ON BECOMING the Conservative leader, Michael Howard promised to expound “the over-arching ideas, the arguments, the principles that will inform everything that we do”.

Ten months after that promise, the one consistent principle the party exemplifies is to buy off interest groups — motorists, pensioners, parents of university students — at public expense.

In the circumstances, a Tory MP who leaves the front bench to argue for change in the party’s philosophical direction has much remedial work to be getting on with. Yet Damian Green, formerly the Conservative transport spokesman, appears intent instead on exacerbating his party’s ideological incoherence: “I want to argue for a form of compassionate Conservatism, the sort of Conservatism that was very effective for George Bush a few years ago,” he told the BBC this week.

President Bush has strengths, but the power of his ideas is not among them. Compassionate conservatism is as insubstantial a notion as the Third Way — a circumlocution to avoid having to choose among conflicting values and competing claims to scarce resources. To talk of a compassionate or caring society is to turn a noble personal virtue into a destructive political affectation.

We feel compassion for those who suffer, without regard to whether their suffering is due to remediable injustice or to life’s unvarying misfortunes (bereavement, accident, unrequited love). A government that legislates compassionately has no sense of the limits of politics. If, say, a religious grouping suffers offence at the publication of a novel that satirises its faith, who is to say that a compassionate society ought not to alleviate that mental anguish by banning the book?

The task of democratic politics is not to assuage emotional pain; it is to set disinterestedly the rules we live by. It is good politics and right in principle for the Conservatives to emphasise their belief in the State’s distributional role in providing public goods and relieving poverty. But that is not compassion: it is equity (enabling people to exercise autonomous choices) and efficiency (providing services where private markets would be inefficient or non-existent).

New Labour has been at its most effective — in monetary and fiscal policy — when it has introduced systems of rules designed to constrain discretionary intervention. How ironic that the Conservatives should meanwhile have become the party of overweening Big Government.