This paper first considers the current confusion in categorizing and even describing mystical states, including experiences of God, the Void, and lesser religious experiences. The paper presents the necessity of studying the neuropsychological substrate of such experiences both to understand them in greater depth and to help resolve scholarly confusion in this area. As a prelude to presenting a neuropsychological model, the basic principles of brain organization are reviewed, including hemisphericity; primary, secondary, and tertiary sensory receptive areas; their motor analogues; prefrontosensorial polarity; and the integration of limbic functioning into cortical activity. A neuropsychological model for mystical states is then presented in terms of differential stimulation and deafferentation of various tertiary sensory association areas, along with integration of various patterns of limbic stimulation. Newberg is a recent graduate of the University of Pennsylvania Medical School and is in his first postgraduate year of medical education. His research experience includes nuclear medicine and brain visualization techniques. He may also be reached at Limina,