A certain broad answer to this inquiry, although it cannot be said to be at all points familiar, is not in reality far to seek. It is an answer which would seem strange indeed to some visitant from a planet peopled wholly by scientific minds. Yet among a race like our own, concerned first and primarily to live and work with thoughts undistracted from immediate needs, the answer is natural enough. For the fact simply is that the intimate importance of this central problem has barred the way to its methodical, its scientific solution.

There are some beliefs for which mankind cannot afford to wait. "What must I do to be saved?" is a question quite otherwise urgent than the cause of the tides or the meaning of the marks on the moon. Men must settle roughly somehow what it is that from the Unseen World they have reason to fear or to hope. Beliefs grow up in direct response to this need of belief; in order to support themselves they claim unique sanction; and thus along with these specific beliefs grows also the general habit of regarding matters that concern that Unseen World as somehow tabooed or segregated from ordinary observation or inquiry.

Let us pa.s.s from generalities to the actual history of Western civilisation. In an age when scattered ritual, local faiths--tribal solutions of cosmic problems--were destroying each other by mere contact and fusion, an event occurred which in the brief record of man's still incipient civilisation may be regarded as unique. A life was lived in which the loftiest response which man's need of moral guidance had ever received was corroborated by phenomena which have been widely regarded as convincingly miraculous, and which are said to have culminated in a Resurrection from the dead. To those phenomena or to that Resurrection it would at this point be illegitimate for me to refer in defence of my argument. I have appealed to Science, and to Science I must go;--in the sense that it would be unfair for me to claim support from that which Science in her strictness can set aside as the tradition of a pre-scientific age. Yet this one great tradition, as we know, has, as a fact, won the adhesion and reverence of the great majority of European minds. The complex results which followed from this triumph of Christianity have been discussed by many historians. But one result which here appears to us in a new light was this--that the Christian religion, the Christian Church, became for Europe the accredited representative and guardian of all phenomena bearing upon the World Unseen. So long as Christianity stood dominant, all phenomena which seemed to transcend experience were absorbed in her realm--were accounted as minor indications of the activity of her angels or of her fiends. And when Christianity was seriously attacked, these minor manifestations pa.s.sed unconsidered. The priests thought it safest to defend their own traditions, their own intuitions, without going afield in search of independent evidence of a spiritual world. Their a.s.sailants kept their powder and shot for the orthodox ramparts, ignoring any isolated strongholds which formed no part of the main line of defence.

Meantime, indeed, the laws of Nature held their wonted way. As ever, that which the years had once brought they brought again; and every here and there some marvel, liker to the old stories than any one cared to a.s.sert, cropped up between superst.i.tion on the one hand and contemptuous indifference on the other. Witchcraft, Swedenborgianism, Mesmerism, Spiritism--these especially, amid many minor phenomena, stood out in turn as precursory of the inevitable wider inquiry. A very few words on each of these four movements may suffice here to show their connection with my present theme.

_Witchcraft._--The lesson which witchcraft teaches with regard to the validity of human testimony is the more remarkable because it was so long and so completely misunderstood. The belief in witches long pa.s.sed--as well it might--as the culminant example of human ignorance and folly; and in so comparatively recent a book as Mr. Lecky's "History of Rationalism," the sudden decline of this popular conviction, without argument or disapproval, is used to ill.u.s.trate the irresistible melting away of error and falsity in the "intellectual climate" of a wiser age.

Since about 1880, however, when French experiments especially had afforded conspicuous examples of what a hysterical woman could come to believe under suggestion from others or from herself, it has begun to be felt that the phenomena of witchcraft were very much what the phenomena of the Salpetriere would seem to be to the patients themselves, if left alone in the hospital without a medical staff. And in _Phantasms of the Living_, Edmund Gurney, after subjecting the literature of witchcraft to a more careful a.n.a.lysis than any one till then had thought it worth while to apply, was able to show that practically all recorded first-hand depositions (made apart from torture) in the long story of witchcraft may quite possibly have been _true_, to the best belief of the deponents; true, that is to say, as representing the conviction of sane (though often hysterical) persons, who merely made the almost inevitable mistake of confusing self-suggested hallucinations with waking fact. Nay, even the insensible spots on the witches were no doubt really anaesthetic--involved a first discovery of a now familiar clinical symptom--the _zones a.n.a.lgesiques_ of the patients of Pitres or Charcot.

