Given the statement in his own “Academic Bill of Rights,” on what grounds can Horowitz possibly maintain these blatantly irreconcilable positions? Whenever he accuses anyone of “shar[ing] negative views of the Bush Administration” with known terrorists (or more briefly, of “hating America”), one can simply reply: “But, Mr. Horowitz, you yourself believe that ‘there is no humanly accessible truth that is not in principle open to challenge.’ So how do you know that anyone hates America, or that the invasion of Iraq was legitimate, or that occupying Iraq was a wise move in the war against terrorism? In fact, given your own statements, how do you know anything at all?”

Given Horowitz’s approach (which inevitably and necessarily combines relativism, skepticism and subjectivism in one particularly nasty mix), he would have no answer—and in fact, he doesn’t know anything, not with certainty, by his own admission.