Michael J. Behe
The Design Debate
Does science point to the existence of intelligent design in the universe? How would we know design if we saw it? Is talk of "design" simply outside the boundaries of science? Such questions have been given urgency in the past decade by the emergence of new arguments against the Darwinian consensus, as exemplified by Michael Behe's widely reviewed book, Darwin's Black Box (1996). To some Christian thinkers, including B&C contributing editor Phillip Johnson, this movement is nothing less than an intellectual revolution, toppling the dictatorship of naturalism, while others—including many in the sciences—regard the intelligent design movement as another wrong turn, leading away from the reconciliation of science and faith and bringing embarrassment and disrepute to the church.
Dean Overman's book, A Case Against Accident and Self-Organization, is another volley in this debate. Like Johnson, Overman is a lawyer, and if he lacks Johnson's superb rhetorical skills, he nonetheless displays a powerful intellect and a lawyerly ability to make a case. His book comes with recommendations from prominent Christian scientists such as cosmologist Owen Gingerich and mathematical physicist-turned-Anglican priest John Polkinghorne (who is interviewed in this issue). Alister McGrath, a theologian with scientific training, also commends Overman's book to our attention. We asked biochemist Michael Behe and biologist Rebecca Flietstra to review Overman's book. Then Behe and Flietstra were given the opportunity to respond to each other's arguments.
Books & Culture is committed to more extensive coverage of science. One purpose of that coverage will be to counter the widespread evangelical notion that science and faith are inherently antagonistic—that is, when science is not being ignored altogether. (Have you looked at the science section in a Christian bookstore lately?) At the same time, we will continue to cover important debates generated by the clash between reductive materialism and a Christian world-view, as well as debates among Christians (and other theists) who tell competing stories of the universe.
Tulips & Dandelions
Michael J. Behe
Yellow flowers grace my yard and my neighbor's yard. His yellow flowers—tulips—grow neatly around his mailbox. My yellow flowers are dandelions, scattered hither and yon. Anyone walking down the street would easily realize that my neighbor arranged his flower bed on purpose. Few would think the same of my flowers.
How do we recognize intelligent design? We ourselves are intelligent beings, acting to accomplish our purposes, and we are adept at discerning telltale signs of intelligent activity. Every day of our lives we decide that certain things were purposely arranged, other things not. But how do we do that? How do we distinguish a cultivated flower bed from a patch of weeds? A chance meeting from a conspiracy? Radio noise in space from a message sent by aliens? A random universe from an arranged one?
Throughout history the detection of design has been a rather intuitive business. As is said of pornography, we couldn't define it, but we knew it when we saw it. That is changing. Prodded by developments in several branches of science, the subject of design itself is coming under scrutiny and being put on a more rigorous footing.1
Briefly (too briefly), we recognize design when we apprehend "specified small probability": a highly improbable event that fits a pattern. The arrangement of tulips around my neighbor's mailbox is highly improbable, and the pattern beautifies his yard. Radio waves coming from space, spelling out "Greetings Earthlings" in Morse code, are highly improbable, and the message is a recognizable pattern.
Rigorously defining the concept of design, discerning criteria to detect it, and applying those criteria to real-life examples, are interesting intellectual exercises. It's fun to know why you judge one event to be random, and another to have been purposefully directed. But what if you get more than you bargained for? What if you find that not only is the tulip bed designed, but so is the tulip? What if all the world's a stage—with a real set designer?
These are questions unexpectedly confronting science at the end of the millennium. Dean Overman's fine book, A Case Against Accident and Self-Organization, compiles many of the features of the universe and life that fit the criterion of specified small probability: highly improbable arrangements that function to permit life. The book is conceptually divided into two parts: the intractability of the problem of the origin of life, and the "fine-tuned" physical features of the universe. Let's reverse that order and first discuss the fine-tuning of the universe.
In the nineteenth century, the cosmos seemed a rather featureless place and matter was pretty bland stuff. For all science could tell, the universe—even the earth itself—had always been there and always would be. As James Hutton observed in a textbook of the time, there were no signs of a beginning nor prospect for an end. But all that has changed. The electron, proton, and neutron were found to be hiding in matter, and ever-more exotic subatomic particles have been teased out of the nucleus in this century. In the 1920s light coming from distant galaxies was discovered to differ in wavelength from earthly light. This was interpreted as showing that galaxies are racing away from each other, as if in the aftermath of a gigantic explosion—the Big Bang.
by Dean L. Overman
foreword by Wolfhart Pannenberg
Rowman & Littlefield
244 pp.; $24.95
The heavier elements (those with more protons than helium) were shown to originate in the nuclear processes of stars, and to be released in the catastrophic explosions of supernovas. By the middle of the twentieth century, the universe was a decidedly complicated place.
