I recorded an interesting bloggingheads discussion today with National Review's Ramesh Ponnuru. We discussed the problem of "epistemic closure," and he agreed that it was primarily a conservative phenomenon and a serious problem. I'll provide the video when it becomes available.

Meantime, Jim Manzi decides to do his part in the fight against epistemic closure, and, in a post at the Corner unlike any I've seen before, absolutely unloads upon Mark Levin. A sample:

I started to read Mark Levin’s massive bestseller Liberty and Tyranny a number of months ago as debate swirled around it. I wasn’t expecting a PhD thesis (and in fact had hoped to write a post supporting the book as a well-reasoned case for certain principles that upset academics just because it didn’t employ a bunch of pseudo-intellectual tropes). But when I waded into the first couple of chapters, I found that — while I had a lot of sympathy for many of its basic points — it seemed to all but ignore the most obvious counter-arguments that could be raised to any of its assertions. This sounds to me like a pretty good plain English meaning of epistemic closure. ...

Does [Levin] think that these various scientists are somehow unaware that Newsweek had an article on global cooling in the 1970s? Or are they aware of the evidence in his book, but are too trapped by their assumptions to be able to incorporate this data rationally? Or does he believe that the whole thing is a con in which thousands of scientists have colluded across decades and continents to fool such gullible naifs as the U.S. Congressional Budget Office, numerous White House science advisors, Margaret Thatcher, and so on? Are the Queen of England and the Trilateral Commission in on it too?

But what evidence does Levin present for any of this amazing incompetence or conspiracy beyond that already cited? None. He simply moves on to criticisms of proposed solutions. This is wingnuttery.