Hallucinations of this kind, whose origin we can trace with more or less probability to some external sensation, may be in some respects compared with the visions seen on blank cards by the subjects of MM. Binet and Féré. But there are other hallucinations which cannot with any plausibility be referred to peripheral excitation. Such, as already said, are many hypnotic hallucinations, and the majority of the fully-developed hallucinations of normal life would appear to fall under the same category. Hallucinations of this class, like what may be called hallucinatory[103] dreams, are no doubt due to the spontaneous activity of the higher cerebral centres; they are simply ideas which take on sensory colouring. And just as the hallucinations of hypnotism, for the most part, are due to external suggestion, so it would seem that amongst the centrally initiated hallucinations of normal life there are some which owe their origin not to the spontaneous activity of the percipient's brain, but to an idea intruded from without—a suggestion not verbal but telepathic.
The proof of this proposition—the proof, that is, of the operation in certain cases of some distant cause external to the percipient's organism—lies in a numerical comparison of those hallucinations which coincide with an external event—e.g., the death of the person seen—and those which do not. For when the relative frequency of hallucinations has been ascertained the probability of chance coincidence in such cases can be exactly calculated. And should it appear that coincidental hallucinations are more frequent than chance would allow, it is certain that some other cause has to be sought for. And here we are met at the outset by a serious difficulty. It would appear from the results of the census just described that hallucinations even of a vivid and interesting character tend very quickly to be forgotten. Thus, to take only the cases of realistic apparitions resembling a living person, we find 157 cases recorded as occurring during the last ten years, and only 166 as occurring more than ten years ago; although, as the average age of our informants is about 40, we might have anticipated that the latter number would be about three times as great as the former.[104] But the discrepancy becomes still more striking if the figures are examined in detail. The subjoined table gives the number of apparitions resembling the human form recorded for each of the last ten years:—
| No. of Years Ago— | 1 and under | b'tw'n— 1 and 2 | 2-3 | 3-4 | 4-5 | 5-6 | 6-7 | 7-8 | 8-9 | 9-10 | Total. |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Realistic } Living | 35 | 19 | 15 | 13 | 15 | 13 | 17 | 12 | 8 | 10 | 157 |
| Human } Dead | 12 | 10 | 7 | 1 | 7 | 6 | 6 | 2 | 8 | 3 | 62 |
| Apparitions } Unrecognised | 17 | 16 | 12 | 17 | 17 | 13 | 11 | 10 | 5 | 8 | 126 |
| 64 | 45 | 34 | 31 | 39 | 32 | 34 | 24 | 21 | 21 | 345 |
It will be seen that the number of hallucinations recorded as occurring between nine and ten years ago is less than one-third of the number recorded for the last twelve months. Nay, if the analysis is carried still further, it is found that within the last year the number of hallucinations remembered decreases month by month as we recede further from the present. The inference is irresistible, that the great majority even of interesting hallucinations do not sufficiently impress the memory to be preserved for a few years. After a careful analysis of the figures the Committee are of opinion that the number of visual hallucinations actually experienced by their informants since the age of ten would be approximately secured by multiplying the recorded number by four.[105]
But if hallucinations in general are not remembered enough, coincidental hallucinations, at least those which coincide with the death of the person seen,[106] would appear to be remembered too well, as will appear from the following figures. There are 13 such cases recorded during the last ten years. Now if we assume that this figure accurately represents the number of such coincidences that have occurred in the experience of our informants during the last ten years, then, since the average age of our informants in this particular case is 46, we should expect to find for the whole period since the age of ten years 47 such coincidences reported; that is on the assumption that no death-coincidence is ever forgotten, and that the liability to such hallucination is practically uniform during the entire period. We do actually find 65 cases; from which it should, the Committee think, be inferred, not only that few or no death-coincidences are forgotten,—a result which is probably not surprising,—but also that a certain number of cases which are not death-coincidences have by the lapse of time grown to appear so.[107] Nor is it difficult to conjecture the particular form of error. It is probable that in most of the 18—more or less—spurious death-coincidences, there was an actual phantasm and an actual death, but that the two events did not stand in close relation to each other. We have already (see Chap. VI.) seen reason to suspect a constant tendency to magnify the closeness of a coincidence of this kind. Seen from a distance the two events—like a binary star-system—are apt to coalesce into one; and a new spectral analysis is required to dissociate them.
