Common descent is the claim that all organisms currently living have descended from one or a few original ancestors through a process Darwin called "descent with modification." According to this idea, not only humans and apes share an ancestor, but so do humans, clams, and fungi. Common descent is a hallowed dogma among today's evolution proponents, held with quasi-religious fervor.
C.S. Lewis clearly believed that Christians can accept evolution as common descent without doing violence to their faith. This is what Lewis was getting at when he wrote to evolution critic Bernard Acworth, "I believe that Christianity can still be believed, even if evolution is true."18 In Lewis's view, whether God used common descent to create the first human beings was irrelevant to the truth of Christianity. As he wrote to one correspondent late in his life, "I don't mind whether God made man out of earth or whether 'earth' merely means 'previous millennia of ancestral organisms.' If the fossils make it probable that man's physical ancestors 'evolved,' no matter."19
In The Problem of Pain (1940), Lewis even offers a possible evolutionary account of the development of human beings, although he makes clear he is offering speculation, not history: "[I]f it is legitimate to guess," he writes, "I offer the following picture -- a 'myth' in the Socratic sense," which he defines as "a not unlikely tale," or "an account of what may have been the historical fact" (emphasis in the original). Lewis then suggests that "[f]or long centuries God perfected the animal form which was to become the vehicle of humanity and the image of himself... The creature may have existed for ages... before it became man."20 Elsewhere, Lewis seemed smitten by the idea of embryonic recapitulation, the discredited evolutionary idea that human beings replay the history of their evolution from lower animals in their womb. And in a letter to his friend Anglican nun Sister Penelope in 1952, he mentioned his previous speculation that the first human being was descended from "two anthropoids."21
Nevertheless, Lewis did not exactly go out of his way to champion the animal ancestry of humans. When pressed on the subject by evolution critic Bernard Acworth in the 1940s, Lewis backpedaled, replying that his "belief that Men in general have immortal & rational souls does not oblige or qualify me to hold a theory of their pre-human organic history -- if they have one."22 A few years later, Lewis relished the exposure of "Piltdown Man" as a hoax. Originally touted as evidence for the long-sought "missing link" between apes and humans, the Piltdown Man's skull was discovered in the 1950s to be a fake forged from the skull of a modern human, the jawbone of an orangutan, and the teeth of a chimpanzee.23 Lewis wrote to Bernard Acworth that although he didn't think the scandal should be exploited, "I can't help sharing a sort of glee with you about the explosion of poor old Piltdown... one inevitably feels what fun it wd. be if this were only the beginning of a landslide."24 He wrote another correspondent, "The detection of the Piltdown forgery was fun, wasn't it?"25 Interestingly, four years before the definitive exposure of Piltdown as a fraud, Lewis had already published a poem that labeled the fossil the "fake from Piltdown."26> His final Narnian story, meanwhile, completed a few months after the Piltdown scandal hit the headlines, features as the villain an ape who insists he is really a human being -- perhaps Lewis's whimsical commentary on "poor old Piltdown."27
Whatever Lewis's final position on the animal ancestry of the human race, it would be wrong to conclude that his acceptance of some kind of human evolution placed him in the camp of mainstream evolutionary biology, or even of mainstream theistic evolution. In fact, Lewis insisted on three huge exceptions to evolutionary explanations of humanity that placed him well outside evolutionary orthodoxy, both then and now.
An Historic Fall
Lewis's first exception to human evolution was his insistence on an actual Fall of Man from an original state of innocence. In Christian theology, God originally created human beings morally innocent. These first humans then freely rejected God's will for them, resulting in a Fall from innocence and harmony into the sinful condition of the human race as we currently find it. According to historic Christian teaching, not only human beings, but the entire creation was tainted by man's initial act of wrongdoing. It was to reverse the impact of the Fall that God became incarnate to save us from our sins. Thus, the Fall provides the necessary "back story" for Jesus Christ and his death on the cross.
Leading theistic evolutionists no less than secular evolutionists insist that an historic Fall is incompatible with mainstream evolutionary theory. In the words of Anglican Bishop John Shelby Spong, "Darwin... destroyed the primary myth by which we had told the Jesus story for centuries. That myth suggested that there was a finished creation from which we human beings had fallen into sin, and therefore needed a rescuing divine presence to lift us back to what God had originally created us to be. But Charles Darwin says that there was no perfect creation." Thus, "there was no perfect human life which then corrupted itself and fell into sin... And so the story of Jesus who comes to rescue us from the fall becomes a nonsensical story."28
Spong is well known for being a theological liberal, but similar views are gaining prevalence among evangelical Christian proponents of evolution. Karl Giberson, a co-founder with Francis Collins of the pro-theistic-evolution group BioLogos, likewise repudiates the traditional teaching that "sin originates in a free act of the first humans" and that "God gave humans free will and they used it to contaminate the entire creation."29 In his book Saving Darwin, Giberson has a section titled "Dissolving the Fall" where he essentially argues that since human beings were created through Darwinian evolution, they were never morally good. Instead, they were sinful from the start because the evolutionary process is based on selfishness: "Selfishness ... drives the evolutionary process. Unselfish creatures died, and their unselfish genes perished with them. Selfish creatures, who attended to their own needs for food, power, and sex, flourished and passed on these genes to their offspring. After many generations selfishness was so fully programmed in our genomes that it was a significant part of what we now call human nature."30 Francis Collins wrote an enthusiastic foreword to Giberson's book.