The Design Interference

October 2002
by Steven Novella, MD

Over a century ago Charles Darwin convinced the scientific community of the fact that life on Earth is the product of organic evolution and that natural selection is the primary mechanism of evolution. Since that time scientists have been almost completely united in their support of evolutionary theory, which has thrived and progressed, revolutionizing our understanding of biology and natural history. Yet the majority of the American public remain unconvinced (only 49% endorse some kind of evolution according to 1997 Gallup poll), both resulting in and resulting from a continued grass-roots social, political, and religious movement against evolutionary thinking.

This movement has taken many forms over the years but always at its center is the pseudoscientific denial of evolutionary theory. At first the movement was simply anti-evolution, preaching that evolutionary theory is both evil and wrong. The early conflict reached its most dramatic climax with the Scopes “monkey” trial, in which Clarence Darrow defended a school teacher who was arrested for teaching evolution. Many people do not realize that the trial was ultimately a victory for the anti-evolutionists, tainting evolutionary ideas as controversial, causing science textbook publishers to cowardly shy away. This strategy, however, began to falter after Sputnik inspired a generation of support for science education in an America still paranoid of communist domination.

In the wake of Sputnik the anti-evolution movement made several failed attempts at blocking the teaching of evolution in public schools. Following these failures the movement recast itself in the 1970’s and 80’s as “creation science” and attempted to lobby for equal time for creation alongside evolution in public schools. Here the battle cry was not “evolution is evil” (at least not to the public at large) but rather, “can’t we just have equal time in the name of fair play.” But despite marshalling the support of a few Ph.D. creationists and forming some scientific sounding organizations, like the Institute for Creation Research, nobody was fooled (at least not the Supreme Court). Creation science was not science at all, just good old-fashioned evolution-denying creationism.

In the last decade a new crop of creationists have been trying out a new costume, called intelligent design (ID). Again, as we will see, ID proponents have no new scientific arguments to bring to bear against evolution, but they have been successful is wrapping creationism in more sophisticated jargon.

Intelligent Design

Among the proponents of ID are Philip Johnson, a lawyer whose main contribution is the criticism that science is based on methodological naturalism, which by necessity excludes any supernatural explanation. Therefore science is “rigged” from the beginning to exclude god as an explanation for any natural phenomenon.
Michael Behe, author of Darwin’s Black Box, coined the term “irreducible complexity.” He argues that nature displays structures which are too complex to have arisen by random processes, and could not function if they were any less complex than they are (therefore irreducible). Therefore, he argues, they could not have evolved and must have been designed. His favorite example is the bacterial flagellum, a tiny protein motor which some bacteria use for locomotion.

William Demske, Executive Director of the International Society for Complexity, Information and Design (ISCID), and author of The Design Inference and No Free Lunch, has also championed Behe’s irreducible complexity, which he calls “specified complexity.” Demske also has added the argument (although not original to him) that information theory rules out evolution because it does not allow for a system which spontaneously increases its specified complexity over time.

At the recent World Skeptics Congress in LA, I had the opportunity to attend a panel discussion on intelligent design. William Demske was there to defend ID, along with Paul Nelson, a “young Earth” creationist and editor of the journal Origins & Design. It was an excellent opportunity to examine the claims of ID proponents first hand. There was even an informal chat with Paul Nelson afterward where I had the opportunity to press him on certain specific questions. (Demske, who displayed a foul mood throughout the conference, did not attend.) I was gratified to learn that ID proponents indeed have nothing new to say. They really are just pushing warmed over creationism in a new box, but they have added a few new twists and logical fallacies that are worth exploring.

The God of the Gaps

The core argument of ID is that life exhibits very complex structures that evolutionary biologists have yet to explain fully. In other words, there are gaps in our current knowledge of how certain things evolved – the nitty gritty details of what exactly evolved into what. Demske characterized these gaps in our current knowledge as “vast lacunes.” In the absence of a detailed evolutionary explanation of how, for example, the bacterial flagellum evolved, ID proponents argue that we must invoke an intelligent designer. The style of argument has been dubbed the “god of the gaps” by unimpressed scientists. The first time it was applied to the origin of life was almost 200 years ago by Paley, who drew the analogy of walking on the beach and finding a watch. The complex and purposeful design of the watch implies a designer, he argued.

