One of the first things that stands out to me about the choice of Alaska Gov. Sarah Palin to be McCain’s running mate is the fact that Palin is an advocate of teaching Intelligent Design Creationism (IDC) in public school science classrooms alongside evolution.

My ScienceBlogs colleague Afarensis reported two years ago:

Palin was answering a question from the moderator near the conclusion of Wednesday night’s televised debate on KAKM Channel 7 when she said, “Teach both. You know, don’t be afraid of information. Healthy debate is so important, and it’s so valuable in our schools. I am a proponent of teaching both.”

This is standard rhetoric for IDC advocates because it taps in to a very basic notion of fairness held by most Americans. If you’re going to teach one theory, it’s only right to teach both theories, right? Well, wrong. The premise here is false, but it’s false in a way that feeds into the ignorance of science that is so pervasive in our society.

The problems with this argument are many. First, while evolution is a theory — and a remarkably successful one at that — IDC is not. There is no “theory of intelligent design” from which one may derive testable hypotheses because IDC has no positive cognitive content. IDC is nothing more than a more sophisticated restatement of an old-fashioned god of the gaps argument:

Evolution is false, therefore God must have done it.

Every single argument offered by IDC advocates relies upon the premise that evolution is false. Michael Behe’s “irreducible complexity,” probably the most prominent and commonly heard IDC positions, is a god of the gaps argument: evolution cannot explain complex biochemical systems, therefore God must have created it out of nothing.

William Dembski’s “explanatory filter,” which he alleges is able to distinguish objects created “intelligently” from objects that evolved naturally, requires the failure of evolution before one even gets to the arguments for concluding that an object was designed. The very first step is that one must rule out the interaction of chance and necessity — i.e. evolution — and once you do that, you’re left only with “God did it.”

Jonathan Wells’ claims in his book Icons of Evolution are nothing more than a series of long-discredited arguments against evolution, each of them based upon egregious distortions of the scientific data. There is nothing in the book that even pretends to be a positive case for IDC.

No one has presented a positive theory of intelligent design because, frankly, none is possible. There’s a famous old cartoon with a scientist at a blackboard filled with a complex formula for something. And in the middle of all those mathematical figures there’s a part of the formula that says “and then a miracle happened,” followed by another big string of figures. And another scientist in the audience is raising his hand and saying, “Can you be a bit more specific about that third step?”

Well no, he can’t be more specific because once you invoke miracles — supernatural actions — you can no longer make any predictions that follow logically. In science, theories are tested largely by their ability to make accurate predictions about the nature of the evidence. Evolution makes a great many specific and explicit predictions that simply must be true if evolution is true, and to no one’s surprise those predictions all turn out to be true.

But IDC cannot make such predictions because it is invoking supernatural actions, actions which take place outside of the bounds of the natural laws of the universe. Once you invoke supernatural actions, all ability to make logical predictions disappears because logical prediction requires the application of natural law. We can predict the behavior of a given physical system if we understand the laws that govern it, but if we posit a supernatural being that can violate those natural laws we can no longer predict the behavior of that system precisely because that being can violate those laws.

The word “theory” has an entirely different meaning in science than it does in everyday usage. Colloquially, we tend to use the word “theory” to mean “wild-assed guess.” In science, theory is actually the highest level of certainty assigned to proposed explanations. And in science, a theory must have specific attributes: it must be testable, it must be falsifiable and it must explain the data well. Evolution meets all of those tests; IDC meets none of them.

The fairness rhetoric used by IDC advocates is false because the two ideas are not the same kinds of ideas. IDC is an alternative “theory” only in the sense that “angels pushing the planets around” is an alternative to Newton’s theories of celestial mechanics. IDC is an alternative “theory” in the same way that “demons (or an angry God) make us sick” is an alternative to the germ theory of disease. None of those “theories” has any place in a public school science classroom.

IDC is not a scientific theory, it is a stripped down version of old fashioned creationism. It is really little more than a public relations campaign against evolution. In fact, the Discovery Institute, the central organization of the IDC movement, hired the same PR firm that represented the Swift Boat Vets during the 2004 election to represent them.

Disclaimer: Ed Brayton is the president of the advisory board of Michigan Citizens for Science, a group that actively fights against the attempts by intelligent design creationists to weaken science education in public schools.