When George Bush starts talking about morality, it usually means he is about to throw a piece of red meat to the Christian right. Last week, they got a particularly juicy morsel when the President vetoed a bill for the first time during his term of office, overturning legislation that would have greatly expanded government funding for stem-cell research. The bill was supported by both main political parties and also has widespread public support, galvanised by such campaigners as the former First Lady Nancy Reagan and the late Superman actor Christopher Reeve.
The President claimed, with a straight face, that he was using his veto because research using embryonic human stem cells "crosses a real moral boundary that our society needs to respect". This is not a view shared by leading members of his own party, including the senior Republican Arlen Specter, who declared that history would compare Mr Bush to the people who imprisoned Galileo. But while listening to the President lecture anyone on morality is a nauseating experience, there is a lot more to his decision than meets the eye.
Stem-cell research upsets exactly the same people who dislike abortion, some of whom are on the lunatic fringe of the Republican party. But one or two of them actually sit in Congress these days and they would like the death penalty for doctors who perform terminations.
Mr Bush's right-to-life rhetoric signalled that he is standing firm on one of the core issues for evangelical voters. These are people who care much more about what happens to embryonic cells in a laboratory than human beings, of whom 152 were dispatched to the execution chamber when the President was Governor of Texas. It is easier to get sentimental about an embryo, which does not have any annoying habits, than a convicted murderer on death row, or even a macaque sitting miserably in a laboratory with wires inserted in its brain. Personally, I am uneasy about experiments on primates, which seem to me to share much of our emotional apparatus and capacity to feel pain, and I would far rather see an expansion in stem-cell research than wider use of live animals.
But we are talking about the weird, disconnected moral universe that Mr Bush inhabits, where there is apparently no problem about vetoing a bill to protect a few human cells while refusing to call for an immediate ceasefire in Lebanon, where hundreds of civilians have been killed and many more will die if the fighting continues.
And while the President's shortcomings as a moral philosopher are widely known, his use of the veto on this occasion is interesting for another reason, exposing his preference for symbolic gestures over addressing profound ethical issues. Mr Bush has not and will not stop embryonic stem-cell research in the US, where it will flourish in the private sector.
What he has done is prevent vital potentially life-saving research being funded by the American government, ensuring that the immense profits that are to be made from, say, a cure for Alzheimer's - the condition Ronald Reagan suffered from after he left the White House - will benefit private health companies. Hundreds, perhaps thousands, of scientists will be unable to do the most up-to-date research on cures for a whole range of conditions - state funding is, of course, another matter - while the private sector can do what it likes.
In that sense, Mr Bush's veto was morally indefensible but politically inspired: it has delighted his hardline supporters and struck a blow for corporate profit. Blocking a few experiments on stem cells is merely a tool in the larger game of pandering to the religious right while also serving Mammon.