Wherever conscious thinking is determined by unconscious mechanisms, and all thinking is more or less so, it is dogmatic in character. Beliefs which serve an unconscious purpose do not require the support of evidence. They persist because they are demanded. This is a common symptom of various forms of psychoneurosis. Ideas "haunt the mind" of the patient; he cannot rid himself of them. He may know they are foolish, but he is compelled to think them. In severe cases, he may hear voices or experience other hallucinations which are symbolic of the obsessive ideas. Or his psychic life may be so absorbed by his one fixed idea that it degenerates into the ceaseless repetition of a gesture or a phrase expressive of this idea. In paranoia the fixed ideas are organized into a system. Brill says: I know a number of paranoiacs who went through a stormy period lasting for years, but who now live contentedly as if in another world. Such transformations of the world are common in paranoia. They do not care for anything, as nothing is real to them. They have withdrawn their sum of libido from the persons of their environment and the outer world. The end of the world is the projection of this internal catastrophe. Their subjective world came to an end since they withdrew their love from it. By a secondary rationalization, the patients then explain whatever obtrudes itself upon them as something intangible and fit it in with their own system. Thus one of my patients who considers himself a sort of Messiah denies the reality of his own parents by saying that they are only shadows made by his enemy, the devil, whom he has not yet wholly subdued. Another paranoiac in the Central Islip State Hospital, who represented himself as a second Christ, spends most of his time sewing out on cloth crude scenes containing many buildings, interspersed with pictures of the doctors. He explained all this very minutely as the _new world system_.... Thus the paranoiac builds up again with his delusions a new world in which he can live.... (Italics mine.)