Free The Canon by Natalie Angier

become more precise, more sophisticated, the absolutes become less absolute." In other words, by accepting that they can never
know
the truth but can only approximate it, scientists end up edging ever closer to the truth. The tonic surgery of chronic uncertainty.
    For those outside the operating theater, however, all the quarreling, the hesitation, the emendations and annotations, can make science sound like a pair of summer sandals. Flip-flop, flip-flop! One minute they tell us to cut the fat, the next minute they're against the grains. Once they told us that the best thing to put on a burn was butter. Then they realized that in fact butter makes a burn spread; better use some ice instead. All women should take hormone replacement therapy from age fifty onward. All women should
stop
taking hormone therapy right now and never mention the subject again. Didn't scientists predict in the 1960s that a population bomb was about to explode, and that we'd all die of starvation or crowd rage? Now demographers in developed countries fret that women aren't breeding fast enough to restock the tax
base and that nobody will be around to pay tomorrow's nursing home bills. Why should we believe anything scientists say? For that matter, why should we do anything that scientists suggest, like thinking about global climate change and the inevitable depletion of Earth's fossil fuels and adjusting our energy policies accordingly? That's what scientists say today. But if I hang on to my Hummer long enough, hey, maybe they'll decide that extravagant plumes of exhaust fumes are good for the environment after all!
    This is one of science's bigger public relations problems. How do you convey the need for uncertainty in science, the crucial role it plays in nudging research forward and keeping standards high, without undermining its credibility? How can you avoid the temptations of dogmatism and certitude without risking irrelevance? "People need to understand that science is dynamic and that we do change our minds," said Dave Stevenson. "We have to. That's how science functions.
    "Part of critical thinking," he added, "includes the understanding that science doesn't deal with absolutes. Nonetheless, we can make statements that are quite powerful and that have a high probability of being correct."
    One trick to critical thinking is to contrast it with cynicism, which happens to be one of my most comfortable and least welcome of mental states. Cynics dismiss all offerings, sight unseen, data unmulled. Another drug that cures breast tumors in mice? Go tell it to Minnie. The fossil of a new dinosaur species disinterred? I can hear Stephen Jay Gould grumbling from the great beyond: Dinosaurs are a cliché. Preemptive cynicism may be rooted in insecurity, defensiveness, a gloomy disposition, or simple laziness; whatever its cause, it is useless.
    Deborah Nolan of the University of California, Berkeley, encounters it constantly in her introductory statistics course—the slapdash bashing, the no-it-all choir. She confronts cynicism calmly and strives to replace it with hard-nosed thought. Each semester she'll present her students with newspaper stories that describe an array of medical, scientific, or sociological studies: Should victims of gunshot wounds be resuscitated by the paramedics in the ambulance, through drugs delivered intravenously, or is it better to wait until they get to the hospital? Does a surgeon perform better while listening to music in the operating room, or not? Does the mental well-being of a mother have a greater impact on her interaction with an infant, or with a toddler? Nolan will ask the students for their impressions of the articles. Regardless of the subject matter, or whether the students are majoring in science, the liberal arts, or hotel management, their initial response is the same: a synchronized sneer. You can't believe what you read in the newspapers, they'll insist. Nolan asks them what, precisely, they don't