HARRISBURG, Pa. - "Intelligent design" is vastly similar to creationism and should be taught as religion, not science, a Catholic theologian testified Friday, on the fifth day of a trial over whether the concept belongs in a public school science curriculum as an alternative to evolution.

Georgetown University theology professor John F. Haught said that while intelligent-design proponents do not explicitly identify God as the creator of life, the concept is "essentially a religious proposition."

"When we have a failure to distinguish science from religion, then confusion will follow," Haught said. "Science and religion cannot logically stand in a competitive relationship with each other."