Guessing isn't Reasoning

J.M. Keynes once quipped that

[w]hen the facts change, I change my mind. What do you do, sir?

Today, Paul Krugman argued that a committment to an ideology isn't like race in that former is mutable and latter isn't. In response, Megan McArdle blathered that

I presume that Paul Krugman holds the beliefs he does because they are his best guess at what is true, and that he could no more change his beliefs than he could change his native language.

McArdle, in short, thinks that people arrive at an unshakeable world view because they "guess" at how the world works and having once guessed they can never alter their guesses, which -- I suppose -- explains her own refusal to change her mind even as the world proves her guess to be wildly off base.

Sort of like John Derbyshire's admission that he can't  or, in any event, won't reason at all., this is really all you need to know of the Glibertarian mindset. See also.