Public defenses of atheism are in vogue. Atheism, of course, predates modern science, but many believe that the findings of modern astronomy, physics, chemistry, and biology have rendered belief in God unnecessary, indeed untenable. “I have no need of that hypothesis,” French mathematician Pierre Laplace purportedly said when Napoleon asked about the place of God in his astronomical theories. “I think one of the great historical contributions of science is to weaken the hold of religion. That’s a good thing,” says physicist Steven Weinberg.

Those who would conclude that science tilts the scales toward atheism must confront two inconvenient facts. First, many (most?) of the giants who founded modern science were themselves deeply religious. As Francis Collins notes in The Language of God, “Copernicus, Kepler, and Galileo…[were] all strong believers in God….” In God’s Universe, Owen Gingerich quotes the prayer with which Johannes Kepler concluded one of his major scientific works:

If I have been enticed into brashness by the wonderful beauty of thy works, or if I have loved my own glory among men, while advancing in work destined for thy glory, gently and mercifully pardon me: and finally, deign graciously to cause that these demonstrations may lead to thy glory and to the salvation of souls, and nowhere be an obstacle to that.

Second, in the United States today, two-fifths of working scientists profess belief in a personal God who communicates with humankind and answers prayers, a number that has apparently remained constant for nearly a century. (One wonders whether belief is as common in the social sciences and humanities.) And some additional number may believe in a God who created the world and its physical laws, but does not intervene directly in human affairs.

So thousands of scientists go about their research every day, untroubled by the notion that science and theism are incompatible. Visit the science departments of religious colleges and universities (other than the few that embrace young-earth creationism) and you will find physics, chemistry, and biology taught exactly as they are at secular institutions. Neither most religious colleges nor religiously minded scientists who work in these institutions believe that the fruits of science contradict religious belief. On the contrary, they may see science, as does Francis Collins, as a kind of worship: “The God of the Bible is also the God of the genome. He can be worshiped in the cathedral or in the laboratory.”

In the past decade, the relation of science to belief has taken a new turn as scientists, philosophers, theologians, and others have asked whether science can demonstrate design in nature, and perhaps then a designer of nature. The three books reviewed here are thoughtful recent efforts to confront the design argument and its implications for science and religious belief. All three authors are scientists who believe in a personal God. Owen Gingerich, emeritus professor of astronomy at Harvard University, is described in the foreword to his book as “a devout Mennonite, for whom faith and science had never been at odds.” Francis Collins, a physician and biologist who headed the federally funded Human Genome Project and now directs the National Human Genome Research Institute in the National Institutes of Health, identifies himself as a member of “the evangelical Christian church.” Michael Behe, a biochemist at Lehigh University and a leading proponent of Intelligent Design, describes himself as “a pretty conventional Roman Catholic” who like “the great majority of the population of the United States and the world believes in God.” As these books show, believing scientists disagree about whether and how science reveals evidence of a Creator-Designer and thus provides rational support for belief in the God of the major Western religions.

At first glance, it would appear that whether scientists are theists or atheists is irrelevant to their work. They study efficient causes, not final causes or purposes: “As a scientist,” Gingerich writes, “I accept methodological naturalism as a research strategy.” Any discussion of purposes or ends, of teleology, is outside the bounds of science. These are metaphysical issues, not scientific ones: “‘Is the universe designed?’ is not a scientific question…. It is a metaphysical question, whose answer will come only out of metaphysical reasoning.” Gingerich seems to believe that science simply has nothing to say about the large questions of meaning and purpose in nature: “Why is there something rather than nothing? or, Does the universe have a purpose? These are teleological questions…and not for science to grapple with.” But if science cannot grapple with them, scientists certainly can. Indeed, this is the whole point of God’s Universe, which comprises three lectures Gingerich presented at Harvard’s Memorial Church.

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Gingerich’s central chapter—”Dare a Scientist Believe in Design?”—confronts the design issue head on. Even though science itself can say nothing about design, the scientist drawing upon the discoveries of science can say quite a bit. Gingerich notes, for example, the congruence between the Big Bang theory of the origins of the universe and the creation account in Genesis, particularly the similarity between God’s command in Genesis 1, “Let there be light!” and the scientific hypothesis that “the universe began with a mighty burst of energetic photons.” Equally impressive is the “staggering intricacy” with which the constants and laws of nature seem to be “fine-tuned” to produce a universe that can support intelligent life. One example is “the incredible balance between the outward energy of expansion and the gravitational forces trying to pull everything back together again.” This “initial balance had to be accurate to about one part in 10⁵⁹,” a remarkably small number, or else the universe would not have developed the stars and planets necessary for life. Thus “it seems as if the universe must have been expressly designed for humankind.”

