first is hysterical insensibility. If a part of a person's body is insensible, lie is not aware of what happens to it; and, on the other hand, the nervous centers in relation with this insensible region may continue to act, as is the case in hysteria. The result is that certain actions, more often simple, but sometimes very complicated, can be performed subconsciously by a hysterical patient; further, these actions may have a psychical nature, and show intellectual processes distinct from those of the subject, thus constituting a second ego, which coexists with the first.
A second condition that may occasion the division of consciousness is the concentration of attention on a single thing. The result of this state of concentration is that the mind is absorbed to the exclusion of other things, and to such a degree insensible that the way is opened for automatic actions; and these actions, becoming more complicated, as in the preceding case, may assume a psychical nature and establish intelligences of a parasitic kind, existing side by side with the normal personality, which is not aware of them.
The real nature of hysterical anæsthesia has long been misapprehended, and it has been compared to common anæsthesia from organic causes, as, for example, from the interruption of the afferent nerve tracts. This way of considering it should be completely abandoned, for we now know that hysterical anæsthesia is not a real local insensibility, but an insensibility due to unconsciousness, to mental disintegration; in short, it is psychical insensibility, arising simply because the personality of the patient is impaired, or even entirely divided.
The existence of unconscious phenomena in the case of hysterical patients need not astonish us, for each one of us may, if we watch ourselves with sufficient care, detect in ourselves a series of automatic actions, performed involuntarily and unconsciously. To walk, to sit down, to turn the page of a book—these are actions which we perform without thinking of them. But it is difficult to study unconscious activity in a normal man, for this activity shows itself chiefly in routine, in formed habits, kept going by repetition: in general, it does little new. Sometimes it seems to judge and reason, but these are old judgments and reasons which it repeats. At all events, it seldom acquires any considerable development, and almost never, one might say, amounts to the dignity of an independent personality. The conditions of study are much more favorable when we apply ourselves to hysterical subjects.
Among these unconscious phenomena are those known as movements of repetition, and these are often provoked by suggestion—as when an order or suggestion is given to a person awake or in a somnambulistic state to imitate all movements that are
