But despite these claims, the dust hasn’t settled. Why do 55 percent of Americans aver that “science and religion are often in conflict”? Why are less than 10 percent of all Americans agnostics or atheists, yet that proportion rises to 62 percent of all scientists at “elite” universities, and to 93 percent among members of the National Academy of Sciences? I consider these questions and more in my latest book, Faith vs. Fact: Why Science and Religion Are Incompatible.
My conclusion: the conflict between science and religion is deep, endemic, and unlikely to be resolved. For this conflict is one between faith and fact—a battle in the long-fought war between rationality and superstition.
The friction exists because science and religion are both in the business of determining what is true in the universe—although religion has other concerns as well. Science’s ambit is well known, but it’s important to realize that religion also depends heavily on claims about what is true: claims about the existence, number, and nature of gods, what behavior one’s god commands, the occurrence of miracles, and whether there are eternal souls, untrammeled free will, and afterlives.
But while science and religion both claim to discern what’s true, only science has a system for weeding out what’s false. In the end, that is the irreconcilable conflict between them. Science is not just a career or a body of facts, but, more important, a set of cognitive and practical tools designed to understand brute reality while overcoming the human desire to believe what we like or find emotionally satisfying. The tools include observing nature, peer review, independent replication of results, and above all, the hegemony of doubt and criticality. The best characterization of science I know came from physicist Richard Feynman: “The first principle is that you must not fool yourself—and you are the easiest person to fool. So you have to be very careful about that.”
In contrast, religion has no way to adjudicate its truth claims, which rest on ancient scripture, revelation, dogma, and above all, faith: belief without strong evidence. The problem, of course, is that faith is no way to decide what’s true. It is, à la Feynman, an institutionalized way of fooling yourself. The toolkit of science is—and will remain—the only way to discover what’s real. Religion can offer communality and can buttress morality, but has no purchase on truth.
But even if science and religion are incompatible, what’s the harm? Most of the damage comes from something inherent in many faiths: proselytizing. If you have a faith-based code of conduct attached to beliefs in absolute truths and eternal rewards and punishments, you’re tempted to impose those truths on others. The most obvious subjects are children, who are usually indoctrinated with their parents’ brand of faith. That can cause real physical harm: 43 of 50 US states, for instance, have codified legal protections for parents who harm their sick children by rejecting science-based medicine in favor of faith healing. Forty-eight of our 50 states allow religious exemptions from vaccination. The results are predictable: children needlessly become sick, and some die. And we in America are familiar with religious incursion into the public sphere, such as the persistence of creationism in schools.
In the end, in both science and everyday life, it’s always good policy to hold your beliefs with a tenacity proportional to the evidence supporting them. That is the foundation of science and the opposite of religion. As the philosopher Walter Kauffman noted, “Belief without evidence is not a virtue, but opens the floodgates to every form of superstition, prejudice, and madness.”
Jerry A. Coyne is a professor of ecology and evolution at the University of Chicago. His 2009 best-seller, Why Evolution Is True, was one of Newsweek’s “50 Books for Our Time.” Read an excerpt of Faith vs. Fact: Why Science and Religion are Incompatible.