There are many fallacies in this style of argument. First, it is fundamentally the logical fallacy of the argument from ignorance – basing a conclusion on a lack of information or understanding. We cannot currently explain how something evolved, therefore god (now referred to as ID) must have made it. This is akin to saying “I do not know what that dot of light in the sky is, therefore it is an alien spacecraft.” This is not a scientific style of argument, primarily because it is not testable or falsifiable. Science requires positive evidence for the hand of a designer (or the existence of an alien spacecraft). When pressed on this, Demske offered that it is testable, and he would be satisfied if an adequate evolutionary sequence were presented for a structure that was previously thought to be irreducible. Ah, but we have heard this so many times before from the creationists. Ken Miller, one of the defenders of evolution on the LA panel and author of Finding Darwin’s God, correctly pointed out that the creationists will only be deprived of their god of the gaps argument when the evolutionary history of every structure, tissue, organ, and organism were fully explained down to the last detail, which of course will never happen. Paul Nelson, when I pushed him on this issue, agreed that the argument from ignorance will never be convincing and that the ID camp must develop a program of positive and testable ID research. Indeed, one strategy of the ID camp is to promise that such research is coming – meanwhile even they admit that it hasn’t yet. While we are waiting (don’t hold your breath) they should abandon any pretense to doing real science.

As stated above, the god of the gaps strategy is simply focusing on what is currently lacking in our understanding of the details of evolutionary history. Not only is this strategy logically flawed, but it is also myopic in an historical sense. ID proponents look at our current knowledge only, point out existing gaps and proclaim, “Aha! Gaps. We must invoke ID to fill them.” The most generous interpretation of this argument is that evolutionary theory has been unable to explain nature as we see it, and therefore must be abandoned or modified (by the inclusion of ID, they argue). However, in order to fairly assess how evolution has performed as a scientific theory, to see if it really deserves to be abandoned or modified, we need to consider the entire history of the theory.

When we look at a century and a half of evolutionary science since Darwin, we find a history of progressively shrinking gaps. Many challenges have been placed before evolutionary theory, and they have mostly been met with stunning success. The discovery of genetics has confirmed a mechanism of inheritance which is compatible with natural selection. Genetics has also validated evolution by producing a map of inheritance that nicely conforms to the fossil record and an evolutionary tree formulated according to morphology alone. Creationists have railed for years about the lack of connections between major groups, and paleontologists have answered with exquisite species connecting birds to dinosaurs, whales to terrestrial mammals, man to apes, mammals to reptiles, and many others. There has been an endless stream of fossils filling in the gaps in an evolutionary pattern.

ID, I would argue, is partly a necessary reaction on the part of creationists to the stunning success of evolutionary theory. They have retreated from an ever advancing fossil record and understanding of biology and genetics all the way down to the smallest and most complex structures in nature. They have retreated to microscopic structures that do not fossilize, and complex enzyme pathways in order to find the gaps they need to fuel their logical fallacy. Wesley Elsberry, the other scientist defending evolution at the conference, quipped that their “god of the gaps” has become a “god of the crevices.”

Disinformation about Information Theory

Another major component of the new ID assault on evolution is based upon information theory, or at least their misinterpretation of it. To my disappointment, this topic did not come up at the conference, but I guess we couldn’t cover everything.

The information theory attack is yet another strategy of creationists which attempts to disprove evolution in a single stroke, by proving that it is impossible. Creationists are very fond of the single-stroke approach, since it saves them from the messy work of having to deal with all of that inconvenient evidence for evolution. Evidence for evolution becomes irrelevant if it is impossible in principle.

Their argument is basically that information theory, which deals with the ways in which the information contained within a system can change, demonstrates that evolution cannot produce an increase in specified information over time. Natural selection is a process which eliminates information, they argue, by selecting against those that are not fit. It therefore does not add any new information to the system. Mutations, they argue, add only random information, or represents a degradation of information, and therefore cannot add specified complexity.