Witchcraft, in fact, was a gigantic, a cruel psychological and pathological experiment conducted by inquisitors upon hysteria; but it was conducted in the dark, and when the barbarous explanation dropped out of credence much of possible discovery was submerged as well.

_Mesmer._--Again, the latent possibilities of "suggestion,"--though not yet under that name, and mingled with who knows what else?--broke forth into a blaze in the movement headed by Mesmer;--at once discoverer and charlatan. Again the age was unripe, and scientific opposition, although not so formidable as the religious opposition which had sent witches to the stake, was yet strong enough to check for the second time the struggling science. Hardly till our own generation--hardly even now--has a third effort found better acceptance, and hypnotism and psycho-therapeutics, in which every well-attested fact of witchcraft or of mesmerism finds, if not its explanation, at least its parallel, are establishing themselves as a recognised and advancing method of relieving human ills.

This brief sketch of the development as it were by successive impulses, under strong disbelief and discouragement, of a group of mental tendencies, faculties, or sensibilities now recognised as truly existing and as often salutary, is closely paralleled by the development, under similar difficulties, of another group of faculties or sensibilities, whose existence is still disputed, but which if firmly established may prove to be of even greater moment for mankind.

At no time known to us, whether before or since the Christian era, has the series of _trance-manifestations_,--of supposed communications with a supernal world,--entirely ceased. Sometimes, as in the days of St.

Theresa, such trance or ecstasy has been, one may say, the central or culminant fact in the Christian world. Of these experiences I must not here treat. The evidence for them is largely of a subjective type, and they may belong more fitly to some future discussion as to the amount of confidence due to the interpretation given by entranced persons to their own phenomena.

But in the midst of this long series, and in full a.n.a.logy to many minor cases, occurs the exceptional trance-history of Emmanuel Swedenborg. In this case, as is well known, there appears to have been excellent objective evidence both of clairvoyance or telaesthesia[1] and of communication with departed persons;--and we can only regret that the philosopher Kant, who satisfied himself of some part of Swedenborg's supernormal[2] gift, did not press further an inquiry surpa.s.sed in importance by none of those upon which his master-mind was engaged.

Apart, however, from these objective evidences, the mere subject-matter of Swedenborg's trance-revelations was enough to claim respectful attention. I cannot here discuss the strange mixture which they present of slavish literalism with exalted speculation, of pedantic orthodoxy with physical and moral insight far beyond the level of that age. It is enough to say here that even as Socrates called down philosophy from heaven to earth, so in a somewhat different sense it was Swedenborg who called up philosophy again from earth to heaven;--who originated the notion of science in the spiritual world, as earnestly, though not so persuasively, as Socrates originated the idea of science in this world which we seem to know. It was to Swedenborg first that that unseen world appeared before all things as a realm of law; a region not of mere emotional vagueness or stagnancy of adoration, but of definite progress according to definite relations of cause and effect, resulting from structural laws of spiritual existence and intercourse which we may in time learn partially to apprehend. For my own part I regard Swedenborg,--not, a.s.suredly, as an inspired teacher, nor even as a trustworthy interpreter of his own experiences,--but yet as a true and early precursor of that great inquiry which it is our present object to advance.

The next pioneer--fortunately still amongst us--whom I must mention even in this summary notice, is the celebrated physicist and chemist, Sir W.

Crookes. Just as Swedenborg was the first leading man of science who distinctly conceived of the spiritual world as a world of law, so was Sir W. Crookes the first leading man of science who seriously endeavoured to test the alleged mutual influence and interpenetration of the spiritual world and our own by experiments of scientific precision.[3] Beyond the establishment of certain supernormal facts Crookes declined to go. But a large group of persons have founded upon these and similar facts a scheme of belief known as Modern Spiritualism, or Spiritism. Later chapters in this book will show how much I owe to certain observations made by members of this group--how often my own conclusions concur with conclusions at which they have previously arrived. And yet this work of mine is in large measure a critical attack upon the main Spiritist position, as held, say, by Mr. A. R. Wallace, its most eminent living supporter,--the belief, namely, that all or almost all supernormal phenomena are due to the action of spirits of the dead. By far the larger proportion, as I hold, are due to the action of the still embodied spirit of the agent or percipient himself. Apart from speculative differences, moreover, I altogether dissent from the conversion into a sectarian creed of what I hold should be a branch of scientific inquiry, growing naturally out of our existing knowledge. It is, I believe, largely to this temper of uncritical acceptance, degenerating often into blind credulity, that we must refer the lack of progress in Spiritualistic literature, and the encouragement which has often been bestowed upon manifest fraud,--so often, indeed, as to create among scientific men a strong indisposition to the study of phenomena recorded or advocated in a tone so alien from Science.

