Next let us turn from natural to induced sleep-waking, from idiopathic somnambulism to the hypnotic trance. Here, too, throughout the different stages of the trance, we find a varying and partial (or elective) power of communication. Sometimes the entranced subject makes no sign whatever; sometimes he seems able to hear and answer one person, or certain persons, and not others; sometimes he will talk freely to all; but, however freely he may talk, he is not exactly his waking self, and as a rule he has no recollection, or a very imperfect recollection, in waking life of what he has said or done in his trance.
Judging, then, from such analogy as communications from one living state to another can suggest to us, we shall expect that the communication of a disembodied or discarnate person with an incarnate, if such exist, will be subject to narrow limitations, and very possibly will not form a part of the main current of the supposed discarnate consciousness.
These preliminary considerations are applicable to any kind of alleged communication from the departed--whether well or ill evidenced; whether conveyed in sensory or in motor form.
Let us next consider what types of communication from the dead our existing evidence of communications among the living suggests to us as analogically possible. It appears to me that there is an important parallelism running through each class of our experiments in automatism and each class of our spontaneous phenomena. Roughly speaking, we may say that our experiment and observation up to this point have comprised five different stages of phenomena, viz., (I.) hypnotic suggestion; (II.) telepathic experiments; (III.) spontaneous telepathy during life; (IV.) phantasms at death; (V.) phantasms after death. And we find, I think, that the same types of communication meet us at each stage; so that this recurrent similarity of types raises a presumption that the underlying mechanism of manifestation at each stage may be in some way similar.
Again using a mere rough form of division, we shall find three main forms of manifestation at each stage: (1) hallucinations of the senses; (2) emotional and motor impulses; (3) definite intellectual messages.