In the mid-1970s, the physicist Brandon Carter published an article entitled "Large Number Coincidences and the Anthropic Principle," first pointing out that the universe is suspiciously suited to foster life. Since then, as Overman cites, other physicists have agreed. For example, Stephen Hawking writes: "The remarkable fact is that the values of [the charge on the electron and the ratio of the masses of the proton and the electron] seem to have been very finely adjusted to make possible the development of life." The Oxford mathematician Roger Penrose has calculated the precision necessary to set up a universe like ours: "This now tells us how precise the Creator's aim must have been: namely to an accuracy of one part in 10^10123. This is an extraordinary figure. One could not possibly even write the number down in full, in the ordinary denary notation." One part in 10^10123 is a very small probability indeed, and specified for the occurrence of life.
Living things also have turned out to be considerably less likely than science first thought. Under midnineteenth-century microscopes, the cell looked like a nearly featureless glob, and Ernst Haeckel declared it to be a "simple little lump of albuminous combination of carbon," not much different from a microscopic piece of Jell-O. Scientists of the age thought that such a simple thing might just spontaneously pop up from sea mud.
It seems they were wrong. Now we know that even the "simplest" cell is sophisticated far beyond any technology that humans have yet produced. The hope that science might be able to explain the origin of life by common chemical processes—engendered by the experiments of Stanley Miller in the early 1950s—is now known to have been quite nave.
Indeed, quotations by scientists freely admitting the mystery of life's origin are not hard to come by. For example, in 1996 the biochemist Franklin M. Harold wrote: "The origin of life stands as the most profound mystery in biology; and we note in passing that, despite all the achievements of investigators in pre-biotic biochemistry, it remains utterly beyond our comprehension." (Curiously, it is easier to find such frank admissions in the science literature than in the popular press. For example, National Geographic recently ran a glib story on the origin of life, neglecting to mention the intractable problems scientists have encountered.)
The flip side of the difficulties facing an undirected origin of life is the specified small probability of cells, which points insistently to design. Information storage (DNA, RNA), information retrieval (genetic code, ribosomes), synthesis of chemical constituents (nucleotides, lipids), and much more have to be delicately interwoven in any viable cell.
Dean Overman stops here, concluding design from the fine-tuning of the universe and the origin of life. But there is good reason to think one can go much further. Two years ago I explained in Darwin's Black Box why many cellular and biochemical systems (not necessary for the bare origin of life) are resistant to the usual Darwinian stories and are better understood as the result of deliberate intelligent design. Quite possibly that conclusion will also extend to the higher levels of biology.
What does all this mean for a Christian? On the one hand, not much. The faith of Christians rests on the historical reality of the events recorded in the Gospels rather than on the next theory coming out of the laboratory. By definition, Christians already believe in design because they believe in a Designer.
It turns out that another way to know that something has been designed, besides specified small probability, is for someone to tell you of the design. If your wife tells you she rearranged the furniture, then you know it wasn't the random actions of your children that changed the living room decor. Through his personal revelation (a source that is not considered by science), God has told us that he designed life. We don't need science to tell us that the universe and life are designed any more than we need science to tell us that they had a beginning.
On the other hand, scientific evidence of design means a lot for Christians, for a couple of reasons. First, an understanding of God's creation allows us to take greater delight in his works. When we see the planning, precision, and detail required for the creation of life, we more fully appreciate his power and better realize that our lives are in strong hands.
Second, Christians live in the world with non-Christians. We want to share the Good News with those who have not yet grasped it, and to defend the faith against attacks. Materialism is both a weapon that many antagonists use against Christianity and a stumbling block to some who would otherwise enter the church. To the extent that the credibility of materialism is blunted, the task of showing the reasonableness of the faith is made easier. Although Christianity can live with a world where physical evidence of God's action is hard to discern, materialism has a tough time with a universe that reeks of design.
Dean Overman has done a service in pulling together scientific evidence for design into a slender, readable volume. With the progress of science, however, it is very likely that future editions of the book will grow ever thicker.
