Four hundred years after Galileo, scientists still face persecution for speaking out. Laws must not be used to stifle debate.
In 1633, the Italian astronomer and physicist, Galileo Galilei, was put on trial by the Catholic Church for suggesting that the Earth might not be the centre of the universe — and found guilty.
Almost 400 years later, scientists and those speaking on their behalf are still being persecuted for expressing opinions based on their scientific expertise.
Three years ago, for example, the Nigerian Academy of Science was taken to court by a local doctor after the academy criticised his claim to have developed an HIV/AIDS vaccine (see HIV 'cure' doctor sues science academy).
Last year, a British science writer, Simon Singh, was found guilty of libel for a newspaper article in which he described certain claims of chiropractors — who believe in treating a range of ailments by manipulating the spine — as "bogus" (the ruling was recently overturned on appeal).
Meanwhile, the University of Virginia in the United States is being investigated by the state attorney general over statements made in grant applications by a former faculty member, Michael Mann, whose views on the severity of global warming are challenged by climate change sceptics.
And now a prominent biologist in Peru has received a suspended jail sentence for describing as a "false truth" a claim by another biologist to have detected modified genetic material produced by commercial companies in local maize crops (see Scientists rally round convicted Peruvian researcher).
Engaging in debate
It would be wrong of course to expect that scientists should operate under different rules from the rest of society. Where a researcher has been caught in fraudulent behaviour, such as using deliberately falsified claims to obtain government funding, the full sanction of the law is surely appropriate.
But the law should not be used to penalise scientists who criticise the views of those who lack scientific credentials, or those whose controversial differences with other scientists spill over into the public domain.
In the cases above, legal action has been taken, or threatened, against scientists or science writers primarily over statements made not about a purely scientific dispute, but about scientific disagreements that form part of important public debates.
At a time when the relationship between science and society plays an increasingly important role in development issues, from disease prevention to food security, it is essential that outdated or misconceived laws do not discourage scientists from engaging in such debates, where they can ensure discussion is based on reliable evidence.
Extent of academic freedom
Of course, academic qualifications do not give scientists the right to say what they like about the behaviour of others. Researchers should restrict themselves to issues in which they can demonstrate an appropriate level of expertise.
Academic freedom does not extend to challenging the motivations of other researchers, only to the truth or otherwise of their statements. This is similar to the way that the freedom of the press does not extend, for example, to invasions of personal privacy.
But in any case, the courts should not be the arbiters in disputes over the validity of claims for demonstrated or hypothesised scientific evidence. The peer review process, despite its many shortcomings, is still the best mechanism we have for making judgments about scientific advances and differences.
Legal action should not be used to prevent a scientist from making public statements based on expert opinion, however strongly expressed — or however contentious the topic.
Bringing laws to heel
It is appropriate that this issue is being taken up by national science academies (as in the case in Peru). But concern should extend beyond the scientific community. All countries should examine their defamation laws and assess whether they may discourage informed debate on key issues of social concern.
For example, Britain's new coalition government has promised to consider legal changes that would better protect individuals such as Singh and allow them to play a robust part in key debates, without the fear that an ambiguous phrase could lead to personal bankruptcy, or even a prison sentence.
Other countries currently empowered — as Peru apparently is — to act against scientists should consider whether it is in the public interest to do so. The recent threat by the Indian government to imprison researchers warning against the dangers of genetically modified crops is a case in point (see Mutual respect in the GM crop debate).
Scientists have a responsibility to speak out about topics on which they hold expert knowledge, particularly if this knowledge can better inform a political debate. But society, in turn, has a responsibility to protect scientists when they do.