Today if you look at most economic textbooks, economics is not defined by subject matter. It's presented as a science of social choice that applies not only to material goods - not only to flat-screen televisions - but to every decision we make, whether it's to get married, or to stay married, whether to have children and how to educate those children, or how to look after our health.

There is a tendency to think that if we engage too directly with moral questions in politics, that's a recipe for disagreement, and for that matter, a recipe for intolerance and coercion.

The other effect that I worry about is the effect on the parent, that the moral teaching of humility and of the limits to our control that parenthood teaches- - that that will be lost and that we will begin to think of children more as consumer goods than as gifts that we can't fully control and for which we aren't fully responsible.

My goal is first of all to promote a public debate about where markets serve the public good and where they don't belong. That's my first goal.

Self-knowledge is like lost innocence; however unsettling you find it, it can never be 'unthought' or 'unknown'.

It's true that to speak of an ethic of giftedness, which is very much the ethic that I deploy in raising questions about designer children and genetic engineering - an appreciation of the giftedness of the child or the giftedness of life does have religious resonance, because a great many religious traditions emphasize the sense in which the good things in life are not all our own doing; they are gifts from God.

I'm a supporter of embryonic stem cell research. I do think there are very important moral and also religious questions at stake in the debate over embryonic stem cell research.