Even more remarkable are “the indications [of design] from the biological realm.” In particular, the formation of the incredibly complex DNA molecule seems “so improbable as to require a designing principle.” Science is “frankly on very shaky turf,” Gingerich writes, when it claims that “random mutations can generate the incredible amount of information content required to produce even the simplest of cells.” Although Gingerich is “happy to concede that ample evidence demonstrates that natural selection is a major force at work” in evolution, he is “hesitant to say that it is the exclusive driving force,” suggesting that at least some mutations might not be random but “inspired.” In the end, “[i]ntimations of design can offer persuasion regarding the role of divine creativity in the universe, but not proof.” “[T]he Book of Nature, in all its astonishing detail…suggests a God of purpose and a God of design.”

This sounds much like the arguments of the modern Intelligent Design movement, especially as found in the writings of William Dembski and Michael Behe (see my “Is God in the Details?” Claremont Review of Books, Winter 2004). But here Gingerich distinguishes between “intelligent design,” in which he believes, and “Intelligent Design” (I.D. for short), which he strongly opposes. The problem with the latter is its claim that science itself can discern evidence of design in nature. This is mistaken, he maintains, because science deals only with efficient causes. Yet much of Gingerich’s book argues that science elicits persuasive evidence (though short of proof) that the universe was designed to support intelligent life. The point seems to be that in conducting their research scientists must eschew questions about design or purpose; but that they are free after hours, so to speak, to try to connect the dots.

How sound is this distinction? Gingerich does not acknowledge the argument of I.D. theorists that some scientists routinely, i.e., as a matter of professional competence, infer design from empirical data. These include, for example, the archeologist who identifies human artifacts, the cryptologist who distinguishes an intelligent message from background noise, and the medical examiner who determines whether a death resulted from natural causes, accident, or human intention. In fact, Gingerich claims that “[w]hether the mutations [responsible for complex life forms] are anything other than mathematically random is a question without answer in a physical or scientific sense.” But why is this so? Why could not mathematical probability theory combined with detailed knowledge of cell biochemistry show that some mutations, or series of mutations, were so improbable as to imply design? Gingerich himself, as we have seen, infers from “the incredible balance” between the forces of expansion and contraction at the moment of the Big Bang that the universe was likely “expressly designed for humankind.” What is the difference in principle between inferring design by calculating and assessing probabilities in this case, and (possibly) inferring design in the creation or development of the DNA molecule using the same methods? And why are these not legitimate scientific questions? Why relegate them to metaphysics? Surely, few professors of metaphysics would be equipped to address them.

In its description of “a richly satisfying harmony between the scientific and spiritual worldviews,” Francis Collins’s The Language of God bears many similarities to God’s Universe. Like Gingerich, Collins believes that science cannot answer the really big questions “such as ‘Why did the universe come into being?’ ‘What is the meaning of human existence?’ [and] ‘What happens after we die?'” Yet also like Gingerich, Collins argues that the findings of modern science point to the divine, and none more so than the theory of the Big Bang:

The consequences of Big Bang theory for theology are profound…. The Big Bang cries out for a divine explanation. It forces the conclusion that nature had a defined beginning. I cannot see how nature could have created itself. Only a supernatural force that is outside of space and time could have done that.

What’s more, the laws of nature and the properties of matter seem fine-tuned in a way that defies natural explanation: “The existence of a universe as we know it rests upon a knife edge of improbability.” Indeed, “there are fifteen physical constants whose values current theory is unable to predict. They are givens: they simply have the values that they have.” The universe is so “wildly improbable” that the conclusion seems inescapable that “our universe is uniquely tuned to give rise to humans.”

Reflecting his own expertise, Collins devotes considerable attention to biology, the origin of life, and DNA. As head of the federal project that, together with the private company Celera, decoded the human genome in 2000, Collins is awed by the “digital elegance of DNA” with its three billion letters. It is so complex that it “seems an utterly improbable molecule to have ‘just happened’—especially since DNA seems to possess no intrinsic means of copying itself.” He calls DNA both “an instructional script, a software program, sitting in the nucleus of the cell” and the “language by which God spoke life into being.”

Again, this sounds like Intelligent Design’s critique of materialistic explanations of life; but Collins, like Gingerich, is no friend to I.D. theory. He offers several objections, some scientific and one theological. Among the scientific objections are that I.D. is “a fringe activity” with little scientific credibility; that it is not testable through predictions; that new research seems capable of explaining the development of irreducibly complex systems (contra the claims of I.D.); and that step-by-step evolutionary pathways for the development of the most complex organs, such as the eye, can be contemplated along Darwinian grounds. Furthermore, I.D. theory is dangerous to religious belief because it is a “God of the gaps” theory that will discredit faith when science fills the gaps, as it surely will: “evolution, as a mechanism, can be and must be true.”

