Timothy Leary's contributions significantly impacted social attitudes toward drugs and consciousness expansion during the 1960s. As a psychologist advocating for the use of psychedelics, particularly LSD, Leary promoted a radical reevaluation of societal norms regarding drug use and personal exploration. His famous phrase, "turn on, tune in, drop out," encouraged individuals to break free from conventional lifestyles and embrace altered states of consciousness. Leary's work fostered a countercultural movement that pushed discussions on mental health, spirituality, and the liberating potential of psychedelics, leaving a lasting legacy in the realms of psychology and social activism.