Subtly shrill

I like a good reason to criticize the current (power-mad, prisoner-abusing, truth-negligent, nuclear-threat reckless, fiscally-undisciplined) administration as much as the next guy. But I'm not sure the President's comments in support of Rafael Palmeiro are such a good reason for criticism, and I'm pretty sure they're not a good reason (though other such reasons may well exist) to go into a brief philosophical discourse on Bush's idiosyncratic use of the concept of belief.

I've never studied it, but my understanding is that part of Bayesian probability is how to revise/discount one's level of belief in a particular statement upon subsequent disconfirming or confirming experiences. Now, lets imagine that Bush and Palmeiro really were close friends at one point, and that Palmeiro has assured him that he was vehemently opposed to use of all performance enhancing substances which baseball has now banned, and that Bush had good reasons to believe in Palmeiro's sincerity, such as many of Palmeiro's other claims being confirmed by subsequent events. So prior to the results of this drug test Bush has a very high confidence that Palmeiro wasn't using any illegal performance enhancing substance substance.

It is not that clear to me that he should have discounted his previous confidence by such a high level that he would no longer believe Palmeiro was clean. One key fact which I don't know, and which I assume Bush doesn't know, is the false positive rate for baseball's drug tests. I do know that one common testosterone test has an 8/1000 false positive rate, but then I don't know if what Palmeiro tested positive for was abnormal levels of testosterone or if MLB uses that test. If one of my close personal friends has assured me that they weren't using performance enhancing drugs and I knew that a test with such a false positive rate was being used, I might well stand by them. This might mean that I trust my friends too much, but I don't think it makes me irrational.

Also, these Palmeiro comments are really not good evidence for how crazy and blind to empirical evidence the people who frequent the Free Republic (I'm certainly not linking there) blogs/discussion groups are. Almost every other thing they say is good evidence for that proposition, but not supporting Bush on this.

I of course think that Palmeiro is using whatever he tested positive for, but I don't have access to all of the knowledge about Palmeiro that Bush may have had beforehand.

Update (8/10): Kleiman has, via e-mail, convinced me that my argument isn't as good as I thought.