Faith Versus Fact : Why Science and Religion Are Incompatible (9780698195516) (29 page)

There are several ways. One is simply the “expanding circle”: a feeling of innate empathy we develop at the plight of strangers. In many cases, such as those of the firefighters and Skutnik, the altruist doesn't know for sure he'll be killed, for otherwise there's no reason to attempt a rescue. In cases like the grenade scenario, everyone is going to be killed anyway, and the sacrificial act may simply have piggybacked on our evolved tendency to help those with whom we're intimately familiar. It's no accident that soldiers who put their lives on the line for their fellows often call them “brothers.”

The nonadaptive hijacking of sentiments that have evolved for other reasons is not rare. Animals that have their own litters will often adopt members of another species.
I've just seen a video
of a mother farm cat suckling a brood of ducklings along with her own litter. It's gone viral because it's so adorable, but there's a biological lesson here: when maternal hormones kick in, you might foster an animal that's not even of your own species, much less your own brood. This happens because the “adoption” option simply
isn't common in nature, and natural selection has operated to promote the suckling of infants that happen to be nearby—which are almost invariably your own.

Such hijacking also occurs in wild species. Cuckoo birds are “nest parasites” that lay their eggs in the nests of other species. The young cuckoos then proceed to kill the host's own offspring, and the unrelated foster parents continue to feed the young cuckoos until they fledge. This grisly tactic is clearly adaptive for cuckoos: by never having to feed their own young, they get permanent babysitters and can have dozens of offspring, all raised by others. But it's very maladaptive for the host birds, who gain no benefit from raising a member of another species, and indeed, lose all their own offspring. The host's maternal instincts have simply been hijacked by cuckoos, and haven't counterevolved to recognize their strange offspring. If this happened in humans—and it does, in the case of people who adopt unrelated children—it would be seen as a case of extreme biological altruism. Yet nobody has argued that the “altruism” of cuckoo hosts, or the phenomenon of cats suckling ducklings, is inexplicable by science and therefore constitutes evidence for God.

In the end, there are ample secular explanations for altruism. While some of our moral sentiments surely derive from evolution in our ancestors, they are refined and expanded through culture: learning and communication. The genetic evidence comes from comparative work on other species, as well as studies of human infants. The cultural evidence, on the other hand, comes from seeing how many moral sentiments are learned, how variable they are across societies (even though readily instilled into infants adopted cross-culturally), and how much they have changed in just the past few centuries. In many ways human morality resembles human language: we're born with the propensity to acquire both, but the specific moral views we adopt, like the specific language we learn to speak, depend on the culture in which we're raised.

So while morality may seem “innate,” at least in adults, that is easily explained as a result of genetic endowment modified by cultural indoctrination. Given that this “Moral Law,” as Francis Collins puts it, does not defy science and psychology, there is no need to invoke some divine tinkering with human behavior.

But the God hypothesis for morality and altruism has its own problems. It fails, for example, to specify exactly which moral judgments were instilled in people by God and which, if any, might rest on secular reason. It doesn't explain why slavery, torture, and disdain for women and strangers were considered proper behaviors not too long ago, but are now seen as immoral. For if anything is true, God-given morality should remain constant over time and space. In contrast, if morality reflects a malleable social veneer on an evolutionary base, it should change as society changes. And it has.

The Argument for God from True Beliefs and Rationality

A more sophisticated argument for natural theology involves our ability to hold beliefs that happen to be true, ranging from “I'd better stay away from that lion” to “Tomorrow morning the Sun will ‘rise.'” Some theologians argue that this ability can be understood only as a gift of God, and this argument has gained some traction in natural theology. To an evolutionary biologist, however, the “argument from true beliefs” seems so clearly wrong that one wonders why it's so popular. Possibly one reason is that theologians, who make this argument most frequently, either don't understand or don't accept the ability of both culture and evolution to give us a propensity to detect the truth. But the argument has also been promulgated by a highly respected philosopher of religion, Alvin Plantinga, and seems impressive because it's framed in arcane language, formal logic, and probability theory. But one need not know math or much evolution to see its problems.

