Ralph Metzner has been exploring states of consciousness for more than fourty years. He earned his B.A. from Oxford University and a Ph.D. in Clinical Psychology from Harvard in 1962. In 1964 he co-authored The Psychedelic Experience with Timothy Leary and Richard Alpert.

He served as the academic dean of the California Institute of Integral Studies from 1979-1988. He is now a psychotherapist and professor at CIIS, where he teaches courses on altered states of consciousness and green or eco-psychology. He is co-founder and president of the Green Earth Foundation, an educational organization devoted to the healing and harmonizing of the relations between humanity and the Earth.