Still the further problem confronts us: How shall we consciously and intelligently control telepathic communication as we now control our communication by speech, letters, or telegrams? A curious instance of unconscious and unaccountable telepathy is the following: There were two individuals who had never met, but who held some mutually antagonistic conceptions of each other,--conceptions that were, too, perhaps more or less mutually erroneous, and this condition had lasted over a prolonged period of time. Then one of these persons had the experience of waking in the night, simply engulfed in an overwhelming wave of tender and compassionate feeling toward the other: seeing, as if with spiritual vision, a nature unstrung, hardly responsible, and one that invited only the most infinite tenderness and care. This wave of new and perfectly clear perception was like a magnetic trance. It was an hour of absolute spiritual clairvoyance, and the evidence was furnished by a letter received, the next morning, from a mutual friend, which entirely substantiated and corroborated the telepathic impression that had been experienced in the night. Now the scientific question is: From whence did this impression proceed? Was it direct telepathy between the two persons concerned? Was it a clairvoyant reading of the letter that was en route during the night? Who can decide? The special point here is that these most vivid and intense experiences are largely, if not entirely, encountered unconsciously. They suddenly--come. One asks for them--and they do not come? Now how are we to pluck out the heart of the mystery?