The authors present a comparison of the cosmological, theological, and anthropological assumptions that underlie the mystical traditions of the Eastern Orthodox Church and certain of Jung's mystical observations about the universe, God, and humankind. It is argued that, one touchstone of scientific validity being the universality of observations independently made, the common ground of the two divergent systems of Eastern Orthodox and Jungian mysticism suggests a universality and scientific validity in Jung's assumptions about the “great unknown.”