ROME, Dec. 31 - The Roman Catholic Church's best-known exorcist led the way down a long hallway that was dark but not particularly spooky, dim in a way that evoked only thrift, to the small office where he performs his rite.
The Rev. Gabriele Amorth, who is an awfully jolly priest given his specialty, did not even take Christmas off this year. These are boom times for his opponent, after all, Father Amorth said. Exhibit A: the world. He sees 10 people a day, give or take, for demonic possessions, obsessions and lower-grade infestations.
In Italy Father Amorth is a well-known author whose book "An Exorcist Tells His Story" has been reprinted 17 times. He describes his life, though, as a hard one, spent misunderstood and marginalized, although never wholly disowned, by his own church, which these days mostly seems embarrassed by the ancient rituals he has refused to update.
Lately Father Amorth, who is 75, has been in all the papers again, this time for taking on Harry Potter. When he recently told ANSA, the Italian news agency, that the Devil was behind Harry, luring children into supernatural adventures, he set off a debate in newspapers and Catholic chat rooms.
In truth, though, the exorcist himself does not seem all that exercised by the young wizard from Hogwarts. "If children can see the movie with their parents, it's not all bad," Father Amorth said in an interview, so mildly that it was impossible not to wonder whether he was not a little bit grateful to Harry.
Certainly he is eager to get out the message that the evil Lord Voldemort of the Potter stories is a softie compared with the real You-Know-Who. "Wars are mostly caused by the Devil; certainly Hitler was consecrated to Satan, and Stalin," he said. "I prefer not to mention living persons."
He has been known to, though. Just last summer he blamed the Devil for Archbishop Emmanuel Milingo's temporary defection, when he was briefly married to a follower of the Rev. Sun Myung Moon in New York.
Father Amorth said the same of a teenage couple convicted of murdering the young woman's mother and brother in Italy last winter. Later the police did report that the two had been reading satanic books. He doesn't seem to hold that against them, though.
Most of the people seeking his professional services are psychiatric cases, he says. "I won't see them until they've seen a doctor first," he said, "and most come after they've seen many, many doctors."
Often he even teams up with psychiatrists, and in listening to him talk it is remarkable how much he would seem to have in common with these colleagues.
Those who complain that therapists let people with imperfect childhoods off the hook for their own behavior, for instance, would really hate Father Amorth's conviction that the possessed person "isn't a bad person, only a suffering one."
Sometimes the person has been dabbling in magic, he said. But most of the time "the problem is the result of a spell, and, in that event, there can be no guilt," though a proper spell is rather hard to come by "because most magicians are fakes and cheaters."
Some of his clients have been with him as long as Woody Allen's movie persona has been on the couch. One has been coming for 16 years. Father Amorth's goals, too, are health and honesty: "I never ask them to become Catholic but to live an honest life."
His father and grandfather were lawyers. After fighting in the Italian resistance as a teenager, he studied the law, too, and was deputy to Giulio Andreotti in the Young Christian Democrats, long before Mr. Andreotti became Italy's seven-time prime minister.
Father Amorth's calling, though, was the church, and later, at the request of his bishop, exorcism. In a drafty back office of the Society of St. Paul, when asked how he works, he showed the crucifix and baptismal oil he uses and playfully spritzed some holy water around the room.
Of course his métier predates the New Testament, in which Jesus casts out demons. In the fall of 2000 the Vatican confirmed Father Amorth's announcement that the pope, too, had said a prayer of exorcism over a young woman who had begun screaming and writhing during his weekly audience in St. Peter's Square.
Yet the Catholic Church is largely mum about the Devil these days. You hardly ever hear a thing about him, Father Amorth said. Meanwhile, he added, the hierarchy is busy trying to tie the exorcist's hands with modern new rules.
"I have bad relations with a number of different cardinals because they have a total ignorance of these problems," he said, rolling his eyes. Two years ago the church came out with an all-new rite that he calls useless.
"We can't touch curses, we can't talk to the Devil, and we can do an exorcism only when it's a sure possession, which, since the exorcism itself is diagnostic, can't possibly work," he said. "An unnecessary exorcism never hurt anybody."
For a real education, he suggested, the hierarchy might want to check out the 1973 horror movie about his line of work. "I'm very grateful to 'The Exorcist,' " he said, promoting that movie far more energetically than he had bad-mouthed Harry Potter, "because they made known what we do."