I have made all kinds of experiments, bringing subjects into catalepsy, somnambulism, giving illusions, hallucinations, post-hypnotic suggestions, etc. As a result of my work one central truth stands out clear, and that is the _extraordinary plasticity of the subwaking self_. If you can only in some way or other succeed in separating the primary controlling consciousness from the lower one, the waking from the subwaking self, so that they should no longer keep company, you can do anything you please with the subwaking self. You can make its legs, its hands, any limb you like perfectly rigid; you can make it eat pepper for sugar; you can make it drink water for wine; feel cold or warm; hear delightful stories in the absence of all sounds; feel pain or pleasure, see oranges where there is nothing; you can make it eat them and enjoy their taste. In short, you can do with the subwaking self anything you like. The subwaking consciousness is in your power, like clay in the hands of the potter. The plasticity of the subconscious is revealed by its extreme suggestibility. I wanted to get an insight into the very nature of the subwaking self; I wished to make a personal acquaintance with it. “What is its _personal_ character?” I asked. How surprised I was when, after a close interrogation, the answer came to me that there cannot possibly be any personal acquaintance with it,--for _the subwaking self lacks personality_. Under certain conditions a cleavage may occur between the two selves, and then the subwaking self may rapidly grow, develop, and attain, apparently, the plane of self-consciousness, get crystallized into a person, and give itself a name, imaginary, or borrowed from history. This accounts for the spiritualistic phenomena of personality, guides, controls, and communications by dead personalities, or spirits coming from another world, such as have been observed in the case of Mrs. Piper and other mediums of like types; it accounts for all the phenomena of multiple personality, simulating the dead or the living, or formed anew out of the matrix of the subconscious. All such personality metamorphoses can be easily developed, under favorable conditions in any psychopathological laboratory. They can be easily formed, by suggestion in trance, hypnotic, and waking states. The newly crystallized personality is, as a rule, extremely unstable, ephemeral, shadowy in its outlines, spirit-like, ghost-like, tends to become amorphous, being formed again and again under the influence of favorable conditions and suggestions, rising to the surface of consciousness, then sinking into the subconsciousness, and disappearing, only to give rise to new personality-metamorphoses, bursting like so many bubbles on the surface of the upper stream of consciousness.