Recently we've seen a rise in interest in exorcism. What makes it so appealing?

We live in a therapy-mad culture. There's been an explosion over the past couple decades of 12-step groups and therapeutic procedures of every imaginable description. Everyone, it seems, has been looking for some kind of an instant fix to problems. Exorcism fits in very nicely because it is a kind of therapy that promises to be immediately and dramatically effective. And for many people, by the way, this in fact is the case. Demon expulsion may be therapeutically beneficial, at least in the short term. There's no question about that. It's a relatively inexpensive therapy that can be taken with dispatch. Exorcism is, for the most part, morally exculpatory. It lets us off the hook.

"The devil made me do it"?

Yes, you know, my sexual infidelities, well, they're not my fault; it's the demons. Or my recurrent animosities toward coworkers? Well, I mean, obviously I'm demonized. We live in a culture where we're encouraged to look for ways to get us off the moral hook and to find excuses. Indisputably, we are also, as a culture, very impressionable. And we are deeply influenced by the images that are presented to us by the popular entertainment industry.

Have you witnessed an exorcism or a deliverance session in which you were convinced demons were really cast out?

I always go on site and interview people directly and take situations seriously. But still there's so much I don't know. I attended more than 50 exorcisms and never once did I walk away convinced that the person being exorcised was really demonized. I always thought that medical, cultural, and psychiatric explanations could have accounted for what was going on. But I could be wrong. And people ...