I know not how much of originality or importance may be attributed by subsequent students of the subject to the step next in order in this series of approximations. To those immediately concerned, the feeling of a new departure was inevitably given by the very smallness of the support which they for a long time received, and by the difficulty which they found in making their point of view intelligible to the scientific, to the religious, or even to the spiritualistic world. In about 1873--at the crest, as one may say, of perhaps the highest wave of materialism which has ever swept over these sh.o.r.es--it became the conviction of a small group of Cambridge friends that the deep questions thus at issue must be fought out in a way more thorough than the champions either of religion or of materialism had yet suggested. Our att.i.tudes of mind were in some ways different; but to myself, at least, it seemed that no adequate attempt had yet been made even to determine whether anything could be learnt as to an unseen world or no; for that if anything were knowable about such a world in such fashion that Science could adopt and maintain that knowledge, it must be discovered by no a.n.a.lysis of tradition, and by no manipulation of metaphysics, but simply by experiment and observation;--simply by the application to phenomena within us and around us of precisely the same methods of deliberate, dispa.s.sionate, exact inquiry which have built up our actual knowledge of the world which we can touch and see. I can hardly even now guess to how many of my readers this will seem a truism, and to how many a paradox. Truism or paradox, such a thought suggested a kind of effort, which, so far as we could discover, had never yet been made. For what seemed needful was an inquiry of quite other scope than the mere a.n.a.lysis of historical doc.u.ments, or of the _origines_ of any alleged revelation in the past. It must be an inquiry resting primarily, as all scientific inquiries in the stricter sense now must rest, upon objective facts actually observable, upon experiments which we can repeat to-day, and which we may hope to carry further to-morrow. It must be an inquiry based, to use an old term, on the uniformitarian hypothesis; on the presumption, that is to say, that _if a spiritual world exists, and if that world has at any epoch been manifest or even discoverable, then it ought to be manifest or discoverable now_.

It was from this side, and from these general considerations, that the group with which I have worked approached the subject. Our methods, our canons, were all to make. In those early days we were more devoid of precedents, of guidance, even of criticism that went beyond mere expressions of contempt, than is now readily conceived. Seeking evidence as best we could--collecting round us a small group of persons willing to help in that quest for residual phenomena in the nature and experience of man--we were at last fortunate enough to discover a convergence of experimental and of spontaneous evidence upon one definite and important point. We were led to believe that there was truth in a thesis which at least since Swedenborg and the early mesmerists had been repeatedly, but cursorily and ineffectually, presented to mankind--the thesis that a communication can take place from mind to mind without the agency of the recognised organs of sense.

We found that this agency, discernible even on trivial occasions by suitable experiment, seemed to connect itself with an agency more intense, or at any rate more recognisable, which operated at moments of crisis or at the hour of death. Edmund Gurney--the invaluable collaborator and friend whose loss in 1888 was our heaviest discouragement--set forth this evidence in a large work, _Phantasms of the Living_, in whose preparation Mr. Podmore and I took a minor part.

The fifteen years which have elapsed since the publication of this book in 1886 have added to the evidence on which Gurney relied, and have shown (I venture to say) the general soundness of the canons of evidence and the lines of argument which it was his task to shape and to employ.[4]

Of fundamental importance, indeed, is this doctrine of telepathy--the first law, may one not say?--laid open to man's discovery, which, in my view at least, while operating in the material, is itself a law of the spiritual or _metetherial_ world. In the course of this work it will be my task to show in many connections how far-reaching are the implications of this direct and supersensory communion of mind with mind. Among those implications none can be more momentous than the light thrown by this discovery upon man's intimate nature and possible survival of death.

