In the land of the blind, Lord Archer is king

'Two men agree that one will tell only the truth, the other only lies. Both get into terrible messes'

I DON'T think that I shall be going to see the new Bruce Willis film, called The Sixth Sense, even if only because I have never seen a Bruce Willis film in my life and I don't want to ruin this proud record. However, I should be curious to see whether the sixth sense referred to in the title links up in any way with the missing sixth sense that was described by Diderot, the 18th-century French writer who never quite got the fame in this country that his mates Voltaire and Rousseau have obtained.

Don't get me wrong. I never read Diderot voluntarily. It was just that when I was half-way through the arduous three-year task of doing French at university, we were given a couple of weeks to get through Voltaire and the Encyclopedistes, and so I found myself being forced to read Diderot's writings and loving every minute of it, as his mind was so much more open and inquiring than anything that had come before, at least since Montaigne.

One idea he played with was based on the study of blind people. Blind people, as he pointed out, make do with four senses. They have touch, taste, smell and sound. Anything visual is beyond them; there is no place in their lives for brightness or colour or the art of painting. In fact, if it were not for the uncomfortable fact that they are surrounded by people who can see, and who keep telling blind people about this well- lit world, they would never know what they are missing. In a world inhabited only by blind people, the gift of sight would be meaningless and not missed at all.

Well, said Diderot, what if we who have five senses are also missing a sense? Might there not be a sixth sense which, if we only had it, would reveal a lot more of the world to us? There is no way of finding out what this sixth sense might be, or what it would measure, but there is a fair chance that it would completely alter our perception of things, just as the restoration of sight would change a blind person's whole view of the world.

Other writers have touched upon this lack of a sense, including the actress Jean Harlow, who wrote a novel about a wife who - in order to explain her nocturnal absences - manages to persuade her blind husband that day is night and night is day.

But the best treatment of this theme that I know came in a story by HG Wells. My father had a volume of Wells's collected short stories, which I never saw him reading, but in which I discovered a mine of wonderful tales including "The Country of the Blind", in which a mountaineer somewhere in the Andes stumbles on a land where everyone is blind. He naturally assumes that his sight will give him dominance over them, but he finds to his horror that their wise use of four senses is more than a match for his perfunctory use of five. Rather than being the one-eyed man who becomes king in the country of the blind, he finds himself completely outsmarted, and condemned by them to have his eyes removed...

I hadn't read that story for 30 years, until I came across a copy of Wells's collected stories in a second-hand bookshop recently, and it was still as chilling a tale as ever. But I couldn't find the Wells story I was really after, and which I remember just as clearly.

It was a story about two men who have an argument about whether it is better to tell the brutal truth or to lie tactfully. Finally they agree to put it to the test; one will tell only the truth for 24 hours, the other one will only lie. The upshot is that both of them get into terrible messes. It was a very funny and pointful story, and still would be, when you think about Jeffrey Archer. I only wish I could find it. If any reader can identify it for me...

A reader writes: Just a moment! Do you mean to say that this whole piece, with Bruce Willis and Diderot and all that, was written just to get help finding one story by HG Wells that you can't locate?

Miles Kington writes: Er, yes. Sorry about that...