Trust in Science

Nothing is more characteristic of a dogmatist epistemology than its theory of error. For if some truths are manifest, one must explain how anyone can be mistaken about them, in other words, why the truths are not manifest to everybody. According to its particular theory of error, each dogmatist epistemology offers its particular therapeutics to purge minds from error. (Imre Lakatos)

If no exception occur from phenomena, the conclusion may be pronounced generally. But if at any time afterwards any exception should occur, it may then begin to be pronounced with such exceptions as occur.(Isaac Newton)

When the physicists started to talk about "electricity," or the physicians about "contagion," these terms were vague, obscure, muddled. The terms that the scientists use today, such as "electric charge," "electric current," "fungus infection," "virus infection," are incomparably clearer and more definite. Yet what a tremendous amount of observation, how many ingenious experiments lie between the two terminologies, and some great discoveries too. - Polya [1954] v.1p.55 -p.95

I watched "Horizon: Science Under Attack" last night, in which Nobel prize winner Sir Paul Nurse went on a journey to find out why science appears to be under attack.

Geneticist and biologist Paul Nurse examines the reasons why public trust in key scientific theories, including the cause of global warming, the safety of GM food and the link between HIV and Aids, seems to have been eroded. He travels to New York to interview scientists and campaigners from both sides of the climate change debate, and meets a man who has HIV but does not believe the virus is responsible for Aids.

We knew that Nurse was a Nobel Prize winner because he told us. And a president of the Royal Society. And throughout the programme, the pedigree of various scientists was elucidated, to give us confidence. But this style of presentation was deeply inimical to Nurse's focus on "the facts" that really mattered. It was really little more than the "men in white lab coats" of countless advertisements on television in the 1960s and 1970s; it was the argument from authority, scientists giving pronouncements, couched in modern terms. It reminded me most of what Orwell noted in his essay on the shape of the earth:

Much the greater part of our knowledge is at this level. It does not rest on reasoning or on experiment, but on authority. And how can it be otherwise, when the range of knowledge is so vast that the expert himself is an ignoramus as soon as he strays away from his own specialty?

Here are a few of Nurse's arguments, and why I disagree with them.

a) Climate Change Deniers are involved in cherry picking data

"You cannot ignore the greater body of evidence in favour of something you would prefer to be true" said Nurse. But it is equally true that you cannot ignore the smaller body of evidence in favour of a greater picture into which it doesn't fit. In other words, there has to be some contradictory data, some exceptions, for the climate change deniers to focus on, and this is marginalised.

What seems to happen is that these exceptions are eliminated by what the philosopher Imre Lakatos termed "piecemeal exclusions", which is the mirror image of cherry picking.

Nurse had an analogies of a garden, and he said science (unlike deniers) say "look at the whole picture", but what he didn't really come to grips with was how are exclusions are dealt with - are they treated as seriously as they should.

In fact, when it came to deniers, he more or less argued that this was a psychological stance, they had a fixed idea, and just looked for evidence of that. He argued that science looks for refutations, yet gave no examples of how this was done with climate change. Instead he just produced pictures and talked to people who produced plenty of supportive facts, and told us how the models were improving all the time, but gave no indication of what would disprove their case.

There was a wonderful Nasa globe, in which real weather patterns could be matched with the mathematical model, and you could see visually how the model was improving all the time. This would be even more convincing if it had the ability to predict the weather, and for example, warn the Australians of the imminent danger of flooding. After all, a theory is only as good as its testing, as Nurse told us repeatedly. I suspect the Nasa models are very weak when it comes to future weather patterns, but very good in real time or retrospectively, which is more or less what we have with weather forecasting today, when we are told why a weather pattern has occurred, but not why the predictions failed (as anyone reading the papers will note).

There was a contradiction between his formal expression of science (as a Karl Popper style program of testing to destruction) and what he was actually presenting to support his case. He virtually came out with a Popper methodology - we test our most cherished science and try to refute it:

At the next step our tentative solution is discussed; everybody tries to find a flaw in it and to refute it.[producing] a competitive struggle which eliminates those hypotheses which are unfit. From the amoeba to Einstein, the growth of knowledge is always the same; we try to solve our problems, and to obtain, by a process of elimination, something approaching adequacy in our tentative solutions (Karl Popper)

In fact Popper often confused his own logic of scientific discovery with the practice of scientific discovery, as philosopher Mary Midgeley noted:

As we know, this is not really the way in which infant ideas get reared. From their first germination, they normally grow in public, in the common soil of the community. They occur to somebody, who mentions them, and they begin to be talked about. Their growth becomes possible because of shifts in the general climate of thought, and is fostered by half-conscious contributions from many sources for a long time before any one person thinks them out explicitly....People who get interested in them usually want to share them with others, and that fertile sharing is the main source of their further development. Of course elimination plays its part in discriminating among various emerging possibilities. But the main work of developing them is the positive, constructive, imaginative process of building them and thinking out better ways to use them, and this work is normally best carried on co-operatively, among circles of friends and acquaintances.

