Timothy Leary, in full Timothy Francis Leary    (born October 22, 1920, Springfield,Massachusetts, U.S.—died May 31, 1996, Beverly Hills, California), American psychologist and author who was a leading advocate for the use of LSD and other psychoactive drugs.

              Leary, the son of a U.S. Army officer, was raised in a Catholic household and attended the College of the Holy Cross, the U.S. Military Academy at West Point, and the University of Alabama (B.A., 1943). In 1950 he received a doctorate inpsychology from the University of California at Berkeley, where he was an assistant professor until 1955. During the 1950s Leary developed an egalitarian model for interaction between the psychotherapist and the patient, promoted new techniques of group therapy, and published a system for classifying interpersonal behaviour. He acquired a reputation as a promising young scholar and was appointed to the position of lecturer at Harvard University in 1959.

            At Harvard Leary began experimenting with psilocybin, a synthesized form of thehallucinogenic agent found in certain mushrooms. He concluded that psychedelic drugs could be effective in transforming personality and expanding human consciousness. Along with psychologist Richard Alpert (later Ram Dass), he formed the Harvard Psilocybin Project and began administering psilocybin to graduate students; he also shared the drug with several prominent artists, writers, and musicians. Leary explored the cultural and philosophical implications of psychedelic drugs. In contrast to those within the psychedelic research community who argued that the drugs should be used only by a small elite, Leary came to believe that the experience should be introduced to the general public, particularly to young people.

Leary’s experiments were highly controversial, and he was dismissed from Harvard in 1963 along with Alpert.                 Their dismissal was partially due to then-student Andrew Weil’s efforts to discredit them by revealing that Alpert had administered drugs to undergraduates in violation of an agreement not to do so.