I think the reason we might hesitate to pay cash to students for doing well on tests or getting good grades or reading books is that we sense that the monetary payment is an extrinsic reward.

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.

They say the state should not impose on its citizens a preferred way of life, but should leave them as free as possible to choose their own values and ends, consistent with a similar liberty for others.

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.

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.

In some parts of the world, that sex selection for boys - and it's usually for boys - reflects sex discrimination against girls, and it leads to very large imbalances - in China, in Korea, in India - in the population between boys and girls, a vast disproportion of boys to girls, and it reflects really this discriminatory attitude toward girls.

I think people who want to use genetic technologies to gain a competitive edge for their children are engaging in a kind of overreaching that could really undermine our appreciation of children as gifts for which we should be grateful and, instead, to view them as products or instruments that are there to be molded and directed.