Timothy Leary, 75, the former Harvard psychologist who became a national figure during the 1960s as the primary apostle of a cultic lifestyle based on the use of LSD and other hallucinogenic drugs, died of cancer May 31 1996 at his hilltop home in Beverly Hills, Calif. A major player in the anti-establishment ambiance of the 1960s, Dr. Leary was hailed as a visionary by his followers and denounced as a fraud and a charlatan by his critics. He infuriated mainstream parents by urging students to drop out of school. It was as a lecturer on the Harvard psychology faculty in 1960 that Dr. Leary first experimented with the hallucinogenic "sacred mushrooms" of Mexican religious rituals. In 1961, he became interested in lysergic acid diethylamide, or LSD, a synthetic psychedelic drug based on a grain fungus, which first was developed in 1938. Through his experiments with LSD at Harvard, he said, he had some success in treating alcoholism, schizophrenia and other psychophysiological disorders. But LSD also was becoming a popular underground drug on several college campuses. In 1963, he was dismissed from the Harvard faculty, along with a colleague, Richard Alpert, who later became known as Baba Ram Dass. They moved to Millbrook, N.Y., where they established a psychedelic drug study center in a 64-room mansion on a 4,000-acre estate donated by William Mellon Hitchcock, a descendant of financier Andrew Mellon. In 1966, New York police raided the Millbrook Center and arrested four people for possession of illegal drugs. The raid was led by assistant prosecutor G. Gordon Liddy, later a figure in the Watergate case. Leary went on to participate in a 1982 lecture-debate tour with Liddy. After the raid, Dr. Leary, who had embraced principles of Hinduism on a 1965 trip to India, founded the League for Spiritual Discovery, which sought constitutional protection for the taking of LSD as a religious sacrament. He spent much of the early 1970s in jail on drug charges or as a fugitive. He began serving prison time in California in 1970 but escaped and fled to Algeria and lived for a time with Black Panther Party leader Eldridge Cleaver. Later, he spent time in Switzerland and the Middle East but, in 1973, was apprehended by U.S. agents at the Kabul airport in Afghanistan and returned to the United States, where he was imprisoned until 1976. Leary attended the U.S. Military Academy at West Point, then served in the Army during World War II and received a psychology degree at the University of Alabama while serving in the Army. He received a master's degree in psychology from Washington State University and a doctorate from the University of California at Berkeley. In 1955, he was director of psychological research at the Kaiser Foundation Hospital in Oakland, Calif. That year, his first wife, Marianne Busch, committed suicide. A daughter from his first marriage, Susan Leary Martino, hanged herself in a Los Angeles jail in 1990. Dr. Leary's marriages to Nena von Schlebrugge and Barbara Chase ended in divorce. In 1995, he remarried his third wife, Rosemary Woodruff. Survivors include two sons.