Read Faith Versus Fact : Why Science and Religion Are Incompatible (9780698195516) Online
Authors: Jerry A. Coyne
While our view of the world is filtered through our senses, evolution has, by and large, molded those senses to perceive the world accurately, for there's a severe penalty to be paid for seeing things wrongly. That holds not only for the external environment, but also for the character of others. Without accurate perceptions, we couldn't find food, avoid predators and other dangers, or form harmonious social groups. And following those perceptions is indeed the pursuit of “true beliefs”: beliefs based on evidence. Natural selection doesn't mold true beliefs; it molds the sensory and neural apparatus that, in general, promotes the formation of true beliefs.
But of course we've seen that not all of our beliefs are true. That's because while natural selection has given us a pretty good truth-detecting apparatus, that apparatus can also be fooled, as in the checker-shadow illusion. And religion could be one of the false beliefs that piggybacks on evolution.
The anthropologist Pascal Boyer
, for instance, proposes that religion began with the inborn and adaptive tendency of our ancestors to attribute puzzling events to conscious agents. If you hear a rustle in the bushes, you're more likely to survive (or get food) if you believe it came from another animal than from a gust of wind. These beliefs about conscious agents in nature can easily be transferred to things like lightning and earthquakes. Because our ancestors lacked naturalistic explanations for such things, conjectures about supernatural humanlike beings or spirits might follow. Studies of child development suggest that religious beliefs are not inbornâthat we have no “God genes.” Rather, as Boyer and others suggest, our evolved cognitive apparatus gives us a
propensity
to accept religious propositions such as God, the afterlife, and the soul, and those specific beliefs are learned.
It's no surprise that children in southern India come to believe in multiple deities, while those in Alabama in the divinity of Jesusâobservations that directly contradict Plantinga's view that our
sensus divinitatis
was vouchsafed by the Christian God.
Rather, religion is likely to be
what Stephen Jay Gould and Elisabeth Vrba called an “exaptation”: a feature that, while sometimes useful, was not itself the object of natural selection, but piggybacked on features that evolved for other reasons.
All in all, there's no reason to see science as incapable of explaining why our beliefs about the world are often true. It also has plausible explanations for beliefs that are false, explanations far more credible than Plantinga's
view that our failure to detect truth indicates a
sensus divinitatis
broken by sin.
A related argument for God is that the human brain has abilities far beyond anything that would be needed by our African ancestors. We can build skyscrapers, fly to the Moon, cook elaborate dishes, and make (and solve) Sudoku puzzles. Yet such abilities could not possibly have been useful during nearly all of the period when our brain evolved. How then do we explain them? To some theologians, the answer is God.
As we learned earlier, the first one to raise this problem was the biologist Alfred Russel Wallace. Although a tireless and selfless promoter of evolution by natural selection (he called his book on the topic
Darwinism
), Wallace could not see how selection could produce the multifarious abilities of the human brain. Here's his argument, tinged with the paternalism of the nineteenth-century Englishman:
We see, then, that whether we compare
the savage with the higher developments of man, or with the brutes around him, we are alike driven to the conclusion that in his large and well-developed brain he possesses an organ quite disproportionate to his actual requirementsâan organ that seems prepared in advance, only to be fully utilized as he progresses in civilization. A brain slightly larger than that of the gorilla would, according to the evidence before us, fully have sufficed for the limited mental development of the savage; and we must therefore admit, that the large brain he actually possesses could never have been solely developed by any of those laws of evolution, whose essence is, that they lead to a degree of organization exactly proportionate to the wants of each species, never beyond those wantsâthat no preparation can be made for the future development of the raceâthat one part of the body can never increase in size or complexity, except in strict co-ordination to the pressing wants of the whole.
In short, the brain seems to defy the idea that natural selection can't prepare organisms for environments they've never encountered. As a result, Wallace concluded that evolution could explain everything but a single organ in a single species.
