Now let us apply the analogy. The mind as a whole represents the rope; its elements or component parts are the threads; and, under certain abnormal conditions, these can become torn away from the original Self--like little rivulets, branching off from the main stream of consciousness, forming independent selves. This is an abnormal condition; a splitting of the mind, a dissociation of consciousness. Another fragment of consciousness, distinct in itself, has been formed. Thus we have a case of so-called double consciousness, of alternating personality; or, if there are three or more such splits or cleavages, of multiple personality.[21] Now we are in a better position to understand the nature of this alien self which has been formed, and which alternately usurps the common body. It is no foreign spirit; it is not a demon or fiend which has entered into the subject; it is merely a portion of the patient's own mind, acting independently a life of its own. It is a portion of the real Self, functioning independently. Let us now see how these splits or dissociations take place. Often they are the result of some shock to the emotional nature. In one of Dr. Morton Prince's cases, the patient happened to look up and saw in the window the face of a man whom she had known years before, and with whom she had tragic emotional associations. It was storming at the time, and a lightning flash revealed the face in the window. It was a highly dramatic scene, and the shock to the patient's emotional nature caused her consciousness to split-up or become dissociated into various selves; and thenceforward for years these separate "selves" lived independent lives, each ignorant of the life of the other. In this case, there were several such personalities which alternated; and they were only finally unified and the real Self again restored by means of hypnotic suggestion, after a careful analysis of the various selves. This synthesis of the various streams of consciousness, and their ultimate unification into one primary normal self, is one of the most startling, as it is one of the most interesting and suggestive, feats of modern psychological medicine. The principle upon which many of these cures rest, and the efficacy of suggestion, is thus apparent. By its aid the skilled specialist in abnormal psychology is enabled to gather up the "loose ends" of conscious life, as it were, and unify and consolidate them into one normal, healthy Self. He is enabled to weave them all together, and again restore the "sheath" or "wrapper" of the individual human will, keeping these threads in place henceforth, and restoring the healthy, normal personality; the _mens sana in corpore sano_.