If there is nothing wrong with that, though, it's hard to see what's wrong with destroying an embryo that is 5 weeks old or 5 months old, if its tissue could be used to help people who are seriously ill. In that case, why limit research to leftover embryos? It would make more sense to let scientists create embryos and let them gestate for months, for the sole purpose of destroying them for their stem cells.
Americans might bridle at that prospect, but proponents of expanded embryonic stem cell research have spared them from the contemplation of such unpleasantness. Their campaign focuses on ends, not means -- alleviating suffering, conquering disease, letting the blind see and the lame walk.
Such advances are only speculative at this point. But their allure is such as to discourage us from looking too closely at the methods needed to bring them about. It's easier to think in terms of excising tissue from blastocysts than in terms of killing human embryos. In reality, they are the same thing.
The problem with embryonic stem cell research is that the goals are so desirable that they override our usual moral impulses. Yuval Levin, a fellow at the Ethics and Public Policy Center in Washington, wrote in 2006 in The New Atlantis, "It is very hard for us to describe something higher than health, or more important than the relief of suffering, so when relief comes at a cost, even the cost of cherished principles or self-evident truths, we all too often pay up."
The court decision against Obama's policy on stem cell research is a rare exception, which may induce us to reconsider the wisdom of what we have sanctioned. "Our problem is not that we are lacking in ethical principles," says Levin, "but rather that we are forgetful of them."