Tell a devout Christian that his wife is cheating on him, or that frozen yogurt can make a man invisible, and he is likely to require as much evidence as anyone else, and to be persuaded only to the extent that you give it. Tell him that the book he keeps by his bed was written by an invisible deity who will punish him with fire for eternity if he fails to accept its every incredible claim about the universe, and he seems to require no evidence what so ever.
The men who committed the atrocities of September 11 were certainly not "cowards," as they were repeatedly described in the Western media, nor were they lunatics in any ordinary sense. They were men of faith—perfect faith, as it turns out—and this, it must finally be acknowledged, is a terrible thing to be.
The difference between faith and insanity is that faith is the ability to hold firmly to a conclusion that is incompatible with the evidence, whereas insanity is the ability to hold firmly to a conclusion that is incompatible with the evidence.
It is time we recognized that belief is not a private matter; it has never been merely private. In fact, beliefs are scarcely more private than actions are, for every belief is a fount of action in potential.
If faith cannot be reconciled with rational thinking, it has to be eliminated as an anachronistic remnant of earlier stages of culture and replaced by science dealing with facts and theories which are intelligible and can be validated.