find less cruel and more sustainable alternatives to eating them.

Can we really believe that we are living a good life, an ethically decent life if we don't do anything serious to help reduce poverty around the world and help save the lives of children or adults who are likely to die if we don't increase the amount of aid we are giving.

I suppose what's happened recently has confirmed suspicions I voiced in the book, and I think made clearer some of those things that I point out. For instance I have a section of the book where I talk about the possibility of torture.

Of all the arguments against voluntary euthanasia, the most influential is the slippery slope: once we allow doctors to kill patients, we will not be able to limit the killing to those who want to die.