Last week, a large agricultural products company whose trial plots of genetically modified crops had been attacked by protesters came up with a simple proposal: that in future, the precise location of experimental crops should be kept secret. The suggestion has obvious attractions. But it would also be a dangerous and misguided move. For nothing generates distrust of science and technology more than excessive secrecy, and the feeling that, if something is being kept out of the public eye, it must be potentially embarrassing — if not dangerous.

The same need for openness applies to science advice to governments. In an earlier era, science could count on public trust, and such advice could be drawn up as a matter of course by expert committees and submitted to decision-makers on a confidential basis. But today — a lesson learnt in the United States through the Watergate affair, and more recently in Britain by the BSE crisis — confidence in political decisions requires confidence in the political process. And this requires responsiveness to the electorate's demand for transparency.

The BSE crisis weighed heavily on the mind of Sir Robert May, Britain's chief scientific adviser, when he made an eloquent plea last week in defence of openness (see page 720). According to Sir Robert, this process should extend to the debates between scientific experts. If respected advisers were encouraged to air their differences in public, he argued, everyone would get a better idea of how scientific knowledge is built up, not by maximizing certainty or striving awkwardly for consensus, but by minimizing uncertainty.

A different but equally radical proposal comes in a submission to the same inquiry from the Royal Society. This is the notion that the chief scientist should have access not only to the principal science advisers in all government departments, but also to debates on scientific issues taking place within those departments; again, BSE provides a demonstration of what can happen when such access is denied.

All such proposals, of course, will meet counter-arguments. Those concerning commercial confidentiality or national security are often (though not always) valid. Others, such as the tradition that policy-related questions require the type of clear, unambiguous answer that science is often unable to provide, can be less so. There will always be those who exploit openness for their own ends, as those responsible for destroying the experimental crops seem determined to do. And there are times when a clear statement of scientific consensus is essential. But the ability to handle openly the type of uncertainty that scientific knowledge can lead to is itself a form of social maturity.