In a democracy government is inevitably a joint venture between experts including civil servants, lay persons and politicians. Good government entails mutually supportive relations between them.

Lord Salisbury, then secretary of state for India, writing to Lord Lytton, the viceroy, on June 15, 1877: "No lesson seems to be so deeply inculcated by the experience of life as that you should never trust experts. If you believe the doctors nothing is wholesome; if you believe the theologians nothing is innocent; if you believe the soldiers nothing is safe. They all require to have their strong wine diluted by a large admixture of insipid common sense."

Problems arise when the required expertise is scientific and the issue one where political common sense is an unreliable dilutant of expert enthusiasms. These problems can be acute where technological risks have to be estimated and tradeoffs between the public or commercial good and public safety negotiated. If the scientific evidence itself is uncertain or contested, as it often is on issues such as climatic change or BSE, then no governmental action will be perceived to be "good" by many.

The Royal Society's 1983 risk assessment report, which attempted to set out how scientific and technological risks might be estimated on a common basis and in a form helpful to administrators and politicians, rapidly became the de facto UK handbook.

ÖйúAƬ

However, social scientists and the public were increasingly uneasy about whether the study group's approaches, though clearly necessary, were sufficient to describe the problems of risk perception and management. When the decision was taken to update the study in 1991 it was decided to involve social as well as natural and physical scientists. The Royal Society hoped to produce as coherent a statement as in 1983, but this proved impossible.

The 1997 conference on "Science, Policy and Risk" has been organised by the Royal Society as one of their contributions to what is becoming an increasingly serious and contested area of public as well as scientific and expert debate.

ÖйúAƬ

John Ashworth was chief scientist in the Cabinet Office from 1976-81.