"Intelligent design" is just another name for creationism - and therefore teaching it in public schools violates the constitutional principle of church-state separation.
That is the bottom line from the decision in perhaps the biggest courtroom clash on the theory of evolution since the 1925 Scopes trial. On Tuesday a federal judge ruled that Pennsylvania's Dover Area School District broke the law when it became one of the first school districts in the United States to include intelligent design in its science curriculum.
The ruling is a blow to certain Christian conservatives, who have been pushing intelligent-design initiatives in upwards of 30 states. It comes as vindication for scientists who have seen this push as an attack on the method of scientific inquiry.
"What's ... important about this case is that it validates the separation of church and state," says Lawrence Krauss, professor of physics and astronomy at Case Western Reserve University in Cleveland. "Even more important, it's a question of teaching good science."
Intelligent design holds that nature is so complex that random natural selection, as argued by Charles Darwin in his 1859 theory of evolution, is an inadequate explanation for its evolution. Instead, the natural world must be the work of an unnamed creator.
Opponents of this view argue that intelligent design is but a gloss on creationism, a belief that the world was created by God as described in the book of Genesis. The US Supreme Court has ruled that creationism cannot be taught in public schools.
Beginning in the fall of 2004, Dover area ninth-grade students, per order of their school board, were read a four-paragraph statement that evolution is a theory, not a fact, and that this theory contains "gaps." The statement directed students interested in exploring this idea to the book "Of Pandas and People," a lengthy explanation of the intelligent-design view.
Eleven parents then sued the school board, claiming that this action had no place in a scientific curriculum.
At issue in the six-week trial in nearby Harrisburg were two things: the actions of the school board per se, and the constitutionality of intelligent design itself.
The ruling by US District Judge John Jones found that members of the school board had lied to conceal the religious foundation of their interest at pushing intelligent design into area schools. Funds to buy copies of "Of Pandas and People," for instance, had come from an appeal at a board member's church.
The trial itself featured lengthy expert testimony about the evidence underlying intelligent design. It delved into such arcane subjects as the nature of bacterial flagellum. In the end, one of the most prominent intellectual defenders of intelligent design, Lehigh University biochemist Michael Behe, conceded that a definition of "science" that included it might also include astrology.
Thus in the end Judge Jones ruled on the viability of the assertion itself.
"In making this determination, we have addressed the seminal question of whether [intelligent design] is science. We have concluded it is not," he wrote in his opinion.
That said, Jones added that proponents of intelligent design have deeply held beliefs, and the concept should continue to be studied and discussed.
Intelligent-design proponents saw in Tuesday's decision the quashing of legitimate ideas and inappropriate judicial activism.
"The Dover decision is an attempt by an activist federal judge to stop the spread of a scientific idea and even to prevent criticism of Darwinian evolution through government-imposed censorship rather than open debate, and it won't work," said Dr. John West, associate director of the Center for Science and Culture at Discovery Institute, the leading think tank researching intelligent design. "He has conflated Discovery Institute's position with that of the Dover school board, and he totally misrepresents intelligent design and the motivations of the scientists who research it."
"It's unfortunate that this continues to be spun as a religious issue," says Dr. William Harris, professor of medicine at the University of Missouri-Kansas City and co-founder of the Intelligent Design Network. "It's a science issue, with religious implications."
The controversy divided the community and galvanized voters to oust eight incumbent school board members who supported the policy in the Nov. 8 school board election.
The dispute is the latest chapter in a long debate over the teaching of evolution dating back to the famous 1925 Scopes Monkey Trial, in which Tennessee biology teacher John Scopes was fined $100 for violating a state law that forbade teaching evolution. The Tennessee Supreme Court reversed his conviction on a technicality, and the law was repealed in 1967.
Jones heard arguments in which expert witnesses for each side debated intelligent design's scientific merits. Other witnesses, including current and former school board members, disagreed over whether creationism was discussed in board meetings months before the curriculum change was adopted.
The case is among at least a handful that have focused new attention on the teaching of evolution in the nation's schools.
• Wire service material was used in this report.