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Unlike Gingerich, Collins doesn’t argue that science is intrinsically incapable of investigating design. Indeed, at times he appears to acknowledge a legitimate scientific debate over the claims of Intelligent Design. For example, what does science tell us about the origins of the bacterial flagellum, the complex outboard motor comprising dozens of different proteins that propels some bacteria? Could it have arisen through an undirected, gradual, step-by-step process? In his best-selling Darwin’s Black Box (1996), Michael Behe had argued that the flagellum and many other enormously complex biochemical systems could not have evolved strictly by Darwinian processes. Is this a legitimate scientific question? On the one hand, Collins cites research by mainstream scientists on precisely this issue, suggesting both that the question is a proper one to ask and that science has the means to address it. On the other hand, he seems to denigrate the entire I.D. enterprise as wrongheaded (not to mention dangerous to faith).

What, then, is his considered view of the relationship of God to nature, and how does it differ from Intelligent Design? Collins embraces “theistic evolution,” which he calls “the dominant position of serious biologists who are also serious believers” and of such religious leaders as the late Pope John Paul II. This is the view, says Collins, that “Maimonides…and Saint Augustine would espouse today if they were presented with the scientific evidence for evolution.” He holds that this theory rests on six premises:

1. The universe came into being out of nothingness, approximately 14 billion years ago.

2. Despite massive improbabilities, the properties of the universe appear to have been precisely tuned for life.

3. While the precise mechanism of the origin of life on earth remains unknown, once life arose, the process of evolution and natural selection permitted the development of biological diversity and complexity over very long periods of time.

4. Once evolution got under way, no special supernatural intervention was required.

5. Humans are part of this process, sharing a common ancestor with the great apes.

6. But humans are also unique in ways that defy evolutionary explanation and point to our spiritual nature. This includes the existence of the Moral Law (the knowledge of right and wrong) and the search for God that characterizes all human cultures throughout history.

Where, one might ask, is the theism in this version of “theistic evolution”? God’s role in theistic evolution seems to be confined to the initial creation of the universe with its fine-tuned parameters, and to some kind of communication or intervention with creatures related to the great apes, whose bodies had evolved without divine guidance and in whom, apparently, God infused a sense of the Moral Law and a desire to know Him. In addition, the premises seem to allow, but do not require, some role for God in the creation of life on earth. It is interesting to compare this description of theistic evolution with the language the Gallup poll (cited by Gingerich) uses to assess public support for a position between “young-earth creationism” and undirected Darwinian evolution: “Human beings have developed over millions of years from less advanced forms of life, but God guided this process” (emphasis added). Unlike the Gallup description, with which a third to two-fifths of Americans concur, Collins’s premises appear to allow for no guidance by God between the creation of life and His intervention with mankind.

In subsequent pages, Collins writes that “God chose the elegant mechanism of evolution” to create living things and “to give rise to special creatures who would have intelligence, a knowledge of right and wrong, free will, and a desire to seek fellowship with Him.” But what exactly was the nature of this choice, if evolution is “an apparently random, potentially heartless, and inefficient process…[that is] full of chance and random outcomes”? If evolution is, in effect, a machine that runs of itself “once life arose,” what does it mean to choose it? Perhaps he means only that God chose the initial conditions at the time of creation some 14 billion years ago. But then we have a theory more properly called “theistic creation” than “theistic evolution.” In fact, Collins’s preferred term is “BioLogos,” which, drawing on the opening words of John’s Gospel, “expresses the belief that God is the source of all life and that life expresses the will of God.”

In the end, it turns out that BioLogos is not a scientific theory at all, or even a theory that modifies conventional Darwinism: “BioLogos doesn’t try to wedge God into gaps in our understanding of the natural world; it proposes God as the answer to questions science was never intended to address, such as ‘How did the universe get here?’ ‘What is the meaning of life?’ ‘What happens after we die?’…. Its truth can be tested only by the spiritual logic of the heart, the mind, and the soul.” Like Gingerich, who relegates the great issues of meaning and purpose to metaphysics, Collins makes these matters of faith.

