Some parents expend great efforts to get their kids into the right nursery school or the right preschool, with the thought that that will set them on the path to success, to competitive success especially.

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.

Over the past three decades, markets and market thinking have been reaching into spheres of life traditionally governed by non-market norms. As a result, we've drifted from having a market economy to becoming a market society.

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.

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.

If we go too far down the road of choosing the genetic traits of children, my worry is that parenting will be less a kind of school for humility than it should be, and we will become too accustomed to regarding children as instruments of our ambition and of our desires.