A Misguided Quest for Proof
Rebecca J. Flietstra
Christians commonly describe themselves as a "community of faith." This faith, our belief in the inexplicably "foolish" crucifixion and resurrection of Jesus, simultaneously separates us from the world and unites us together as Christ's body. Our history is sprinkled with miracles and visions; our theology embraces events, such as the Incarnation, that we cannot logically explain.
But living by faith creates tensions—the tensions of trying to reconcile what we know and what we hope. And with the rest of society, we often find ourselves searching for proof rather than faith.
Our hunger for proof is reflected in our apologetics. Not too surprisingly, we have discovered that proof is easier to proclaim than promise. And, when it comes to proof, nothing does it better than science. Many evangelical Christians, therefore, have enthusiastically greeted recent news from the academic community that we finally have scientific proof of God's activity in the world. We have uncovered intelligent design.
Although Dean Overman never specifically uses the phrase "intelligent design" in A Case Against Accident and Self Organization, it is clear he supports this theory. Using language from information theory to explore accident and self-organization in terms of their relationship to abiogenesis (life arising from nonliving matter), he concludes that the improbability of abiogenesis points to an originating intelligence.
Overman compares the gulf dividing nonlife from life to the difference between order and complexity. Order describes something that is repetitious and predictable. Complexity, on the other hand, refers to the "information content" or "minimum number of instructions" that completely define a structure. Crystals are ordered; the genetic code of living organisms is complex. The move from crystal to chromosome, according to Overman, is difficult because, as nonliving things become more highly ordered, they tend to become less complex.
Self-organization research, however, including origin-of-life studies, is a relatively young area of scientific study, and it is thus too soon to claim that science shall never find an explanation for how ordered systems may become complex. Further, while information theory currently appears to be an appropriate paradigm for studying abiogenesis, additional research may reveal that the relationship between order and complexity does not adequately model the move from nonlife to life.
Additionally, Overman's argument contains some crucial misunderstandings of scientific method. First, he claims that "inference from the universal to the particular is valid" while "inference from the particular to the universal is not valid." These principles work well in our judicial courts: we start with a universal understanding that murder is wrong, then apply this principle to particular cases. But science is not law; what is necessary for the lawyer is impossible for the scientist. That is, every experiment is a study of the particular, and every theory an "inference from the particular to the universal."
For example, in the early 1800s Theodor Schwann developed the cell theory, which states that all organisms are composed of cells. Schwann had not universally examined individuals from all the different species—or even every individual of a single species—to make sure they were cellularly organized. Instead, he made particular observations of several organisms and developed a universal principle that continues to inform biological studies.
Furthermore, because modern science is necessarily inductive rather than deductive, our understanding of scientific processes, including abiogenesis, is incomplete. For example, biochemist Stanley Miller has shown that an electrical spark applied to a chemical mixture similar (but not identical) to the early earth's atmosphere can produce amino acids. Since this mixture does not exactly replicate conditions present in the early earth, Overman suggests that scientists should not use this experiment as a basis for origin of life theories. Such a conclusion, Overman argues, produces an "invalid syllogism" from an "unwarranted inference" "because most is not all, and there are ingredients in the early earth's atmosphere not included in the mixture so the mixture and the atmosphere are not the same."
But what Overman describes as a logical misstep is more accurately understood as a result of an incomplete understanding of abiogenesis. And so, while it certainly is a leap to move from Miller's experiments to a full-fledged explanation of life's origins, that does not mean it is impossible for us to derive any information from his experiments.
For example, we currently have a limited understanding of cancer prevention and treatment. Thus drugs used for chemotherapy are not always effective. Years from now, when we finally develop a cure for certain cancers, it is doubtful those treatments will employ the drugs currently in use. But those treatments will employ some of the principles that underlie current therapies. Similarly, if we discover that the current mechanisms proposed for abiogenesis are incorrect, it is likely that the principles underlying these mechanisms could still have some validity and applicability.
Of course, as Overman reminds us, even if scientists uncover a workable mechanism for abiogenesis, they must still grapple with the mathematical probability of this event. He cites several studies that have attempted to calculate the odds of producing a living cell, including one that places the odds of producing a single bacterium at 1 in 1040,000. Based on this calculation, Overman makes this startling claim: "Any theory with a probability of being accurate larger than 1 in 1040,000 must be considered superior to random process. The probability that life was assembled by an intelligence has a vastly greater probability."
