I am trying to get at the moral arguments and the ethical status of various attempts at enhancement, or genetic engineering, or the bid for designer children. But there are implications for society at large.

Parenthood is a school for humility. We can't choose the precise traits of our children, and that is morally important. It teaches us what William May, a theologian whom I greatly admire, calls "an openness to the unbidden."

Very often when we aim at the best, or what we may think is the best for our children, we aim really at lesser things, such as getting into a certain college.

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.

A better way to mutual respect is to engage directly with the moral convictions citizens bring to public life, rather than to require that people leave their deepest moral convictions outside politics before they enter.

In natural pregnancy, more than half of fertilized eggs fail to implant or are otherwise lost. Should we regard that as an instance of infant mortality? And if so, why are we not mounting ambitious public health campaigns to try to save and rescue all of the fertilized eggs that are lost in natural pregnancy? We would need a public health campaign of massive proportions if there really were over a fifty percent rate of infant mortality.

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.