On dark Mediterranean nights the ancients observed the movements of the planets and stars, and during the day they observed the movement of the sun. They noticed general regularity marked by particular irregularity. Movements shifted slowly during the year, the sun rising and setting farther to the north, then farther to the south, the planets swimming among the stars, racing one another through the constellations, sometimes overtaking one another, sometimes apparently moving backward. Even the stars themselves processed through the skies.
Since man is incapable of not drawing inferences from observations, the ancients guessed at the arrangement of heavenly bodies. Some surmised that the sun, like a candle quenched in a bowl, was extinguished each evening as it was swallowed by the sea. Others thought this improbable and speculated that the sun circled behind the earth at night. Even to the unsophisticated, the planets and stars seemed ordered; perhaps they too circled the earth. Thus there arose astronomical hypotheses.
Proto-astronomers, such as the Wise Men of Matthew’s Gospel, went further, carefully measuring the movements, keeping records of the rising and setting of the sun, the journeys of the planets, the positions of the stars. The accuracy of their measurements was limited by the power of the naked eye and the absence of chronometers, yet they adduced evidence, applied it to the prevailing hypotheses, and ended up with theories, which are hypotheses united with evidence that tends to support them. The longest-lasting and most influential was that of Ptolemy, who, relying on earlier observers such as Hipparchus and Timocharis, developed a geocentric theory that seemed to account for all observed movements—as the medievals later put it, his theory “saved the appearances.” For centuries few doubted that the earth stood at the center of what today we call the solar system.
But the Ptolemaic theory, raised from mere hypothesis through the application of scientific measurements, proved in the end to be false. The sun, not the earth, is the center of the solar system; the planets move along ellipses, not along cycles and epicycles; the stars, so distant that their movements are almost imperceptible, do not circle the earth, but are, for practical purposes, fixed.
Thus it is in science. Initial observation produces hypotheses, which are mere guesses, some immediately seen to be improbable (such as that the setting sun is extinguished each day), some seen to be possible (such as that the sun, planets, and stars circle the earth). Through scientific investigation and the gathering of innumerable tiny facts, scientists come to single out one hypothesis and produce an overarching explanation that accommodates the evidence. This explanation is called a theory.
But a theory is not the same as a truth. A theory may be true, or it may be false. Aristotelian physics was supplanted by Newtonian physics, which in turn was supplanted by Einsteinian physics, which, in all likelihood, will be supplanted by something else. Newton thought there to be no necessary limit to the speed of light in a vacuum. Einstein demonstrated that the speed of light is a constant. Today some scientists speculate that Einstein erred and that Newton may have been right after all.
This brings us to the theory of evolution and to Pope John Paul II’s recent statement to the Pontifical Academy of Sciences. It is not my purpose in this article to comment on evolution per se; I do not propose to address its merits or demerits. I just want to look at what the Pope said and how a prominent evolutionist, Stephen Jay Gould, has understood (or misunderstood) the papal statement.
Gould is professor of biology, geology, and the history of science at Harvard and is perhaps the best-known popularizer of evolution. He calls himself a Jewish agnostic: “I am not, personally, a believer or a religious man in any sense of institutional commitment or practice. But I have enormous respect for religion, and the subject has always fascinated me, beyond almost all others (with a few exceptions, like evolution, paleontology, and baseball).” In a lengthy and well-crafted essay in the March 1997 issue of Natural History magazine, he argues that religion and science are separate domains, each with its own magisterium. There is no necessary conflict between the two. Gould sees science as covering “the empirical universe: what is it made of (fact) and why does it work this way (theory).” Religion, by contrast, “extends over questions of moral meaning and value.”
Of course, this is not a differentiation that a Christian will be satisfied with. Although every revealed dogma has something to do with “questions of moral meaning and value,” the faith can’t be straitjacketed. It also deals with “physical” facts: the Son taking flesh and living on earth at a particular time and in a particular place, the return from the dead of his material (not imaginary) body, the establishment of a Church which, while having an invisible spiritual dimension, is composed of physical human beings. All these things are subject to scientific investigation, as are all historical events.
Was Abraham Lincoln a real person or a fictional character? No one living today could have had a chance to see him and to judge directly, but his existence, like the existence of an antediluvian stegosaurus or of a modern lily, is subject to scientific investigation, to proof that relies on the application of the five senses and on inferences drawn from measurements. When I was a boy, there still lived veterans of the Civil War. It is possible that one of those survivors had met Lincoln. If so, then there was a living witness to Lincoln’s existence, and the testimony of that witness would have been subject to scientific investigation.
Then there are the daguerreotypes of Matthew Brady, those haunting images in which we see Lincoln (or at least what purports to be Lincoln) in profile, rigidly looking at something outside the camera’s range. Are the photographs authentic or faked? That is something for scientific investigation to determine.
We also have books and other documents about Lincoln. They are filled with testimonies of people who knew and worked with him, of people who knew and opposed him. These are evidentiary exhibits, each subject to scientific investigation, the way fossils are subject to investigation.
Gould, for all his scientific learning and literary art, fails to delineate properly the spheres of science and religion. There is an overlap, and it won’t do to restrict religion to “questions of moral meaning and value,” as though those questions have no interplay with the material world. That said, let me turn, finally, to the central part of Gould’s long essay, the whole of which occupies six pages of text. Gould is concerned with comparing John Paul II’s statement to the 1950 encyclical by Pius XII, Humani Generis. He wants to see if the Catholic Church has made “progress” in its understanding of evolution, and he concludes it has.
Gould notes that “Pius writes the well-known words that permit Catholics to entertain the evolution of the human body . . . so long as they accept the divine creation and infusion of the soul. . . . In short, Pius forcefully proclaimed that, while evolution may be legitimate in principle, the theory, in fact, had not been proven and might be entirely wrong. One gets the strong impression, moreover, that Pius was rooting pretty hard for a verdict of falsity.”
