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

by Coyne, Jerry A.

  Now turn the question around: ask religious people what evidence it would take to make them abandon their faith. While some will actually give thoughtful responses, what you’ll hear most often is the answer of Karl Giberson cited in the previous chapter: no data could dispel his belief in God. He also gave some reasons for this stand, reasons that Christians don’t often admit:

  As a purely practical matter, I have compelling reasons to believe in God. My parents are deeply committed Christians and would be devastated, were I to reject my faith. My wife and children believe in God, and we attend church together regularly. Most of my friends are believers. I have a job I love at a Christian college that would be forced to dismiss me if I were to reject the faith that underpins the mission of the college. Abandoning belief in God would be disruptive, sending my life completely off the rails.

  This shows what we already know: belief may arise by indoctrination or authority, but is often maintained by social utility. But if no conceivable evidence can shake your faith in a theistic God, then you’ve deliberately removed yourself from rational discourse. In other words, your faith has trumped science.

  What About Miracles?

  Scientific analysis of miracles, at least those that happened in the distant past, suffers from two problems: determining whether they occurred at all, and determining whether they violated the laws of nature. If those miracles are supposed to be purposefully caused by a deity, that adds a third problem—or even a fourth if we want evidence that the miracles vindicate a specific faith like Christianity. Because miracles by definition can’t be replicated, it’s no coincidence that the pivotal doctrines of many religions now rest on ancient, one-off events like the dictation of the Quran by Allah and the Resurrection of Jesus. Must we then suspend judgment on such things? I think not. Let’s take the Resurrection as an example.

  The physicist Ian Hutchinson argues that the uniqueness of miracles makes them immune to science. If human levitation occurred repeatedly, he argues, science could test it, but “a religious faith that depended upon a belief that levitation was demonstrated on one particular occasion, or by one particular historic character, does not lend itself to such a scientific test. Science is powerless to bring unique events to the empirical bar.”

  But this can’t be true, for historians have ways of confirming whether unique events are likely to have occurred. Those methods depend on multiple and independent corroboration of those events using details that coincide among different reporters, reliable documents that attest to those events, and accounts that are contemporaneous with the event. In this way we know, for example, that Julius Caesar was assassinated by a group of conspirators in the Roman Senate in 44 BCE, though we’re not sure of his last words. As has been pointed out many times, the biblical account of the Crucifixion and Resurrection fails these elementary tests because the sources are not independent, none are by eyewitnesses, all contemporary writers outside of scripture fail to mention the event, and the details of the Resurrection and empty tomb—even among the Gospels and the letters of Paul—show serious discrepancies. Nor, despite ardent searching, have biblical archaeologists found such a tomb.

  Theologians, of course, have their own arguments for why the Resurrection is true: Paul had a vision of the resurrected Christ; the empty tomb was found by women (bizarrely, some see this as “evidence” because a fictional Resurrection concocted in those sexist times would not involve the testimony of women); and although the scriptures and Paul’s vision were not written down within Jesus’s lifetime, they were described only a few decades later. But if you see that as convincing evidence, consider the “testimonies” that begin the Book of Mormon. Opening the book, you’ll find two separate statements, signed by eleven named witnesses, all swearing they actually saw the golden plates given to Joseph Smith by the angel Moroni. Three of the witnesses—Oliver Cowdery, David Whitmer, and Martin Harris—add that an angel personally laid the plates before them. Unlike the story of Jesus, this is actual eyewitness testimony! Christians of other sects reject this testimony, but why then do they accept the tales about Jesus in the New Testament that are not only secondhand but produced by unknown writers? That’s not a consistent way to deal with evidence.

  The classic test for the truth of miracles is that of the Scottish philosopher David Hume. Foreshadowing Sagan’s principle of “extraordinary evidence,” Hume claimed that miracles were so extraordinary that to accept them, you would have to regard the suspension of nature’s laws as more likely than any other explanation—including fraud or mistakes. When weighing evidence for nonmiraculous explanations, you should also consider if the witnesses stand to benefit from describing the miracle. Because we know that mistakes, fraud, and confirmation bias aren’t that rare, to Hume they became the default explanation. Using this principle, if you reject the eyewitness testimony of eleven Mormons as fraud, error, or delusion, then you must also reject the Resurrection.

  This is simply the scientific principle of parsimony: when you have several explanations for a phenomenon, it’s usually (but not always) best to go with the one that has the fewest assumptions. And when miracles are sufficiently recent or sufficiently common to study scientifically, Hume’s principle has held up. The Shroud of Turin, bearing the image of a half-naked man with wounds, has been considered for centuries as the burial shroud of Jesus, whose image was miraculously imprinted on the cloth. Although the Catholic Church does not give it official status as a genuine relic, it has been endorsed by several popes, including Pope Francis, in a way that implies that it might be real. Nevertheless, radiocarbon dating shows that the shroud was produced in medieval times, and its image of Jesus has been reproduced by an Italian chemist using materials available in medieval Europe.

