Transpersonal psychology is a relatively new field of psychology and has developed from various spiritual and philosophical traditions. 

The transpersonal approach is understood as the 4th force of psychology, with psychoanalysis being the 1st force, behaviourism ( or behavioural psychology ) the 2nd, and humanism the 3rd force of psychology.

Transpersonal psychology promotes a view that integrates all the forces before it, including contributions from Carl G. Jung (Analytical Psychology), Abraham Maslow, Viktor Frankl (Logotherapy), Ken Wilber, Stanislav Grof, Fritz Pearls and Max Wertheimer (Gestalt Psychology).

Here I would like to express my most sincere gratitude to all the transpersonal psychologists, thinkers and philosophers from whom I have had the honour to have learned. To mention a few: Leonardo Boff, Roberto Crema, Lúcia Helena Galvão, Eneida Lima, Ricardo Neto, Jairo Salles, Claudio Thebas, Sônia Tommasi.