But what of those scientific questions that Collins addresses throughout, and that impinge on larger issues of purpose and divine intervention in the natural world? For example, does the Big Bang and the “wildly improbable” fine-tuning of nature’s laws imply a creator outside of nature? (Recall that Collins was quite willing to plug God into the gap of scientific explanations of the Big Bang.) How was the “utterly improbable” DNA molecule created with its awe-inspiring “digital elegance”? If the coding within DNA is the functional equivalent of sophisticated computer software, did it self-assemble through blind material processes or did it require a guiding intelligence? Put differently, if DNA is the “language of God,” through which life came into being, is there evidence of a designing intelligence in its structure, complexity, and subtlety? In words that Collins helped to write, President Clinton said at the White House ceremony announcing the completion of the mapping of the human genome: “Today we are learning the language in which God created life. We are gaining ever more awe for the complexity, the beauty, and the wonder of God’s most divine and sacred gift.” Either this signifies a creative act by God, evidence of which science might discern, or it is a mere rhetorical flourish to dignify the results (DNA) of blind matter in motion.

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Despite the opposition of mainstream scientists, including many religious ones, to the Intelligent Design project, Michael Behe pushes ahead with The Edge of Evolution: The Search for the Limits of Darwinism. Behe makes clear at the beginning (and reiterates throughout) that he is not challenging common descent: “Darwin had this point right, that all creatures on earth are biological relatives.” The results of modern DNA sequencing seem to settle the question. Instead, what Behe rejects is the notion that random mutation combined with natural selection can account for the construction of enormously complex molecular machines within the cell, and thus for important aspects of evolutionary history. For this the evidence is “terrible”: “the power of natural selection coupled to random mutation…has been grossly oversold to the modern public.”

If Behe’s earlier Darwin’s Black Box made the bacterial flagellum famous, The Edge of Evolution may do the same for “intraflagellar transport” (or IFT). When a researcher in 1993 focused his powerful new microscope at a cell’s cilium (the thin hairlike projection whose motion can propel a cell through liquid), he discovered bumps moving up and down the cilium. (“[C]ilia are also sometimes called ‘flagella,’ hence ‘intraflagellar.'”) Further research disclosed a highly complex machinery through which “[m]olecular containers carry protein cargo from the cell to the tip of the flagellum…[and] return empty.” The discovery of this machinery “exponentially increases the difficulty of explaining the irreducibly complex cilium.” This is just one example of structures in the cell “whose complexity is substantially greater than we knew just ten years ago.” For Behe, the “critical question is…[c]an mutation of DNA explain this? Or rather, can random mutation explain it?” In fact, “[t]here is no evidence that Darwinian processes can make anything of the elegance and complexity of cilia.”

What, then, can random mutation accomplish? What does the evidence show? Much of The Edge of Evolution is an assessment of what we have learned about the power of random mutation from studies of three organisms: the parasite that causes malaria, the HIV virus, and the bacterium E. coli. The malaria parasite in particular has had enormous opportunities to test the limits of random mutation. It has infected billions of humans over its history, reproducing up to a trillion times in each infected person. As Behe interprets the evidence, the age-old warfare between the human genome and malaria has not generated the “productive arms-race cycle of improvements on each side” that Darwinists portray, but rather “a destructive cycle, more like trench warfare, where conditions deteriorate.”

To build up rather than tear down requires “multiple coherent genetic mutations” and the kind of top-down organization and planning that Darwinian processes cannot provide. Here Behe devotes considerable attention to the technical details involved in getting even a few proteins to work together constructively. To those who say that given enough time anything can happen, Behe responds that “the chief factor in evolution” is not time but “population numbers.” The malaria cell and the HIV virus have each produced something like a hundred billion billion (10²⁰) copies without developing anything “significantly new or complex.” Indeed, “[t]he intensive studies of malaria discussed in this book are the equivalent of a Michelson-Morley experiment [which in physics disproved the existence of the ether] for Darwinism…. Darwinism’s most basic prediction is falsified.” Behe’s conclusion: “The elegant, coherent, functional systems upon which life depends are the result of deliberate intelligent design.” (Those who wish to follow the technical aspects of the ongoing debate between Behe and his critics can do so at his Amazon blog.)

In his final chapters, Behe presents his own “extended fine tuning” interpretation. This enlarges and extends the fine-tuning (and purposeful design) that many researchers find in physics and cosmology (e.g., the laws of nature, physical constants, amount of matter in the universe, etc.) to include the properties of elements and chemicals (including biochemicals like DNA), the origin of life, cells, multiprotein complexes, molecular machines, and the basic divisions of the biological world from kingdoms down “at least to the level of the major classes of vertebrates, perhaps further.” The “edge of evolution”—the line that separates what unguided evolutionary processes can do from what they cannot do—lies somewhere between the major classes of vertebrates and individual species. Accordingly, random mutations and natural selection can account for much of the variety of the living world but not the largest kinds of differences, nor the “stupendously complex structures” found in cells.

