Psychiatrist M. Scott Peck is known for his best-sellers "The Road Less Traveled" and "People of the Lie." While most readers are familiar with the spiritual bent of Peck's works and his struggle to come to terms with human evil, few realize that Peck himself conducted exorcisms in the 1980s.

After twenty years, Peck describes these exorcisms in his book "Glimpses of the Devil." In this Beliefnet interview, Peck discusses why he thinks demonic possession needs to be recognized--and grappled with--as a reality.

Can you talk a little bit about your own beliefs? Religiously speaking, how were you raised?

I was raised in a pretty profoundly secular home. Only after her death did I realize my mother was what I came to call a crypto-Christian. In some ways, I am grateful that I was raised in a secular home, because that meant that I didn't have any old religious baggage to carry with me. I was free to go and think what I wanted.

Even though it was a secular home, as I look back on it, I was a freakily religious kid. From the age of three on, as far back as I remember, I just knew there was a God behind everything.

My first contact with religion was taking a world religions course my senior year in high school. I immediately gravitated toward the mystical writings of Hinduism and Buddhism and the Upanishads and then Zen Buddhism. I kind of stayed with that until my late twenties.

I was what you might call a mystic, but definitely not a Christian. Christianity made no sense to me. I didn't believe Christ was divine, I didn't know where all this stuff in the Bible came from.

I found myself thirsting for something a little more solid and gravitated somewhat from Zen to Sufism and got interested in the Muslim mystics, the explosion of Muslim mystics in the 13th century in Persia.

I had been led into Sufism by Idris Shaw, who was a mentor of mine. One of the things that put the clinch on my moving toward Christianity was at a lecture, somebody asked him what book would he refer somebody to about mysticism. He instantly replied, "Mysticism" by Evelyn Underhill. It was the first time I realized that there was a huge, rich tradition of Christian mysticism.

That was not the only thing that converted me. I started to be converted way back before when I first saw "Jesus Christ Superstar," about 1971. That was one of the first things that made Jesus really come alive for me as a human. Another was reading the gospels seriously for the first time at age 40 or 39, after I'd written the first draft of "The Road Less Traveled." Having quoted Jesus a couple of times, it seemed incumbent upon me to check the references. So I used the time in between drafts to read the gospels. I was thunderstuck by the reality of the man in there. Gradually I moved into Christianity through the back door of Christian mysticism, or maybe it's the front door...

I hope it's the front door.

Or the top door or whatnot. So I was finally baptized at the age of 43 in 1980. I was deliberately non-denominationally baptized, and I've very jealously guarded my non-denominational status ever since. I am very Eucharistic, which means I celebrate communion or the Eucharist. I never thought I would ever be middle of the road anything, much less a middle of the road Christian, but it actually ended up I'm extremely middle of the road.

It was right around the time of your baptism that you came to consider the possibility that people might be demonically possessed. You sort of struggled with this, because you're a scientist and a psychiatrist as well as a spiritual person. Could you talk about that struggle?

I had come to believe in the reality of benign spirit or God, as well as the reality of human goodness. I'd come to believe distinctly in the reality of human evil, and that left me an obvious hole in my thinking. Namely was there such a thing as evil spirit, or the devil specifically? In common with 99.99 percent of psychiatrists and with 80 percent of Catholic priests--as confidentially polled back in 1960, the figure would be much higher now--I did not believe in the devil.

But I was a scientist, and it didn't seem to me I should conclude there was no devil until I examined the evidence. It occurred to me if I could see one good old-fashioned case of possession, that might change my mind. I did not think that I would see one, but if you believe that something doesn't exist, you can walk right over it without seeing it.

What was it about these two "possessed" women you describe in your book that helped you to rule out psychiatric causes like schizophrenia, and caused you to settle on demonic possession as what was wrong with them?

These cases, in a whole number of ways--the more I studied them, the more they did not fit in a typical psychiatric picture.
The second case [Becca], for instance. As she should have been getting better, she got worse.