The world appears suddenly engulfed in an epidemic of uncertainty. Uncertainty plagues banks and the economy, the Middle East, elections in the U.S. and other countries, the Euro, and the weather, of course. But now it has cropped up in a most unexpected place: science.

Wasn’t science immune to uncertainty, with its measurements of things like the weight of an electron out to 8 or so decimal places? In fact wasn’t science actually in the business of getting rid of uncertainty, of rooting it out and disposing of it? Get some data, do some calculations, get the computer to run a new algorithm and wait for the answer to come rolling out the other end of the hopper. Science got answers.

#### Stuart Firestein ##### About Stuart Firestein studies the vertebrate olfactory system at Columbia University, where he is Chair of the Department of Biological Sciences. His laboratory seeks to answer that fundamental human question: How do I smell? Firestein serves as an adviser for the Alfred P. Sloan Foundation’s program for the Public Understanding of Science. He is the author of a book on the workings of science for a general audience called *[Ignorance, How It Drives Science](http://ignorance.biology.columbia.edu/)*.

Suddenly, with a few leaked emails between climate scientists and some ugly reports on drug trials with ambiguous results – and a very savvy PR machine at work among certain special interests – we are being treated to the unsettling sight of uncertain scientists – scientists who say things like, “Well, we can’t be sure beyond this stage which way things will go,” or, “Our models don’t predict things reliably at this point; we need more data and it’s difficult to get this data," and so forth.

Is something wrong here? Is science running out of gas? Not at all. In fact, science is doing just as it has always done; it is we who are trying to make it something it is not. The public view of science as an ever-expanding edifice of knowledge, of an encyclopedic accumulation of facts, is both new and wrong. Science is, and always has been, about doubt, uncertainty – what the 18th century physicist James Clerck Maxwell called “thoroughly conscious ignorance.”

Of course scientists do experiments and amass data, but the purpose of this data is to frame better questions, it is not an end in itself. Identifying DNA as the hereditary molecule was a tremendous advance, but it served mostly to provide the next 60 plus years of biological research with more and more refined questions about inheritance, evolution, speciation, extinction and a host of detailed inquiries in fields from immunology to neurobiology.

Science often traffics in doubt and readily welcomes revision. And these are precisely the attributes that make it deserving of our confidence. This may seem contradictory, but give it a second thought. It is just those systems of thought that would have us believe that they know the answers with certainty because they have been received from an unerring supreme being and interpreted by a chosen priesthood, that should give us pause. Creation myths from the ancient Greeks to the Old Testament give complete descriptions of how the universe was created. No doubt there. Alternatively, science – cosmology, geology, archaeology, biology – give incomplete descriptions filled with open questions. Which would you prefer to use?

Revision is a victory in science, and that is precisely what makes it so powerful.

But this strategy of skepticism, this healthy appreciation of the current state of ignorance, this triumph of revision over the doctrinaire, can be abused and misinterpreted in dangerous ways that wrongly and treacherously undermine the validity of scientific knowledge. When a scientist expresses less than certitude, often the only honest response she can make, then this opens the door for all the charlatans and special interests who aren’t happy for one or reason or another with where the existing evidence is clearly pointing. So we get doubters of evolution and vaccinations, doubters of climate change and the health dangers of tobacco, proponents of all sorts of quackery and foolish notions about terrorist attacks and hurricanes being due to God’s unhappiness with homosexuals living in our midst.

My colleague, astronomer David Helfand, traces how our view of bad weather has evolved from the primitive to the scientific: beginning with “the wind is angry,” followed by “the wind god is angry,” and finally “the wind is a measurable form of energy.” The first two statements provide a complete explanation but have no useful information; the third admits of our ignorance (we can’t predict or alter the weather yet) but is surely more valuable.

What is the public to do with this sort of informed ignorance when decisions have to be made – hard decisions about climate change and therapeutic stem cells and nuclear energy and genetically fortified crops? The answer is simple, but the practice of it more difficult. Erwin Schrodinger, the brilliant physicist and philosopher said, in 1948, “In an honest search for knowledge you quite often have to abide by ignorance for an indefinite period.” Abiding by ignorance is an attitude that does not come easily.

Our brains are not wired for ambiguity, for shades of grey, if you will. You can experience this personally in the variety of popular visual illusions, known as ambiguous figures, which can be seen in more than one way. The Necker cube is a line drawing of a three dimensional cube that sometimes is seen as coming toward the viewer and sometimes away; the black Greek vase that can also be seen as two white facial silhouettes; the picture of the old hag/young woman. These are all examples of ambiguous figures because they can be viewed in at least two ways. The key observation though is that you can never see both possibilities at once, they seem to flip instantaneously from one to the other. Your brain does not like ambiguity and so it simply jumps from one solution to the other, never resting in a transitional undecided place.

That’s fine if you’re nomading around the savannah, and you think you see a tiger using his stripes to hide in the bushes or what might be a tasty brown rabbit trying to blend in with the underbrush. Deliberation may not be the best strategy in these situations. But in a modern day supermarket with packed shelves, a little deliberation about what food ingredients you want to put into your kids is a good thing, even if all the facts about them are not perfectly known and seem to change weekly.

Let’s take the case of the climate and global warming. The science, as far as it goes, is clear, but then we reach a patch where we’re still building the road. The temperature of the atmosphere is unquestionably rising, probably about 2 or so degrees, and the cause of this is clearly human activity, especially the stuff that burns up carbon. But neither the effects of this nor the proper response to it are at all clear. It may be a disaster, or it may not be much more severe in effect than other historical climate changes (which we only know a limited amount about); it may be best to limit carbon usage severely or it may be best to develop technologies for trapping CO2.

Those decisions have political, economic and social costs associated with them and this is part of the calculus. But it is downright stupid to let the current uncertainty about the science deter us from action, and it is downright dangerous when agents with financial agendas try to cast doubt on the value of science. They are more than welcome to present their economic arguments, but they cannot be allowed to confuse the public about the science for their personal benefit.

And just in case anyone reading this thinks that I am making a political case against right wing political operatives, I can readily make the same arguments against those on the left who seek to block the research and production of genetically modified crops, which have the potential to feed millions of starving people, by using specious arguments about the science being incomplete. The science, while not complete, is in fact quite sophisticated; the contestable issues have come down to social viewpoints and vague notions about what’s “natural.” Partisans are welcome to argue the various sides of those issues, but they are being deceitful when they use a researcher’s expressions of honest doubt about a particular detail to suggest that the science is unreliable.

We no longer live in the midst of predatory animals and we are no longer dependent on hunting and gathering. We live in a complex world that depends on sophisticated scientific knowledge. That knowledge isn’t perfect and we must learn to abide by some ignorance and appreciate that while science is not complete it remains the single best method humans have ever devised for empirically understanding the way things work. And most importantly it will get better – because that’s what science does and has always done.

Image: Lawrence Berkeley Laboratory