Genetic Future has a post which mulls over the idea that not screening for particular diseases is similar to child abuse. I was interested in this last comment:
Naturally there are objections to embryo screening among religious conservatives who believe that inflicting severe disease on children is the will of God - but why does the prospect raise such unease among even the secular community? I share Le Page's puzzlement on this question,
and would invite opponents to lay out any well-reasoned arguments
against routine screening in the comments below.
Religious conservatives, particularly Roman Catholics, do have well-reasoned arguments once you grant their premises. But I would like to take a step back and suggest that though reason is the "front side of the house" in this discussion, the real work is being done by intuition in concert with social consensus in the kitchen. I think this is even true for religious conservatives at the end of the day; today some religious couples who receive fertility treatment thank God for their multiple births. I suggest that the nature of the reasoned arguments will directly track the underlying social consensus. Reasonable arguments which will be very persuasive at time t when procedure x is extant at proportion ~ 0.01 will magically become far more implausible at time t + n when procedure x is extant at proportion ~0.50. The best way to be on the "right side of history" in this sort of discussion isn't to argue in bioethics journals, it's to make sure that the cost of the procedure comes down and its marketing makes it seem innocuous, or the inverse if that is your position. Today many younger people assume you have a cell phone, and find it almost rude if you don't. This had nothing to do with reasoned arguments about the utility of the cell phone, and all to do with market penetration and social expectations. In any case, in regards to Dr. MacArthur's original point about how one could posit a reasoned argument against genetic screening by couples if one was not religious, I suspect that skepticism is far more warranted presupposing that secular individual has a liberal political philosophical world-view. By which I mean that individual satisfaction and liberty lay at the heart of their idea of what the ultimate ends of a social & political order should be. On the other hand, if someone is a communitarian there might be all sorts of rationales one could construct based on utilitarian logic where social cohesion was a paramount good.