The Magazine

Survival of the Evolution Debate

Why Darwin is still a lightning rod.

Jan 16, 2006, Vol. 11, No. 17 • By ADAM WOLFSON
Widget tooltip
Single Page Print Larger Text Smaller Text Alerts

WHAT IS IT ABOUT EVEN the slightest dissent from Darwin's theory of natural selection that drives liberal elites (and even some conservative elites) bonkers? In the 1920s, in the days of the Scopes trial, it was the fact that anyone could believe the story of Genesis in a literal way that offended the delicate sensibilities of our cultural mavens. Then in the 1970s it was something called "creation science" that drove them apoplectic. Today it is the heresy of "intelligent design" that they seek to extirpate root and branch. To paraphrase H.L. Mencken, liberals are haunted by the specter that someone, somewhere harbors doubts about Darwin's theory.

But in truth most people nowadays do believe evolution's basics--which is to say that species evolve--and most people believe that natural selection explains part of the change or adaptation. Where there is doubt or disagreement, as there always has been, is over whether natural selection explains everything. Despite what you might think from reading the New York Times, there is nothing indecent or philistine about this question, a question Darwin himself considered of the utmost importance. As he commented in On the Origin of Species, "If it could be demonstrated that any complex organ existed, which could not possibly have been formed by numerous, successive, slight modifications, my theory would absolutely break down."

Enter in the 1990s the intelligent design movement, also known simply as ID, an interconnected group of biochemists, mathematicians, and philosophers of science who argue that certain forms of biological complexity, what they call "irreducible complexity," cannot in fact come into being by Darwin's "numerous, successive, slight modifications" but require instead an intelligent designer. Some scientists with first-rate credentials, namely Michael J. Behe and William Dembski, are the driving intellectual force behind the theory of intelligent design. Relying in particular on recent discoveries in biochemistry and mathematical physics, they argue that Darwin's theory of evolution by natural selection cannot explain the existence of some complex biological systems. That is to say, the emergence of these systems is neither mathematically nor biochemically plausible without some intelligent designer in the background. For example, according to the biochemist Behe, we haven't a clue how certain highly complex biological systems at the cellular level, such as the mechanism of blood clotting, could have emerged via natural selection. "All parts must function in synchrony or the system breaks down," he explains.

In making such claims the IDers are putting old wine in a new bottle. Some version of the design thesis is to be found in the philosophy of Thomas Aquinas and, perhaps most famously, in the writings of William Paley. The 18th-century English theologian argued that when we find a watch we infer a watchmaker; so too when we discover evidence of design in nature we properly infer a Maker or Creator. The basic point is that one can make a legitimate, rational inference from the orderliness and regularity of the cosmos to some sort of intelligent first mover. And it's important to point out that this inference was thought, up until recent times, to stand on its own merits, requiring no assistance from Divine Revelation.

In rejecting this inference, Darwin himself was hardly a path breaker, though clearly his assault on the inference was one of the most powerful ever made. For example, before him, the philosopher David Hume unleashed an influential critique of the notion of what he called an "intelligent cause"--a notion he viewed as utterly useless and uncertain. In sum: This is a venerable debate, indeed, and one that has never been settled.

But is this really a scientific debate, a question that science in the strict or modern sense of the term can solve? Here's where things get tricky. It is the contention of many IDers that their case for intelligent design is science, and that it should thus be taught as a part of the science curriculum in the public schools. Similarly, it is the mantra of the Discovery Institute, a think tank dedicated to furthering the cause of intelligent design, that the controversy between intelligent design and natural selection should be a part of any science curriculum. Even President Bush has weighed in on the matter, declaring that "both sides ought to be properly taught."

ID's liberal critics disagree, calling intelligent design a cover for religion, and in late December, in the case of Kitzmiller v. Dover, a federal judge reached the same conclusion. At issue was the constitutionality of including in the science curriculum the reading of the following statement: "Intelligent Design is an explanation of the origin of life that differs from Darwin's view. . . . With respect to any theory, students are encouraged to keep an open mind."