Nor would it be safe to assume that the tendencies which have demonstrably operated to falsify the more remote records have been altogether inactive during the last ten years. The causes which tend to sophisticate narratives of this kind, as already shown, are many and difficult to detect; the kind of evidence required to place the alleged death-coincidence beyond reasonable doubt has in some cases never existed; in others, through the destruction of documents, the death of friends, or the mere lapse of time, it is now unattainable. Of the 65 reported coincidences perhaps not more than one-fifth reach the evidential standard of the cases included in this volume. And whilst there is a strong presumption that some proportion of those, which from one or other of the causes suggested inevitably fall below the standard, yet represent facts with substantial accuracy, we have no test which will enable us to determine with precision what narratives and to what extent are worthy of credence. Many of the best-attested cases are printed in full in the Report already referred to, and any reader who is interested in the matter will be able to form an estimate for himself. Meanwhile, an attempt has been made, by means of a careful examination of each narrative in detail, to estimate its evidential value. In the result it would appear that about 44 narratives rest on evidence that may be regarded as fairly good. Of these 44 cases, however, 12 must be struck out, 3 as having been imported into the census,[108] and 9 because a certain amount of anxiety may be presumed to have existed, and may be supposed—though the evidence for such action is very slight—to have caused the hallucination. We thus have 32 cases remaining, in which we have evidence of the occurrence of a hallucination, without apparent cause, within twelve hours of the death of the person seen.
The total number of recognised apparitions of living persons recorded at first-hand as occurring in the circle of 17,000 persons from which these death-coincidences were drawn, is 322.[109] But if, in order to allow for forgetfulness, as already indicated (p. 221), we multiply the number recorded by 4, we shall arrive at a total of 1288, as representing the probable number actually experienced by our informants since the age of ten. We have, therefore, 32 cases of hallucinations coinciding with the death of the person seen, in an estimated total of nearly 1300 recognised apparitions of living persons—or about 1 in 40. But the death-rate for England and Wales in the last completed decade being 19.15 per 1000 per annum, the average probability that any particular person will die on any particular day is 1000 × 365⁄19.15 = about 1 in 19,000. That is, there is one chance in 19,000 that a man will die on the day on which his apparition is seen and recognised, supposing there to be no causal connection between the two events. Or in other words, for every hallucination which coincides with the death of the person seen, we should have to find about 18,999 similar hallucinations (i.e., recognised apparitions of living persons) which do not so coincide.
But after making due allowance for forgetfulness on the one hand, and for the creative activity of the imagination on the other, we find the actual proportion to be 1 to 40. In the face of these figures it would be preposterous to ascribe the reported cases of hallucinations at the time of death to chance. And the argument for some causal connection between hallucinations and external events is of course considerably strengthened if, in addition to (a) the coincidences of visual hallucinations with death, we take account of (b) the coincidences of auditory hallucinations with death, and (c) the coincidences of both visual and auditory hallucinations with other events than death, and (d) the cases in which the coincidence of the apparition with the death is nearer than twelve hours, the limit assumed in the above calculations.
It may not be superfluous to repeat (see ante, p. 27, footnote) that the calculation above given does not purport to establish thought-transference as the cause of these coincidences. The cause may be a greater prevalence of exaggeration and memory-illusion than the Committee have allowed for. What the calculation does is to bring us face to face with the problem: Here are certain phenomena, demonstrably not due to chance: do they reveal a new mode of communication between human minds, or merely a new source of fallacy in human testimony? It will hardly be disputed that, in either event, to find an answer to the question will justify much labour spent upon the search.