Perhaps no department of Psychical Research is looked upon from such divers and even quite opposite standpoints as that which relates to Apparitions or Phantasms. Many intelligent people, in a general way, accept them as realities but assign for them a supernatural origin; while others discredit them altogether because they have apparently no basis except an assumed supernatural one.

It has been said that primitive, undeveloped, and ignorant people almost universally believe in ghosts; while with the advance of civilization, culture, and general intelligence, the frequency of alleged apparitions and the belief in ghosts diminishes or altogether disappears. If this statement were to stand unqualified, by so much would the reality and respectability of phantasms be discredited. Possibly, however, it may be found that the last word has not yet been said, 224 and that there may exist a scientific aspect for even so unstable and diaphanous a subject as ghosts.

Instead of going over the literature of the subject from the earliest times - a literature, by the way, which in the hands of Tylor, Maury, Scott, Ralston, Mrs. Crowe and others certainly does not lack interest - it will better suit our present purpose to examine some facts relative to perception in general and vision in particular, and give some examples illustrating different phases of the subject.

Perception may be defined as the cognizance which the mind takes of impressions presented to it through the organs of sense, and possibly also by other means.

One class of perceptions is universally recognized and is in a measure understood, namely, perceptions arising from impressions made by recognized external objects or forces upon the organs of sense, sight, hearing, smell, taste, and also the general sense of touch. These perceptions in particular are designated as real or true, because they correspond to recognized external realities.

But impressions are also made upon the organs of special sense by influences which are not rec-15 ognized as having any objective reality, but which nevertheless affect the senses in a manner often identical with that in which they are affected by recognized external objects, and they cause the same perceptions to arise in the mind. Hence another broad class of perceptions includes those which are taken cognizance of by the mind from impressions made upon the organs of sense in other ways and by other means than by external objects, and often where there is no evidence that any external object exists corresponding to the impression so made. Perceptions arising in these various ways are called hallucinations.

On close examination, however, it is found that the sharp line of separation between what has and what has not an objective reality is not easily drawn, any more than in biology the sharp line between animal and vegetable life can be easily drawn, or at the lower end of the scale between the living and the not living.

So the origin of those perceptions which are classed as hallucinations has always been a subject of controversy, even among philosophers of the greatest merit and eminence.

Without following out the discussions which have arisen on this point - discussions which are often confusing and generally inconclusive, a fairly distinct view of the subject may be obtained by considering the origin of these perceptions under three heads - namely: -

(1) Perceptions which are reckoned as hallucinations may be originated centrally; that is, they may arise wholly within the mind itself without any direct external stimulus. For instance the characters drawn by the novelist may become so real to him, and even to some of his readers, that they become externalized - actual objects of visual perception and are seen to act and even heard to speak. The instance is repeatedly quoted of the painter who, after carefully studying a sitter's appearance, could voluntarily project it visibly into space and paint the portrait, not from the original, but from the phantasm so produced; and of another who could externalize and project other mental pictures in the same manner, pictures which so interested him and were so subject to the ordinary laws of vision that he would request any one who took a position in front of them, to move away so as not to obstruct his view.

It will be noticed in these cases that although the perception has its origin centrally, in the mind itself, and is even voluntarily produced, still, it is seen as an impression made upon the visual organ in exactly the same manner as a picture thrown upon the retina by a real external object; it disappears when the eyes are closed or an opaque object intervenes, and follows the laws of optics in general; hence, strictly speaking, these perceptions are also real.

(2) Perceptions may have their origin peripherally - that is, the point of excitation which causes the act of perception in the mind may exist in the external sense organs themselves, even when no external object corresponding to the perception exists at the time, or it is not in a position on account of distance or intervening objects to affect the senses.

In examining the cases which may be placed under this head they resolve themselves into two classes: those which occur in connection with some disease or defect in the sense organ concerned, and those which are recrudescences or after-visions, arising from over-excitation of those organs; for instance, after looking through a window in a very bright light - even a considerable length of time afterwards - on shutting the eyes or looking into a dark room, an image of the window is seen with all its divisions and peculiarities of construction distinctly presented. To the country lad returning home at night from his first visit to the circus the whole scene is again presented; and ring, horses, equestrians, acrobats and clowns are all seen and externalized with the utmost distinctness; even the crack of the ringmaster's whip is heard and the jokes and antics of the clowns repeated.