Timothy Francis Leary (October 22, 1920 – May 31, 1996) was an American writer, psychologist, futurist, modern pioneer and advocate of psychedelic drug research and use, and one of the first people whose remains have been sent into space.

An icon of 1960s counterculture, Dr. Leary is most famous as a proponent of the therapeutic and spiritual benefits of LSD.

As a psychology professor at Harvard University, Leary, along with Dr. Richard Alpert (who later became Ram Dass), performed the famous Good Friday Experiment [PDF]  in which Harvard divinity students were given psilocybin before a church service.

Leary coined and popularized the catch phrase “Turn on, tune in, drop out.”

Rightly called the Galileo of Consciousness, Dr. Leary went public with his observations of the mind made with psychedelic mindscopes and helped initiate a renaissance which is still only beginning to elaborate itself.