Okay, so President Bush has come out in support of Intelligent Design (and if anyone knows intelligence, it's George). He said that the ultimate decision should remain with the school districts, but that in his opinion, both sides should be taught "so that people can understand what the debate is about," adding that "part of education is exposing people to different schools of thought."
Believe it or not, I actually agree with the president on that last point. Exposing people to different schools of thought is a major part of education - in the right context. In literature, religion, philosophy, art, there are lots of equally valid schools of thought that should all be explored. Other areas, though, are one-school-of-thought-based. Take math class; there may be a variety of ways to solve a math problem, but if you start out disputing the fact that 5 x 5 = 25, you're going to end up with an objectively wrong answer.
And so it is with much of science. Not all of science, by any means. Science is always growing and changing, new discoveries are being made every day, and while some theories (gravity) are fairly solid, others are still being tested. If science were completely rigid, there would be no point in further experimentation, because we'd have the answers already. But there is one school of thought that science takes pretty seriously: a theory is only scientifically valid if it can be disproved.
Now, this isn't my area of expertise,* but I did take science classes and I love the Discovery channel and I remember that scientific theories must be testable. I also remember that no theory can actually be proved; it can only be tested over and over and over and over again, with the consistent result that it is not disproved. But that fact that it can be tested, that the potential for it to be disproven exists, is crucial for a theory to be scientifically valid.
Intelligent Design doesn't fit. How do you prove that a higher power didn't create or contribute to the creation of the world? How do you prove that a higher power doesn't even exist? What tests do you do? Gravity can be tested. You can throw a ball up in the air a hundred times, and as long as no other forces intervene, it'll fall right back down. If, just once, that ball doesn't fall (and no other forces have intervened), you've disproved the theory of gravity and set science on its collective nose. But you can't do that with Intelligent Design.
I personally don't have a problem with ID. I happen to believe it. As a Catholic, I certainly believe in the existence of a higher power, and I think it's more than likely that he had a hand in the changes over time demonstrated by evolution. But I realize that ID is a theory that requires faith, the belief in a higher power, in conjunction with disprovable science, and I just can't justify that being taught in schools. There's no reason that parents can't teach their kids whatever they want regarding the origins of life, and there's no reason that teachers can't say, "Now, your parents might have different and perfectly valid feelings on the subject, but for our purposes, this is how life began." But science class is for science, and ID just plain doesn't qualify.
*That one's for you, Daddy. You're the scientist here; feel free to correct me on this, or to tell me how shocked you are that I actually got it right.