It's worth remembering, however, that though a clean copy fresh off a printer may look terrific, it will read only as well as the thinking and writing that have gone into it.

But if the priest comes to examine it and the mildew has not spread after the house has been plastered, he shall pronounce the house clean, because the mildew is gone.

The arrival of Mr Obama represents something of a clean slate—though Spain’s recent unilateral withdrawal of soldiers from Kosovo, without warning, has not gone down too well in Washington.