Fear as the primary cause of hysteria—Natural somnambulism—Doubling of personality—Some examples of somnambulists—Analogy between somnambulism and the life of anthropoid apes—The psychology of crowds—Importance of the investigation of hysteria for the problem of the origin of man The study of fear is interesting in other respects than those with which I have been dealing. It is also a primary cause of the obscure and complicated phenomena of hysteria. Thus, for instance, amongst twenty-two hysterical women observed by Georget[162] the primary causes were: terror, 13 cases; extreme grief, 7 cases; extreme annoyance, one case. A patient of M. Pitres, of Bordeaux, first exhibited hysteria after being extremely terrified. A man with a tame bear had come to the village. The patient went to see the performance and elbowed her way through the crowd until she got to the front row. The bear, whilst dancing, passed so close that its cold muzzle touched the cheek of the young girl. Marie—for that was the patient’s name—was terrified. She ran quickly home, and almost on her arrival fell on her bed in an attack of convulsion and extreme delirium. Since then the attacks have been repeated many times, and the delirium associated with them always turns upon the terror caused by the bear touching her. A hysterical woman at the Salpétrière is haunted by terrifying dreams. She thinks someone is trying to murder her, or to cut her throat, or that she is falling into water, and she keeps crying for help.[163] Some of the most curious phases of hysteria are the paradoxical and extraordinary cases of so-called natural somnambulism, in which the patients, whilst asleep, perform all sorts of acts of which they remember nothing in their waking hours. Cases of duplication of personality are also known, in which the patients live in two different states without, in one of these, having the slightest remembrance of what takes place in the other. One of the most curious observations was that of the somnambulist who became _enceinte_ whilst in her second state. In her first, or normal condition, she was ignorant of the reason of her physical changes, although in the second state she knew about it quite well and spoke freely of it (Pitres, _op. cit._ II, 215). In the state of natural somnambulism the patients generally reproduce the normal acts of their daily life which they have acquired the habit of performing unconsciously. Artisans devote themselves to their manual work, sempstresses begin to sew, maid servants brush shoes or clothes, lay the table and so forth. Educated persons devote themselves to intellectual work to which they are accustomed. Clergymen have been known to compose their sermons in the somnambulistic condition, and to read them over to correct mistakes in style or in spelling.