Human beings are empowered to exercise dominion over nature and even to be participants in creation; and yet, at the same time, there are strictures against idolatry, which is a kind of overreaching and confusing human beings' role with God's.

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.

Markets are useful instruments for organizing productive activity. But unless we want to let the market rewrite the norms that govern social institutions, we need a public debate about the moral limits of markets.

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.

I do not argue that nature is sacrosanct in the sense that we must never tamper with nature. That would disempower, really, all of medicine. That would mean that we can't combat dread diseases - malaria, polio, all of which are given by nature, if one thinks about it.

If parents are aiming at choosing children who will be good athletes, or great musicians, or who will get into Ivy League schools, or who will be tall enough to make the basketball team, then there is a danger that the life of the child will bear the burden of that expectation; and the risk of disappointment and the cost of disappointment will be even higher than they are now, and even now they can be considerable.

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.