We'll see in a moment that science has long since disposed of Wallace's teleology, but the idea of the overengineered human brain is still with us. It is in fact touted by Plantinga, who argues that because evolution can't explain our ability to do complex mathematics and physics, those aptitudes also come from God:
These abilities far surpass
what is required for reproductive fitness now, and even further beyond what would have been required for reproductive fitness back there on the plains of Serengeti. That sort of ability and interest would have been of scant adaptive use in the Pleistocene. As a matter of fact, it would have been a positive hindrance, due to the nerdiness factor. What prehistoric female would be interested in a male who wanted to think about whether a set could be equal in cardinality to its power set, instead of where to look for game?
This passage, written 140 years after Wallace's, is eerily similar.
But in the time separating Wallace and Plantinga, we've come to understand a lot about evolution, and we know now that our overengineered brain is not a puzzle for science. It's certainly true that our brain wasn't molded by natural selection for future contingencies. That is indeed impossible under naturalism, and Plantinga is also correct that doing mathematics would not have improved the fitness of our preliterate ancestors. But once the human brain attained a certain state of complexityâand it has to be pretty complex to handle language and the skills of living in bands of hunter-gatherersâit already had the ability to perform novel tasks that had nothing to do with evolution. Likewise, a computer designed to do certain things can, when its hardware becomes sufficiently complex, do things never envisioned by its maker.
Lest you think that this answer is special pleading, realize that similar phenomena occur in many animals. Crows, for instance, can use reason to solve complicated puzzles designed by humans (of course, there must be a food reward at the end). Parrots can imitate human speech, and even sing opera arias, while lyrebirds can imitate chain saws and car alarms. These talents are by-products of skills acquired for living in nature. Species often solve novel problems never encountered in nature, like the famous blue tits
of Britain, who learned in the 1920s to open milk bottles delivered to doorsteps and guzzle the cream from the top. Chimpanzees have learned to crack nuts with rocks, to “fish” for termites by dipping chewed grass stems into the nest entrances, and to make sponges out of masticated leaves to soak up drinking water.
None of these behaviors could have been direct objects of natural selection; all were side effects of
other
aspects of the brain and body that were presumably the result of natural selection. If the human brain was overdesigned, then so were the brains of other animals, including our closest living relatives. That is no problem for biology, but it is for theists who claim that the
human
brain was uniquely overdesigned by a godâprobably to apprehend and worship that god.
Before we leave this topic, it's worth noting that science is actually the best way to
correct
our false beliefs: beliefs that severed tetherballs fly away in spirals or that the Sun literally rises and sets. The elaborate cross-checking and doubt that pervade science, and the complicated instruments we've devised to supplement our senses, are all tools designed to check which of our beliefs are true.
All knowledge that is not the genuine product of observation
, or of the consequence of observation, is in fact utterly without foundation, and truly an illusion.
âJean-Baptiste Lamarck
One of the most common complaints of accommodationists and critics of “scientism”âthe supposed overreaching of scientists that we'll discuss shortlyâis that science has no monopoly on finding truth. In
The Language of God: A Scientist Presents Evidence for Belief,
Francis Collins asserts that “
science is not the only way of knowing
.” The next sentence gives his alternative: “The spiritual worldview provides another way of finding truth.”
But these “other ways of knowing,” as they're commonly called, include more than spirituality and religion. Additional candidates are the humanities,
social science, art, music, literature, philosophy, and mathematics. The whole panoply of “other ways” is touted not just by advocates of the humanities defending their bailiwick, but also by theists who want to use their own “ways of knowing”âfaith, dogma, revelation, scripture, and authorityâto buttress their claims about the divine.
I will argue that insofar as some of these disciplines can indeed yield knowledge, they do so only to the degree that their methods involve what I'll describe as “science broadly construed”: the same combination of doubt, reason, and empirical testing used by professional scientists. Economics, history, and social science, for instance, can certainly yield knowledge. But religion doesn't belong in these ranks, for its “ways of knowing” can't tell us anything with assurance.
