In other words, and to summarize this part of the discussion, I can only say that there seems to me no valid reason for thinking that the spirit-hands in Home's séances were probably hallucinatory in character because only some of the sitters saw them. They might just as well be explained by supposing that certain of the sitters were more psychic or mediumistic than the others, and these saw—clairvoyantly or by some similar mode of psychic perception—hands and forms invisible to those less sensitive. It need hardly be said that the carrying about of objects by these hands renders their objective nature and existence far more probable than if such movements had never taken place. These physical phenomena remain, no matter what view we take of the visible (or invisible) hands.
In speaking next of Home's "full-form phantasms," Miss Johnson draws attention to the fact, so often pointed out by Mr. Podmore, that the various witnesses in subsequent accounts do not describe the phenomena in the same terms or in precisely the same manner. The narrative differs in the various accounts, and the phenomena appear far more remarkable in some than in others. The inference is that none of them is right—certainly not the more remarkable ones—and that the inaccuracy of the reports invalidates the records.
Now I have nothing to say against this method as a method. But I think it can be pushed too far and wrong deductions drawn therefrom. It is right to discount the value of the evidence, but that is a different thing from discrediting it altogether. If individual records differ when describing any particular phenomenon it is right that the less marvellous be accepted as the more probable; but this is not saying that the phenomenon did not take place at all! Any two accounts of a given phenomenon must necessarily differ—more or less, according to circumstances. But if all the accounts obviously concern a given phenomenon, and if they agree, even in the essential outlines, it is probable that the event resembled the description more or less; and if in all these accounts there is no evidence of fraud forthcoming, and no indications that it existed, we must take it for granted that no suspicious circumstances were noted and no fraud detected—for otherwise it would have found its way into the records. And the fact that it never did find its way into any of them (with one doubtful exception, Journal, S.P.R., vol. iv. pp. 120-21, and Jan. and May 1903) seems to indicate, not that the phenomena were necessarily genuine, but that the central theme of the account, so to speak—the phenomenon—was seen alike by all, and was variously described by the witnesses afterward in the subsequent reports. The minor discrepancies do not suffice to explain away the phenomenon altogether. They serve merely to render it less marvellous. Many psychic researchers, however, seem to imagine that because the various accounts do not agree, the fact recorded probably did not occur at all. That is surely an entirely unwarranted supposition, and were this carried to its logical conclusion, would suffice to disprove the whole of the past history of the human race.
Miss Johnson's discussion of Home's famous levitation out of one window and in at another is surely masterly, and is precisely the kind of criticism which psychic research needs. After reading her account, I can only say that were this case an isolated incident, unsupported by any similar eases of a like nature, it would be so far "explained away" as to lose all evidential value. At the same time I think that Count Solovovo sums the whole argument up when he says that none of Home's phenomena were ever proved to be hallucinatory; all that has been done by the discussion is to show that some of them might possibly have been so. And there is a great difference between the two. There is a natural tendency in many minds to assume and take for granted that because a given phenomenon might possibly have been produced by fraud, it was unquestionably produced in that manner. That is quite an unwarranted supposition, and fraud should be clearly proved in every given instance before a medium be charged with trickery. This is a rule far too seldom observed by sceptical investigators, but an important one nevertheless.
Leaving aside this particular case of Home's levitation, however, it may be said that there are others on record far more conclusive in character, and against which many of Miss Johnson's criticisms could not be levelled. Taken singly, it is probable that no single case of any class of phenomena would prove convincing to a sceptic; sufficient objections could be raised, and sufficient discrepancies in the records pointed out, to invalidate any evidence whatever. Quite apart from any a priori objections, any single incident can almost invariably be "explained away." It is the weight of a great mass of cumulative evidence which tells the tale. The most expert and exact description of the fall of a meteor would not have forced an acceptance from the scientific world; the relative improbability of the whole of the past experience of the human race would have been so much greater than the fact that the latter would have been discredited. Gradually it would have receded in the mind, and even the original witness might ultimately be persuaded that he had not in reality seen a meteor at all!
