Defending Science by Defining It

By David Brown and Rick Weiss
Washington Post Staff Writers
Wednesday, December 21, 2005

The opinion written by Judge John E. Jones III in the Dover evolution trial is a two-in-one document that offers both philosophical and practical arguments against "intelligent design" likely to be useful to far more than a school board in a small Pennsylvania town.

Jones gives a clear definition of science, and recounts how this vaunted mode of inquiry has evolved over the centuries. He describes how scientists go about the task of supporting or challenging ideas about the world of the senses -- all that can be observed and measured. And he reaches the unwavering conclusion that intelligent design is a religious idea, not a scientific one.

His opinion is a passionate paean to science. But it is also a strategic defense of Darwinian theory.

When evolution's defenders find themselves tongue-tied and seemingly bested by neo-creationists -- when they believe they have the facts on their side but do not know where to find them -- this 139-page document may be the thing they turn to.

"That will be extremely useful not only in future cases but to the scientific community, to science teachers and others who are struggling against this tremendous pressure to bring religion into the classroom," said Alan I. Leshner, chief executive of the American Association for the Advancement of Science, the largest general science organization in the country.

Halfway through his opinion, Jones asks "whether ID [intelligent design] is science." It is a question at the core of the case -- and he does not shy from it.

"While answering this . . . compels us to revisit evidence that is entirely complex, if not obtuse," he writes, "after a six-week trial that spanned 21 days . . . no other tribunal in the United States is in a better position than are we to traipse into this controversial area."

He makes plain his hope that many months of intellectual heavy lifting "may prevent the obvious waste of judicial and other resources which would be occasioned by a subsequent trial involving the precise question which is before us."

The ruling gives two arguments for why intelligent design is not science but is, in the judge's words, "an old religious argument for the existence of God."

The first is that intelligent design invokes "a supernatural designer," while science, by definition, deals only with natural phenomena. Second, the court found that intelligent design suffers from blatant flaws in logic, one of the chief tools of science.

Since the scientific revolution of the 16th and 17th centuries, "science has been limited to the search for natural causes to explain natural phenomena," Jones writes, noting that the scientific revolution was explicitly about the rejection of "revelation" in favor of empirical evidence.

Since then, he writes, "science has been a discipline in which testability, rather than any ecclesiastical authority or philosophical coherence, has been the measure of a scientific idea's worth."

As part of that fact-based approach, Jones emphasizes, science goes out of its way to avoid a search for "meaning" or "purpose."

By contrast, intelligent design's views on how the world got to be the way it is offer no testable facts, choosing instead to rely on authoritative statements. Adherents posit, for example, that animals were abruptly created (many in the same form in which they exist today) by a supernatural designer.

The court found that intelligent-design documents are quite open about the movement's goal of changing "the ground rules" of science to accommodate much more than natural phenomena -- a broadening so great, one witness for intelligent design testified, that science would embrace even astrology.

"Science cannot be defined differently for Dover students than it is defined in the scientific community," Jones writes.

The judge also cites several ways in which he says proponents of intelligent design failed to think logically, each example offering a take-home lesson that could prove useful to people trying to rebut challenges to evolutionary theory.

First, Jones writes, people would be well advised to remember that an argument against one thing cannot necessarily be interpreted as an argument for something else. For example, the fact that the fossil record is incomplete is not evidence that human beings must have been created in their current form.

The world, in other words, is not a zero-sum, dichotomous one in which a vote against one candidate equals a vote for another.

"Just because scientists cannot explain today how biological systems evolved does not mean that they cannot, and will not, be able to explain them tomorrow," the judge says.

Another logical failing cited by the court concerns one of intelligent design's central arguments: "irreducible complexity."

That argument states that some biological systems -- such as the bacterial flagellum, a whiplike appendage that offers some microbes a means of propelling themselves -- are made of components that, individually, do not have any purpose. Because there would be no evolutionary advantage for those individual parts, they must have arisen all at once -- and expressly for the purpose of serving in that complex organ.

But Jones notes that just because a complex organ cannot work today with one component removed, that does not mean the component did not evolve independently to serve a different purpose and later took on a new role when combined with other parts. The judge notes multiple examples involving the immune system, the blood clotting system, and even the bacterial flagellum itself, in which this appears to have been the case.

Irreducible complexity is in many ways a theological argument -- and a rather old one. A theologian testified at the trial that Thomas Aquinas argued in the 13th century that wherever there is complex design, there must be a designer, and that because nature is complex, it must also have a designer.

While many of the scientists who defended intelligent design in the Pennsylvania trial stopped short of saying that the idea requires belief in God, the defense's chief expert, biochemist Michael J. Behe of Lehigh University, noted that intelligent design's plausibility depends on the extent to which a person believes in God.

"As no evidence in the record indicates that any other scientific proposition's validity rests on belief in God . . . Professor Behe's assertion constitutes substantial evidence that in his view . . . ID is a religious and not a scientific proposition," Jones notes in his opinion.

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