We gradually discovered that the accounts of apparitions at the moment of death--testifying to a supersensory communication between the dying man and the friend who sees him--led on without perceptible break to apparitions occurring after the death of the person seen, but while that death was yet unknown to the percipient, and thus apparently due, not to mere brooding memory, but to a continued action of that departed spirit.

The task next inc.u.mbent on us therefore seemed plainly to be the collection and a.n.a.lysis of evidence of this and other types, pointing directly to the survival of man's spirit. But after pursuing this task for some years I felt that in reality the step from the action of embodied to the action of disembodied spirits would still seem too sudden if taken in this direct way. So far, indeed, as the evidence from apparitions went, the series seemed continuous from phantasms of the living to phantasms of the dead. But the whole ma.s.s of evidence _prima facie_ pointing to man's survival was of a much more complex kind. It consisted largely, for example, in written or spoken utterances, coming through the hand or voice of living men, but claiming to proceed from a disembodied source. To these utterances, as a whole, no satisfactory criterion had ever been applied.

In considering cases of this kind, then, it became gradually plain to me that before we could safely mark off any group of manifestations as definitely implying an influence from beyond the grave, there was need of a more searching review of the capacities of man's incarnate personality than psychologists unfamiliar with this new evidence had thought it worth their while to undertake.

It was only slowly, and as it were of necessity, that I embarked on a task which needed for its proper accomplishment a knowledge and training far beyond what I could claim. The very inadequate sketch which has resulted from my efforts is even in its author's view no more than preparatory and precursive to the fuller and sounder treatment of the same subject which I doubt not that the new century will receive from more competent hands. The truest success of this book will lie in its rapid supersession by a better. For this will show that at least I have not erred in supposing that a serious treatise on these topics is nothing else than the inevitable complement and conclusion of the slow process by which man has brought under the domain of science every group of attainable phenomena in turn--every group save this.

Let me then without further preamble embark upon that somewhat detailed survey of human faculty, as manifested during various phases of human personality, which is needful in order to throw fresh light on these unfamiliar themes. My discussion, I may say at once, will avoid metaphysics as carefully as it will avoid theology. I avoid theology, as already explained, because I consider that in arguments founded upon experiment and observation I have no right to appeal for support to traditional or subjective considerations, however important. For somewhat similar reasons I do not desire to introduce the idea of personality with any historical _resume_ of the philosophical opinions which have been held by various thinkers in the past, nor myself to speculate on matters lying beyond the possible field of objective proof.

I shall merely for the sake of clearness begin by the briefest possible statement of two views of human personality which cannot be ignored, namely, the old-fashioned or common-sense view thereof, which is still held by the ma.s.s of mankind, and the newer view of experimental psychology, bringing out that composite or "colonial" character which on a close examination every personality of men or animals is seen to wear.

The following pa.s.sage, taken from a work once of much note, Reid's "Essay on the Intellectual Powers of Man," expresses the simple _prima facie_ view with care and precision, yet with no marked impress of any one philosophical school:

The conviction which every man has of his ident.i.ty, as far back as his memory reaches, needs no aid of philosophy to strengthen it; and no philosophy can weaken it without first producing some degree of insanity.... My personal ident.i.ty, therefore, implies the continued existence of that indivisible thing which I call myself.

Whatever this self may be, it is something which thinks, and deliberates, and resolves, and acts, and suffers. I am not thought, I am not action, I am not feeling; I am something that thinks, and acts, and suffers. My thoughts and actions and feelings change every moment; they have no continued, but a successive existence; but that _self_ or _I_, to which they belong, is permanent, and has the same relation to all succeeding thoughts, actions, and feelings which I call mine.... The ident.i.ty of a person is a perfect ident.i.ty; wherever it is real it admits of no degrees; and it is impossible that a person should be in part the same and in part different, because a person is a _monad_, and is not divisible into parts. Ident.i.ty, when applied to persons, has no ambiguity, and admits not of degrees, or of more and less. It is the foundation of all rights and obligations, and of all accountableness; and the notion of it is fixed and precise.

Contrast with this the pa.s.sage with which M. Ribot concludes his essay on "Les Maladies de la Personnalite."

