Timothy Leary

Timothy Francis Leary (October 22, 1920 – May 31, 1996) was an American psychologist and author known for strongly advocating 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", while writer Tom Robbins called him a "brave neuronaut". President Richard Nixon disagreed, calling Leary "the most dangerous man in America". During the 1960s and 1970s, at the height of the counterculture movement, Leary was arrested 36 times.

As a clinical psychologist at Harvard University, Leary founded the Harvard Psilocybin Project after an experience with magic mushrooms he had in Mexico in 1960. For two years, he tested psilocybin's therapeutic effects, in the Concord Prison Experiment and the Marsh Chapel Experiment. He also experimented with lysergic acid diethylamide (LSD), which was then legal in the US. 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 learned of psychedelics after the Harvard scandal. Leary 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".

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. He also wrote and spoke frequently about transhumanism, human space migration, intelligence increase, and life extension (SMI²LE).