Here again, creationists demonstrate their ability to get things only superficially correct but to miss a true understanding of the material. Their argument is the logical equivalent of saying that cars cannot possibly operate because the engine is not capable of steering the vehicle, and the steering column is not capable of propelling the vehicle. Correct, but irrelevant.

Mutations do increase the raw amount of information in a living system. Recombination, the mixing together of genes from parent individuals in their offspring, also increases variability and in fact has a much greater effect on genetic variability than mutations. Natural selection then provides for differential survival of those individuals with the mutations or genetic variability that provides some specific survival advantage.

The increase in specifically complex information in living systems which occurs through organic evolution is therefore a two-stroke process: increased random information followed by natural selection. In this way meaningful (specified) information can increase over time.

The Wedge

In 1991, Philip E. Johnson, a law professor, published his now infamous Wedge document in which he stated that the goals of the ID/Creationist movement are twofold: to promote the acceptance of ID in education and academia; and to challenge naturalism as the foundation of science. ID is therefore the sharp edge of a wedge that will be driven into mainstream science, dethroning naturalistic materialism with a more theologically friendly science. Yes, this is exactly what creationism critics have been warning against all these years – a (not so) hidden agenda to promote religion as science.

This “wedge” strategy remains an important goal of the ID movement, which they freely admit. This is therefore not solely a scientific argument over the best interpretation of available evidence (and in fact there has been no serious such debate for over a century) but rather a debate over the proper philosophy which should underlie the scientific endeavor. ID critics would charge that the ID movement is at its core an attempt to interject religion into science, and the “wedge” strategy seems to reflect that.
But how do the ID proponents view the debate. The ISCID (Demske’s organization) website opens with the following statement:

“The International Society for Complexity, Information, and Design (ISCID) is a cross-disciplinary professional society that investigates complex systems apart from external programmatic constraints like materialism, naturalism, or reductionism.” ( )

This stance was defended by Paul Nelson and William Demske at the conference. What they are claiming is that evolutionary scientists are not playing fair. They are eliminating from consideration the design inference because methodolocial naturalism does not allow for hypotheses which involve supernatural agents. God is eliminated from consideration a priori. In a world with a god, methodological naturalism is doomed to fail in its search for truth, because the truth is not contained within naturalism.

Philip Johnson and others go as far as to characterize naturalism as just another religious philosophy. Therefore, evolutionists are not practicing objective science but rather are simply displaying faith in the religion of naturalism. This style of argument on the part of the ID proponents strikes at the heart of science and skepticism.

The naturalism argument is flawed in two major ways. The first is that the accusation that ID is being dismissed a priori and not being given a fair hearing is untrue. ID does not hold up on its own merit, based upon evidence as logic, as the earlier part of this article demonstrates. If it did, then it would be given consideration, and scientists would search for a naturalistic explanation to explain the appearance of design in nature.

Also, proponents often claim that ID does not imply a deific creator – all they are arguing is that nature shows evidence of a designer, but they don’t know who or what the designer is. Such statements are meant to sound objective and scientific, and have successfully fooled some (sharpening the thin edge of the wedge). But in reality such statements are disingenuous and coy; ID proponents know exactly who the designer is. The naturalism argument contradicts their coy denial of this, however. If ID does not imply a supernatural designer, then why would scientists dismiss it as not being naturalistic?

The second, and actually primary, flaw in the naturalism argument stems from a fundamental misunderstanding of the nature of science itself. Science, by the very nature of its method, must only consider hypotheses that can be empirically tested. It does not allow for any steps which are not at least potentially grounded in physical evidence. Scientists are not allowed the functional equivalent of “and then a miracle happens.” In other words, arbitrary outside agents with unconfined properties and abilities cannot be introduced to solve problems, fill gaps in understanding, or explain scientific mysteries (methodological naturalism).

What the ID camp does not understand is that methodological naturalism as described above is not a simple choice that scientists make because of philosophical dedication (philosophical naturalism), but rather a necessity born of the methods of science. Introducing arbitrary omnipotent agents does not work in science because such agents are compatible with all possible evidence, and therefore they are not testable and falsifiable.