And so it is with psychic research; and so it is with the theory under discussion. No single incident, taken by itself, can be said to prove anything; only the great mass of facts, taken together, and all pointing in the same direction, can be said to do so. One can quite see how this would be the case, e.g. in Mrs. Piper's automatic utterances or writings. No matter how conclusive any individual "test" might be, it would prove nothing by itself. No matter how well attested an apparition at the moment of death, singly it would indicate no telepathic communication nor other supernormal factor at work. But together these cases form a strand[30] which becomes too strong to be broken, and which, taken together, practically prove telepathic communication at the moment of death—at least so thought Professor Sidgwick's Committee, of which Miss Johnson was one member. (See Proceedings, S.P.R., vol. x. p. 394.)
In Home's case, then, the evidence for his levitation phenomena rests, not on any one case taken by itself, but on the mass of cumulative testimony offered by scores of witnesses. However completely one case might be explained away, the other cases still remain to us—each case standing on its own merits, and many of them excellently observed, if not so well recorded. For example, the cases mentioned by Sir. William Crookes (Journal, S.P.R., vol. vi. p. 342) are certainly far superior, in point of observation, to the famous case so severely criticized by Miss Johnson. And I think that if one is going to offer any hypothesis at all, it must be one that covers all the facts, and not merely one which explains only some of them. The hallucinatory nature of Home's phenomena is certainly not inclusive—it does not include many of the more striking incidents to say nothing of the lesser phenomena. For this reason, it does not appear to me to be conclusive either.
After a brief discussion of Home's fire-tests, which Miss Johnson practically admits are inexplicable by any process either of fraud or of hallucination known to her (p. 498), she passes on to what are called "quasi-hypnotic" effects. To many of the incidents classed by Miss Johnson as due to suggestion, I should be inclined to give an entirely different interpretation. Some of them doubtless resemble hallucinations in a striking degree, but what evidence is there that, e.g., passes made over the heads of the sitters can induce identical hallucinations in all of them; or that, because one of the circle becomes hysterical, the others are thereby rendered susceptible to suggestion? However, I shall defer this question until we come to discuss hallucination in general.
After some wholesome criticisms devoted to the "recognition" of materialized forms, and the very true statement (p. 509) that "a very small error in perception may sometimes lead to a very large error of inference," Miss Johnson ends her remarkably interesting paper with two illustrations—one a hallucination (?)[31] induced by false association of ideas; the other an incident in her own experience, occurring at a séance with Eusapia Palladino. Both of these are of importance, and should be studied carefully.
Count Solovovo on the contrary considers it somewhat in favour of the hallucination theory that hands were found to melt in the sitters' grasp, when they were forcibly retained (p. 441). I cannot agree with this. It is a different thing to say that hallucination might account for the facts, and saying that the facts tell in favour of hallucination. Chance might account for an experimental apparition, but the fact that the apparition occurred does not prove it to be chance. One must be careful to distinguish facts and inferences, in a case of this character. Whether or not the hands were hallucinatory will depend, not upon a priori probability, or the fact they were visible to some, invisible to others, (for all this might just as well be accounted for on the opposing theory), but upon the fact that, so far as we know, there is no analogy whatever between this oft-recorded event and any of the phenomena of suggestion known to us. If we offer a theory to explain certain facts, it must not only explain them in a rational manner, but must dovetail into what we know—into the known. That is the whole method of science. If, therefore, a man advances "hallucination" as an explanation of such facts as those under discussion, he must show how it is that hallucination might be supposed to work: he must bring forward some analogies and examples of somewhat similar instances in order to have a case at all. In science, we cannot speculate in vacuo, but must connect with what is already known, if we wish to be scientific at all. What analogies, then, have we that spirit-hands, similar to those described, can be created by suggestion; and that suggestion can cause a number of investigators, at various times, in various places, to believe that these hands melted in theirs while they were trying to retain them?