Besides raising an irreverently obvious question (what numbers enter into calculating the probability of a creator?), Overman's probability argument includes several unsubstantiated assumptions. First, we currently are unaware of all the parameters that may define the development of life from nonlife. And, for those parameters we have identified, we don't know if we have accurately assessed their probabilities. For this reason, it is currently impossible to form an accurate probability calculation.
Second, Overman ignores how contingency, the idea that one parameter restricts other parameters, automatically excludes some outcomes from consideration. It is misleading, therefore, to say that "all outcomes" must be considered. For example, suppose someone decided to produce a genetic replica of me without resorting to cloning. The probability of doing this by a random combination of all genetic possibilities would be extremely low. But the possibility of my parents producing a second "me," while still unlikely, has a much greater probability. Why? Because there are far fewer possible genetic combinations. Going further, rather than trying to produce another "me," my parents' goal could simply be to produce a healthy child—and my specific genetic code is not the only combination capable of producing such a child.
These same considerations must be applied to any analysis of self-organization theories. Besides ignoring contingency, Overman assumes that only one outcome—our present reality—is compatible with life. By "intuition" and according to our current state of knowledge, it may seem that this is the only combination that produces a "healthy" universe. But we honestly don't know how many other combinations could produce life, and probability calculations based on ignorance are not useful.
Third, Overman, by asking "whether the origin was guided, or accidental and by chance," suggests that these two scenarios are diametrically opposed. Instead, a better question might be: "Is it possible to scientifically distinguish between an origin that was guided versus one that is accidental and by chance?" I don't think it is.
Christianity's greatest contribution to modern science has been to differentiate creation from its Creator. As a result, scientists can now study nature independently from a particular understanding of God's characteristics. That is, the same scientific description of a particular biological event could be given by an atheist and by a Christian. This obviously makes many of us uncomfortable—particularly as we reflect on Romans 1:20. If creation gives evidence of a Creator, science should provide proof for God. We expect that the natural world must exhibit some obviously supernatural traces—particularly as relates to the origin of life.
But there are dangers associated with seeking God exclusively in the supernatural. Primarily, this approach often sets up a false dichotomy, confining God's activity to the miraculous and neglecting his providential control over all aspects of the natural world. Subsequently, as naturalistic explanations are uncovered for seemingly supernatural events, God's role in the world appears to shrink. If natural law is involved, we reason, somehow God can't be. Since many naturalistic descriptions invoke chance events, we may thus, with Overman, place God against, rather than over, random chance.
Such reasoning ignores that chance itself was created and may be controlled by God in nonmeasurable ways. Just because we view something as random doesn't mean that it actually is. God could thus work by influencing seemingly random and chance events to guide the emergence of life.
Forfeiting intelligent design's claim of scientific proof for God is admittedly difficult, but not theologically unprecedented. Absolute proof for God from any source, not just science, is hard to find. Jesus himself, God's clearest revelation, is described as both a "precious cornerstone for a sure foundation" (Isa. 28:16) and as "a stone that causes people to stumble and a rock that makes them fall" (Isaiah 8:14; see also 1 Peter 2:1-8). In a similar way, both the atheist and the Christian can look at the same scientific facts and come to the same descriptions of natural processes. But our faith separates us from secular scientists because we know that all these seemingly nonteleological processes are actually under the control of the Creator. Such a faith does not contradict science, nor does it look for God in the gaps of science, but it instead proclaims that God is sovereign over all.
A Response to Rebecca Flietstra
Michael J. Behe
The main point of Professor Flietstra's intriguing review seems to be that Christians should not look for "scientific proof" of what they believe; we live by faith, not by sight. Unfortunately, if we aren't careful, the meaning of that aphorism can easily become distorted into fideism.
Flietstra's chief difficulty is a confusion of proof with evidence. Proof is a concept associated with the deductive reasoning of mathematics or philosophy, and it signifies that something must be accepted by dint of logical necessity. Science, however, does not "prove" anything because, as Flietstra points out, science proceeds by inductive, not deductive, reasoning. Science can only marshal evidence for a hypothesis, always aware that newer data might invalidate it. Because of this intrinsic restriction, no one is logically forced by scientific evidence to subscribe to Christianity (nor does Dean Overman claim otherwise).
Here is an illustration. Nobel laureate Francis Crick has famously proposed that, since an undirected origin of life seems so unlikely, perhaps space aliens sent a rocket ship to Earth in the distant past to seed the planet with life. As this example shows, while scientific evidence may point strongly to intelligent design, people like Crick who are repelled by the supernatural, can always simply refuse to accept design, or they can come up with exotic candidates, such as space aliens, for the role of designer. No one is forced by science to believe in God, let alone in Jesus. Consequently, Flietstra's fear that the role of faith will be eliminated is unfounded.
