Scientists no longer need to read him, but don't tell that to the rare book collector
Who says that life does not imitate art? A little drama that could have come out of Simon Raven's novel The Roses of Picardie is being played out at Oxford University. A 32-year-old lecturer, Dr Simon Heighes, has been charged with stealing a rare antiquarian book from the library of Christ Church College. Dr Heighes, it is alleged, took a copy of the first edition of Isaac Newton's Principia Mathematica, sometimes described as "the bible of science".

In the Principia, Newton set out the universal theory of gravity, showing that the force which caused the proverbial apple to fall from its tree in an English orchard was the same force which bound the Moon in its orbit about the Earth and the planets in their paths around the Sun. Published in 1687, this monumental work also set out the laws of motion which became known as "Newtonian dynamics" and lasted until Einstein promulgated the Theory of Relativity more than two centuries later, in 1905.

Newton's achievement dazzled his contemporaries and successors, generating an admiration perhaps best summed up by Alexander Pope's little doggerel: "Nature and nature's laws lay hid in night; God said, 'Let Newton be', and all was light."

According to Andrew Hunter, who heads the science department of the antiquarian booksellers Bernard Quaritch, about 300 to 400 copies of the first edition were printed. "Even in rough condition, a first edition would fetch at least pounds 50,000," he says. Thames Valley Police value the Christ Church copy "in excess of pounds 67,000".

Mr Hunter says: "It all depends on the condition of the book, from absolutely ghastly to magnificent. Some have been made very messy by careless librarians. We have a copy in stock now for pounds 120,000. But it's a very nice copy." Several copies have been on the market recently, Mr Hunter says. "If it's really on your wish-list, you won't have to wait a lifetime to get it." Or as one (Cambridge) don put it on hearing of the alleged Oxford theft: "They're two a penny around Cambridge."

But the bizarre thing about this valuable "bible of science" is that it is unlikely that a single living scientist has ever read it, professionally. If all 400 copies were to vanish from the face of the earth tomorrow, the antiquarian book trade might be devastated, but science would proceed as if nothing had happened. Science would be unaffected even if all copies and facsimiles of the book disappeared.

The hard truth is that Newton's own writings simply do not matter any more. Philosophy may remain forever a series of footnotes to Plato, but science is different. It is "the art of the soluble", in the words of the late Sir Peter Medawar, and once a problem has been solved, the scientists lose interest in it and move on to something new and different. Science students do not learn their trade from the original texts, or even paperback reprints. They pay modern publishers exorbitant prices for textbooks where all connection with the social and personal circumstances in which the science was created have been carefully removed.

Science, moreover, lives in a sort of perpetual present. In this week's issue of Nature, the world's leading scientific journal, it is difficult to find a reference to any research earlier than 1980.

Textbooks are usually not written by practitioners; they oversimplify for didactic purposes and often tend to perpetuate mistakes by the simple process of one generation of textbook writers copying from their predecessors. The papers in scientific journals represent glimpses of understanding of new science and are therefore often incomplete or sometimes wrong in some details. (Einstein's famous 1905 paper on relativity actually contains at least one minor slip-up.)

So why does an original edition of the Principia matter? The short answer is that it doesn't. The ideas of gravitation and Newtonian dynamics are freely available to everyone - and they are incomparably more valuable than a pounds 67,000 book.