Not among the believers.
Daniel Dennett, Professor of Philosophy and Director of the Center for Cognitive Studies at Tufts University, in his office on campus. (© Rick Friedman)
WHEN THE philosopher Daniel Dennett was a teenager, he played the backwoods holy man Elijah in his prep school's production of ''Inherit the Wind." ''Bearded, wild-haired, dressed in a tattered burlap smock," Elijah comes down from the hills, on the eve of Bert Cates's trial for teaching evolution, to sell Bibles out of an old vegetable crate. ''Are you an evolutionist? An infidel? A sinner?" Elijah asks an out-of-town newspaperman.
Until he went to graduate school, Dennett claims, the play, famously based on the 1925 Scopes ''monkey trial," was the source of most of what he knew about evolution and natural selection. Today Dennett has a prophet's beard, one corner of which he will sometimes fold into his mouth for a ruminative chew, and he is one of Darwinian theory's foremost promoters. He sees it not just as an explanation for the origin of species, but for the fundamental whys and hows of human habits, beliefs, thinking, and desires. The logic of evolution, Dennett wrote in his 1995 book ''Darwin's Dangerous Idea," is a ''universal acid," it ''eats through just about every traditional concept, and leaves in its wake a revolutionized worldview."
A month ago, when federal Judge John E. Jones III ruled that intelligent design could not be taught in a Pennsylvania school district, scientists and secularists celebrated the decision as a victory not only for the separation of church and state, but of church and science. A few editorials quoted Harvard evolutionary biologist Stephen Jay Gould's argument that science, concerned as it is with facts, and religion, concerned with human purposes and values, were ''Non-Overlapping Magisteria," separate sources of authority that could exist in ''respectful noninterference." Judge Jones himself took pains to emphasize that the theory of evolution ''in no way conflicts with, nor does it deny, the existence of a divine creator."
Daniel Dennett, however, is no great believer in respectful noninterference, and in his new book, ''Breaking the Spell: Religion as a Natural Phenomenon" (Viking), he argues vehemently against it. Religion, Dennett says, is human behavior, and there are branches of science to study human behavior. ''Whether or not [Gould] was right," Dennett told me in his office at Tufts University, where he is director of the Center for Cognitive Studies, ''and I don't think he was, I'm not making a claim that he would disagree with. I'm not saying that science should do what religion does. I'm saying science should study what religion does."
The argument that religion can be explained as a natural rather than a supernatural phenomenon is not new. The Scottish philosopher David Hume set himself a similar task over 250 years ago. Marx and Freud had their own explanations. Over the years, scholars have enlisted everything from rational choice theory to brain scans in their efforts to trace the origins of faith.
Dennett himself is not a researcher, nor is his book a sustained argument for any one theory. His primary role, as he sees it, is to be as much a standard-bearer as a thinker, introducing the world to the work of scholars who, in sometimes conflicting ways, are setting out to explain the workings of belief.
Dennett opens his book by comparing religion to a parasite. The lancet fluke is a microorganism that, as part of its unlikely life cycle, lodges in the brain of an ant, turning it into a sort of ant zombie that every night crawls to the top of a blade of grass and waits to get eaten by a grazing cow or sheep, in whose liver the lancet fluke can propagate. Dennett is being provocative, but he is also making a point: Certain religious behaviors-abstinence, for example, or martyrdom, or ritually sacrificing livestock in the middle of a famine-can look decidedly, almost inexplicably, irrational both to nonbelievers and behavioral scientists, so much so that it might be worth asking who or what is actually benefiting from them.
Until a few decades ago, the assumption in much social science research was that religion was the product of ignorance: Unfamiliar with the germ theory, primitive tribes believed that vengeful spirits brought disease; lacking an education, the farmboy believed in the virgin birth. In a world of increasing technological and educational advancement, the influential anthropologist Anthony Wallace wrote in 1966, ''the evolutionary future of religion is extinction. Belief in supernatural beings and in supernatural forces that affect nature without obeying nature's laws will erode and become only an interesting historical memory."
In the intervening years, of course, religion has not gone extinct-by most measures the United States is a more religious country than it was 40 years ago-and social scientists have started to take another look at it. Dennett's new book is concerned primarily with this more recent work, in which a new generation of researchers have begun to suggest that religion may be neither a matter of revealed truth nor willed ignorance, but something a bit more complicated.
Several of these new theories enlist Darwin. David Sloan Wilson, a professor of anthropology and biology at Binghamton University, is a leader of the ''functionalist" school. His argument, which borrows from the early French sociologist Emile Durkheim, is simple: Religion evolved because it conferred benefits on believers. In terms of natural selection, human groups that formed religions tended to outcompete those that didn't, surviving longer and propagating more. Calvinism brought social cohesion to 16th-century Geneva, the ''water temple" system on Bali coordinates the island's complex irrigation scheme.
''There are practical benefits that are shortchanged when most people think about religion," Wilson told me. In a way, ''religion is basically providing the kinds of services we always associate with a government."
Rodney Stark, a sociologist at Baylor University, has for years been applying basic economic theory to religious behavior. Wilson describes religion as an evolved behavior, often followed reflexively. For Stark, on the other hand, ''We're thinking beings. People think about these things in the same way we think about getting married, or buying cars." People join and remain in religious communities because for them the benefits-the sense of purpose, support and camaraderie-outweigh the costs. In his model, churches are like corporations, marketing a suite of services and competing for customers. An evolutionary explanation for religion, he says, ''isn't any more necessary than finding a gene for algebra."