It is the organism, with the brain, its supreme representative, which const.i.tutes the real personality; comprising in itself the remains of all that we have been and the possibilities of all that we shall be. The whole individual character is there inscribed, with its active and pa.s.sive apt.i.tudes, its sympathies and antipathies, its genius, its talent or its stupidity, its virtues and its vices, its torpor or its activity. The part thereof which emerges into consciousness is little compared with what remains buried, but operative nevertheless. The conscious personality is never more than a small fraction of the psychical personality. The unity of the Ego is not therefore the unity of a single ent.i.ty diffusing itself among multiple phenomena; it is the co-ordination of a certain number of states perpetually renascent, and having for their sole common basis the vague feeling of our body. This unity does not diffuse itself downwards, but is aggregated by ascent from below; it is not an initial but a terminal point.

Does then this perfect unity really exist? In the rigorous, the mathematical sense, a.s.suredly it does _not_. In a relative sense it is met with,--rarely and for a moment. When a good marksman takes aim, or a skilful surgeon operates, his whole body and mind converge towards a single act. But note the result; under those conditions the sentiment of real personality disappears, for the conscious individual is simplified into a single idea, and the personal sentiment is excluded by the complete unification of consciousness. We thus return by another route to the same conclusion; _the Self is a co-ordination_. It oscillates between two extremes at each of which it ceases to exist;--absolute unity and absolute incoherence.

The last word of all this is that since the consensus of consciousness is subordinated to the consensus of the organism, the problem of the unity of the Ego is in its ultimate form a problem of Biology. Let Biology explain, if it can, the genesis of organisms and the solidarity of their const.i.tuent parts. The psychological explanation must needs follow on the same track.

Here, then, we have two clear and definite views,--supported, the one by our inmost consciousness, the other by unanswerable observation and inference,--yet apparently incompatible the one with the other. And in fact by most writers they have been felt and acknowledged to be even hopelessly incompatible. The supporters of the view that "The Self is a co-ordination,"--and this, I need hardly say, is now the view prevalent among experimental psychologists,--have frankly given up any notion of an underlying unity,--of a life independent of the organism,--in a word, of a human soul. The supporters of the unity of the Ego, on the other hand, if they have not been able to be equally explicit in _denying_ the opposite view, have made up for this by the thorough-going way in which they have _ignored_ it. I know of no source from which valid help has been offered towards the reconcilement of the two opposing systems in a profounder synthesis. If I believe--as I do believe--that in the present work some help in this direction is actually given, this certainly does not mean that I suppose myself capable of st.i.tching the threadbare metaphysical arguments into a more stable fabric. It simply means that certain fresh evidence can now be adduced, which has the effect of showing the case on each side in a novel light;--nay, even of closing the immediate controversy by a judgment more decisively in favour of _both_ parties than either could have expected. On the one side, and in favour of the co-ordinators,--all their a.n.a.lysis of the Self into its const.i.tuent elements, all that they urge of positive observation, of objective experiment, must--as I shall maintain on the strength of the new facts which I shall adduce--be unreservedly conceded. Let them push their a.n.a.lysis as far as they like,--let them get down, if they can, to those ultimate infinitesimal psychical elements from which is upbuilt the complex, the composite, the "colonial" structure and const.i.tution of man. All this may well be valid and important work. It is only on their _negative_ side that the conclusions of this school need a complete overhauling. Deeper, bolder inquiry along their own line shows that they have erred when they a.s.serted that a.n.a.lysis showed no trace of faculty beyond such as the life of earth--as they conceive it--could foster, or the environment of earth employ. For in reality a.n.a.lysis shows traces of faculty which this material or planetary life could not have called into being, and whose exercise even here and now involves and necessitates the existence of a spiritual world.

On the other side, and in favour of the partisans of the unity of the Ego, the effect of the new evidence is to raise their claim to a far higher ground, and to substantiate it for the first time with the strongest presumptive proof which can be imagined for it;--a proof, namely, that the Ego can and does survive--not only the minor disintegrations which affect it during earth-life--but the crowning disintegration of bodily death. In view of this unhoped-for ratification of their highest dream, they may be more than content to surrender as untenable the far narrower conception of the unitary Self which was all that "common-sense philosophies" had ventured to claim. The "conscious Self" of each of us, as we call it,--the empirical, the supraliminal Self, as I should prefer to say,--does not comprise the whole of the consciousness or of the faculty within us. There exists a more comprehensive consciousness, a profounder faculty, which for the most part remains potential only so far as regards the life of earth, but from which the consciousness and the faculty of earth-life are mere selections, and which rea.s.serts itself in its plenitude after the liberating change of death.

