This is sometimes an inferior species of insanity, the patient being unconscious of what he is doing. A case is mentioned of a monk who was remarkable for simplicity, candor and probity, while awake, but who during his sleep in the night, would steal, rob, and even plunder the dead. Another case is related of a pious clergyman, who during his sleep, would plunder even his own church. And a case occurred in Maine, where the somnambulist attempted to hang himself, but fortunately tied the rope to his feet, instead of his neck.
It is evident, that if an act should be done by a sleep walker, while totally unconscious of his act, he would not be liable to punishment, because the intention and will would be wanting. Take, for example, the following singular case: A monk late one evening, in the presence of the prior of the convent, while in a state of somnambulism, entered the room of the prior, his eyes open but fixed, his features contracted into a frown, and with a knife in his hand. He walked straight up to the bed, as if to ascertain if the prior were there, and then gave three stabs, which penetrated the bed clothes, and a mat which served for the purpose of a mattress; he returned. with an air of satisfaction, and his features relaxed. On being questioned the next day by the prior as to what he had dreamed the preceding night, the monk confessed he had dreamed that his mother had been murdered by the prior, and that her spirit had appeared to him and cried for vengeance, that he was transported with fury at the sight, and ran directly to stab the assassin; that shortly after be awoke covered with perspiration, and rejoiced to find it was only a dream.
A similar case occurred in England, in the last century. Two persons, who had been hunting in the day, slept together at night; one of them was renewing the chase in his dream, and, imagining himself present at the death of the stag, cried out aloud, "I'll kill him! I'll kill him!" The other, awakened by the noise, got out of bed, and, by the light of the moon, saw the sleeper give several deadly stabs, with a knife, on the part of the bed his companion had just quitted.