American psychologist, intellectual historian, and astrologer. A graduate of Harvard University and Saybrook Institute, he was formerly Director of Programs and Education at Esalen Institute. Tarnas is the author of "The Passion of the Western Mind," 1991, a highly acclaimed history of Western thought which became both a bestseller and a widely used text in colleges and universities. The book has been acclaimed by some scholars as the best history of Western thought ever written. He is the founding director of the Philosophy, Cosmology, and Consciousness graduate program at the California Institute of Integral Studies in San Francisco. He is also on the faculty of the Pacifica Graduate Institute in Santa Barbara.