I have a broad but not an expert or scholarly background in the Jewish tradition. I've tried to learn what I can from childhood, but I am not an expert on Jewish teachings.

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 other effect that I worry about is the effect on the parent, that the moral teaching of humility and of the limits to our control that parenthood teaches- - that that will be lost and that we will begin to think of children more as consumer goods than as gifts that we can't fully control and for which we aren't fully responsible.

It's possible to make sense of what's morally at stake in an appreciation of the gift of life, or the gift of a child, without necessarily presupposing that there is a giver. What matters is that the gift - in this case, the child - not be wholly our own doing, our own product.

The norm of unconditional parental love, I think, depends on the fact that we don't pick and choose the traits of our children in the way that we pick and choose the features of a car we might order, or a consumer good.

It is true that the Jewish tradition emphasizes the moral mandate to save life. It also has a different position from the Catholic Church on the moral status of the embryo. It has a more developmental view of when human life, in the sense of personhood, begins than does the Catholic Church.

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.