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.

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."

Other animals can make sounds, and sounds can indicate pleasure and pain. But language, a distinctly human capacity, isn´t just for registering pleasure and pain. It´s about declaring what is just and what is unjust, and distinguishing right from wrong. We don´t grasp these things silently, and then put words to them; language is the medium through which we discern and deliberate about the good.

Aiming at health, restoring health - that is a goal that is both morally important and limited, because it aims at the restoration of normal human functioning, which is an important part of human flourishing.

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.

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.

I think part of being a parent, to love one's child, is to accept them as they come - not to see them as instruments of our ambition or as creatures to be molded, as if they were themselves commodities.