But there's a difference between deciding to believe something and actually believing it. A starving person could no doubt make herself feel better by believing she's just eaten, the Harvard psychologist Steven Pinker has pointed out, but it's probably not something she can convince herself of for long. Plus, as Pinker recently put it to me, cost-benefit analyses involving religion would have to factor in, as a benefit, some form of spiritual satisfaction, but ''the fact that people get some sort of spiritual payoff is exactly the phenomenon we need to explain" in the first place.
As for Wilson, Dennett notes that his theories ''have found very little support." Most evolutionary biologists are suspicious of Wilson's idea of ''group selection," arguing that it makes more sense to understand human and animal behavior in terms of individuals, or, better yet, individual genes, competing for reproductive success-sometimes in a way that benefits the group, sometimes not. By this logic, one should look at the value of religion for the individual. Nicholas Humphrey, a psychologist at the London School of Economics, has suggested that religious conviction might have a placebo effect for believers, helping them fight off diseases to which they might otherwise succumb.
Skeptics of both functionalist and economic explanations point out that neither has much to say about the spiritual aspects of the world's religions. Nearly all religions, for example, have some idea of a soul, and, to some extent, a faith in supernatural beings. But it's unclear what evolutionary purpose these beliefs serve. Plus, as Scott Atran, a cognitive anthropologist and psychologist with joint appointments at the University of Michigan and the Centre National de la Recherche Scientifique, in Paris, argues, ''Christianity sometimes served the elites, sometimes the downtrodden, depending on what time period and what country. Sometimes it stimulates creativity, sometimes it fosters ignorance." Christianity, in other words, hasn't had any single ''function" over the course of its history.
Atran is one of the leading thinkers putting forward an alternate theory, in which religion is, as Yale psychologist Paul Bloom puts it, ''an accidental byproduct of stuff that is part of human nature." Religion, in this account, didn't arise because it served any purpose, but because the human brain is amenable to certain supernatural ideas. As social animals, we evolved to be acutely sensitive to the intentions of others, so much so that we are prone to see intention and agency where it doesn't exist-in things that go bump in the night or the way tea leaves settle. This makes a certain evolutionary sense: In a prehistoric, pre-scientific society, not paying attention to a rival's (or, for that matter, a mate's) state of mind carried a high cost. Believing in ghosts carried little.
Work by Bloom and other cognitive scientists has emphasized the human preference for intentional rather than merely mechanical explanations. Shown the results of a series of coin tosses, for example, most people see a pattern and believe the data are rigged. Research by the psychologists Deborah Kelemen, of Boston University, and Margaret Evans, of the University of Michigan, suggest that children, no matter what kind of explanation their parents provide them, tend to intuit some being who has created aspects of the world for certain purposes: clouds are ''for raining," mountains ''for climbing," lions ''for to go in the zoo."
If the proponents of the byproduct explanation are right, belief in supernatural beings and forces is likely to persist even in the face of countervailing information. As Bloom wrote in an article last month in The Atlantic Monthly, for most people the problem with natural selection, for example, is not simply that it conflicts with the text of the Bible, but ''that it makes no intuitive sense."
''It is like quantum physics; we may intellectually grasp it," he wrote, ''but it will never feel right to us. When we see a complex structure, we see it as the product of beliefs and goals and desires. Our social mode of understanding leaves it difficult for us to make sense of it any other way."
As for Dennett, he thinks the effort to identify any one cause for religion may be reductive. In ''Breaking the Spell" he takes a stab at reconciling rational and pre-rational, individual and group explanations under the umbrella of ''meme" theory. Memes, an invention of the British biologist Richard Dawkins, are gene-like units of culture that proliferate, virus-like, using human minds as carriers: a preference for a certain brand of sneakers, say, or the opening bars of Beethoven's 5th Symphony, or, in Dennett's version, an article of faith like the belief in reincarnation. Dennett is one of the idea's few serious proponents.
Ultimately, though, Dennett just wants people to question religion; he's less concerned with how they do it. ''There are a lot of ill-explored claims made on behalf of religion," he told me. ''Is religion good for your health? The evidence there seems to be yes. Does religion make you more moral? The evidence there seems to be no. The prison population of the United States is not statistically different in its religious makeup from the larger population." (This last claim is also in his book, though goes un-footnoted.)
Dennett, an outspoken atheist, insists in conversation that he is ''genuinely agnostic, not lip-service agnostic, about whether the world would be a better place without religion than it is." Yet his feelings about religion are not hard to determine. ''History gives us many examples of large crowds of deluded people egging one another on down the primrose path to perdition," he writes.
David Sloan Wilson has talked with Dennett at length about evolution and human behavior. ''I have the highest respect for Dan," he says. But Dennett's condescension toward religion-it can seem as if he's a Victorian explorer who has stumbled upon a tribe of self-mutilating animist cannibals-troubles Wilson. ''What evolutionist would make a value statement about the organism that they study, even if it's a horrible organism like the AIDS virus or the great white shark?" To do so distorts science into polemic, and runs the risk of making Dennett sound less like a philosopher and more like a prophet.
Drake Bennett is the staff writer for Ideas. E-mail email@example.com.