Clinical judgment is characterised by the singular meeting between an analyst and his analysand. If he can, it is the analyst’s task to think about the concept of his analysand’s symptom. Therefore the clinic unites the Real and a theory of links between symptoms and structure which psychoanalytic science has established. In the Sigmund Freudian theory of neurosis, reworked by J. Lacan, the sexual Thing is given as symptom. This symptom is induced by a phantasy that cocoons the real of the object of the drive. The clinical question consists in unveiling the specific operating phantasy. Freud establishes a structural difference between neurosis and psychosis with the concept of narcissism. It is a theory of egoic investment. In psychosis, the Ego cannot be modified; it must remain the invested object of the subject. The link between transference and elaboration of a clinical knowledge can only be understood if psychoanalytic treatment includes the analyst’s act in the subject’s history.