Timothy Leary is most famous for his promotion of the “nature religion” interpretation of psychedelic experiences. After earning a doctorate in psychology (UC Berkeley, 1950) and authoring a highly innovative and influential theoretical system (Interpersonal Diagnosis of Personality, 1957), Leary was appointed Lecturer at Harvard in 1959. Ambitious, idealistic, eager for an intellectual revolution, the brilliant young psychologist found his calling while summering in Mexico in 1960, when he ingested psilocybin mushrooms and underwent the first of his several hundred psychedelic voyages. Leary's intellectual contributions were obscured by the social tumult that ensued, including Harvard's controversial firing of Leary and his collaborator Richard Alpert in 1963, their subsequent campaign to “turn on” the world, arrests and legal battles, a dramatic escape from prison, exile abroad, and recapture, to name just some.
From The Encyclopedia of Religion and Nature in Oxford Reference.