In electricity, e.g., what are known as "relays" are constantly employed, and beautifully illustrate the principle here outlined. In working over long lines, or where there are a number of instruments in one circuit, the currents are often not strong enough to work the recording instruments directly. In such a case there is interposed a "relay" or "repeater." This instrument consists of an electro-magnet round which the line current flows, and whose delicately-poised armature, when attracted, makes contact for a local circuit, in which a local battery and the receiving Morse instrument (sounder, writer, etc.) are included. The principle of the relay is, then, that a current too weak to do the work itself may get a strong local current to do its work for it.
It may be the same in the case of mental action. Volition or thought may be too weak, per se, to influence nervous processes; but, when exceptionally active or potent, they may set into activity specific nerve energies which manifest in the manner known to us as motor and physical phenomena. Here is, it seems to me, a rational explanation of the facts, and one which is in accord, not only with ordinary psychological phenomena, but with those more puzzling and obscure manifestations witnessed from time to time in psychic research.
13. It may be objected that such a conception of the facts supposes that will (and conscious thought) are physical energies—for however slight we make this energy, it is still energy none the less. The air which closed the door would not move it of itself—unless some pressure were exerted upon it from without. Could "life" act otherwise?
One reply to this objection is that the distinguishing characteristic of life is this very power of original, spontaneous movement. It is life, and life alone, which possesses this power. Were this doctrine true, it would of course upset the present theory of the Conservation of Energy, for it would admit the constant infusion into the world of energy from without. Despite the theoretical difficulty thus presented, it seems probable that life is, in a certain sense, a physical energy, or at least its manifestation is. It is possible that the two states are similar to the difference between potential and kinetic energy; and we must remember that energy is always noticed or experienced by us, as energy, in its expenditure, never in its accumulation.[8]
If life be a physical force, if vitality be a specific energy, then, it seems to me, many things fall into line—many phenomena, hitherto inexplicable, become at once intelligible.
Let me illustrate this conclusion by mentioning a few such facts:
Take, for instance, the phenomena manifested in the presence of Eusapia Palladino. I shall not now stop to discuss the reality of these manifestations, because I consider them just as certain as any other facts in life, and not at all open to discussion. Now, in these phenomena there is an intelligence of some sort at work producing them; that is certain. But as to the nature of this intelligence—what it is—that is altogether another matter, and a much more difficult question to answer. Whether this be a low order of deceiving and "lying spirits," as Professor Barrett and others are apparently inclined to believe, or whether it be a fraction of the medium's own mind (Flournoy, Morselli), or whether it be the spirit it claims to be, or whether it belongs to some other even more doubtful order of intelligence, such as postulated by the Theosophists and certain Mystics and Occultists, that is a question which we cannot at present answer, and for which we may have to wait for several hundred years before one can be satisfactorily given.
But, granting the reality of the phenomena, they themselves demand solution, solely from the point of view of physics and physiology, and quite aside from the nature of the intelligence with which they are at times associated. The facts themselves still need elucidation.
Some years ago a gentleman of my acquaintance started out with the intention of constructing a telephone by means of which it would be possible to speak directly to the spirit world! He had in mind great delicacy of apparatus, a system of "relays," by means of which it would be possible to augment an initial stimulus, however slight, a magnifying apparatus which would greatly increase the volume of sound, on the lines of the ampliphone and the microphone, etc. I do not believe that very definite results were ever achieved, and he is still at work upon the problem. Needless to say, this idea of his was ridiculed in all quarters; but I myself do not see any valid reason why some such device should not succeed—provided, of course, that a spiritual world exists at all. If such a world exists, if the intelligences which reside therein can at times produce physical phenomena, then it is certainly conceivable that some energy may be set into operation which may produce the desired results—some energy which we, too, can utilize and which the spiritual entity can also manipulate; in other words, an energy common to the two worlds. Were such a common medium or mediator found, communication would certainly be established, and it only remains for us to discover the common energy. Personally, I believe that this intermediary is most probably vitality—the life-force, without the presence of which such manifestations would be impossible. A living, human being is necessary, upon whose presence these phenomena depend, and without whom they could not occur. It is thus obvious that there is a definite connection between these phenomena and life, which can hardly be due to chance; it must stand in some intimate and causal relation.[9]
14. Many students of psychical phenomena believe that, in the case of Eusapia Palladino, e.g., this connection is clearly discernible, and that it is upon the externalization of her vital force that many of these phenomena depend. Even the materializations are thought to be due to this same cause—due to the moulding, in space, of this plastic intermediary projected beyond the limits of her bodily organism. Certain it is that such a projection does at times take place, and it seems rational to suppose that "raps" may be due to the explosive expulsion of this neural energy after it has reached a certain "tension." One quite striking incident which has been narrated to me by a physician of my acquaintance tends rather to confirm this view. It is that, when he was trying on various occasions to move a table, à la Palladino, he failed to do so, but whenever he lifted his hands away from the table, "sparkling" took place between his hands and the table-top, closely resembling the electric spark which jumps from point to point when the tension has reached a certain limit.