Reality is under no obligation to conform to human definitions.

That, a lecturer said Tuesday, is why scientists shouldn’t be hasty to exclude theories — such as intelligent design, an argument purporting that design by an external agent can be detected in nature — from discussion and consideration.

“There are many people who argue that that kind of talk about a supernatural designer … is forbidden in science,” said Del Ratzsch, professor of philosophy at Calvin College, during an address at the Scheman Building. Organizers estimated about 200 people attended.

“The risk is putting artificial and perhaps arbitrary restrictions on science and then having reality not pay attention to those restrictions,” he said.

Ratzsch’s speech was based on the question, “Could Intelligent Design be Legitimate Science?” His conclusion was that intelligent design deserves attention in the scientific community as it competes with naturalistic evolution as a possible explanation for why things are the way they are.

He stipulated that he didn’t mean he espoused the claims of intelligent design theorists.

“I don’t think the design case has yet been convincingly made,” Ratzsch said. “I think that design advocates have raised some intriguing issues.”

Ratzsch said design is often a legitimate or even essential term in science in order to explain and then describe the world. Whether a thing was designed can be determined without knowing who — or why or how — did it, he said.

An explanation offered by some — that science by definition rules out supernatural explanations — is not satisfactory, Ratzsch said.

“No one has a completely defensible definition of science,” he said.

Isaac Newton and Charles Darwin, to give examples, Ratzsch said, argued against long-established theories and ultimately increased knowledge about the physical world — and they did it following a scientific principle of following natural facts where they led.

“What happens if it turns out that nature looks like it was telling us there might be something to the whole design idea?” Ratzsch asked.

Allowing the concept of a designer that may be supernatural, he said, didn’t necessarily mean scientific inquiry into tough questions would stop because investigators would start attributing unexplainable concepts to the supernatural.

“Design doesn’t just pose risks. It also in this exact context has some positive features as well,” he said, giving the example of making an absurd move in a chess game that forces an opponent into a furious search for the purpose or design behind the move.

Jonathan Shier, junior in philosophy, said he came to the lecture to hear a “professional” account of intelligent design.

He said Ratzsch’s speech and responses to questions addressed the legitimacy of intelligent design “only in the broadest sense that it could possibly be a question we need to keep in our minds.”