I recently heard Bill Maher speak about his new film, Religulous (a made up word that combines religion and ridiculous), which offers a blistering attack on religion and the religious life. He argues that faith necessarily means a lack of critical thinking, that "to be religious at all is to be an extremist, [because] it is to be extremely irrational."

I understand his critique of religion. I understand the problems inherent in the notion of an...