HYPOTHESES

I have a confession to make. I'm a fan of The X-Files, particularly the first series with its excellent mix of science fiction and drama. I especially like the episode where the murderer can stretch and enter through a crack under the door. It seems quite natural, and very common, to be fascinated by the unnatural. Why then do I so dislike, even have contempt for, claims for the paranormal? Why does the BBC2 series Secrets of the Paranormal fill me with distaste and despair?

Those involved in the paranormal are always particularly enthusiastic to put their investigations on a scientific footing. Matthew Manning, a self-proclaimed healer in the BBC2 series, repeatedly claimed his special powers had been investigated and confirmed by scientists. He even said he could influence cancer cells and make medical diagnoses with minimal effort. If this were true, it would rank as a wonderful new scientific discovery: radioactivity, X-rays and radio waves would look very pale by comparison. But where were the scientists rushing to investigate these new forces? For scientists are not slow to follow up such discoveries. Science is competitive and how foolish they must seem to neglect this golden opportunity to gain for themselves fame, if not fortune. Manning has, of course, no such powers. If he had, the so-called scientists who investigated him would be rushing into print in the leading scientific journals, Nature and Science, with their exciting findings.

Good science requires the rigour of review and careful scrutiny by other scientists. The more remarkable the findings, the greater the scrutiny must be. There are no miracles in science, only amazing findings. What could be more amazing, even supernatural, than the Big Bang theory for the origin of the Universe? Or that all of our physical characteristics and much of our behaviour is determined by a very long but simple molecule, DNA, which carries the information in a four-letter code.

An essential feature of paranormal phenomena is that they cannot be explained by current science. They also contradict what is known. Levitation, psychokinesis, telepathy and astrology all fit into this category. Homeopathy is at the edge. Many of these paranormal phenomena fit quite neatly with what the chemist Irving Langmuir called "pathological" science. The effect observed is small and near the limit of detectability; the size of the effect is independent of the cause; and there is usually a fantastic theory associated with it.

Criticisms are met with ad hoc excuses. A nice example of this is that attempts to observe the phenomenon prevent it occurring. One need not be surprised that after 100 years of research into extra sensory perception, not a single individual has been found who can demonstrate this "power" to the satisfaction of investigators.

Scientific research in my field, the development of the embryo, is painstaking, slow and difficult. It can take months, even years of hard work punctuated with failures to make some quite small contribution. In the world of the paranormal, one can make momentous discoveries hourly. Levitation, spoon bending and telepathy defy Newton and demonstrate quite new forces. No wonder I am unashamedly envious, but also contemptuous.

Belief in the paranormal can be benign, even fun, like believing in Father Christmas. But its proponents are anti-science, since they wish to persuade us that there are special forces and spirits to which science has as yet no access. It is thus misleading and potentially harmful when it is used in a medical context. It prompts irrationality and a return to primitive beliefs. The field contains charlatans and tricksters as well as the honestly self-deluded. I'd happily give pounds 1,000 to the favourite charity of any paranormalist, like Uri Geller or Paul McKenna, who can demonstrate telepathy or psychokinesis under controlled conditions and under the critical eye of two other magicians of the skill of Paul Daniels. I am in total agreement with the TV review in the Sunday Telegraph, headlined "The BBC Should Be Ashamed."

! Lewis Wolpert, of University College London, is chairman of Copus (the Committee on the Public Understanding of Science). His book, 'The Unnatural Nature of Science', is published by Faber.