The origin of PPT traces back to the development of humanistic psychology and psychotherapy, pioneered by Kurt Goldstein, Abraham Maslow and Carl Rogers. Personal encounters with leading psychotherapists, such as the psychoanalyst Heinrich Meng (Switzerland), Viktor Frankl (Austria) and his existential psychology or Logotherapy, Jacob Levi Moreno (United States) as the founder of group therapy and psychodrama, and training experiences with some of them left a lasting impression on Nossrat Peseschkian. As for the quarrels between the various schools and methods, Nossrat Peseschkian describes his observations in Germany, where psychoanalysts and behavior therapists sometimes even refused to have lunch together.
Additionally, the strong prevailing influence of psychoanalysis and its Neo-Freudian, psychosomatic and focus orientated (Balint) developments at that time also made an impression on Nossrat Peseschkian. He hoped to construct a metatheory that would be a bridge between these methods.
Positive Psychotherapy: An Introduction Hamid Peseschkian and Arno Remmers