It's rascality, pure rascality."

Those words are the closest Ferdinand W. Demara Jr. has ever come to explaining why he spent almost two decades assuming other people's identities. From naval surgeon to dean of philosophy, from prison warden to Trappist monk, Fred Demara became known as "the Great Impostor," an expert at making other people's names and professions his own.

For the last 14 years, however, Demara has been a bona fide non-denominational preacher, ministering to rural hamlets in the Pacific Northwest and to skid row derelicts in Los Angeles. Two years ago he was named chaplain at the Good Samaritan Hospital in Anaheim, Calif.

Looking back, the hulking (6', 250 lbs.) Demara claims his role-playing was a search for reality. "Reality to me is best defined by the Latin adage Esse quam videri," says Demara. "That means, To be, rather than to seem.' I have learned that now, but in my earlier years I reversed it."

And he did so brilliantly. As plain Fred Demara, he was a high school dropout who ran away from his Lawrence, Mass. home to join a monastery. He enlisted in the Army in 1941, promptly went AWOL to join the Navy. Deserting the Navy, Demara began his career of impersonating other people.

Surgeon-Lt. Joseph C. Cyr was Demara's most astonishing impersonation. In his role as a doctor in the Royal Canadian Navy in Korea, Demara operated on wounded South Korean soldiers. In one case, he took only 10 minutes to extract a bullet lodged a quarter inch from a patient's heart. In another, he removed a man's lung after a bullet had torn through his chest. Because he had had no formal medical training whatsoever, Demara's feat was later compared to "taking someone out of the Stone Age and telling him to fix a jet engine." Ironically, Demara's expertise proved his downfall. The publicity he received flushed out the real Dr. Cyr, a general practitioner in New Brunswick.

Throughout the 1950s Demara popped up in different places with different names and guises. Dr. Ben Jones was an assistant warden at the Huntsville (Texas) Penitentiary. Martin Godgart was a Latin teacher in North Haven, Maine. Dr. James Lore was assistant to the prefect at the Mount Alverno School for Boys in Cincinnati.

Each time Demara was unmasked, he found his fame had grown, peaking with the publication of Robert Crichton's The Great Impostor in 1959 and the movie in 1961. Yet fame did not mean fortune. "Being an impostor is a notoriously underpaid profession," he said at the time. He got $4,000 for the film rights.

Since he walked into Los Angeles' Union Rescue Mission in 1963, Demara has dedicated himself to the ministry—and used his own name. He says the "thread of religion" has run through his entire life, and now he has found his niche. Dr. Gerald Nilsson, part owner of the Good Samaritan Hospital, believes Demara is "the most humble and the most accomplished man I have ever known. [As chaplain] he has the ability to take a person and guide him through by making him feel secure."

Demara insists his deceptions are over. "I hate to look back," he says. "I'm not proud of my impostor days."