Design, which is “the purposeful arrangement of parts,” requires “[r]ational agents…to coordinate pieces into a larger system.” Just how did the designer coordinate the parts of the DNA, of the intraflagellar transport, of the many other complex machines in the cell? As William Dembski, the principal theorist of Intelligent Design, has written, I.D. “is not an interventionist theory at all.” It seeks not to explain how the designer operated in natural history, but simply how to discern evidence of design in nature. Nonetheless, in his final chapters Behe offers some tentative speculations about the designer’s acts.

The origin of life, he writes, “is best viewed not as lawlike, but as one more of the long, long chain of anthropic ‘coincidences’ very, very finely tuned to yield life. In this view the origin of life was…purposely arranged,” perhaps involving a string of collisions and chemical reactions in the “primeval ocean” that resulted in the first cell. Later, although most mutations were random, “many were not…[and] felicitous mutation kept piling on felicitous mutation.”

What drove these felicitous mutations? At first, Behe seems to accept the notion of an “active, continuing involvement of a designer” in the natural world: if “continuing ‘interference'” is required to explain the design of our world, “we should be happy to benefit from it.” But then he attributes this conclusion to “a lack of imagination”: “[t]here’s no reason that the extended fine-tuning view I am presenting here necessarily requires active meddling with nature any more than the fine-tuning of theistic evolution does.” This is because “intelligent design is quite compatible with the view that the universe operates by unbroken natural law, with the design of life perhaps packed into its initial set-up.” Hence, “[t]hose who worry about ‘interference’ should relax. The purposeful design of life to any degree is easily compatible with the idea that, after its initiation, the universe unfolded exclusively by the intended playing out of natural laws.”

This appears to be Behe’s preferred position, and it raises at least two issues. First, what of the creation of the first cell, the beginning of life, which, according to him, “is best viewed not as lawlike”? Doesn’t “not as lawlike” mean that no set of laws or initial conditions could ensure the creation of life, that some active “interference” was necessary? Second, mutations are errors introduced when DNA is copied through the chemical and physical processes of the cell. Copying errors occur, nearly all apparently randomly, in ways and at rates that scientists can measure. But the felicitous mutations that evolution requires are not, according to Behe, random at all. How is it, then, that the “playing out of natural laws,” given certain finely tuned initial conditions, could give rise to a succession of essential felicitous mutations? Are the mutations somehow programmed into matter at the time of the Big Bang, or perhaps into the first cell? It is hard to conceive how the former could be true; and, in the latter case, one might well ask: where did such a program reside? Did the first DNA molecule somehow include within it instructions for how and when it should mutate as cellular processes produced copies over billions of years? Did such a program reside elsewhere in the cell? Thus, it is not obvious that Behe has solved the problem of accounting for a succession of felicitous, non-random mutations without “interference” by the designer, however persuasive his case for the creative limits of random mutation. Nonetheless, Behe will accept “continuing interference” if that is where the science leads.

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When scientists infer design from the discoveries of science (as Gingerich, Collins, and Behe all do-although the first two limit their inferences to physics and cosmology), what should we call the reasoning process that leads them to their conclusions? Near the end of his book Behe asks whether this is “science, philosophy, religion, or what”? Surely, computing that the balance between the forces of expansion and contraction at the moment of the Big Bang had to be accurate to one part in 1059to get a universe hospitable to intelligent life is not philosophy, metaphysics, or theology as commonly understood. The same can be said for calculating the likelihood that a variety of different proteins with their peculiar shapes, binding sites, and chemical forces could self-assemble into a coherent and functional whole. Behe argues forcefully that design is “a completely scientific conclusion,” with “scientific” defined as “any conclusion that relies heavily and exclusively on detailed physical evidence, plus standard logic. No relying on holy books or prophetic dreams. Just the data about nature that is publicly available in journals and books, plus standard modes of reasoning.”

Why should it matter what we call this reasoning process? It matters because those who relegate issues of design entirely to philosophy, metaphysics, or theology imply that natural science has nothing to say about the matter. Yet scientists hold that Darwinian evolution is a scientific theory, that its claim that random mutation and natural selection were sufficient to progress from the first cell to modern man and the rest of the living world is indeed a scientific claim. Surely, then, testing that claim through the weighing of evidence and, where appropriate, mathematical and logical reasoning must also be a scientific activity. If not, then Darwinism is a scientific theory impervious to scientific refutation. The testing of Darwinism’s claims is, of course, a large part of the Intelligent Design enterprise and the whole point of The Edge of Evolution.

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For Correspondence on this review, click here.