Design can’t be separated from the designer.

Arguments that the universe was intelligently designed fail to identify anything substantive about that designer, two ISU professors said in a presentation Thursday — a failure they said destroys the scientific validity of those arguments.

Hector Avalos, associate professor of religious studies, and John Patterson, professor emeritus of materials science and engineering, both said advocates of intelligent design — which purports that design of the universe by an external agent can be detected in nature — don’t represent anything new in science.

Instead, the two professors, who are atheists, said those advocates recycle and repackage old, defeated arguments, often those proposed by Christians to support creationism.

“Intelligent design often does not fulfill its own criteria for what is science and what is religion,” Avalos said.

Not identifying the designer, Avalos said, didn’t remove a thorny problem for intelligent design.

“It doesn’t get you away from the problem that you have to match the result with intention,” he said.

The lecture, sponsored by the Atheist and Agnostic Society, attracted about 150 people who heard Avalos, who teaches in the humanities, and Patterson, a scientist, offer their critiques of “The Privileged Planet,” a book published this spring and co-written by Guillermo Gonzalez, assistant professor of physics and astronomy.

“When you’re talking about a designer that has created the entire universe, where do you go for independent evidence? There’s nowhere to go,” Patterson said.

Avalos cited several examples of historical arguments for a designer and said intelligent design was merely the latest in that progression.

“It’s not new; it’s pretty old,” he said. “This has been a concerted action that has been going on for 2,000 years.”

Patterson said he thinks intelligent design theorists have an ulterior motive in their work.

“It is the latest failure to make creationism seem to be scientific so that it can be a viable alternative in the classroom,” he said.

Intelligent design, Patterson said, is a new attempt at making creationism as science seem palatable to courts and to school classrooms.

Supernatural explanations, Patterson said, have repeatedly in history fallen to superior naturalistic explanations.

“Science thrives on unanswered questions,” he said. “Religion, by contrast, thrives on unquestioned answers.”

Tom Ingebritsen, associate professor of genetics, development and cell biology, asked Patterson whether he was opposed to intelligent design — such as a civilization produced by aliens — or only to supernatural design by a god.

Ingebritsen, a Christian, said he thought Patterson’s response reflected a confounding bias against the supernatural.

“I think that his worldview is coloring his [view] of whether intelligent design could be legitimate in science,” he said.