FRANCES'S GREATEST LEXICOGRAPHER, Emile Littre, was once found by his wife in flagrante, and in the conjugal bedroom at that, with their housemaid. Happily, the exchange that followed makes sense almost as well in English as in French.

“Emile,” cried Mrs. Littre, “I am surprised!”

“No, my dear,” replied the erring lexicographer calmly. “You are astonished. It is we who are surprised.”

His precision was right, certainly in his own language, and at least arguably in English: the original sense of surprise is indeed “to take unawares”. But Mrs. Littre, had she been speaking English, could have replied that her usage went back at least to Daniel Defoe: Robinson Crusoe was “exceedingly surpriz'd with the print of a man's naked foot”. The question is whether Mr Littre was right… in his attitude to language. Is the more precise word always to be preferred? And how rigorously, if at all, is a derived or secondary usage to be rejected?

The stylebook of The Economist offers an example in point. Anticipate, it says firmly, does not mean expect; Jack and Jill may well expect a happy marriage without anticipating it. That particular example of the distinction may be unlikely to arise these days. But a distinction there is, and it is worth observing.

How rigidly, though, and till when? The meaning of anticipate has been on the slide for centuries: from “act before something/someone else”, via “act in expectation of something else” to today's straightforward “expect”. And you can find examples of this last use a good 150 years ago. Linguistic liberals will ask how much longer it must wait for respectability. Conservatives could ask… whether 150 years of wrong usage make it right.

Such issues arise with thousands of sliding words and usages. They are part of the endless debate between the pedantic view of language and the anyfink-goes one. The wise man expects no resolution of this debate; and the clever men who think their inquiries into language prove this a non-issue, merely, in fact, prove him right. Johnson's heart is with the pedants; his head tells him that what is “right” really is often relative. It depends who is talking to whom, where, why, about what.