TIM COLLINS, the Tory vice-chairman, was on the defensive last week, unlike his boss Michael Ancram, who well understands that the best form of defence is attack. You could tell that Mr Collins was in a weak position as soon as he started complaining that the party's accounts had been hacked into "to discredit anyone who stands in the way of this government's lust for power". Anyone who accuses the other side of lusting for power has lost the argument already.

Lust is certainly a nastier word than it was. Always lurking somewhere in the background of such remarks is the idea, admittedly absurd, that the government is run by a bunch of dirty old men and raunchy women who are sublimating their desires by trampling on the Opposition. (Conversely, we all know that power has an aphrodisiac effect, so that even if they weren't lustful before they got in they probably are now.) But in its early days lust did not necessarily have anything to do with sex, or with any sort of inordinate desire. What it meant was joy or pleasure (as it does in German), or even just "inclination".

When the Israelites got to the Land of Milk and Honey they said to each other, according to the 1611 Bible, "If the Lord delight in us he will give us this land"; but in Miles Coverdale's 1535 translation it was "If the Lord have lust in us", and it was common in those days for the devout to declare that their lust was in the Lord. In a different mood, someone might say they had no lust to leave the house. It was much the same word as list, when people would say "Do what you list", when they meant "Do what you like".

Andrew Marvell told his coy mistress that if she wasn't careful they'd both be dead and "all his lust" would be turned to ashes, but I doubt if he would have been crass enough to use the word today if he wanted to get her to bed. So perhaps it's our latter-day preoccupation with sex that has narrowed the connotations of the word?

Well, no. The early medieval church was obsessed with the subject, and there was a common feeling among the 11th-century priesthood that if a man enjoyed making love to his wife he was guilty of one of the Seven Deadly Sins. They took their cue from St Jerome, who thought Adam and Eve must have been celibate till after the Fall. Lust was pleasure, but also forbidden pleasure.

They had almost spoilt a nice word, but it survived, and in the 16th and 17th centuries people were using it in its religious and secular meanings indiscriminately, relying on the context; churchmen would add "of the flesh" to make everyone sure they knew what they were talking about. The Oxford English Dictionary thinks that when people started talking about "lust for power" (the first example it could find of the expression dates from 1786) they may have carried in their minds "some transferred notion" of what it calls "libidinous desire" - which, indeed, they still do today.

But it's not much of a jibe.