Towards this conclusion, which a.s.sumed for me something like its present shape some fourteen years since,[5] a long series of tentative speculations, based on gradually accruing evidence, has slowly conducted me. The conception is one which has. .h.i.therto been regarded as purely mystical; and if I endeavour to plant it upon a scientific basis I certainly shall not succeed in stating it in its final terms or in supporting it with the best arguments which longer experience will suggest. Its validity, indeed, will be impressed--if at all--upon the reader only by the successive study of the various kinds of evidence to which this book will refer him.

Yet so far as the initial possibility or plausibility of such a widened conception of human consciousness is concerned;--and this is all which can be dealt with at this moment of its first introduction;--I have not seen in such criticism as has. .h.i.therto been bestowed upon my theory any very weighty demurrer.[6]

"Normally at least," says one critic, summarising in a few words the ordinary view, "all the consciousness we have at any moment corresponds to all the activity which is going on at that moment in the brain. There is one unitary conscious state accompanying all the simultaneous brain excitations together, and each single part of the brain-process contributes something to its nature. None of the brain-processes split themselves off from the rest and have a separate consciousness of their own." This is, no doubt, the apparent dictum of consciousness, but it is nothing more. And the dicta of consciousness have already been shown to need correction in so many ways which the ordinary observer could never have antic.i.p.ated that we have surely no right to trust consciousness, so to say, a step further than we can feel it,--to hold that anything whatever--even a separate consciousness in our own organisms--can be proved _not_ to exist by the mere fact that we--as we know ourselves--are not aware of it.

But indeed this claim to a unitary consciousness tends to become less forcible as it is more scientifically expressed. It rests on the plain man's conviction that there is only one of him; and this conviction the experimental psychologist is always tending to weaken or narrow by the admission of coexistent localised degrees of consciousness in the brain, which are at any rate not obviously reducible to a single state. Even those who would stop far short of my own position find it needful to resort to metaphors of their own to express the different streams of "awareness" which we all feel to be habitually coexistent within us.

They speak of "fringes" of ordinary consciousness; of "marginal"

a.s.sociations; of the occasional perception of "currents of low intensity." These metaphors may all of them be of use, in a region where metaphor is our only mode of expression; but none of them covers all the facts now collected. And on the other side, I need not say, are plenty of phrases which beg the question of soul and body, or of the man's own spirit and external spirits, in no scientific fashion. There seems to be need of a term of wider application, which shall make as few a.s.sumptions as possible. Nor is such a term difficult to find.

The idea of a _threshold (limen, Schwelle)_, of consciousness;--of a level above which sensation or thought must rise before it can enter into our conscious life;--is a simple and familiar one. The word _subliminal_,--meaning "beneath that threshold,"--has already been used to define those sensations which are too feeble to be individually recognised. I propose to extend the meaning of the term, so as to make it cover _all_ that takes place beneath the ordinary threshold, or say, if preferred, outside the ordinary margin of consciousness;--not only those faint stimulations whose very faintness keeps them submerged, but much else which psychology as yet scarcely recognises; sensations, thoughts, emotions, which may be strong, definite, and independent, but which, by the original const.i.tution of our being, seldom emerge into that _supraliminal_ current of consciousness which we habitually identify with _ourselves_. Perceiving (as this book will try to show) that these submerged thoughts and emotions possess the characteristics which we a.s.sociate with conscious life, I feel bound to speak of a _subliminal_ or _ultra-marginal consciousness_,--a consciousness which we shall see, for instance, uttering or writing sentences quite as complex and coherent as the supraliminal consciousness could make them.

