Even if debating creationists and psychics were handled by bright, informed college students, the prestigious scientists would still end up leaving, because those sorts of dialogues affect the general reputation of the site and thus the reputation of those who speak there. Many scientists will (correctly, imo) infer that a site that thinks creationism is an "interesting and important" topic that reasonable people can disagree on is a site that has low intellectual standards.

I just watched Wright's diavlog with George Johnson, at the end of which he says that he would have gotten an astrologer on right after Obama made the comment in a debate about astrology and Nancy Reagan, if he could have. Wright clearly has different ideas about what is worthy of discussion than many of his academic guests, which is why they are parting ways. The extremely vague and overly broad editorial policy he put up makes this clear.

On your point that BHTV never having creationists on is akin to you never debating advocates of interpretations other than MW, the relevant differences between the two scenarios are that (1) many experts in the relevant science believe those other interpretations (not true of creationism), and most importantly, (2) they present arguments and react to and update on counter-arguments in the manner that we all expect intellectually honest people to do when participating in intellectual discourse (not true of creationists).

For me, the more compulsory content filtering a hosting service implements, the less usable it becomes.

Bloggingheads.tv is NOT a hosting service (it could be, but it's not). It is a thematic forum, with an audience.

Wow, I haven't seen Phil Plait's post until now. Bloggingheads "called Creationism science"? I can only guess what tortured reasoning gave rise to this claim.

But I think, Eliezer, that you're being too charitable to those who are jumping ship. Sean and Carl aren't doing so because they're anti-accomodationist, they just can't stand the thought of being within 300 internet meters of Creationists if they don't think they can leverage the situation against them. Whether this particularized form of distaste is justifiable is an interesting issue and one I look forward to losing more karma points arguing here. Suffice to say, I would be surprised if there's a non-arbitrary standard that would dictate that advocating Creationism is the most boycott-worthy of all views represented on BhTV.

But this does raise a lot of issues that I'd like to see developed here a little more. We talk about "raising the sanity waterline", but there's not much discussion of how exactly this would be done, what exact institutions and rules of rhetorical engagement tend to actually promote becoming less wrong. One thought that I was toying around with was that irrationality, like many other problems of insufficient virtue, is something that should be attacked from the demand side, not the supply side - meaning that boycotts on ideologies should be looked upon skeptically. I suspect that much of my discomfort with "silencing" tactics arises from my background in the social sciences, where politics frequently manages to honest inquiry because of well-intentioned tactics such as those employed by those who would boycott Bloggingheads for daring to host a podcast they found irresponsible.

I think Behe's critics should just admit that what's really motivating the reaction is the notion that Creationists not only should not be given forums to speak, but those who do grant Creationists forums to speak should be actively identified and boycotted in a way which is reserved for an arguably arbitrarily-defined set of social undesirables.

What critic will not admit that? It's hardly a fringe opinion in the scientific community that Creationists should not be given forums to speak on the thoroughly unscientific topic of Creationism, and that those who do so and call it science are being absurdly and unnecessarily tolerant. Creationism has never been more or less than an attack on science. It's extremely toxic, and while I would never try to "silence" anyone, I don't think it deserves more publicity. I grew up being taught that dreck in a fundamentalist Christian school and I'm more familiar with Behe than I'd care to be. Frankly, he's an idiot, and his life purpose seems to be toward making more idiots. He doesn't need anyone's help.

As for McArdle, I don't really care. Politics is not a hard science, and while she's something of a crackpot, she's not that way because somebody proved her map doesn't follow the territory. It's the difference between someone who thinks the earth is flat and someone who thinks it's run by the Illuminati. The former is just wrong, the latter is just crazy. I don't mind crazy, because crazy isn't nearly as dangerous as wrong.

Should BHTV invite Perez Hilton to debate the fearsome Man Bat? Michael Behe is as credible an author as Pamela Anderson, although not quite as illuminating. I used to think that the worst kind of ignorance was when you knew you were wrong and refused to accept it. Now I think the worst kind is when you know you're capable of knowing when you're wrong but refuse to let yourself. Michael Behe wants to be ignorant of his own ignorance. Let him do so in the peace and quiet of his own sad little world.

The "unwashed masses", as you call them, are already getting plenty of exposition to crackpottery, much more than they get to real science, so that a few crackpots on BHTV are barely a drop in the ocean. That's not what concerns me, no.

What concerns me is that BHTV has a reputation as a respectable website thanks to the participation of respectable academics and experts. It's reasonable to assume that such a respectable website wouldn't invite crackpots to promote their brand of crackpottery; in fact, that's an assumption I made myself until I read Sean's and Carl's posts. Inviting crackpots therefore gives the impression that these people should be taken seriously, even if we think they're wrong.

In any event, your own motives are suspect, to say the least. Characterizing creationist nuts as "people whom [Sean and Carl] don't like", as if creationism was merely a distasteful political opinion, or something, makes you sound like a crackpot yourself, or worse, a postmodernist.

You're one of the last people I would have expected to be concerned with 'fairness' when one of the sides is blatant crackpottery. I suppose you wouldn't have a problem if BHTV invited an astrologer, as long as they paired him up with an astronomer?

Sean Carroll and Carl Zimmer are leaving Bloggingheads, mostly because it's started playing nice with creationists. Click their names to read their full explanations.

One person's "overarching narrative" is another person's set of Bayesian priors.

Take, for example, your pollution discussion. An economics textbook will tell you that there is an ideal level of taxation, yes. However, it won't tell you about regulatory capture, mission creep, the Hayekian knowledge problem, etc. There is always a correct set of contextual data to be used to interpret and resolve problems in isolation, yes - but determining what this set is and how we should interpret the probabilities of various events occurring is pretty much always going to invoke an overarching narrative unless you really, really think that this screws everything up.

But as an economist - a Masonomics student, no less - I'm inclined to see a greater harm in "markets fail, so assume a benevolent social planner and imagine what policies she could implement" approach to solving economic questions than the harms of dirtying one's self in the morass of historical context. This is why social science is hard - and why it should be hard. It's not that we should be indifferent to the injection of ideology into these debates, but that it's liable to create greater harm if we try to avoid all questions which cannot yield precise analytical answers which are self-apparent to reasonable minds.

Hopefully I'm not strawmanning your point here - maybe you're primarily trying to explain how ideology mucks things up, but I also get the impression that you think it's reasonably feasible to avoid questions that lend themselves to ideological answers... I definitely would disagree with such an assertion.

Yup, that was when I decided to grit my teeth and use non-gendered language no matter what it did to prosody. Once I transitioned from "ve" to "they" it grew on me surprisingly fast, and no longer takes a conscious effort; male-specific language now seems jarring.