112. 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 hitherto been bestowed upon my theory any very weighty demurrer. I summarise in a note an attack of this kind, with what seems to me an adequate reply from a colleague's pen.2

1 See, for instance, Proceedings of the Society for Psychical Research (henceforth in this book referred to as the Proceedings S.P.R.). vol. iv. p. 256, Jan. 1887.

2 See an article in Proceedings S.P.R., vol. xi. pp. 317 to 325, entitled "Subliminal Self or Unconscious Cerebration," by Mr. A. H. Pierce, of Harvard University. Mr. Pierce maintains (1) that the hypothesis of a subliminal self or secondary consciousness is chiefly based on a study of hysteria, in which sensations and movements are not governed by the primary consciousness. But these hysterical phenomena are, he argues, simply analogous to the actions of animals deprived of their cerebral hemispheres, and it is unnecessary to suppose that they are accompanied by any consciousness at all. (2) The ordinary automatic actions of normal persons are ascribed by some to a secondary consciousness. But " if this theory... be made to do its full duty, the doctrine that habits are due to well-worn nervous paths must be abandoned, and all the phenomena now ascribed to habit must be classed under the head of relegations to a secondary consciousness".

Further, the secondary consciousness is, ex hypothesi, divided into two parts, - one associated with physiological functions and the other with the highest mental processes, such as the "inspirations of genius"; and if we once admit the possibility of such subdivision, consistency demands that we should posit a separate consciousness for each physical process.

(3) We have no direct testimony for the existence of a split-off consciousness. The dream-consciousness is said to be thus split off because dream-images - forgotten on waking - are sometimes observed to recur in another dream. But this in itself proves "Normally at least," says another 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 anticipated 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 that the fact of recurrence and knowledge of the recurring events were present in the primary consciousness, which is thereby shown not to be separate from the dream-consciousness. If the primary consciousness attempts to bear witness to the existence of a secondary dissociated fragment, "it thereby proves that the fragment is a portion of itself and therefore no fragment at all."..." All the facts usually taken in support of a double-consciousness theory appear explicable in terms of brain alone".

In reply to this, Mr. Podmore (op. at. pp. 325 to 332) has well pointed out that the criticism rests almost wholly on an attempt to explain mental phenomena on a physical basis. The fact is that, accompanying the mental phenomena - states of consciousness, there are physical phenomena - brain-changes; but no knowledge of the one throws any light on the other. The physical explanation cannot be substituted for the mental one, because it applies to a different category of facts. The two sets may indeed be diverse aspects of the same essential fact, but for practical purposes we have to regard them as distinct and treat them separately. From the actions of brainless animals we cannot therefore argue to the consciousness of hysterics. Again, to ascribe mental habits to well-worn brain-paths has no bearing on the question whether they are accompanied by consciousness or not. With regard to direct testimony to the existence of a secondary consciousness, perhaps the strongest is to be found in the hypnotic condition. " The hypnotised subject presents, or may present,... all the phenomena which we associate with consciousness, not merely in our own case, but in the case of the same person when in his normal state.

He talks, acts, reasons; exhibits emotion, judgment, volition." His actions " are frequently so difficult and complicated as necessarily to imply the exercise of the fullest intelligence of which [he] is capable. Moreover, the re-hypnotised subject remembers the performance of the enjoined act, and can explain any peculiarities in its performance, and correct mistakes made. It would surely be extravagant to refuse to admit that such acts are deliberately and consciously performed."..." And the consciousness of the hypnotic is certainly not identical with the consciousness of the waking state. With rare exceptions it is more extensive; it includes the waking consciousness as a larger includes a smaller concentric circle, itself not included by it" 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" associations; 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 assumptions 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 constitution 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 associate with conscious life, I feel bound to speak of a subliminal or ultra-marginal consciousness,1 - 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 threshold 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 assume 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.

1 It is naturally impossible to express by the help of any single metaphor the complex and changing relation between that part of our personality with which in waking life we consciously identify ourselves, and that part which is not habitually represented in our consciousness. A field of view is quite as natural a metaphor as a threshold, and we may naturally speak of intra-marginal and extra-marginal.

These terms, of course, are merely superficial, - denoting a relationship to consciousness which is capable of frequent change, and is not in itself fundamental.

We may attempt, indeed, deeper distinctions, and speak of the empirical self on the one hand, and the surviving or the transcendental self on the other hand. But my object at present is to use whatever title makes the least assumption; and to leave it to our evidence gradually to give definite meaning to a distinction at first apprehended in a vague superficial way.