Timothy Leary was an American psychologist and writer, known for his advocacy of psychedelic drugs. On September 19, 1966, Leary founded the League for Spiritual Discovery, a religion declaring LSD as its holy sacrament, in part as an unsuccessful attempt to maintain legal status for the use of LSD and other psychedelics for the religion's adherents based on a "freedom of religion" argument. "The Psychedelic Experience" was the inspiration for John Lennon's song "Tomorrow Never Knows" in The Beatles' album "Revolver". He published a pamphlet in 1967 called "Start Your Own Religion" to encourage just that (see below under "writings") and was invited to attend the January 14, 1967 Human Be-In a gathering of 30,000 hippies in San Francisco's Golden Gate Park In speaking to the group, he coined the famous phrase "Turn on, tune in, drop out".