But what is the argument? In short, Plantinga claims that humans could never have true beliefs about
anything
without God's intervention. Natural selection, he says, promoted only our ancestors' ability to leave copies of our genes through differential survival and reproduction. It doesn't give a hoot about whether our
beliefs,
such as they are, are true. Considering our cognitive faculties, for instance, Plantinga says:

What evolution underwrites
is only (at most) that our
behavior
is reasonably adaptive to the circumstances in which our ancestors found themselves; hence it does not guarantee mostly true or verisimilitudinous beliefs. Our beliefs might be
mostly
true or verisimilitudinous . . . but
there is no particular reason to think they
would
be: natural selection is not interested in truth, but in appropriate behavior.

The most important “truth” that Plantinga thinks humans perceive is, of course, the existence of the Christian God and Jesus, and the salvation that can be attained only by accepting these deities. But he also claims that without God we wouldn't be able to perceive
scientific
truths, including those involving biology and physics:

God created both us and our world
in such a way that there is a certain fit or match between the world and our cognitive faculties. The medievals had a phrase for it:
adequatio intellectus ad rem
(the adequation of the intellect to reality). The basic idea, here, is simply that there is a match between our cognitive or intellectual faculties and reality, thought of as including whatever exists, a match that enables us to know something, indeed a great deal, about the world—and also about ourselves and God himself.

Elsewhere he writes, “
This capacity for knowledge of God
is part of our original cognitive equipment, part of the fundamental epistemic establishment with which we have been created.”

Plantinga argues that the naturalistic process of evolution is incapable of producing a brain that apprehends the truth of
evolution,
much less of any other idea. He therefore sees a conundrum: “
What I'll argue
is that naturalism is incompatible with evolution, in the sense that one can't rationally accept them both.” Plantinga himself waffles about whether
he
accepts evolution, for he seems to have a fondness for intelligent design.

What we have here, then, is the claim that a critical part of human cognition can't be explained by naturalistic evolution. Plantinga argues that our real truth detector is a “
sensus divinitatis
” (“sense of divinity”) installed in humans—and no other species—by God, as part of our creation in his image. (This idea derives from John Calvin, a figure much admired by Plantinga.) This is clearly a “god of the gaps” argument, one that Plantinga sees as forging a harmony between science and religion:

There is superficial conflict
but deep concord between science and theistic religion, but superficial concord and deep conflict between science and naturalism.

I won't belabor the obvious objection that even if we had such a divinely installed
sensus,
it's not evidence for Plantinga's Christian God as opposed to any other god. While he sees the Christian divinity as a “basic belief,” something as obvious as believing that you ate breakfast this morning, there's no reason why other deities could also have given us a
sensus divinitatis—
in fact, the firm belief of Muslims in Allah argues that the whole notion of a Christian
sensus
is insupportable.

But let's leave this theological ground and ask ourselves two questions: Do humans really have consistently accurate beliefs about the world? And, whether they do or not, can the truthfulness of
some
beliefs be explained by evolution and neuroscience?

The answer to the first question is yes: we generally see the external world accurately, and often have a good take on our fellow humans as well. But, importantly, we're also prone to all kinds of false beliefs. Steven Pinker lists a few:

Members of our species commonly believe
, among other things, that objects are naturally at rest unless pushed, that a severed tetherball will fly off in a spiral trajectory, that a bright young activist is more likely to be a feminist bankteller than a bankteller, that they themselves are above average in every desirable trait, that they saw the Kennedy assassination on live television, that fortune and misfortune are caused by the intentions of bribable gods and spirits, and that powdered rhinoceros horn is an effective treatment for erectile dysfunction. The idea that our minds are designed for truth does not sit well with such facts.

