§ 4. The moral is one which the authors of the present undertaking have every reason to lay to heart. For the endeavour of this book, almost throughout, is to deal with themes that are in a sense familiar, by the aid, partly, of improved evidential methods, but partly also of conceptions which have as yet no place in the recognised psychology. Not, indeed, that the reader is about to be treated to any large amount of speculation; facts will be very much more prominent than theories. Still, the facts to be adduced carry us at least one step beyond the accepted boundaries. What they prove (if we interpret them rightly) is the ability of one mind to impress or to be impressed by another mind otherwise than through the recognised channels of sense. We call the owner of the impressing mind the agent, and the owner of the impressed mind the percipient; and we describe the fact of impression shortly by the term telepathy. We began by restricting that term to cases where the distance through which the transference of impressions took place far exceeded the scope of the recognised senses; but it may be fairly extended to all cases of impressions conveyed without any affection of the percipient's recognised senses, whatever may be his actual distance from the agent.

I of course do not mean by this merely that the channel of communication is unrecognised by the person impressed - as in the drawing-room pastime where hidden pins are found through indications which the finder receives and acts on without any consciousness of guidance. By the words "otherwise than through the recognised channels of sense," I mean that the cause or condition of the transferred impression is specifically unknown. It may sometimes be necessary or convenient to conceive it as some special supernormal or supersensuous1 faculty; and in that case we are undoubtedly assuming a faculty which is new - or at any rate is new to science. But we can at least claim that we take this step under compulsion; not in the light-hearted fashion which formerly improvised occult forces and fluids to account for the vagaries of hysteria; or which in our own day has discovered the dawn of a new sense, or the relic of some primeval instinct, in the ordinary exhibitions of the "willing-game." Our inference of an unrecognised mode of affection has nothing in common with such inferences as these; for it has been made only after recognised modes have been carefully excluded.

1 It seems impossible to avoid these terms; yet each needs to be guarded from a probable misunderstanding. Supernormal is very liable to be confounded with supernatural; while supersensuons suggests a dogmatic denial of a physical side to the effect.

§ 5. It is not, however, with the ultimate conditions of the phenomena that the study of them can begin: our first business is with the reality, rather than with the rationale, of their occurrence. Telepathy as a system of facts is what we have to examine. Discussion of the nature of the novel faculty in itself, and apart from particular results, will be as far as possible avoided. That, if it exists, it has important relations to various very fundamental problems - metaphysical, psychological, possibly even physical - can scarcely be doubted. So far from the scientific study of man being a region whose boundaries are pretty well mapped out, and which only requires to be filled in with further detail by physiologists and psychologists, we may come to perceive that we are standing only on the threshold of a vast terra incognita, which must be humbly explored before we can even guess at its true extent, or appreciate its relation to the more familiar realms of knowledge. But such distant visions had better not be lingered over. Before the philosophical aspects of the subject can be profitably discussed, its position as a real department of knowledge must be amply vindicated.

This can only be done by a wide survey of evidence; the character of the present treatise will therefore be mainly evidential.

In demonstrating the reality of impressions communicated otherwise than through the known sensory channels, we rely on two distinct branches of evidence, each of which demands a special sort of caution. The larger portion of this work will deal with cases of spontaneous occurrence. Here the evidence will consist of records of experiences which we have received from a variety of sources - for the most part from living persons more or less known to us. Narratives of the same kind have from time to time appeared in other collections. These, however, have not been treated with any reference to a theory of telepathy such as is here set forth; nor have their editors fulfilled conditions which, for reasons to be subsequently explained (Chapter IV (General Criticism Of The Evidence For Spontaneous Telepathy)), we have felt bound to observe; and we have found them of almost no assistance. In scarcely a single instance has a case been brought up to the standard which really commands attention.1 The prime essentials of testimony in such matters - authorities, names, dates, corroboration, the ipsissima verba of the witnesses - have one or all been lacking; and there seems to have been no appreciation of the strength of the a priori objections which the evidence has to overmaster, nor of the possible sources of error in the evidence itself.

It is in analysing and estimating these sources of error, and in fixing the evidential standard which may fairly be applied, that the most difficult part of the present task will be seen to consist.

1 An exception should perhaps be made in favour of a few of the late Mr. R. Dale Owen's narratives. The Rev. B. Wrey-Savile's book on Apparitions contains some careful work, but it deals chiefly with remote cases. Dr. Mayo, in his Truths contained in Popular Superstitions, adduces very inadequate evidence; but he has given (p.67) what is perhaps the first suggestion of a psychical explanation.

But though the records here presented will be more numerous, and on the whole better attested, than those of previous collections, the majority of them will be of a tolerably well-known type. The peculiarity of the present treatment will come out rather in the connection of this branch of our evidence with the other branch. For our conviction that the supposed faculty of supersensuous impression is a genuine one is greatly fortified by a body of evidence of an experimental kind - where the conditions could be arranged in such a way as to exclude the chances of error that beset the spontaneous cases. In considering this experimental branch of our subject, I shall of course, after what has been said, be specially bound to make clear the distinction between what we hold to be genuine cases and the spurious " thought-reading " exhibitions which are so much better known. This will be easy enough, and will be done in the next chapter.