The object of research of this work is the condition of the existence of the human being, in its principal psychic manifestations: the mental disorders. This clinical and theoretical research on neurosis and psychosis in its contemporary aspects called: normal neurosis and ordinary psychosis, crosses several approaches. - A practice of psychoanalysis, starting from an analysis with didactic vocation, followed by a direction of cure in city cabinet after some experiences in institutions; - A clinical and theoretical research in psychoanalysis and clinical sociology on "the impact of precariousness on mental health" and "the wandering, following the disavowal as preliminary to the perversion"; - A search for authors in psychoanalysis and other disciplines related to the social and human sciences; - A validation in university research On the theme of the unconscious before Freud and after Freud, the author wanted to try to highlight the importance of Freud and his work, while illustrating the relevance of Lacan with other clinical authors. However, some philosophical authors seem to be forerunners and witnesses of the unconscious from the beginning of culture.