Mr. Galton was next “greatly struck by the frequency of the replies in which my correspondents” (sane and healthy) “described themselves as subject to ‘visions’”.  These varied in degree, “some were so vivid as actually to deceive the judgment”.  Finally, “a notable proportion of sane persons have had not only visions, but actual hallucinations of sight at one or more periods of their life.  I have a considerable packet of instances contributed by my personal friends.”  Thus one “distinguished authoress” saw “the principal character of one of her novels glide through the door straight up to her.  It was about the size of a large doll.”  Another heard unreal music, and opened the door to hear it better.  Another was plagued by voices, which said “Pray,” and so forth.

Thus, on scientific evidence, sane and healthy people may, and “in a notable proportion do, experience hallucinations”.  That is to say, they see persons, or hear them, or believe they are touched by them, or all their senses are equally affected at once, when no such persons are really present.  This kind of thing is always going on, but “when popular opinion is of a matter-of-fact kind, the seers of visions keep quiet; they do not like to be thought fanciful or mad, and they hide their experiences, which only come to light through inquiries such as those that I have been making”.

We may now proceed to the waking hallucinations of sane and healthy people, which Mr. Galton declares to be so far from uncommon.  Into the causes of these hallucinations which may actually deceive the judgment, Mr. Galton does not enter.

STORY OF THE DIPLOMATIST {56a}

For example, there is a living diplomatist who knows men and cities, and has, moreover, a fine sense of humour.  “My Lord,” said a famous Russian statesman to him, “you have all the qualities of a diplomatist, but you cannot control your smile.”  This gentleman, walking alone in a certain cloister at Cambridge, met a casual acquaintance, a well-known London clergyman, and was just about shaking hands with him, when the clergyman vanished.  Nothing in particular happened to either of them; the clergyman was not in the seer’s mind at the moment.

This is a good example of a solitary hallucination in the experience of a very cool-headed observer.  The causes of such experiences are still a mystery to science.  Even people who believe in “mental telegraphy,” say when a distant person, at death or in any other crisis, impresses himself as present on the senses of a friend, cannot account for an experience like that of the diplomatist, an experience not very uncommon, and little noticed except when it happens to coincide with some remarkable event. {56b} Nor are such hallucinations of an origin easily detected, like those of delirium, insanity, intoxication, grief, anxiety, or remorse.  We can only suppose that a past impression of the aspect of a friend is recalled by some association of ideas so vividly that (though we are not consciously thinking of him) we conceive the friend to be actually present in the body when he is absent.