It all started with Stephen Hawking, whose first popular book, A Brief History of Time, hit the bookshops in 1988. Very soon, others (myself included) jumped on the bandwagon, and popular science soon gained its own section in many bookshops.

With the boom, inevitably, there came a torrent of rubbish. The stylistic innovations of the trendsetters soon became, in the hands of the disciples, stale recipes, recycled over and over in formulaic and uninspiring ways. Even the titles began to seem repetitive: The Panda's Thumb, Galileo's Finger, Einstein's Brain ... What a pity nobody had the chutzpah to write a book about Newton's penis.

A decade and a half later, there are signs that the popular science boom is running out of steam. Unlike scientists, the public has a limited appetite for facts. That is, to my mind, a healthy state of affairs. The eternal curiosity of the scientist may appear touching, like the enthusiasm of a schoolboy for collecting conkers, but what is cute in a child is often quite pathological in an adult.

Nobody could put it better than Oscar Wilde. In his essay The Decay of Lying, he decries what he calls the "monstrous worship of facts". There is something truly monstrous about scientific curiosity because it seems to extend to facts something they do not deserve. Facts must be respected but never worshipped.

What did Wilde mean by "worship of facts"? I think he meant an attitude that regards facts as valuable in themselves, rather in the way that a miser regards money. The scientist spends his life accumulating facts without caring what their value is - that is, what the facts "mean". Unlike the engineer, the scientist does not necessarily want to do anything with the facts he collects. He just wants to gather more of them up in his storehouse of personal knowledge.

This is why Trivial Pursuit is a great metaphor for science. In that game, players compete by answering questions about all sorts of facts, from facts about sport to facts about geography. Science is similar, except that all the questions are about one particular sort of fact, namely laws of nature, and the various pieces of evidence relevant to these laws. Scientists spend their working lives playing this restricted version of the game, without ever becoming bored or admitting that it is trivial. Each day, they turn over another card with the same undiminished excitement. "Oh my!" one can hear them exclaim as they read out the next question: "How does local accumulation of the plant growth regulator auxin mediate pattern formation in Arabidopsis roots and influence outgrowth of lateral root- and shoot-derived primordia?" And off they go to discover the answer.

Wilde was right. There is something truly monstrous about scientific curiosity. It is myopic, forgetting the wider context of enquiry that endows facts with meaning. This wider context of enquiry is, ultimately, a philosophical one, in which the burning questions concern the purpose of human existence in general, and the purpose of one's own life in particular.

It is not that scientists should abandon science for philosophy, but they should at least put their questions in perspective. There is nothing wrong with dedicating your life to collecting rather trivial facts, just as there is nothing wrong with earning a living by cleaning toilets. But nobody pretends that cleaning toilets is the most noble activity to which man can aspire, while there are many who say that about science.

Scientists have vested interests in persuading other people to share their views about the transcendent significance of their research. There are lots of scientists chasing a limited amount of funding, and one way to grab a larger slice of the pie is to make exaggerated claims about the importance of one's own field of study. But the end of the boom in science writing shows that the public are getting wise to - and weary of - the overblown rhetoric.

I hope now that the flood of popular science books will go back to being the small but higher quality trickle it used to be. And I hope the non-fiction market will now begin to see, at long last, some more profound reflections on what the facts mean.

Responses: (names withheld)