982. Returning now to the question of retrocognition, let us consider to what extent our knowledge of the Past will sometimes open itself beyond the familiar bounds. We may begin by inquiring in what ways we ordinarily and normally acquire our knowledge of the Past. We acquire such knowledge partly from direct personal memory, and partly from retrospective inference based on what we see or hear. We might, indeed, define memory as an acquisition of fresh potential changes of consciousness concomitant with changes in our organism, which imply certain past events as their cause. But this definition, which sounds natural enough when applied to diffused or organic memories, such as the cricketer's memory of the feel of the bat, would seem pedantic if applied to the minute cerebral changes which accompany the learning of a new fact. In such a case we ignore in common speech the real organic change which the learning of any fact implies in us, and we merely refer to the specialised sensory channel through which the information comes to us - as hearing, reading, and so forth.

In a vague but quite intelligible way, we thus mark off organic memory from definite sensory or intellectual memories.

In our inquiry into retrocognition it will be well to keep roughly to some division of this sort, and to begin by inquiring into the extensions which seem to be given to organic memory.

We know, of course, that there is a great difference between our evocable memory - that which we can summon up and use at will - and that much ampler memory which we must suppose to exist, in some potential form at least, imprinted upon our organism. The faint and crude recollections of sensations and movements, which are all that we can call into ordinary consciousness, would be far from enabling us to recognise sensations, or to repeat movements, as we actually do recognise and repeat them. The study of hypnotic suggestion, moreover, has shown us how these potential or latent memories may be grasped and used. The increased power over the organism which the subject under suggestion shows necessarily implies an increased memory of the organism's past; the hyperboulia, as I have termed it, is hypermnesia as well. That wider will-power, indeed, is probably no more aware of the exact mechanism which it employs in its control of secretions, etc, than I am of the exact mechanism by which I raise my hand to my head. And, similarly, the hypnotic memory is probably itself very shallow as compared to what a complete summation of all the lapsed memories of the organism might be.

But already we find it descending deeply to gland and blood-vessel, implicated as these are in stigmatisation and similar phenomena, and we can draw no clear line below which all organic consciousness must cease, and memory must become no more than a metaphor.

We cannot draw such a line, I say, either on the basis of smallness of magnitude or of remoteness in time. We cannot assert that organic memory may not inhere in a single cell or neuron, or even in a single living molecule. Neither can we assert that organic memory cannot be prolonged backwards before birth. Birth, indeed, is but an incident in each organism's history; that organism has an embryonic life before birth, - and a pre-embryonic life in countless lines of ancestry. Although we no longer say with the "traducianist" schoolmen that Adam's body included not only his own soul but the souls of all his descendants, we still trace to ancestors more remote than Adam characteristics which even now influence our psychical life.

It is a moot point how far the life-experiences of each organism modify by what we regard as purely physiological transmission the characteristics of its descendants. The rude suggestion (so to term it) of the amputated limb, or other injury, is commonly not accepted by the offspring; the embryo develops unaffected by the shock which the parent has undergone previously to the act of union. But if that shock fall upon the mother during the embryo's life, and if it chance - (in post-natal suggestions also there seems much of what we must needs call chance in this) - if it chance to reach the mother's subliminal self in effective fashion, it may then transfer itself to the embryo, and imprint upon the child the organic memory of the mother's emotion of admiration, disgust, or fear. No one doubts this form of heredity when it is exhibited on a striking scale, - as with children born during the alarms of a siege, or of the Reign of Terror in France. And I believe that there is evidence enough to show that isolated and momentary suggestions - as the sight of a crushed ankle or missing finger - may produce a definite localised effect on the embryo in much the same way as a hypnotic suggestion may produce a localised congestion or secretion.1

If, then, we thus find imprinted on the child's organism such a conspicuous, specialised memory of perhaps an almost instantaneous emotion of the mother's, we must surely suspect that his organism may contain also some inborn memories less conspicuous and more purely cerebral than such a gross phenomenon as a mark on the face or a deformed finger. And by this new route we shall come round again to something like the innate ideas of certain philosophical systems. Nor can we absolutely limit such influence to the actual parent organism alone. For aught we know, the "germ-plasm" - whatsoever may be the continuous link of all generations - may be capable of reacting to psychical suggestions as sensitively as the embryo. The shaping forces which have made our bodies and our minds what they are may always have been partly psychical forces, - from the first living slime-speck to the complex intelligences of to-day.

This view is not inconsistent with the suggestion which I have made elsewhere, that the human spirit's supernormal powers of telepathy and telaesthesia are survivals from the powers which that spirit once exercised in a transcendental world. It may well be that the spirit, already modified by cosmic experiences dating back to infinity, may inform the body already modified by terrene experiences dating back to the first appearance of life on our planet. Both the old traducianist and the old transmigrationist view would thus possess a share of truth; and the actual man would be the resultant not only of intermingling heredities on father's and mother's side, but of intermingling heredities, one of planetary and one of cosmic scope.

Passing on from hereditary or pre-natal memories, through the various other types, - e.g. the organic memory of impressions received by each man during his own past life; the occasional sudden revival of a series of life-memories both swifter and fuller than conscious effort could have supplied; cases of ecmnesia, where the recent impressions are suppressed in favour of the old; cases where the hysteric under skilful hypnotic treatment can recall and reveal the long-forgotten incident which started her malady; - we may place next cases of clairvoyant insight into the organic condition of an absent person. Here we come to a definitely supernormal power; and it is a power which claims to involve both backward and forward knowledge such as actual medical examination of the patient could not attain. There are further cases in which a definite fact in a man's life has become known supernormally; or sometimes a recent event unconnected with the percipient is revealed; and there are, of course, numerous trance communications where knowledge of the past is claimed to proceed from some more or less definite disembodied intelligence.

Supernormal retro-cognition depends, it appears, on the perception by us of knowledge contained in other minds, embodied or disembodied, and possibly on the absorption by us of knowledge afloat, so to say, in the Universe; - which may be grasped by our spirit's outreaching, or which may fall on us like dew.

1 See vol. i., 526 and 526 A, B, and C.