In a valedictory speech to mark the end of his five year presidency of the Royal Society, Lord May of Oxford will claim that fundamentalist thought in all its guises, from religious beliefs to the ideologies of green lobby groups, is skewing debates over some of the most pressing issues facing humanity, such as climate change and emerging diseases.
Such is the influence of groups that ignore or misinterpret scientific evidence, that the core values that underpinned the Enlightenment and led to "free, open, unprejudiced, uninhibited questioning and inquiry, individual liberty and separation of church and state" are being eroded, Lord May believes.
In his address to the society, titled Threats to Tomorrow's World, Lord May will criticise groups for putting their own traditions, unsupported beliefs and dogmas above scientific evidence. "Fundamentalism doesn't necessarily derive from sacred texts. It's where a belief trumps a fact and refuses to confront the facts.
"All ideas should be open to questioning, and the merit of ideas should be assessed on the strength of evidence that supports them and not on the credentials or affiliations of the individuals proposing them. It is not a recipe for a comfortable life, but it is demonstrably a powerful engine for understanding how the world actually works and for applying this understanding," he will say.
The problem is most prominent in the debate over climate change, Lord May claims, comparing the climate change denial lobby, which is "funded to the tune of tens of millions of dollars" by the petroleum industry, with the tobacco lobby, which continues to deny that smoking causes lung cancer. The green groups were not spared criticism."We need to recognise that on the one hand there are huge problems with nuclear energy, while on the other hand there are huge problems with putting carbon into the atmosphere." It was hard to see renewable energy replacing nuclear power "on the timescale we need."
Lord May is particularly critical of the Catholic church and its comments on the use of condoms, which are proven to reduce the spread of sexually-transmitted diseases. "The Vatican in particular promotes abstinence outside marriage, and condemns condom use. This disapproval, for all its putative high-mindedness, simply is not an effective strategy for preventing dissemination of HIV."
The speech warns of the emerging problem of creationism being taught in school science lessons as a theory on equal footing with evolution. Lord May called on scientists to be more proactive in making their voices heard.
"Sadly, for many, the response is to retreat from complexity and difficulty by embracing the darkness of fundamentalist unreason. The scientific community should be energetically engaging the political process in all the avenues that can be pursued." He urged scientists to be "more energetic as citizens and getting out there and trying to convince people".
Lord May, an Oxford University professor of zoology, stands down as president of the Royal Society today, making way for Professor Sir Martin Rees, the Cambridge University-based Astronomer Royal.