In fact, despite what Nurse was saying, he neither gave no examples of how scientists committed to climate change are trying to refute their own hypothesis, but on the contrary, provided lots of shots of scientists telling us that climate change was undeniable because of the "facts", which were presented in superficial glossy Horizon way. It was an opportunity missed.

There was no real consideration of the logic of refutations, which is no doubt why Nurse cannot understand how people don't accept his position when the evidence is so clear-cut. This is a sketchy approach (based on Lakatos) that I would consider to understanding the problems involved; it is probably a simplification, but I think it is more realistic than the Popperan approach suggested but not practiced here.

If a "proof" of a conjectures - such as climate change - can be broken down into subconjectures which support the main conjecture, then we may have a global counterexample, which contradicts all the subconjectures, or a local counterexample which contradicts a smaller subconjecture, but does not completely overturn the main conjecture. But that may mean that several supporting subconjectures are in fact false, or are not giving the complete picture.

Unless we can see this process clearly at work, and the weaknesses of the cases of exceptions (which may not matter, and we need to explain why), the production of exemptions will simply suggest that climate change scientists, as much as deniers, are shutting their eyes to what they don't want to see. That, I think, is the public perception, and why climate change science is so much under attack.

b) Look at all the evidence, science is evidence based.

This was Paul Nurse's other argument - we can see how the data is used, there are peer reviewed scientific journals, and scientific evidence is there, open to scrutiny by anyone who doubts.

Yet then he goes on to speak to the scientist at the centre of the "climategate" affair who complains about being bombarded with freedom of information requests for his supporting data. And the scientist in question says this is evidence of a conspiracy against him, not that he should have put all his data out into the public domain anyway!!

Even Paul Nurse realised there was a contradiction here, and said that the model way of doing things should be the Human Genome Project. Unfortunately the human element of science, namely staking a claim to fame by priority, still counts for a good deal.

"Scientists have got to get out there. They have to be open about what they do ... even if it does put their reputation in doubt", he said. Keeping evidence back from public view suggests that what does get on display may be selective, it certainly fuels suspicions, and rather than Nurse talking to camera about a more open public access to science and data, he didn't question the climategate scientist at all about keeping his data to himself, and why that somehow legitimate. Instead he seemed to almost let that slip by.

c) Cherry Picking

Paul Nurse cited selective use of evidence, and yet when it came to GM crops, there was an appalling amount of cherry picking in his presentation. For example, on GM foods, he said "of course they contained genes, everything does", suggesting that the public were somehow ignorant of this basic fact. This was patronising and completely untrue; it was a a gross oversimplification of the issues at stake. Somehow he forgot to mention:

1) gene splicing (such as introducing scorpion genes into vegetables) rather than selective propagation is one cause of concern, as no one has any idea about alien genes and long term side effects of these in the food chain.

2) GM crops are produced not just to be resistant to blight (his example of "good GM"), but also resistant to extremely strong pesticides, regardless of the environmental hazard to the ecosystem that produces

3) terminator seeds, are manufactured, which are designed not to be able to be propagated, so that the manufacturer retains a monopolistic control of the food chain.

"Trust no-one. Trust only what the experiment and the data tell you. We have to continue to use that approach if we are to solve problems such as climate change." said Nurse. If his presentation on GM crops is anything to go by, no one is likely to trust him on climate change.

He also provided his "killer question" -

Suppose you were ill with cancer would you wish to be treated by "consensus" medicine or something from the quack fringe? (Paul Nurse)

what he is in fact providing is a medical version of Pascal's wager, and it overlooks the fact that while most people will opt for "consensus medicine", it may still kill them.

Going back to the issue of hygiene and the work of Semmelweis, the "consensus medical practice" for doctors was (in the 19th century) not to practice strict hygiene and as a result were killing women by infecting them in childbirth. Semmelweis noted this and proved that these infections could be stopped with effective hygiene. He was hounded out by the "consensus".

Oxygen supplied to premature babies (as best consensus) caused blindness.

Thalidomide enjoyed a wide spread "consensus" among the medical profession that it was a safe and effective treatment for morning sickness in pregnant women.

It wasn't so long ago that the medical consensus was that stomach ulcers were caused by worry rather than helicobacter pylori.

I'm not saying one shouldn't seek medical advice rather than "quack medicine", but just that by overlooking the flaws in consensus medicine along the way (and I'm not going to start on psychiatry), Nurse is painting a much rosier picture than he should. You may have "consensus medicine" for cancer, but you may well die anyway. Either / or is simplistic - most people will go for both "consensus" medicine, and unorthodox treatments.

"I think today there is a new kind of battle. It's not just about ideas but whether people actually trust science... Science has created our modern world so I would like to understand why scientists are under such attack and whether scientists are partly to blame," Sir Paul said.

Overall my son was unimpressed. Why couldn't he show us the whole email in Climategate about ""Mike's Nature trick" rather than telling us what it meant? Why did they just show nice graphics, and not give much in the way of solid data? That, of course, is why he hates most Horizons nowadays, which eschew real science for glossy visuals, and dumbing down.

If you treat people like idiots, people won't trust you - that is more or less why people don't trust scientists like Paul Nurse. Watching the Horizon, I suspect he will have alienated more people than he won over to his point of view. And he will have been partly to blame.