The most notable is arguably Swiss psychiatrist Carl Jung, who was a student of Sigmund Freud. Freud divided the human personality into the id, ego and superego, while Jung proposed the human psyche was composed of the id, the personal unconscious and the collective unconscious. The two men split over Jung’s belief that Freud was too limited in his thinking and that the unconscious was more than repressed thought and motivations and could be a prolific source of creativity. The 1960s became a primary time of growth for transpersonal therapy as Abraham Maslov announced transpersonal therapy as the fourth force in psychology and strived to separate it from the humanistic school of psychology. The use of the term transpersonal has been credited to early notable figures Stanislov Groth and Anthony Sutich, who were associates of Maslov. The Institute of Transpersonal Psychology was opened in 1975 by Robert Frager and James Fadiman and was in response to the hostility transpersonal psychology received from the established scientific and academic environment. The Institute is now Sofia University, and offers coursework in the field, specifically at the master’s-level.