I’ll post more on your general point, I hope, but it’s late at night here, and I’m off to bed.

Now, should they stick to a diet that works for them, and reject the truth claims of scientists to the contrary, or should they stay fat? I should think most of them will reject the scientific conclusion as either wrong or inapplicable to them.

Dieting is just one example. You may argue that it’s false to think the choice is between Atkins and being fat, but if science stands opposed to the doctrine that if it works you should probably stick to it, it’s not going to gain much traction with people.

Alternative medicine, organic foods, the utility of prayer, astrology, feng shui – call it placebo effect or confirmation bias or whatever you like. The world is full of people who will tell you this stuff works for them and will suggest you’re full of it if you expect them to believe scientific studies rather than their own eyes.

It’s a somewhat counterintuitive finding that dieting doesn’t work, but that’s what the scientific method shows. And, once science has demonstrated the results statisticially, it’s easy for people to find confirming instances in their immediate circle of acquaintances – people who’ve tried dozens of diets and are still fat, or at least unhappy about their weight. A Google search for “dieting” suggests, contra your point about people who lose weight on a diet that they’re told is nonsense, that scepticism about dieting is gaining ground, and may already be the dominant view.

As you say, this is problematic in a society that makes achievement of a healthy weight difficult in all sorts of ways, but I still don’t think this example supports your case.

(I’d like to see Sebastian explain when science polict has ever been about “reasoned analysis of facts” too.)

There are real questions about how scientific claims are made and whether any non-ideologically driven way exists, or even can exist, to decide between them. These questions aren’t silly. They affect the lives of everyone. Millions of people use alternative medical therapies – and swear by their efficacity – because they have explicitly rejected some claims to scientific authority. People eat organic food because they do not trust claims that food raised otherwise is just as safe and nutritious. Practically every person in America has been on a diet at some time in their lives with little no scientific support because people with impecable scientific credentials tell them that the only way they can loose weight is to change their lifestyles in ways that they can’t afford.

It’s not even clear that a neutral, factual, clear, certain, scientific way to address these issues exists. Every person who gets relief from a medicine that they’re told has no value; who feels better after switching to organic produce; who loses weight on a diet that they’re told is nonsense; every such person starts to ask how much credence they really can give to scientific claims to authority. It’s not too hard to see how such people can start to question evolution, a doctrine that as far as they can see concerns events in a distant and remote past that can’t be known with certainty anyway. It makes it easier to believe the renagade “sound scientist” who says that smoking is good for you, that there’s no global warming and that science proves there’s a god.

If Republicans are manipulating this, I submit that they’re not really the cause.

That it also demonises postmodernists fits the pattern with uncanny accuracy.

This is a huge claim, Sebastian, and I’m eagerly looking forward to you backing it up.

In effect, here, we are back to the fact-value distinction that was at the centre of 20th century debates about positivism. In Mooney’s view, scientists do their best (or should do their best) to determine the facts that should inform public debate. It is then up to political processes to determine the course of action most consistent with the values held by the public. By contrast, Sarewitz views the two as inextricably entwined, to the point where he does not appear to be aware that such a distinction might be suggested.

In the 20th century, rejection of the fact-value distinction came mostly from the left, first from Marxists who saw all truth-claims made in a class society as being incorrigibly saturated with ideology and then from postmodernists and social constructivists who attacked the whole idea of an independently existing truth, which might be ascertained, or at least approached, by scientific inquiry.

One of the central conceits of postmodernism has been to pluralise abstract nouns like truth, abandoning attempts at a unified view of the world in favour of a celebration of difference. The great lesson learned by postmodern Republicans has been that, where multiple ‘truths’ contend, the ‘truth’ favoured by powerful interests is likely to prevail. Since scientific truth is refractory and not amenable to political control, its claims to special privilege must be challenged, in order that politically reliable alternatives such as ‘sound science’ can replace it.

This is a key insight. I’m not going to defend the Republicans one bit on the Intelligent Design front—stupid political pandering. But the climate change issue has had some key problems with both sides pretending that the facts and values are identical. The climate change people of the late 1970s (Ice Age Fearmongers) and the current Global Warming Agitators (as opposed to the investigative scientists) both act as if the nearly inevitable fact of climate change (human driven, sun output driven, or otherwise driven) absolutely insists on a human response. The fact that the climate changes does not mean that climate change must be stopped. Even assuming we could stop it (not proven in any case) it is not at all obvious that it would be the best use of our resources to do so. The reaction to that has been very unfortunate—in an ideal world, Republicans would have reacted with a “lets focus on the facts” type of response. Responding to “you just don’t caaaare about the Earth” (with its social equivalent of “you just don’t caaare about people starving”) is always difficult when you do in fact care about the Earth and don’t want people to starve.

The proper response from either side from those who care about science ought to be that we should focus on getting accurate answers for scientific questions and then focus on helping people understand them enough to apply moral reasoning.

I think it is ok to call it the Republican war on science, because it currently is. But a better understanding might come from seeing the ugly cycle of which the Republican reaction is only the most current iteration. The overconfident social sciences (especially Marxism) did a number on reasoned analysis of facts with the full support of huge swaths of the university. You note that post-modernism had a similar trajectory. We need to get off the ride, not just change cars.

“The great lesson learned by postmodern Republicans has been that, where multiple ‘truths’ contend, the ‘truth’ favoured by powerful interests is likely to prevail.”

Yes and this is best battled by embracing the idea of TRUTH again, not by merely fending off the current Republican attack.

And I don’t have time to retype, but as I read it my comment sounds more like a criticism than I intended. It is a focus-based clarification.