In this article, written for a Catholic medical journal, Roland Cahen first emphasises the importance of the psyche, not only because illnesses often have psychological roots, but also because psychopathology is one of the driving forces in the world. Secondly, he describes the psychotherapeutic task and its difficulties: the removal of projections, the transference, the contradictory needs to remain blind and to become healthy. In conclusion, the author claims the psychoanalysis of Freud, Jung and Adler as being the powerful therapeutic tools in psychiatry.