  In 2012, a statue of Jesus in Mumbai began oozing water from its feet. The “holy water,” some of which was consumed, was seen as a miracle, and hundreds of Catholics flocked to worship the image. Unfortunately, the Indian skeptic Sanal Edamaruku discovered that the “miracle” was due to faulty plumbing: blocked drainage of a nearby toilet caused the statue to wick fecally contaminated water into the base, emerging at Jesus’s feet. One would think that would settle the matter, but outraged believers caused Edamaruku to be indicted for violating Indian laws against hurting religious sentiments. He fled the country to avoid jail, a refugee from superstition. In an age of critical scrutiny and public media, the regular debunking of such miracles should give pause to those who see ancient miracles as genuine.

  Hume’s principle also promotes scientific reasoning in another way: look for alternative explanations. If you can think of a naturalistic, nondivine explanation for a “miracle,” you should become agnostic about that miracle, and if you can’t test it, then refuse to accept it. If there are such alternatives, the last thing you should do is make that miracle the pivot on which your whole faith turns.

  There are, for instance, many alternative and nonmiraculous explanations for the story of Jesus’s Resurrection. One was suggested by the philosopher Herman Philipse. It seems likely—for Jesus explicitly states this in three of the four Gospels—that his followers believed he would restore God’s kingdom in their lifetime. Further, the apostles were told they’d receive ample rewards in their lifetime, including sitting on twelve thrones from which they’d judge the tribes of Israel. But, unexpectedly, Jesus was crucified, ending everyone’s hope for glory. Philipse suggests that this produced painful cognitive dissonance, which in this case was resolved by “collaborative storytelling”—the same thing modern millennialists do when the world fails to end on schedule. The ever-disappointed millennialists usually agree on a story that somehow preserves their belief in the face of disconfirmation (for example, “We got the date wrong”). Philipse then suggests that in the case of the Jesus tale, the imminent arrival of God simply morphed into a promise of eternal life, a promise supported by pretending that their leader himself had been resurrected.

  If you a
ccept that an apocalyptic preacher named Jesus existed, who told his followers that God’s kingdom was nigh, this story at least seems reasonable. After all, it’s based on well-known features of human psychology: the behavior of disappointed cults and our well-known attempts to resolve cognitive dissonance. Like disillusioned millennialists, the early Christians could simply have revised their story. Is this really less credible than the idea that Jesus arose from the dead? Only if you have an a priori commitment to the myth.

  It’s no surprise then that the Jesus Seminar, a group of more than two hundred religious scholars charged with evaluating the historical truth of the words and deeds of Jesus, concluded that there was no credible evidence for either the Resurrection, the empty tomb, or Jesus’s postmortem reappearance. They commented dryly, “The body of Jesus probably decayed as do all corpses.” And they added a warning:

  The pre-eminent danger faced by Christian scholars assessing the gospels is the temptation to find what they would like to find. As a consequence, the inclination to fudge tends to be high—even among critical scholars—when working with traditions that have deep emotional roots and whose critical evaluation has sweeping consequences for the religious community.

  Of course, more conservative Christians have criticized this historical approach, even branding the work of the Jesus Seminar as heresy.

  Does Hume’s criterion mean, then, that we can never accept miracles? I don’t think so, for Hume took it too far. No amount of evidence, it seems, could ever override his conviction that miracles were really the result of fraud, ignorance, or misrepresentation. Yet perhaps there are some events, though they’re hard to imagine, when a divinely produced violation of nature’s laws is more likely than human error or deception. It would be a close-minded scientist who would say that miracles are impossible in principle. But Hume was right about one thing: to have real confidence in a miracle, one needs evidence—massive, well-documented, and either replicated or independently corroborated evidence from multiple and reliable sources. No religious miracle even comes close to meeting those standards.

  Three Test Cases

  When science disproves religious beliefs that are negotiable—that is, parts of church doctrine that aren’t critical parts of belief—the faithful are often happy to simply jettison them. Such beliefs include Jonah and the giant fish (no fish could swallow a human whole, much less keep him alive in its stomach for three days) and the tale of Noah’s Ark, which defies not only geology but reason (how could all of Earth’s species, including dinosaurs, stay alive for a year on an ark with a single window?).

  But not all beliefs are negotiable. For Christians, the story of how sin came into the world through Adam and Eve, and was expiated by Christ’s death, is vital. It is the fundamental belief of Christianity, and rests critically on the historical existence of Adam and Eve and their status as the genetic ancestors of all humanity. Without their existence, and their transgression in the Garden of Eden, there would be no inherited sinfulness of humans, and without such sin there was no need for Jesus to appear on Earth, undergoing Crucifixion and Resurrection to redress our sins.

  For other believers, the creation story as portrayed in Genesis, while perhaps not literally true, must somehow affirm the uniqueness of humans among all species—something that doesn’t comport with purely naturalistic evolution. The involvement of God in the appearance of humans is, for many believers, nonnegotiable. After all, Genesis specifies that “God created man in his own image, in the image of God created he him; male and female created he them.” This explains why, among those Americans who do accept human evolution, more than half of them believe that the process was guided by God, with the “guidance” usually nudging evolution toward our own species.

