A federal judge barred a Pennsylvania school district yesterday from mentioning "intelligent design" as an alternative to evolutionary theory in a scathing opinion that criticized local school board members for lying under oath and for their "breathtaking inanity" in trying to inject religion into science classes.

U.S. District Judge John E. Jones III, a Republican appointed by President Bush, did not confine his opinion to the missteps of a local school board. Instead he explicitly sought to vanquish intelligent design, the argument that aspects of life are so complex as to require the hand, subtle or not, of a supernatural creator. This theory, he said, relies on the unprovable existence of a Christian God and therefore is not science.

"The overwhelming evidence is that Intelligent Design is a religious view, a mere re-labeling of creationism and not a scientific theory," Jones wrote in a 139-page decision. "It is an extension of the Fundamentalists' view that one must either accept the literal interpretation of Genesis or else believe in the godless system of evolution."

In November, voters in Dover threw out eight of nine school board members; the ninth was not up for reelection. The new school board, which favors teaching evolution, will not appeal the ruling.

Jones's decision puts an exclamation mark on a courtroom battle widely hailed as the successor to the Scopes "Monkey Trial" of 1925, when proponents of modern scientific methods first battled creationists in court over the teaching of Darwin's theory of evolution. State and local school boards from Kansas to Georgia and Florida have begun challenges to evolution, and these officials watched Dover closely in hopes of divining how much leeway they might get in federal court.

If yesterday's decision is any guide, opponents of evolution now face a very tough task, advocates on both sides agreed.

"The court has held that it's not a scientific theory," said Witold Walczak, legal director of the Pennsylvania chapter of the American Civil Liberties Union and one of the trial lawyers for parents who sued the school board. "At a time when this country is lagging behind other countries, we can ill afford to shackle our children's minds with 15th-century science."

John West, a senior fellow at the Discovery Institute's Center for Science & Culture, a leading intelligent design think tank in Seattle, took a dim view of the judge, saying that he evinced a "grandiosity" and "egregious" judicial activism. But he agreed that the decision comes as a heavy blow.

"There's no doubt that people will trumpet this and that now they can say a federal judge agrees and that doesn't help," West said. "His angry tone was not helpful."

This latest skirmish in a centuries-long cultural war began when the school board in Dover, a small central Pennsylvania farm town slowly becoming a suburb of Harrisburg, voted last year to require ninth-grade biology teachers to read a four-paragraph statement casting doubt on Darwin's theory of evolution.

The mandatory statement notes that intelligent design offers an alternative theory for the origin and evolution of life.

The board members made little secret of their own views, which hewed not so much to intelligent design as to Young Earth Creationism, the fundamentalist Christian belief that the world is but 6,000 years old and that Noah's flood shaped the earth.

One board member told a public meeting -- in a remark he later tried to deny -- that the nation "was founded on Christianity, and our students should be taught as such."

Eleven parents filed a lawsuit in federal court, seeking to block the new policy on the grounds that intelligent design was but biblical creationism in the cloth of science. The Supreme Court had ruled in 1987 that nothing like creationism could be taught in public school science courses.

"The board was selfish," said Eric Rothschild, who represented the parents along with the ACLU and Americans United for Separation of Church and State. "This was all about imposing their religious viewpoint on a diverse community."

Steve Fuller, a philosopher of science at the University of Warwick in England who testified at the trial for the defense, acknowledged that the school board members undercut the case for a new theory.

"Intelligent design has to be de-theologized," Fuller said. "But it will be a shame if a result of this decision is that we can't question Darwinism, which is not just a theory but an entire secular world view that flattens the distinction between humans and other life."

When the trial ended in early November, Jones faced two choices. He could have construed the case narrowly and ruled on whether the school board had a religious motive. That, in Jones's view, was an easy call. He found that school board members had committed "outright lies under oath" and displayed a "striking ignorance" of intelligent design.

But Jones went further. "Intelligent Design is not science," he wrote. "Proponents . . . occasionally suggest that the designer could be a space alien or a time-traveling cell biologist [but] no serious alternative to God as designer has been proposed."

Intelligent design scientists are adept at finding holes in the science of evolutionary theory. Some notable mainstream scientists acknowledge these gaps. But Jones concluded this effort does not amount to a new theory of life's origins and development.

He found that the Discovery Institute had a wedge strategy, to use doubts about evolution to replace modern science with "theistic and Christian science."

The sheer breadth of Jones's decision set the legal barriers much higher for intelligent design. But even those who applauded the court's ruling doubted he had closed the door. Most polls show that 40 to 55 percent of Americans favor a strict biblical creationist view of evolution.

"We thought we had put a stake through the heart of creation science 25 years ago and it evolved and here we are again," said Michael Ruse, a philosopher of science at Florida State University who frequently debates intelligent design advocates. "Jones saw it for the shoddy theory it is, but its advocates are intelligent and savvy men and women and they'll be back."

Barrie Callahan, left, a plaintiff from Dover, Pa., and lawyer Witold Walczak talk to reporters.