Moderator: We're here today to debate the hot new topic, evolution versus Intelligent Des---
(Scientist pulls out baseball bat.)
Moderator: Hey, what are you doing?
(Scientist breaks Intelligent Design advocate's kneecap.)
Intelligent Design advocate: YEAAARRRRGGGHHHH! YOU BROKE MY KNEECAP!
Scientist: Perhaps it only appears that I broke your kneecap. Certainly, all the evidence points to the hypothesis I broke your kneecap. For example, your kneecap is broken; it appears to be a fresh wound; and I am holding a baseball bat, which is spattered with your blood. However, a mere preponderance of evidence doesn't mean anything. Perhaps your kneecap was designed that way. Certainly, there are some features of the current situation that are inexplicable according to the "naturalistic" explanation you have just advanced, such as the exact contours of the excruciating pain that you are experiencing right now.
Intelligent Design advocate: AAAAH! THE PAIN!
Scientist: Frankly, I personally find it completely implausible that the random actions of a scientist such as myself could cause pain of this particular kind. I have no precise explanation for why I find this hypothesis implausible --- it just is. Your knee must have been designed that way!
Intelligent Design advocate: YOU BASTARD! YOU KNOW YOU DID IT!
Scientist: I surely do not. How can we know anything for certain? Frankly, I think we should expose people to all points of view. Furthermore, you should really re-examine whether your hypothesis is scientific at all: the breaking of your kneecap happened in the past, so we can't rewind and run it over again, like a laboratory experiment. Even if we could, it wouldn't prove that I broke your kneecap the previous time. Plus, let's not even get into the fact that the entire universe might have just popped into existence right before I said this sentence, with all the evidence of my alleged kneecap-breaking already pre-formed.
Intelligent Design advocate: That's a load of bullshit sophistry! Get me a doctor and a lawyer, not necessarily in that order, and we'll see how that plays in court!
Scientist (turning to audience): And so we see, ladies and gentlemen, when push comes to shove, advocates of Intelligent Design do not actually believe any of the arguments that they profess to believe. When it comes to matters that hit home, they prefer evidence, the scientific method, testable hypotheses, and naturalistic explanations. In fact, they strongly privilege naturalistic explanations over supernatural hocus-pocus or metaphysical wankery. It is only within the reality-distortion field of their ideological crusade that they give credence to the flimsy, ridiculous arguments which we so commonly see on display. I must confess, it kind of felt good, for once, to be the one spouting free-form bullshit; it's so terribly easy and relaxing, compared to marshaling rigorous arguments backed up by empirical evidence. But I fear that if I were to continue, then it would be habit-forming, and bad for my soul. Therefore, I bid you adieu.
UPDATE (22 Oct.): If you're a creationist or IDiot , and you're suddenly possessed by the urge to comment on this post, please don't bother. I know what you're going to say. When I was an undergrad, I read talk.origins for a while, and I have seen every single creationist argument under the sun. I spent many an hour watching people knowledgeable about evolution debating creationists: patiently debunking the same tired arguments over and over and over and over and over and over and over and over and over and over and over again, responding in good faith to arguments that were clearly disingenuous, dumbing down their writing style to a second-grade level so that creationists could understand (and even then creationists wouldn't understand), and even copying and pasting from FAQs because creationists were too lazy to open up URLs in their web browser. All to no avail.
So, you may think you're going to blow me away with your amazing show of rhetoric, but believe me, I have seen it before, and you're wrong. The thing that you're about to write is not only wrong, but transparently, stupidly, embarrassingly wrong, so wrong that it makes me wince inwardly with shame at the fact that you're a member of the same human race that I am. What you're about to write is evidence that you haven't bothered to read the FAQs, or comprehended a single book on evolutionary biology that's not written by one of your crackpot creationist pseudo-intellectuals. So don't bother writing what you're going to write. Just go away.
 Really, creationists and Intelligent Design advocates are the same thing, just like a clown and a clown carrying an umbrella are really the same thing.
First, I stand by the position that the above post is the only debate on Intelligent Design that's worthy of its subject. Now, in a democratic society one must, in the public sphere, sometimes engage in good-faith debate with people or ideas that do not deserve it --- with ignorant or dishonest people, with bad ideas --- and indeed, there are legions of people with backgrounds in evolution who are doing exactly that. Call me an asshole if you want, but don't you dare claim that my post is somehow representative of evolution advocates. For literally decades, evolution advocates have responded to the abuse and astonishing mendacity of creationists/IDiots with patience, careful explanations, and copious fact-checking.
Nevertheless, I'm not one of those people. I'm never going to debate Intelligent Design seriously in this forum. This is a personal weblog, the Internet equivalent of my front yard, and under normal circumstances it's only read by myself and a handful of my friends. If I'm having a barbecue in my front yard with some friends, and we make derisive noises about Intelligent Design, then Intelligent Design advocates who overhear and venture into my yard can expect to be viciously mocked. They should not expect to be taken seriously, any more than anti-Semitic conspiracy theorists or flat-Earthers can expect to be taken seriously, in my yard. If someone believes in Intelligent Design, I believe (s)he's either a nutball, or simultaneously ignorant and too lazy to take elementary steps to remedy their ignorance. Were I writing for an Op-Ed page or teaching in a classroom, I could muster all kinds of reasoned argument against ID, but I'm not, and I won't.
Second, there seems to be a distressingly common misperception among non-ID advocates that ID's somehow valid in its own (non-scientific) sphere of debate. But that, too, is a load of crap. ID is not a generic theological or philosophical argument for the possibility of a designer. ID is a specific intellectual/political movement that explicitly seeks to establish scientific grounds for rejecting the possibility of evolution without a designer. If ID were simply a theological or philosophical argument, there would be no way to introduce it to school science curricula. But that's one of the ID movement's stated primary objectives. People get confused by this, because ID's methods are so fundamentally unscientific, but always remember that ID calls itself science.
Let me repeat that: ID calls itself science. ID calls itself science. ID calls itself science. And therefore, ID must be judged by the criteria of science, not philosophy or theology.
And as science, ID is absolutely the pits. It is a fundamentally non-scientific argument that calls itself scientific (note my use of the the restrictive subordinating conjuction, "that", instead of "which"). Therefore, it's a contradiction in terms to say that ID is "valid" when considered nonscientifically.
UPDATE''' (23 Oct.): IDiots, unsurprisingly, seem to lack basic reading comprehension skills. What part of "Just go away" do you not understand? If I read one more comment claiming there's no evidence for evolution, then I'm just going to delete it, period. No, I'm not going to point you to evidence. If you're too lazy to type the words "evidence evolution" into Google and hit Enter before you post such an outrageous claim, then I don't believe I have any obligation to respect your desire to defecate into my comment box.
UPDATE'''' (24 Oct.): Well, it had to happen. Godwin's Law strikes again. Unlike Usenet, however, blog technology permits threads to be closed for comment, and I've done that here. Go post on your own blog, kiddies.