One can imagine a kind of hormonal arms race or genetic arms race, whether it's to do with height or IQ, conceivably, in the future. So it's limitless, and that's another of the features that sets it apart from medical intervention.

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.

There's no necessary connection between maximizing social utility or economic wealth and creating a flourishing democracy. The first does not guarantee the second. The only way to create a flourishing democracy is to find ways to reason together about the big questions, including hard questions about justice and the common good, to reason together about these questions so that we as citizens can decide how to shape the forces that govern our lives.

Aiming at giving our kids a competitive edge in a consumer society - that, in principle, is a goal that is limitless.

The way things are does not determine the way they ought to be

I think very often when we think we are aiming at the best for our children, what we are really doing is trying to position them for competitive success in an intensely driven kind of society. I'm not sure that always leads to the good life or to happiness.

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.