According to a venerable way of thinking about science and its place in our lives, science is value-free. Science sets its sights on the facts. It is interested in the way the world is apart from inherently subjective matters of interpretation. Science can learn the facts without needing to take a stand on values. Science needn't concern itself with tedious and undecidable debates about matters of value.
But is this true?
I'm not interested in whether some scientists are biased, or dishonest, or whether the path of research is sometimes influenced unduly by the agencies or industries that fund research. These are important questions, but they take for granted that science is value-free in its workings, at least when it is not subject to corrupting influences from without.
No, my question is this: Is it ever true that science can be a value-free engagement with the facts as they are in themselves?
Here's a reason to be skeptical: as the philosopher Hilary Putnam has argued for years, science relies on epistemic values. A good scientist, like a good detective, uses his or her judgment. Not all possibilities are worth considering, not because they are impossible, or because the evidence at hand rules them out, but because, given what we know about how the world works in general, they seem irrelevant and far-fetched. It's not reasonable to worry about far-fetched possibilities.
Scientists seek to predict and to explain; they build theories that organize a wealth of information and they try to do so in ways that are simple and coherent and believable. How do you decide when you've landed on the truth? The truth is not like gold, with its own immutable features. You recognize the truth of that which it would be unreasonable to doubt in light of the weight of the evidence.
Reasonableness, explanatory adequacy, predictive power, simplicity, coherence — these are values one-and-all. And they are the stuff of science. Disagreement between scientists can come down to values. It can come down to whether they feel satisfied that they got the story right.
And all the more so when skepticism about science from without comes into play. When scientists try to engage with climate-change deniers or with defenders of so-called "intelligent design," what is at stake are not the facts as much as the values. The skeptics simply reject the epistemic values of science. Their positions are unreasonable and unsupported. But this is not a matter of fact. It is a matter of value!
What is the moral? I think it would be a mistake to conclude that a recognition of what Putnam calls the entanglement of fact and value should force us to view science as no better than open-ended moralizing, mere assertions of what "we" think. The upshot, rather, is that we need to elevate our assessment of the nature of conflicts in the domain of value.
The fact that we lack ways of settling these conflicts once and for all does not mean that there is not progress to be made in thinking them through together.