It would naturally be expected that the nature and subject-matter of the more frequent types of coincidences and presentiments would throw some light upon their origin, and would in some measure reinforce the general position above taken. We should expect that such coincidences would relate to persons and affairs that are frequently in our thoughts, and that similarities of thought and presentiments based upon them should occur among persons intimately acquainted with one another's thought-habits, at least in regard to that line of thought to which the coincidence relates; these expectations are fairly well borne out by the facts. It is a commonplace observation that presentiments and unusual psychic experiences most frequently relate to those who are dear to us, or in whom we have a momentarily strong interest; that they deal with events which we have anxiously dreaded or desired, or with matters over which we have puzzled or worried; and again, that they occur under conditions of emotional strain, excitement, or anxiety. In brief, they deal with what is frequently in our minds or what more or less unconsciously furnishes the general emotional and intellectual background which gives character to our mood and to our associations of ideas. I need hardly add that it is the more successful and striking coincidences that we remember and record, and the others that are quickly forgotten. Moreover, so large a share of mental operations of the type in question takes place in the region of the subconscious, that our recollection of what has occupied our thoughts is by no means a final authority. Occasionally we detect these subconscious similarities of mental operations, when after a silence the same question or thought shapes itself on the lips of two speakers at the same time; and here again, are not many of those who give utterance to the same thoughts, or finish one another's sentences, intimate companions in the walks of life? Is it strange that in the daily intercourse with a congenial spirit, they should have absorbed enough of one another's mental processes to anticipate, now and then, a step in their association of ideas?
Still another factor that figures somewhat in coincidences relates to events which are sooner or later very likely or quite certain to occur, and in which the coincidence is confined to the close simultaneity of the action on the part of two or more persons concerned. The crossing of letters is easily the best illustration of this type of occurrence which has the semblance of thought-communication. It is so easy to fall into the habit of delaying all delayable matters as long as possible that it must frequently happen that your own sense of duty is aroused and your correspondent's patience is exhausted at nearly the same time. If A is to hear from B, or B from A, within a period not very definite but still reasonably limited, every day's delay makes it more and more probable that their letters will cross. The same consideration applies to other affairs of daily life; we delay a matter of business and are just about to attend to it when the other party concerned comes to us, or we delay offering some social attention until just as we are about to do so it is asked of us; and so on. In brief, we find not only in sickness and death, in family ties and friendships, in travel and adventure, but also in the special and in the complicated interests of our civilized life an abundant opportunity for coincidences; and we find that their frequency is clearly related to the commonness of the event, and to its familiarity and closeness of relation to our habits of thought.
V
Reviewing the arguments which have been presented, we find a tendency to underestimate the possibilities of expression and communication through the normal channels of the senses and the subtle inferences based upon them, and also an insufficient appreciation of the unrecognized but by no means supernormal capabilities, which special and unusual susceptibility or training of these same powers of interpretation and thought-revelation may bring about; we find, further, a prevalent underestimation of the generic and at times the specific similarity of the products of our several diverse and yet homogeneous mental equipments, and with it a lack of consideration of the greatly increased facilities for such mental community afforded by modern conditions of rapid transit and rapid sharing of the common benefits of civilization. We find a misconception of the nature of the application of the doctrine of chances to mental coincidences, which brings about an apparent recognition but an intrinsic belittling of the rôle which chance really plays in the evidence advanced for telepathy; we find that this error is probably due to an unfortunate, intensely individual view of the problem, which insists upon an explanation of personal experiences, and disregards the essentially impersonal and statistical nature of the inquiry. This unfair attitude (which is equally unfair if applied to other and more exact data) renders difficult, if not impossible, a just appreciation of the theoretical aspect of the problem and of the application of theory to practice. We find, furthermore, that the recorded data are likely to involve an unusual degree of unreliability owing to such natural psychological tendencies as defective observation, exaggeration, preconception, and the ordinary limitations and failings of humanity; nor is any serious amount of such neglect needed to bridge the gap between intelligible fact and unintelligible mystery. Finally, it is not sufficiently borne in mind that the data are in large part created by the subjective attitude of expectation and interest in such experiences, and that the nature of the more frequent coincidences furnishes satisfactory evidence of their natural relations to dominant interests and occupations. The concordant suggestion from these various considerations is that a very large part of the experiences offered in evidence of mental telegraphy, finds a much more natural and more consistent explanation when viewed as the complex and irregular results of types of mental processes included within the legitimate and recognized domain of psychology. There is no desire to overlook the loose and distant connection that often pertains between the general considerations and the particular phenomena here relevant; on the contrary, this lack of explicit and intimate connection is a logical characteristic of the relation of theory to practice in dealing with such complex and irregular material, and is likely for a long time to remain so. A more properly cultivated logical sense will bring about a more satisfactory appreciation of and a greater intellectual content with this aspect of the problem; it will be recognized that it is wiser to make the best of actual though admittedly unsatisfactory conditions than to fly to evils that we know not of.
