RODIN'S sculpture, The Kiss, now on show in Lewes, Sussex, was banished by the genteel folk of that town 70 years ago, I read in the Times, "for fear of its erotic affect". And in the same issue my old colleague Jasper Gerard tells us in his diary column that an introduction, of Peter Mandelson to the head of Goldman Sachs, was "affected" by its chief economist Gavyn Davies. Tut, tut, you may say.

But before you start what Private Eye's Glenda Slag would have called "asneerin' and ajeerin' " at the illiterate hacks on the Times, who don't seem to know the difference between affect and effect, I must remind you that they are by no means the first to have confused them. The Oxford English Dictionary records instances dating from between 1494 and 1772, when that very mistake was made by the great globe-trotting travel writer James Cook, who put effect, when he should have put affect.

Both James Cook and Mr Gerard have their excuses, though they are very different ones. Johnson's dictionary, which did more than anything else to regularise our spelling, had been out less than 20 years when Cook was writing. As for Mr Gerard, no doubt he, or his sub-editor, used a computer spell-checking facility before the column went to press, so they couldn't be accused of neglectfulness.

The trouble with those spell-checkers is that their little electronic brains know nothing about the context, so they were no help to Mr Gerard. They are treacherous friends. It is often pointed out that spelling mistakes became more common when too many teachers stopped bothering to correct them, but our increasing reliance on spell-checks is probably going to make things worse rather than better.

Nor are they much help when, as in this case, two quite different words tend to sound the same. (I did have a great-aunt who pronounced one of them "iffect" to make sure we knew what exactly it was she was talking about.)

It is just remotely possible, however, that whoever wrote that bit about The Kiss had at the back of his or her mind another pronunciation of affect, the one that has its stress on the first syllable. An affect in this sense is an emotion, more or less uncontrolled, of pain or pleasure, and I suppose you could talk about an erotic affect, though that sort of talk is more suited to psychologists than to journalists on daily papers, and I don't think the Times deserves the benefit of the doubt.

The psychologists' word must presumably have come from the original verb, to affect (as pronounced normally), which at first meant to love or like. Only later did it take on the meaning "to assume a liking for", leaving the genuine emotion to be expressed by affection, and the false by affectation. The other affect, "to influence" or "act on", seems to come from a similar Latin verb that had nothing to do with the emotions, which is perhaps why you can be deeply affected by a friend's kindness while at the same time complaining that your lungs are affected by his smoking.

Not that etymology can define meanings. But it does show how meanings have changed, a very different matter.