St. Louis ? A prominent Kansas proponent of intelligent design says scientists feel threatened by the theory and want to demonize school boards that have considered allowing it to be taught in their districts.

But at a weekend debate in St. Louis, a Cleveland professor said that if intelligent design were real science, those pushing it would be opening laboratories and performing experiments.

“They have no viable predications, no results, no science,” said Lawrence M. Krauss, a professor of physics and astronomy at Case Western Reserve University.

John H. Calvert, a retired attorney from Lake Quivira who helped found the Intelligent Design Network, said because intelligent design can’t be discussed – and subsequently, because Darwin’s theory of natural selection can’t be criticized – in schools, students aren’t getting enough information to decide for themselves.

“Can evolution ever be falsified if it can’t be criticized?” Calvert asked. “Isn’t the role of public education to inform?”

The debate Saturday drew about 400 people to Washington University’s Center for the Study of Ethics and Human Values.

Intelligent design says some features of the natural world are best explained by an intelligent cause because they are well-ordered and complex. Its advocates attack evolutionary theory that natural chemical processes could have created the basic building blocks of life, that all life had a common ancestor and that man and apes shared a common ancestor.

But many scientists see intelligent design as another form of creationism, which the U.S. Supreme Court has banned from public schools.

Intelligent design has gained prominence recently as challenges to the theory of evolution mounted.

In Harrisburg, Pa., eight families are trying to remove intelligent design from the curriculum of the Dover Area School District, which requires students to be exposed to the concept.

And in Kansas, the State Board of Education has given preliminary approval to science standards that include language proposed by intelligent design advocates reflecting skepticism about the theory of evolution.

Krauss said Saturday he wasn’t opposed to teachers discussing the idea of intelligent design, much as history teachers would tell students that some people believe the Holocaust never happened. But they should not be forced to do so, and students shouldn’t have to learn those ideas and know them come test time.

“Teachers should be able to throw out the idea, but it should not be required to be part of the curriculum, and students should not be tested on something that’s not science,” he said.