Last month, Scott Walker, the governor of Wisconsin and a presumed Presidential candidate, delivered an address at Chatham House, an international-affairs think tank in London. For Walker, the point of the address was to bolster his foreign-policy credentials. That’s probably why the last question—“Are you comfortable with the idea of evolution?”—took him by surprise. “I’m going to punt on that one,” he said.

It’s obvious why politicians avoid the evolution question. A large fraction of the population—including more than fifty per cent of Republican voters—doesn’t believe in it. But politicians aren’t the only ones who punt. When it comes to questions that confront religious beliefs, many scientists and teachers do it, too. Recent studies—including a comprehensive national survey by researchers at Penn State University, in 2007—show that up to sixty per cent of high-school biology teachers shy away from adequately teaching evolution as a unifying principle of biology. They don’t want to risk controversy by offending religious sensibilities. Instead, many resort to the idea, advocated by the late Stephen Jay Gould, that science and religion are “non-overlapping magisteria”—separate traditions of thinking that need not contradict one another._

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“Non-overlapping magisteria” has a nice ring to it. The problem is that there are many religious claims that not only “overlap” with empirical data but are incompatible with it. As a scientist who also spends a fair amount of time in the public arena, if I am asked if our understanding of the Big Bang conflicts with the idea of a six-thousand-year-old universe, I face a choice: I can betray my scientific values, or encourage that person to doubt his or her own beliefs. More often than you might think, teaching science is inseparable from teaching doubt.

Doubt about one’s most cherished beliefs is, of course, central to science: the physicist Richard Feynman stressed that the easiest person to fool is oneself. But doubt is also important to non-scientists. It’s good to be skeptical, especially about ideas you learn from perceived authority figures. Recent studies even suggest that being taught to doubt at a young age could make people better lifelong learners. That, in turn, means that doubters—people who base their views on evidence, rather than faith—are likely to be better citizens.

Last year, writing in the Times, the political scientist Brendan Nyhan explained how “identity often trumps the facts.” We would rather reject evidence than change our sense of who we are. Knowledge is comparatively helpless against identity: as you grow better-informed about the issues, you just get better at selectively using evidence to reinforce your preëxisting commitments. A 2014 Yale Law School study, for example, demonstrated that the divergence between religious and non-religious peoples’ views on evolution actually grows wider among those who are familiar with math and science. Describing Nyhan’s work for this Web site, Maria Konnikova summarized his findings by writing that “it’s only after ideology is put to the side” that the facts become “decoupled from notions of self-perception.” One conclusion we might draw is that we ought to resist ideology in the first place. If we want to raise citizens who are better at making evidence-based judgments, we need to start early, making skepticism and doubt part of the experience that shapes their identities from a young age.**

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Meanwhile, earlier this year, an AP-GfK poll revealed that less than a third of Americans are willing to express confidence in the reality of human-induced climate change, evolution, the age of the Earth, and the existence of the Big Bang. Among those surveyed, there was a direct correlation between religious conviction and an unwillingness to accept the results of empirical scientific investigation. Religious beliefs vary widely, of course—not all faiths, or all faithful people, are the same. But it seems fair to say that, on average, religious faith appears to be an obstacle to understanding the world.

Science class isn’t the only place where students can learn to be skeptical. A provocative novel that presents a completely foreign world view, or a history lesson exploring the vastly different mores of the past, can push you to skeptically reassess your inherited view of the universe. But science is a place where such confrontation is explicit and accessible. It didn’t take more than a simple experiment for Galileo to overturn the wisdom of Aristotle. Informed doubt is the very essence of science.

Some teachers shy away from confronting religious beliefs because they worry that planting the seeds of doubt will cause some students to question or abandon their own faith or the faith of their parents. But is that really such a bad thing? It offers some young people the chance to escape the guilt imposed upon them simply for questioning what they’re told. Last year, I received an e-mail from a twenty-seven-year-old man who is now studying in the United States after growing up in Saudi Arabia. His father was executed by family members after converting to Christianity. He says that it’s learning about science that has finally liberated him from the spectre of religious fundamentalism. The same week, I received an e-mail from a young man who lives in Indiana; he feels isolated and damaged because of the reaction of his friends and family to his rejection of religion and his love of science. I get e-mails like this regularly. We owe it to these young people to help them feel, as another young letter-writer put it, that “I’m not the only one who has these thoughts.”

Religious fundamentalism exists closer to home than you might imagine**.** Consider Roy Moore, the chief justice of the Alabama Supreme Court, famous for refusing to remove the Ten Commandments from his courtroom wall: in a recent speech, he declared that the First Amendment only applies to Christians. Or consider the new freshman class in the House of Representatives: it includes Jody Hice, a man who claims that “blood moons” are fulfilling Biblical prophecies. In a recent decision, Pope Francis officially recognized, under canon law, the International Association of Exorcists. He called exorcism “a form of charity.” (When I tweeted about the decision, another user pointed out that the policy must be working—after all, no one has seen any demons recently.)**

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A new generation is always more comfortable dispensing with old ideas than are its predecessors; in this sense, we are never more than a generation away from altering long-held beliefs. The battle for gay marriage, for instance, has already been won because it is simply a non-issue for young people. Is it naïve to imagine that we can overcome centuries of religious intransigence in a single generation through education?

One thing is certain: if our educational system does not honestly and explicitly promote the central tenet of science—that _nothing _is sacred—then we encourage myth and prejudice to endure. We need to equip our children with tools to avoid the mistakes of the past while constructing a better, and more sustainable, world for themselves and future generations. We won’t do that by dodging inevitable and important questions about facts and faith. Instead of punting on those questions, we owe it to the next generation to plant the seeds of doubt.