Existential psychotherapy is the movement which, although standing on one side on the scientific analysis owed chiefly to the genius of Freud , also brings back into the picture the understanding of man on the deeper and broader level man as the being who is human. It is based on the assumption that it is possible to have a science of man which does not fragmentize man and destroy his humanity at the same moment as it studies him. It unites science and ontology .