And we're particularly prone to self-deception. Psychological studies confirm that many of us tend to think we're smarter, better-looking, and more popular than we really are (for many examples, see Robert Trivers's book
The Folly of Fools: The Logic of Deceit and Self-Deception in Human
Life
)
.
Such consistent self-overrating may in fact have an evolutionary basis, for it helps us get our way when dealing with other people. Nobody is more convincing than a liar who believes his own lies, so an inflated self-presentation in our ancestors may have gained them leverage with others—and a reproductive advantage.

Now add to our distorted self-image the prevalence of delusions and errors like climate-change denialism, as well as belief in UFOs, alien abduction, astrology, ESP, and so on (I'd add for believers, “all religions with the possible exception of the ‘right one'—yours”), and we see that our species is vulnerable to all manner of false beliefs. We're deceived by optical illusions too, like Ted Adelson's stunning “
checker-shadow illusion
,” in which a light square falling in the shaded part of a shadowed checkerboard is mistakenly perceived as being much lighter than a square lying outside the shadow—even though both are exactly the same shade. That too is probably a by-product of natural selection, which is likely to have given our visual system a way to detect and compensate for the effect of shadows on the color and hue of objects.

The skeptic and science writer Michael Shermer
has written extensively about why people believe untrue things. The many reasons include confirmation bias (a preference for believing what we find comforting), ignorance of how probability works, resistance to change, and a penchant for indoctrination. Many of these tendencies could have been useful in the environment of our ancestors, an environment in which we no longer live. After all, our ancestors didn't encounter checkerboards in partial shadow, and didn't know probability theory.

To sum up, our brains are fairly reliable but hardly perfect organs for detecting truths. And many of these imperfections, pervasive in people of all faiths, can be plausibly understood as products of natural selection. So much for the argument that God gave us a reliable truth-detecting apparatus. In fact, if Plantinga's own
sensus divinitatis
were working properly, he wouldn't have accepted the scientifically discredited notion of intelligent design!

Of course, Plantinga has an answer for why there are so many atheists, Hindus, Jews, Muslims, and pre-Christian believers, like the Aztecs and ancient Egyptians, who were somehow unable to form true belief in the Christian God. The answer is that in those individuals the
sensus divinitatis
is or
was “broken,” dismantled by the effects of sin. Curiously, Plantinga argues that your broken
sensus
need not stem from your own sin:

Were it not for sin and its effects
, God's presence and glory would be as obvious and uncontroversial to us all as the presence of other minds, physical objects and the past. Like any cognitive process, however, the
sensus divinitatis
can malfunction; as a result of sin, it has been damaged. . . . It is no part of the model to say that damage to the
sensus divinitatis
on the part of a person is due to sin on the part of the same person. Such damage is like other disease and handicaps: due ultimately to the ravages of sin, but not necessarily sin on the part of the person with the disease.

Here we have an untestable explanation for an insupportable thesis. But we needn't mire ourselves in such arguments. Rather, let's address the real situation: humans are good at detecting some truths and poor at detecting others. Some of our beliefs are rational and supported by evidence, while others are not. Can we plausibly explain this using naturalism alone, including evolution?

Indeed we can. The first thing to realize is that humans aren't
born
with explicit beliefs; we're born with a brain molded by natural selection to
form
beliefs when the brain gets input from the environment. Some of those beliefs involve learning from parents and peers, others from empirical observation. It's easy to imagine that in our millions of years of living in small bands of hunter-gatherers, we, like many vertebrates, evolved a tendency to absorb what our parents taught us (surely one reason why religion persists). Your chances of surviving are a lot better if you benefit from the experience of adults rather than having to learn everything for yourself. We might have learned, for instance, to avoid large mammals that look like cats but not those that look like antelopes: those who didn't learn this distinction didn't become our ancestors. Other things, like which of our peers we can trust and which we should avoid, could have been figured out on our own. Still other rational tendencies—not beliefs, really, but adaptive behaviors—could have been directly produced by natural selection. Preference for kin and wariness toward strangers have obvious adaptive consequences, and would assume the status of “beliefs” at a certain age (“I believe that we should be wary of people we don't know”).