The renowned British philosopher Antony Flew was following the Socratic rule of going where the evidence led him when he converted from staunch atheist to believer.

His was not a Damascus-style conversion but a "pilgrimage of reason" as he writes in his 2007 book, There is a God: How the world's most notorious atheist changed his mind.

Having set the atheist agenda for the latter half of the 20th century - his Theology and Falsification being the most widely reprinted philosophical publication of the last 50 years - Flew's rethink came after a sober assessment of the scientific evidence.

The fact that the same evidence leads others in the opposite direction isn't surprising given human nature and the limitations of science. Contrary to popular perception, science doesn't always deal in 100 per cent certainty.

The UK Science Media Centre puts out a guide to help scientists "communicate uncertainty in a soundbite" to the non-scientific media. It tells scientists how to answer questions such as, "why is science uncertain?" by saying things like: "Scientists don't know everything." "Science works in shades of grey, not black and white." "Science doesn't always have the answer - we're scientists, not politicians." And: "Science is rarely about absolute certainties. It is a process of assessing evidence and coming to the best conclusions we can."

The reason is what scientists claim is the continuing misreporting of scientific advances, by a media which is too often ill-equipped to interpret and assess scientific evidence.

It's easy to see why we non-scientists prefer absolutes and quantified risks to nuanced explanations and uncertainties. We want nice, simple answers. How deadly is the misnamed swine flu likely to get? Is Tamiflu as good as it's made out to be? Is a flu vaccine the answer to our prayers? We want the kind of certainty that science can't always give us.

But we pay a high price for our ignorance.

In his book Bad Science, Ben Goldacre, a doctor and Guardian columnist, laments the way "scientists and doctors find themselves outnumbered and outgunned by vast armies of individuals who feel entitled to pass judgment on matters of evidence ... without troubling themselves to obtain a basic understanding of the issues".

"Without anybody noticing, bullshit has become an extremely important public health issue, and for reasons that go far beyond the obvious hysteria around immediate harms ..."

Given the daily bombardment of "sciency-sounding claims" in the media, and the deliberate distortions generated by corporate lobbies and cranks, Goldacre sees an urgent need for those interested in the truth to arm themselves with the skills to assess and interpret scientific evidence.

Which begs the question: is science getting too complex for the non-scientist? How do we sort out the wheat from the chaff?

If you have half a million dollars to spare, you might do what economist Gareth Morgan did to settle the question of whether global warming was the myth that politicians like Rodney Hide make it out to be. The result is a book, Poles Apart, written with journalist John McCrystal, which comes out on the side of the so-called global warming "alarmists".

The climate scientists whose arguments and evidence helped to convince Morgan and McCrystal are pleased, of course - but they can't help asking why the findings of an economist and journalist should hold more sway than a panel of international climate experts following a robust scientific process.

As environmental scientist Dr Andy Reisinger says, the book raises "some significant questions ... about how to best explore complex problems that have a scientific basis and major social, economic and environmental implications".

"The climate is an enormously complex system ... it is impossible for any single individual to know enough in all the areas required ... if we believe that an economist and a journalist can resolve a question about climate science more conclusively than ... a large panel of climate scientists ... then we run the serious risk of drowning in a cacophony of opinions while making decisions of international significance."

And three scientists based at the Antarctic Research Centre at Victoria University who'd also contributed - Dr Dave Lowe, Dr Lionel Carter, and Dr Peter Barrett - have written that "while satisfied with the outcome, and most of the scientific explanations the book contains, we feel we never did get Gareth and John to understand the process by which good science proceeds, and we think this process therefore takes more of a beating in their book than it deserves.

"Still it's interesting that this is how scientists are seen by Gareth and no doubt many others in society at large. And that's worth knowing."

Says John McCrystal: "Are we living in a technocracy, then, where we must shrug and do what the scientists tell us to do without question? ... Gareth and I never claimed to be judges in the case of global warming: only jurors.

"We didn't claim any special legal or scientific knowledge, just a willingness to apply ourselves, to the limits of our ability, to the expert testimony being presented. After all, it's the jurors who bring back a verdict, not the judge in a jury trial, just as it's the voters who ultimately decide what they can stomach in terms of policy."

Yes, but if it takes that much money to find out the truth, something's wrong.