The norm of unconditional parental love, I think, depends on the fact that we don't pick and choose the traits of our children in the way that we pick and choose the features of a car we might order, or a consumer good.

I think very often when we think we are aiming at the best for our children, what we are really doing is trying to position them for competitive success in an intensely driven kind of society. I'm not sure that always leads to the good life or to happiness.

One can imagine a kind of hormonal arms race or genetic arms race, whether it's to do with height or IQ, conceivably, in the future. So it's limitless, and that's another of the features that sets it apart from medical intervention.

My argument is not that we must never intervene in nature. My argument is that there is a moral difference between intervention for the sake of health, to cure or prevent disease, and intervention for the sake of achieving a competitive edge for our kids in a consumer society.

The majority of American states had laws by the 1930s that allowed for forced sterilization of socially undesirable categories of people, so-called feeble-minded, for example, and with Hitler culminating in genocide.

The relief of suffering is a great good. The curing of illness and disease - these are great human goods. This is the mission of medicine.

One of the ways in which parenting is a learning experience and an opportunity for moral growth is that we learn as parents that we don't choose the kind of child that we have.