Timothy Leary

Timothy Francis Leary (October 22, 1920 – May 31, 1996) was an American psychologist and author known for his strong advocacy of psychedelic drugs. Evaluations of Leary are polarized, ranging from bold oracle to publicity hound. According to poet Allen Ginsberg, he was "a hero of American consciousness", and writer Tom Robbins called him a "brave neuronaut". During the 1960s and 1970s, Leary was arrested 36 times. President Richard Nixon allegedly described him as "the most dangerous man in America".

As a clinical psychologist at Harvard University, Leary founded the Harvard Psilocybin Project after a revealing experience with magic mushrooms he had in Mexico in 1960. He led the Project from 1960 to 1962, testing the therapeutic effects of lysergic acid diethylamide (LSD) and psilocybin, which were legal in the U.S., in the Concord Prison Experiment and the Marsh Chapel Experiment. Other Harvard faculty questioned his research's scientific legitimacy and ethics because he took psychedelics himself along with his subjects and allegedly pressured students to join in. Harvard fired Leary and his colleague Richard Alpert (later known as Ram Dass) in May 1963. Many people only learned of psychedelics after the Harvard scandal.

Leary believed that LSD showed potential for therapeutic use in psychiatry. He developed an eight-circuit model of consciousness in his 1977 book Exo-Psychology and gave lectures, occasionally calling himself a "performing philosopher". He also developed a philosophy of mind expansion and personal truth through LSD. After leaving Harvard, he continued to publicly promote psychedelic drugs and became a well-known figure of the counterculture of the 1960s. He popularized catchphrases that promoted his philosophy, such as "turn on, tune in, drop out", "set and setting", and "think for yourself and question authority". He also wrote and spoke frequently about transhumanism, human space migration, intelligence increase, and life extension (SMI²LE).