VI
I therefore regard the inclination towards a telepathic hypothesis as the result of a defective logical attitude, which in turn may be regarded as the outcome of a natural but unfortunate psychological tendency. In considering the question, "What is the proper inference to be drawn from the accumulated data apparently suggestive of 'communication between mind and mind otherwise than through the known channels of the senses'?" we are considering a logical problem—a problem of considerable difficulty, not one to be entered upon without deliberation and preparation. In considering the question, "How is it that such evidence is readily accepted as proof of telepathy? How is it that this hypothesis is favored above others intrinsically no less improbable?" we are likewise entering upon a complex problem, but one that is psychological in scope and nature. It is to a more fundamental consideration of these questions that we now turn.
I have based my discussion of mental telegraphy almost wholly upon the occurrence of coincidences (using that term not as the equivalent wholly of chance occurrences, but including suggestive or interesting conjunctions of circumstances in general), for the reason that coincidences—both those of a commonplace character and those that seem to possess a striking personal significance—have prepared the popular mind for the acceptance of the telepathic hypothesis, and still constitute the most formidable array of evidence presented for that hypothesis. The other class of evidence to be considered is the experimental, which may be said to include as its most distinctive type the results of tests in which intentional attempts at mental telegraphy were made under definite conditions and usually with specially selected subjects; and as another type, the precise verification and registration of presentiments and peculiar and startling "psychic experiences" with reference to their coincidence with death, accidents, and other serious events in life. It may be admitted that the experimental data are equally worthy with the others of a logical analysis, and indeed that they present in some respects different and more favorable conditions for the application of such an analysis. In general, however (and I desire to confine this discussion to the general principles involved and not to the analysis of special cases), the considerations that determine the logical value, or the lack of it, of the one type of evidence are applicable without undue modification to the other. Nor do I consider that the experimental data have seriously modified the logical status of the problem as a whole; nor that they have, except in relatively few cases, been of themselves sufficient to make converts to a belief in telepathy. They have undoubtedly very much strengthened and disseminated that belief; but this implies that a favorable disposition to the belief was already present. It is because it seems to me that the presence of this favorable disposition, albeit in suppressed or half-acknowledged form, is in most cases due to some phase of the argument from coincidences, that I have made it central in my discussion. I must not fail to point out, however, that experiments in thought-transference have one important, and that a logical, advantage over observations of coincidences; this is the possibility which they present of quite accurately allowing for the effect of chance. In coincidences the estimate of chance as the source of the conjunction of events is frequently, if not always, a matter of complex judgment over which serious differences of opinion will occur. Some of the published quantitative estimates made by serious and able students of such problems, of the probabilities that certain coincidences have been due to chance have been pronounced altogether wide of the mark and even absurd by others. In experiments arranged with due precautions there can be no uncertainty on this point; the proportion of successes, that is, of striking coincidences, may be calculated. If the actual number of chance coincidences appreciably exceeds the calculated proportion, and if the theory on which the calculation was based corresponds to the actual conditions, then the results were not due to chance alone. But whether they were due to fraud, or to some unconscious transference of indications, or to telepathy, or to spirit influence, or to interference of the devil, or to the fact that the participants in the experiment were born when the stars and planets presented certain conjunctions, or to the existence of a totally unrecognized form of mental vibrations,—all these are mere hypotheses which may be strong or weak or absurd, according to their power to really account for the results, to their concordance with the sum total of scientific knowledge in this field and with the logical principles guiding the formation of scientific hypotheses. To jump from the conclusion that the results are not due to chance to the conclusion that they are due to telepathy, is no whit more absurd than the position of the astrologer, or the spiritualistic explanation of conjuring tricks. That there is something in these results to be explained is admitted; whether the results have been obtained and recorded in such a way as to contain the clue to their explanation cannot be affirmed; whether our present state of knowledge enables us to explain them may be argued pro and con; whether they are worth serious attention is also a debatable question; but none of these conditions warrants a resort to the telepathic hypothesis. That hypothesis as all others must be weighed in the logical balance without prepossession, and with full realization of the possibility, that "general appearances suspicious," or "not proven," or a complete suspension of judgment, may be among the present verdicts.
