Lambeth Palace's opposition proves that Duncan Smith is on the right track, just as back in 1985 the fulminating Anglican report Faith in the City proved that Margaret Thatcher was doing something right. But Dr Williams deserves a reply. Duncan Smith believes that returning the unemployed to work is not merely good for society, but above all for those individuals and their families. The Pauline work ethic, based on Jewish tradition and bequeathed to the Church, follows logically from the commandment to love our neighbour as we love ourselves. To abandon someone we love to idleness, even a relatively affluent idleness, is a callous form of neglect. "We would all be idle if we could," said Dr Johnson. By reducing the temptation to live on state handouts, by rewarding effort and by rekindling the habit of work in those who have lost it, we restore their dignity as well as their productivity.

The Archbishop is right that the unemployed are prey to despair. That is why the work ethic is such a vital defence mechanism: communities that encourage it — not only Protestants but Catholics, Jews, Hindus and Chinese, for example — tend to have low rates of unemployment. By contrast, half of Muslim men and three quarters of Muslim women are unemployed in Britain, according to the Equality and Human Rights Commission. Dr Williams is right, too, that most people are not unemployed because they are wicked, stupid or lazy. But it is too glib merely to blame "circumstances". Such fatalism would not have passed muster with St Paul, or Moses. The whole point of a work ethic is to keep us busy in adversity, even in despair.  We now have the curious spectacle of a Catholic Cabinet minister defending the work ethic against a Protestant primate.

The Judaeo-Christian tradition does not sanctify greed, but it does see the work of human hands as a reflection of the divine labour of Creation. To keep entire communities in enforced idleness — as Gordon Brown's monstrous attempt to bribe us with our own money did throughout the long boom — is to exclude them from full participation in humanity. For the Archbishop of Canterbury to single out for criticism Iain Duncan Smith, one of the few Christians in the Cabinet who has the courage of his convictions, is perverse. But for Duncan Smith, braving archiepiscopal censure is all in a day's work. There will be plenty more odium theologicum in the coming years. His work, and the work of the Coalition, has hardly begun.