But even if evidence does not eliminate the need for Christian faith, isn't it better to have less evidence so there can be more room for faith? Of course not. The fallacy of such reasoning is quickly shown by a reductio ad absurdum: If it is better to have less evidence, then it is best to have no evidence. Our faith would be purest if there were no basis for it. Although Flietstra's essay does not go quite that far, it points in that direction.
Faith and evidence are not opposed to each other. On the contrary, faith presupposes evidence. The more evidence I have that a person is trustworthy, the more faith I will have that, say, he will not become corrupted if elected to political office. The more evidence I have that the historical events recorded in the Gospels are accurate, the more faith I will have that their theological claims are true. If Luke alleges that Jesus was born when Cyrenius was governor of Syria, and archaeological studies support it, my faith is strengthened. If Scripture asserts that the universe had a beginning, and astronomical studies support it, again my faith is strengthened.
The clear evidence for intelligent design coming from several branches of modern science is quite congenial to theism. Like archaeological data demonstrating the Bible's reliability, it strengthens our faith without replacing it. We should recognize the limitations of any scientific theory, but we should not disdain supportive evidence out of a false humility.
A Response to Michael Behe
Rebecca J. Flietstra
For advocates of intelligent design, the presence of highly improbable events in the natural world proves there is an originating intelligence. As Michael Behe says, "We recognize design when we apprehend 'specified small probability'—a highly improbable event that fits a pattern." As such, we could say that yellow tulips in a flower bed give the appearance of design, while a lawn dotted with yellow dandelions does not.
The appearance of design, however, is not necessarily evidence of a designer. The human eye is overly eager to detect design, and the human brain is equally ready to come up with simplistic stories to explain putative design. In previous centuries, people observed that mushrooms commonly grew in circles. Convinced that these rings of mushrooms could not arise from natural causes, they supposed that some sort of supernatural event—the dancing of fairies—caused the circular design to appear. Even today, many skeptics are unwilling to accept that the "face" on Mars is only a trick of lighting on an uneven terrain.
The simple use of mathematics does not guarantee a firmer foundation for design than intuition. A probability calculation's reliability depends on the accuracy of our original assumptions. These, in turn, are based on our correct understanding of all the parameters governing a particular event. When it comes to origin-of-life studies, most biologists recognize that our understanding of the parameters affecting abiogenesis is currently so limited as to render probability calculations based on these parameters virtually meaningless. Such attempts are comparable to a sixteenth-century scientist trying to calculate the probability that the Copernican view of the universe was correct. The appropriate data simply do not exist; more experiments are required.
By uncritically presenting the probability equations catalogued by Overman, Behe tacitly suggests that these calculations accurately describe the probability of life's origin. Behe's acceptance of Overman's numbers is not surprising, since Behe makes similar probability assumptions in his book, Darwin's Black Box. For example, Behe suggests that all 19 proteins of the blood-clotting cascade needed to appear simultaneously with their production and activation instantly balanced in a way compatible with life. Such a scenario would indeed render a Darwinian account highly improbable.
Behe's assumptions, however, may be premature. We cannot simply assume that the blood-clotting cascade could only appear as a complete system to be functional. Because there is a real possibility that this apparently irreducibly complex system may have arisen in a step-wise manner, any probability calculation based on the presumption that this entire system instantly appeared is without foundation.
Because probability calculations can drastically change as our scientific knowledge increases, it is extremely important that we, as Christians, do not use these calculations as proof for God. For, if we base our apologetic on presumably supernatural events that are subsequently explained by naturalistic processes, God appears to shrink. Such an apologetic eventually compromises our spiritual witness rather than "showing the reasonableness of the faith."
At the same time, we must reject materialism, the belief that the physical world is all that there is, not because there are scientific things "utterly beyond our comprehension," but because we recognize that without God nothing could happen—or even exist. We don't need to inject God into natural history in order to explain scientific mystery because our God is entirely capable of working supernaturally through apparently natural processes—not just in the miraculously large steps touted by Overman and Behe.
Michael J. Behe is a professor of biochemistry at Lehigh University and a fellow of the Discovery Institute. Rebecca J. Flietstra is assistant professor of biology at Point Loma Nazarene University.
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