To evaluate any of these claims, we'll first need to define “truth” and “knowledge,” which I'll admit can be tricky, for these concepts are historically mired in philosophical controversy. For consistency, I'll again use the
Oxford English Dictionary
's definitions, which correspond roughly to most people's vernacular use. “Truth” is “conformity with fact; agreement with reality; accuracy, correctness, verity (of statement or thought).” Because we're discussing facts about the universe, I'll use “fact” as Stephen Jay Gould defined “scientific facts”: those “
confirmed to such a degree
that it would be perverse to withhold provisional assent.” Note that these definitions imply the use of
independent
confirmation
âa necessary ingredient for determining what's realâand
consensus,
that is, the ability of any reasonable person familiar with the method of study to agree on what it confirms. Mormons confirm the verities of their faith by revelation and authority, but everyone else, including members of other faiths, withholds their assent. That's simply because there are no widely accepted observations that confirm Mormon dogma. It therefore fails to qualify as truth, scientific or otherwise. Finally, “knowledge” is simply the public acceptance of facts; as the
Dictionary
puts it, “The apprehension of fact or truth with the mind; clear and certain perception of fact or truth; the state or condition of knowing fact or truth.” What is true may exist without being recognized, but once it is it becomes knowledge. Similarly, knowledge isn't knowledge unless it is factual, so “private knowledge” that comes through revelation or intuition isn't really knowledge, for it's missing the crucial ingredients of verification and consensus.
According to these criteria, science certainly finds truths and yields knowledge, for it includes not only procedures for generating theories about the universe, but the testability and repeatability that bringsâor erodesâconsensus. The consensus need not be
absolute:
there are a very few scientists who reject the truth of evolution. And there are still people who believe that the Earth is flat. But the rejection of evolution almost invariably rests on religious grounds, and the rejection of a round Earth is based on a kind of fanaticism that's blind to all evidence. While I'd hesitate to call these people “perverse,” I'd certainly call their behavior irrational.
As I've noted, the conceptual tools of science (though not the title of “scientist”) are available to everyone. I see science as a method, not a profession. Science construed in this broad way embraces all acts, including those of plumbers and electricians, that involve making and testing hypotheses. Indeed, that's exactly what we do when fixing our cars or trying to find lost objects by retracing our steps rather than looking elsewhere or praying for the answer. Any discipline that studies the universe using the methods of “broad” science is capable in principle of finding truth and producing knowledge. If it doesn't, no knowledge is possible.
Valid “ways of knowing,” then, certainly include history, archaeology, linguistics, psychology, sociology, and economics, all of which, to greater or lesser degrees, use the methods of science. Historians, for instance, verify that Julius Caesar existed not only from the evidence of his own writings, but from writings by others, including contemporaries, who give consistent accounts, as well as from coins and statues made during his time. Holocaust denial, based largely on wish-thinking, has been refuted both in the courts and by historians armed with empirical evidence: interviews with survivors, guards, locals, and camp officials (and the agreement between their accounts); photographs of gas chambers and of the “selection” process at concentration camps; remains of the camps themselves; official Nazi documents; and population studies showing a severe attrition of European Jews during World War II. The evidence for a planned extermination of Jews, Romanis (“Gypsies”), gays, and others is so strong that Holocaust denialists can be classified as “perverse” under Gould's definition.
The social sciences are a bit less “scientific,” because until recently the culture of these areas was less influenced by hard science, and the analyses
and conclusions are usually still far less rigorous than those of, say, chemistry or biology. Nevertheless, sociologists can make testable predictions using lab studies or observations. One verified prediction (we could cite Marx as the source) is that decreasing the equality of income among members of a population will make it more religious. Psychologists often do experiments that are in every sense scientific: controlled, replicated, and analyzed statistically. And although economics is called the “dismal science,” it becomes less so when conducting experiments about human greed or generosity, as in “behavioral economics,” the field that fuses psychology and economics. Because microeconomic theories are hard to testâsocieties aren't often replicatedâthis area is perhaps the least scientific of the social sciences.
Nevertheless, microeconomics has produced
knowledge, including the shapes of supply and demand curves, the diminishing marginal utility of goods as they accumulate (the more doughnuts you have, the less you want another), and the relatively small effect on unemployment rates of extending unemployment benefits.