John Paul reiterates his predecessor’s teaching that the idea of the evolution of the body is not itself opposed to Catholic doctrine. “The novelty and news value of John Paul’s statement,” says Gould, “lies, rather, in his profound revision of Pius’s second and rarely quoted claim that evolution, while conceivable in principle and reconcilable with religion, can cite little persuasive evidence and may well be false.” The present pope, thinks Gould, has taught “that evolution can no longer be doubted by people of good will.”
Gould quotes from the Holy Father’s October 23, 1996, address to the Pontifical Academy of Sciences: “Today, almost half a century after the publication of the encyclical [Humani Generis], new knowledge has led to the recognition of more than one hypothesis in the theory of evolution. It is indeed remarkable that this theory has been progressively accepted by researchers, following a series of discoveries in various fields of knowledge. The convergence, neither sought nor fabricated, of the results of work that was conducted independently is in itself a significant argument in favor of the theory.”
This is how Gould interprets these lines: “John Paul . . . adds that additional data and theory have placed the factuality of evolution beyond reasonable doubt. Sincere Christians must now accept evolution not merely as a plausible possibility but also as an effectively proven fact.” We now have “John Paul’s entirely welcoming ‘it has been proven true.’”
Suddenly one’s admiration for Gould wanes—no longer is he a careful parser of papal statements. He has been transformed into the ideologue, pressing himself to a conclusion that the facts he has served up just don’t demonstrate. He seriously misconstrues John Paul’s words.
For one thing, Gould uses a bogus translation. (I should point out that this was not his fault; early reports of the speech gave an incorrect rendering.) The Holy Father did not say that there is “more than one hypothesis in the theory of evolution.” The French original reads ” plus qu’une hypothèse.” The Pope said evolution is “more than a hypothesis.” And what is “more” than a hypothesis, which is nothing other than an intelligent guess? The next step up is a theory, which is a hypothesis for which scientific evidence has been adduced. Theories, as followers of Ptolemy learned, may be true or false. They are provisional explanations based on observation and measurement, but they are distinct from incontrovertible truths.
If you search the Pope’s statement, you will find nothing that supports Gould’s assertion that “additional data and theory have place the factuality of evolution beyond reasonable doubt.” The Pope doesn’t use the phrase “beyond reasonable doubt” or anything like it. He doesn’t say that evolution has progressed beyond the level of a theory. He says merely that, from multiple disciplines, scientific evidence has been gathered and that the evidence is “a significant argument in favor of the theory”—not a conclusive argument, but a strong argument.
Nowhere does John Paul assert that “sincere Christians must now accept evolution not merely as a plausible possibility but also as an effectively proven fact.” He does not claim that the theory “has been proven true.” The Pope’s reticence to say such things—if he believed them, he could have said them plainly, after all—more rightly should lead a reader to suspect that the Pope is not entirely convinced that evolution is true. The theory is still that—just a theory. It’s more than a hypothesis, since there seems to be substantial evidence in its favor, but there was substantial evidence in favor of Ptolemy’s theory too.
Reading Gould’s essay (which, except at this point, is not tendentious and doesn’t attempt to draw more from papal statements than those statements actually hold), one senses a desperation. Gould tries too hard to get John Paul to say what he wants him to say—so hard that he deliberately puts words into the Pope’s mouth. (Given the disparity between what the Pope actually said and Gould’s sharply contrasting paraphrase of it, I don’t think that’s too strong a judgment.)
Nowhere in his essay does Gould advert to problems with evolution. Darwinism, which has been the chief explanation of how evolution works (through slow, almost imperceptible changes), is in trouble. In recent years learned books have argued that the perfecting of science has shown Darwinism to be untenable. The missing links are still missing. There is no reasonable way that a protracted series of minute changes can turn, say, a sun-sensitive blot on the skin into an eye. Living things are far more complex, especially at the microscopic level, than Darwin could have imagined.
Even unwavering evolutionists such as Gould have admitted that Darwinism is on shaky legs. Many of them have rejected Darwin’s notion of small mutations adding up, over millions of years, into a positive alteration that allows the fit to be even more survivable. These evolutionists have proposed an alternative, “punctuated equilibrium.” Instead of a long series of minute changes, there is one spectacular mutation: The blot becomes a fully developed eye in a single or perhaps in a handful of generations, not in thousands of generations. This idea has problems of its own and has not received universal acceptance among evolutionists.
Taking all this together—new books that argue that Darwin got it wrong, plus pro-Darwinists’ implicit acknowledgement that Darwinism has problems—we can envision this scenario: Darwinism, the chief explanation of how evolution does what it is supposed to do, is seen to be unsalvageable. It must be abandoned, to be replaced by—what? So far there is no alternative, which means that evolutionists might find themselves in an anomalous position: arguing that evolution is true, but unable to explain how it might occur. And if that point is reached, the whole theory might be junked as untenable. I’m not saying that this is likely, but, given the unsettled state of evolution as a theory, it is possible.
So what is the Holy Father’s bottom-line position on evolution? He didn’t say what Gould imagines that he said, which is that evolution is indubitably true. For this Pope evolution remains a theory—a step up from a mere hypothesis, but a step below a truth. He told the Pontifical Academy of Sciences that “a theory’s validity depends on whether or not it can be verified” by being “constantly tested against the facts.” A theory must be “rethought” if it “no longer can explain” the facts.
John Paul knows what a theory is and what it isn’t, and he also knows the history of science. He realizes that today’s scientific certainty may be tomorrow’s also-ran. While praising scientists for trying to “save the appearances,” the Pope can’t forget what happened to Ptolemy.