Perceiving further that this conscious life beneath the threshhold or beyond the margin seems to be no discontinuous or intermittent thing; that not only are these isolated subliminal processes comparable with isolated supraliminal processes (as when a problem is solved by some unknown procedure in a dream), but that there also is a continuous subliminal chain of memory (or more chains than one) involving just that kind of individual and persistent revival of old impressions, and response to new ones, which we commonly call a Self,--I find it permissible and convenient to speak of subliminal Selves, or more briefly of a subliminal Self. I do not indeed by using this term a.s.sume that there are two correlative and parallel selves existing always within each of us. Rather I mean by the subliminal Self that part of the Self which is commonly subliminal; and I conceive that there may be,--not only _co-operations_ between these quasi-independent trains of thought,--but also upheavals and alternations of personality of many kinds, so that what was once below the surface may for a time, or permanently, rise above it. And I conceive also that no Self of which we can here have cognisance is in reality more than a fragment of a larger Self,--revealed in a fashion at once shifting and limited through an organism not so framed as to afford it full manifestation.

Now this hypothesis is exposed manifestly to two main forms of attack, which to a certain extent neutralise each other. On the one hand it has been attacked, as has already been indicated, as being too elaborate for the facts,--as endowing transitory moments of subconscious intelligence with more continuity and independence than they really possess. These ripples over the threshold, it may be said, can be explained by the wind of circ.u.mstance, without a.s.suming springs or currents in the personality deep below.

But soon we shall come upon a group of phenomena which this view will by no means meet. For we shall find that the subliminal uprushes,--the impulses or communications which reach our emergent from our submerged selves,--are (in spite of their miscellaneousness) often characteristically different in quality from any element known to our ordinary supraliminal life. They are different in a way which implies faculty of which we have had no previous knowledge, operating in an environment of which hitherto we have been wholly unaware. This broad statement it is of course the purpose of my whole work to justify.

a.s.suming its truth here for argument's sake, we see at once that the problem of the hidden self entirely changes its aspect. Telepathy and telaesthesia--the perception of distant thoughts and of distant scenes without the agency of the recognised organs of sense;--those faculties suggest either incalculable extension of our own mental powers, or else the influence upon us of minds freer and less trammelled than our own.

And this second hypothesis,--which would explain by the agency of discarnate minds, or spirits, all these supernormal phenomena,--does at first sight simplify the problem, and has by Mr. A. R. Wallace and others been pushed so far as to remove all need of what he deems the gratuitous and c.u.mbrous hypothesis of a subliminal self.

I believe, indeed, that it will become plain as we proceed that some such hypothesis as this,--of almost continuous spirit-intervention and spirit-guidance,--is at once rendered necessary if the subliminal faculties for which I argue are denied to man. And my conception of a subliminal self will thus appear, not as an extravagant and needless, but as a limiting and rationalising hypothesis, when it is applied to phenomena which at first sight suggest Mr. Wallace's extremer view, but which I explain by the action of man's own spirit, without invoking spirits external to himself. I do not indeed say that the explanation here suggested is applicable in all cases, or to the complete exclusion of the spirit-hypothesis. On the contrary, the one view gives support to the other. For these faculties of distant communication exist none the less, even though we should refer them to our own subliminal selves. We can, in that case, affect each other at a distance, telepathically;--and if our incarnate spirits can act thus in at least apparent independence of the fleshly body, the presumption is strong that other spirits may exist independently of the body, and may affect us in similar manner.

The much-debated hypothesis of spirit-intervention, in short, still looms behind the hypothesis of the subliminal Self; but that intermediate hypothesis should, I think, in this early stage of what must be a long inquiry, prove useful to the partisans of either side.

For those who are altogether unwilling to admit the action of agencies other than the spirits of living men, it will be needful to form as high an estimate as possible of the faculties held in reserve by these spirits while still in the flesh. For those, on the other hand, who believe in the influence of discarnate spirits, this scheme affords a path of transition, and as it were a provisional intelligibility.

These far-reaching speculations make the element of keenest interest in the inquiry which follows. But even apart from its possible bearing on a future life, the further study of our submerged mentation,--of the processes within us of which we catch only indirect, and as it were, refracted glimpses,--seems at this time especially called for by the trend of modern research. For of late years we have realised more and more fully upon how shifting and complex a foundation of ancestral experience each individual life is based. In recapitulation, in summary, in symbol, we retraverse, from the embryo to the corpse, the history of life on earth for millions of years. During our self-adaptation to continually wider environments, there may probably have been a continual displacement of the threshold of consciousness;--involving the lapse and submergence of much that once floated in the main stream of our being.

