There's a species of villain, familiar to moviegoers and readers of fiction, distinguished by a blend of high intelligence, suave charm, and pathological narcissism. Above all, such characters love the sound of their own voices, and stories in which they play a leading role often climax with a scene in which Dr. X (let's call him) is gloating over his triumph—and then, at last, gets his comeuppance.

Reading Daniel Dennett's new book is like being trapped in an elevator with Dr. X for more than 400 pages. If John Shelby Spong is the aging poster child for liberal Christianity and Phillip Johnson is the pit bull of Intelligent Design, Dennett is the professional bad boy of evolutionary philosophy. In contrast to many of his peers, he is willing and able to write lucidly for a general audience as well as for the scholarly guild, and he relishes his role as an urbane provocateur. ("Belief can be explained in much the way that cancer can," he told interviewer Deborah Solomon recently in The New York Times Magazine.) He is perhaps best known as the author of Consciousness Explained (1991) and Darwin's Dangerous Idea (1995); for a bracing response, see philosopher Alvin Plantinga's May/June 1996 review in Books & Culture entitled "Dennett's Dangerous Idea". You may also recall the brief hubbub that attended Dennett's July 2003 op-ed in The New York Times, "The Bright Stuff," in which he endorsed "the efforts of some agnostics, atheists, and other adherents of naturalism to coin a new name for us nonbelievers," as he recalls in Breaking the Spell. The term was bright (as in "Richard Dawkins and Daniel Dennett are prominent brights"). As far as I can tell, it hasn't really caught on. But give it time.

So what ...