With respect to ID, the intelligent designer could have designed nature to look like anything it desired. Therefore, all possible observations in nature are compatible with ID (formulated in this non-scientific way). Nature looks the way it does because the designer designed it that way. Is there any possible way nature can look or behave which is incompatible with the designer? No.

Paul Nelson reflected this style of thinking during the conference. He criticized the arguments of some evolutionary scientists, who have argued that nature displays features which do not look designed. For example, (to borrow from Gould) hens have the genetic information to grow teeth, which are never expressed. Nelson dismissed all such arguments by saying that we cannot question the mind of the all-powerful designer. Therefore it is not possible for nature to “not look designed.”

Demske has adopted a more subtle form of this circular logic. Unlike Nelson, Demske is an “old Earth” creationist. During the conference he presented his views as accepting that life on Earth is billions of years old and has changed in an evolutionary pattern over time. Therefore his views are compatible with an evolutionary interpretation of the fossil record, biochemistry, and genetics. Where he departs from evolutionary theory is that he does not believe natural selection is capable of being the sole mechanism of evolution. There must, he argued, have been a property inherent in living matter which propelled its evolution. That intrinsic force is the power of the intelligent designer – god.

So Demske has dealt with all the physical evidence for evolution (in essence by accepting it as an historical fact) but retains the notion that there is an omnipotent designer as the mechanism, rejecting that blind natural selection could be adequate by itself. Although this hypothesis is more rational and sophisticated than Nelson’s “young Earth” creationism model, it suffers the same logical problem that at its core it cannot be tested. Despite the fact that Demske boasts that he is on the verge of creating a positive research program, all he has left himself is the god of the gaps argument from ignorance.

Both Demske and Nelson (and in fact all ID proponents) are trapped in a closed loop of circular logic – nature looks like it’s designed because it cannot possibly not look that way because the designer is omnipotent and can seamlessly create any possible natural world by a supernatural mechanism which can look exactly like evolution.
What about the claim by ID proponents that methodological naturalism is not capable of dealing with a supernatural world? Well, that’s true. If it turns out that we do live in a supernatural world, scientific methods will ultimately prove inadequate to fully explain nature. At best, science could identify anomalies that would forever defy explanation.
And here lies a critical point in the battle between scientific skepticism and supernaturalism – how long must an anomaly go unexplained before it is reasonable to conclude that it cannot be explained scientifically, and therefore supernatural forces should be invoked? True believers leap to a supernatural explanation after only a perfunctory consideration of scientific explanations (that blob of light on my picture must be a ghost). Philosophical naturalists would say never (a reasonable position to take). ID proponents have argued that evolution has already failed to explain anomalies (complexity), and therefore ID is warranted.

I’m not sure if I am a philosophical naturalist, or a strict methodological naturalist, but either way I would say that so far the two are functionally the same. Scientific knowledge in general, and evolutionary theory in particular, have succeeded wonderfully since their inception. Scientific and evolutionary knowledge have continued to progress relentlessly forward. Intractable problems may last for a few years or decades, or even centuries, but eventually fall to expanding understanding. I argue that it is reasonable to look upon the history of science as a metaexperiment in methodological naturalism that so far strongly argues for its validity. Evolutionary theory too has not stalled, it has not run up against intractable anomalies, and the progress and success that it enjoys continues to make more and more greater fools out of its deniers.


On September 26th 2002 Cobb County, the second largest school district in Georgia, voted to allow alternate theories of origin, including Intelligent Design (but not “creationism”), into its public school science classrooms. The school board that voted for this cited the “evolution is only one theory” and “it is only fair to present all sides of a debate” arguments to defend their decision.

Evolution deniers, clearly motivated by their prior religious beliefs, continue to relentlessly attack the idea of evolution, attacking the foundations of science in the process. They have already done, and continue to do, significant harm to the quality of science education in the United States. ID is only their latest effort, and represents an evolution in the sophistication of their strategy. The complexity of ID arguments, the subtlety of their illogical and misinformation, and their popular appeal to fair play and intellectual openness, make ID proponents very dangerous and seems to be more than a match for a public that creationists themselves have helped to make largely scientifically illiterate.