Timothy Leary (1920–1996) was an American psychologist and writer known for his strong advocacy of psychedelic drugs. An icon of countercultural rebellion, Leary coined the phrase "Turn on, tune in, drop out" which became a slogan for the 1960s psychedelic experience and the youth rebellion against conservative societal norms of the time. Initially, Leary was a lecturer at Harvard University and, together with colleague Richard Alpert (later known as Ram Dass), conducted experiments with psychedelics such as LSD and psilocybin. However, their research and Leary's advocacy of psychedelics led to controversy, and he was dismissed from his academic position. Leary's activities made him a critical figure in the cultural and social movements of the 1960s. He was arrested multiple times for drug possession and became a symbol of the clash between the counterculture and traditional authority. Despite his contentious relationship with the law, Leary was an influential thinker who wrote extensively on topics relating to psychedelic drugs, consciousness, and human potential.