VII
So far as the strength and weakness of the arguments for mental telegraphy depend upon the perspective of value attached to the various data and to the conditions under which these have been gathered, I have presented my estimate and indicated the burden of my conclusions. But I am aware that I may have laid myself open to the charge—which will be brought not by the advocates of telepathy, but by its most emphatic opponents—of a neglect of consideration of the general logical status of telepathy as a germane and legitimate hypothesis. That the hypothesis of telepathy when carefully interpreted is capable, if not of explaining the data, at least of being fitted without undue straining to a large portion of the data, may be claimed with some plausibility; that I regard the hypothesis as unwarranted and unnecessary has been made sufficiently clear. But what if the hypothesis is not a legitimate one, not one which the methods and spirit of science can properly or profitably consider? If this be the case, it would seem superfluous to consider whether the hypothesis is warranted by the data or capable of explaining them. That it is the policy of science to allow the utmost latitude of opinion and theory and to interpret the possible in an unprejudiced and liberal spirit will readily be conceded. That it is equally the policy of science to demand of all claimants for recognition authentic credentials framed in accordance with the laws of logic and the principles of evidence and probability, is sometimes overlooked. Science cannot possibly consider all hypotheses, but only legitimate ones. To explain coincidences and the success of experiments in thought-transference by assuming that there is a demon, whose special business it is to make people have uncanny feelings when their relatives in distant places are dying or in danger, and to suggest to the guesser what is in the mind of the party of the second part in the experiment, is certainly not an hypothesis worthy of consideration by science; and incidentally be it noted that this hypothesis may be successfully shaped to fit the facts, and cannot be definitely disproved. Some absurd hypotheses may be readily disproved and others not; but are scientists really called upon to disprove them? There recently fell under my observation a claim for the theory that when persons felt an unaccountable aversion for one another, either at once or after a time of friendship, it was due to their opposite horoscopic natures, and it would be found that their birthdays were not far from six months apart, that is, nearly as far apart as they possibly could be. Divorces, breaches of promise, family feuds, and antipathies at first sight could thus be accounted for. Now, it would involve no very burdensome undertaking to disprove this theory; but I should not expect a cordial approval of my efforts on the part of my colleagues if I carried through the investigation. The hypothesis is unscientific, or even anti-scientific, and its examination unnecessary and unprofitable. Yet it is not always possible to render so decisive a verdict; and in the present case, while I incline to the belief that the hypothesis of telepathy is, as usually advanced and in essence, an illegitimate one, I still regard it as possible that in the future some modification of this hypothesis may be framed, which will bring it within the scope of a liberal conception of the scientific. It is important to make this attitude perfectly clear: if telepathy means the hypothesis of a new force, that is, the assumption of an as yet uncomprehended mode of the output of energy, subject rigorously to the physical bonds of material causation which make possible a rational conception of psycho-physiological processes; and if, further, some one will put forth a rational conception of how this assumed action can take place apart from the exercise of the senses, I am prepared to admit that this hypothesis is (not sound, or strong, or in accordance with the facts, or capable of explaining the facts, or warranted by the facts, but) one which it is legitimate, though perhaps not profitable, to consider. If, however, telepathy is put forward as a totally new and peculiar kind of action, which is quite unrelated to the ordinary forces with which our senses and scientific observation acquaint us, and which is not subject to the limitations of the material world of causation; if telepathy is supposed to reveal to us a world beyond or behind or mysteriously intertwined with the phenomena of this world,—a world in which events happen not in accordance with the established physical laws, but for their personal significance even in defiance of those laws,—then it becomes impossible for the scientist to consider this hypothesis without abandoning his fundamental conceptions of law and science.
My defense, therefore, for not beginning and possibly confining this discussion to the question of the scientific legitimacy of the telepathic hypothesis is that, in the present status of opinion, it does not seem to me hopeful to influence belief by such a presentation. It seems to me a far more practical step to present the unwarranted character of the hypothesis and its logical insufficiencies as a means of influencing those who had been, or were likely to be, impressed by coincidences and death-warning experiences and guessing experiments. And, moreover, it is necessary, so long as such experiences have a strong hold on the popular imagination and shape the popular conceptions of the nature both of mental processes and of the field of psychology, to portray as well as may be the natural explanation and significance of the phenomena, and to indicate the general trend of the conceptions under which they may be profitably viewed; and this, even though it be but measurably possible to apply general principles to special cases. This step is an essential part of the logical task here attempted. Under other circumstances it would have been advisable, as it always would be proper, to determine the legitimacy of an hypothesis before considering it as worthy of detailed examination on other counts. But here, as is frequently the case, it is a condition and not one of our own choosing that confronts us.