  Finally, a critical claim of Mormonism is that Native Americans—including Moroni, the supposed creator of the golden plates that became the Book of Mormon—descend from a group of people who migrated to North America from the Middle East around 600 BCE.

  Genetics, evolutionary biology, and archaeology show that all these claims are dead wrong. But because they are among the “nonnegotiables,” they must somehow be saved. That is a job for accommodationists. Let’s examine the claims and see how their believers buttress them against the winds of scientific evidence. We’ll find that their defense demonstrates the failure of accommodationism: despite attempts to torture the facts into compliance with religious dogma, this strategy fails miserably. I concentrate on these cases not only because they involve crucial religious beliefs, but also because they involve my own areas of study: evolution and genetics. Further, more than any other area of science, it is biology in general and evolution in particular that are seen as being in direct opposition to scripture. With the possible exception of cosmology, which we’ll discuss in the next chapter, religion can live happily with the modern findings of chemistry, physics, and nonevolutionary areas of biology like physiology and development.

  Adam and Eve

  The central lesson of Christianity is that sin was brought into the world by the transgression of Adam and Eve, the Primal Couple, and expiated by the Crucifixion and Resurrection of Christ, whose acceptance as savior removes the taint of sin. You can hardly call yourself a Christian without accepting these claims.

  The idea that sin arrived with Adam and Eve’s transgression originated in the epistles of Paul, but was transformed into dogma by Augustine and Irenaeus several centuries later. None of these writers doubted the historical existence of the Primal Couple. What could be clearer than Paul’s declaration, “For since by man came death by man came also the resurrection of the dead. For as in Adam all die even so in Christ shall all be made alive”? As we’ve learned, Augustine, often praised for seeing Genesis as an allegory, actually regarded Adam and Eve as historical figures. Finally, the Catechism of the Catholic Church affirms a historical First Couple: “The account of the fall in Genesis 3 uses figurative language, but affirms a primeval event, a deed that took place at the beginning of the history of man. Revelation gives us the certainty of faith that the whole of human history is marked by the original fault freely committed by our first parents.”

  There’s not much wiggle room here. And Americans as a whole take this doctrine literally as well: in a 2010 poll, 60 percent of them agreed with the proposition “All people are descendants of one man and one woman—Adam and Eve.”

  But science has completely falsified the idea of a historical Adam and Eve, and on two grounds. First, our species wasn’t poofed into being by a sudden act of creation. We know beyond reasonable doubt that we evolved from a common ancestor with modern chimps, an ancestor living around six million years ago. Modern human traits—which include our brain and genetically determined behaviors—evolved gradually. Further, there were many species of proto-humans (all called “hominins”) that branched off and died before the ancestors of our own species remained as the last branch. As many as four or five species of humanlike primates may have lived at the same time! Some of these extinct groups, like the Neanderthals, had culture and big brains, and were “modern” humans in all but name. Theologians, then, are forced to square the sudden incursion of sin with the gradual evolution of humans from earlier primates.

  More important, evolutionary geneticists now know that the human population could never have been as small as only two individuals—much less the eight who rode out the flood on Noah’s Ark. Since sequencing of human genomes became possible on a large scale, we can back-calculate from the observed genetic diversity in our species to find out roughly when different forms of human genes diverged from one another, and how many forms of a given gene existed at a given time. Because each human has two copies of each gene, this gives us a minimum estimate of how many humans existed at a given time. We’ve also been able to use genes to trace the path of ancient human populations as they spread from Africa throughout the world.

  The genetic evidence tells us several things. First,
the genes in all modern humans diverged from one another a long time ago—long before the 6,000 to 10,000 years estimated from scripture. We can, for example, trace all the Y chromosomes of existing males back to a single man who lived between 120,000 and 340,000 years ago. This individual is often called “Y-chromosome Adam.” But that’s a bit misleading, for although all the Y chromosomes of modern humans descend from this one individual, the rest of our genome descends from a multitude of different ancestors who lived at various times ranging from 10,000 to about 4 million years ago. Our genome testifies to literally hundreds of “Adams and Eves” who lived at different times—a result of the fact that different parts of our DNA were inherited differently based on the vagaries of reproduction and the random division of genes when sperm and eggs are formed.

  The observations that different parts of our genomes have different ages, some going back millions of years, and that they come from different ancestors, completely dispel the biblical date of human origins and the idea that all of our DNA was bequeathed by a Primal Couple.

  But the evidence is even stronger, for we can also back-calculate from DNA sequences the size of human populations at different times in the past. And we know that when our ancestors left Africa between 100,000 and 60,000 years ago to colonize the world, the size of the migrating group dropped to a minimum of 2,250 individuals—and that’s an underestimate. The population that remained in Africa stayed larger: a minimum of about 10,000 people. The total number of ancestors of modern humans, then, was not two but over 12,000 individuals. This is a very strong scientific refutation of the Adam and Eve scenario.

  And it puts Christians in a tight spot. If there were no Adam and Eve, then whence the original sin? And if there was no original sin transmitted to Adam’s descendants, then Jesus’s Crucifixion and Resurrection expiated nothing: it was a solution without a problem. In other words, Jesus died for a metaphor.