Our consciousness at any given stage of our evolution is but the phosph.o.r.escent ripple on an unsounded sea. And, like the ripple, it is not only superficial but manifold. Our psychical unity is federative and unstable; it has arisen from irregular accretions in the remote past; it consists even now only in the limited collaboration of multiple groups.

These discontinuities and incoherences in the Ego the elder psychologists managed to ignore. Yet infancy, idiocy, sleep, insanity, decay;--these breaks and stagnancies in the conscious stream were always present to show us, even more forcibly than more delicate a.n.a.lyses show us now, that the first obvious conception of man's continuous and unitary personality was wholly insecure; and that if indeed a soul inspired the body, that soul must be sought for far beneath these bodily conditions by which its self-manifestation was clouded and obscured.

The difference between older and newer conceptions of the unifying principle or soul (if soul there be) in man, considered as manifesting through corporeal limitations, will thus resemble the difference between the older and newer conceptions of the way in which the sun reveals himself to our senses. Night and storm-cloud and eclipse men have known from the earliest ages; but now they know that even at noonday the sunbeam which reaches them, when fanned out into a spectrum, is barred with belts and lines of varying darkness;--while they have learnt also that where at either end the spectrum fades out into what for us is blackness, there stretches onwards in reality an undiscovered illimitable ray.

It will be convenient for future reference if I draw out this parallel somewhat more fully. I compare, then, man's gradual progress in self-knowledge to his gradual decipherment of the nature and meaning of the sunshine which reaches him as light and heat indiscernibly intermingled. So also Life and Consciousness--the sense of a world within him and a world without--come to the child indiscernibly intermingled in a pervading glow. Optical a.n.a.lysis splits up the white ray into the various coloured rays which compose it. Philosophical a.n.a.lysis in like manner splits up the vague consciousness of the child into many faculties;--into the various external senses, the various modes of thought within. This has been the task of descriptive and introspective psychology. Experimental psychology is adding a further refinement. In the sun's spectrum, and in stellar spectra, are many dark lines or bands, due to the absorption of certain rays by certain vapours in the atmosphere of sun or stars or earth. And similarly in the range of spectrum of our own sensation and faculty there are many inequalities--permanent and temporary--of brightness and definition. Our mental atmosphere is clouded by vapours and illumined by fires, and is clouded and illumined differently at different times. The psychologist who observes, say, how his reaction-times are modified by alcohol is like the physicist who observes what lines are darkened by the interposition of a special gas. Our knowledge of our conscious spectrum is thus becoming continually more accurate and detailed.

But turning back once more to the physical side of our simile, we observe that our knowledge of the visible solar spectrum, however minute, is but an introduction to the knowledge which we hope ultimately to attain of the sun's rays. The limits of our spectrum do not inhere in the sun that shines, but in the eye that marks his shining. Beyond each end of that prismatic ribbon are ether-waves of which our retina takes no cognisance. Beyond the red end come waves whose potency we still recognise, but as heat and not as light. Beyond the violet end are waves still more mysterious; whose very existence man for ages never suspected, and whose ultimate potencies are still but obscurely known.

Even thus, I venture to affirm, beyond each end of our conscious spectrum extends a range of faculty and perception, exceeding the known range, but as yet indistinctly guessed. The artifices of the modern physicist have extended far in each direction the visible spectrum known to Newton. It is for the modern psychologist to discover artifices which may extend in each direction the conscious spectrum as known to Plato or to Kant. The phenomena cited in this work carry us, one may say, as far onwards as fluorescence carries us beyond the violet end. The "X rays"

of the psychical spectrum remain for a later age to discover.

Our simile, indeed--be it once for all noted--is a most imperfect one.

The range of human faculty cannot be truly expressed in any linear form.

Even a three-dimensional scheme,--a radiation of faculties from a centre of life,--would ill render its complexity. Yet something of clearness will be gained by even this rudimentary mental picture;--representing conscious human faculty as a linear spectrum whose red rays begin where voluntary muscular control and organic sensation begin, and whose violet rays fade away at the point at which man's highest strain of thought or imagination merges into reverie or ecstasy.