I have a sufficient variety of cases to prove the continuity between all the forms of visualization, beginning with an almost total absence of it, and ending with a complete hallucination. The continuity is, however, not simply that of varying degrees of intensity, but of variations in the character of the process itself, so that it is by no means uncommon to find two very different forms of it concurrent in the same person. There are some who visualize well and who also are seers of visions, who declare that the vision is not a vivid visualization, but altogether a different phenomenon. In short, if we please to call all sensations due to external impressions "direct," and all others "induced," then there are many channels through which the induction may take place, and the channel of ordinary visualization in the persons just mentioned is very different from that through which their visions arise.
The following is a good instance of this condition. A friend writes:
The number of persons who see visions no less distinctly than this correspondent is much greater than I had any idea of when I began this inquiry. I have in my possession the sketch of one, prefaced by a description of it by Mrs. Haweis. She says: