ITP core faculty member Charles T. Tart, Ph.D., the author, is attributed with creating the term "Altered States of Consciousness" and is considered one of the founders of the field of transpersonal psychology.

The study of consciousness is an arduous process, be it from either psychological or philosophical perspectives. The scientific consideration of states of consciousness that differ from ordinary waking consciousness is a path filled with hazards and booby traps.

Charles is internationally known for his psychological work on the nature of consciousness (particularly altered states of consciousness), as one of the founders of the field of transpersonal psychology, and for his research in scientific parapsychology. His two classic books, Altered States of Consciousness (1969) and Transpersonal Psychologies (1975), became widely used texts that were instrumental in allowing these areas to become part of modern psychology.

He is currently a Core Faculty Member at ITP and a Senior Research Fellow of the Institute of Noetic Sciences (Sausalito, California), as well as Professor Emeritus of Psychology at the University of California, Davis, where he served for 28 years. He was the first holder of the Bigelow Chair of Consciousness Studies at the University of Nevada in Las Vegas and has served as a Visiting Professor in East-West Psychology at the California Institute of Integral Studies, as an Instructor in Psychiatry at the School of Medicine of the University of Virginia, and a consultant on government funded parapsychological research at the Stanford Research Institute (now known as SRI International).

The Pigasus Awards , which seek to expose parapsychological fraud, awarded Tart in 1981 for discovering that the further in the future events are, the more difficult it is to predict them.

As well as a laboratory researcher, Tart has been a student of the Japanese martial art of Aikido (in which he holds a black belt), of meditation, of Gurdjieff's work, of Buddhism, and of other psychological and spiritual growth disciplines. His primary goal is to build bridges between the scientific and spiritual communities, and to help bring about a refinement and integration of Western and Eastern approaches for knowing the world and for personal and social growth.