It is part of the mechanism of this process, as understood by these authors, that the physical symptoms of hysteria are constituted, by a process of conversion, out of the injured emotions, which then sink into the background or altogether out of consciousness. Thus, they found the prolonged tension of nursing a near and dear relative to be a very frequent factor in the production of hysteria. For instance, an originally rheumatic pain experienced by a daughter when nursing her father becomes the symbol in memory of her painful psychic excitement, and this perhaps for several reasons, but chiefly because _its presence in consciousness almost exactly coincided with that excitement_. In another way, again, nausea and vomiting may become a symbol through the profound sense of disgust with which some emotional shock was associated. Then the symbol begins to have a life of its own, and draws hidden strength from the emotion with which it is correlated. Breuer and Freud have found by careful investigation that the pains and physical troubles of hysteria are far from being capricious, but may be traced in a varying manner to an origin in some incident, some pain, some action, which was associated with a moment of acute psychic agony. The process of conversion was an involuntary escape from an intolerable emotion, comparable to the physical pain sometimes sought in intense mental grief, and the patient wins some relief from the tortured emotions, though at the cost of psychic abnormality, of a more or less divided state of consciousness and of physical pain, or else anæsthesia. In Charcot's third stage of the hysterical convulsion, that of "_attitudes passionnelles_," Breuer and Freud see the hallucinatory reproduction of a recollection which is full of significance for the origin of the hysterical manifestations.