In any attempt, then, to influence the human mind in order to use its power and its reserve energy for therapeutic purposes, the place of the body and its influence upon the mind must always be remembered. It is quite impossible to lift people up to enable them to use their mental reserve force if they are living in discouraging physical conditions, which use up so much of energy as to make it impossible to have any to spare. Many of the phases of mental discouragement and lack of initiative which are reflected in what we call lowered resistive vitality and lack of immunity to infection, are really consequent upon physical states representing a drain upon the system that can be removed, or at least greatly improved, if they are discovered and properly treated. Victims of chronic malaria and of hook-worm disease cannot be lifted up by psychotherapy. Neither can sufferers from other forms of chronic physical debility. After the removal of the debilitating cause, however, mental influence may be brought to bear to encourage them to rise to their opportunities, to literally take on new life, and gradually accumulate reserve energy that will enable them to accomplish, not only the average work of mankind, but even better, in the reaction that comes with the new feeling of physical energy. And what is thus true in these extreme cases is even more true of minor ailments and conditions.
CHAPTER IV
THE MECHANISM OF THE INFLUENCE OF MIND ON BODY
The question as to how mind influences body, and body mind, has always proved a riddle to all but those with a special theory in the matter. The facts of the mutual influence of mind on body are so obtruded on observation that they could never be missed, but it is quite another thing to reach a satisfactory explanation of them. How the will initiates motion continues in spite of all our advance in psychology, to be as much a mystery as ever. Just how sensation is transformed into ideas is a parallel mystery. Since the mind is able to influence motion, it is not surprising that it should be capable of modifying secretion or inhibiting other kinds of functions. Any of these various activities is scarcely more mysterious than the other. Since the transformation of sensation into thought takes place, it is comparatively easy to conclude that the mental processes are able to exclude, or to some extent inhibit, sensation. All these activities have actually been observed. How does this mutual influence of mind on body take place? What principles underlie it?
At present, it would be futile to hope to outline the absolute principles on which the mechanism of mental influence or suggestion depends, but we can discuss recent explanations that have been offered, and this will help us to understand, not the mystery itself, but just where the mystery lies and what the physical mechanism connected with it is.
Fig. 2.—CORTEX OF HUMAN BRAIN ILLUSTRATING COMPLEXITY OF THE SYSTEMS AND PLEXUSES OF NERVE FIBERS (Combination of the methods of Weigert and Golgi—after Andriezen). c, z., clear zone free from nerve fibers; M.P., Exner's plexus in the molecular layer; A. str., ambiguous cell stratum; Subm, P., sub-molecular plexus; Gt. P. P., great pyramidal plexus; Pol. P., polymorphic plexus; W., white matter. (Barker.)
These explanations are as yet only theoretic, but theories have often helped students in science to make their thoughts more concrete and their investigations more practical. It would be a mistake to conclude that because some of the theories advanced are very plausible, we have, therefore, reached definite truth with regard to the mechanics of the brain that underlie suggestion and mental influence.
Brain Complexity.—The most interesting feature of the discoveries in brain anatomy during the past generation, has been that the central nervous system is of even greater complexity than had been thought. Because of this, these new discoveries, instead of solving the biological mystery they subtend, or even helping very much to solve it, have made it still harder to understand just how we succeed in controlling and directing this immensely complex machine, of whose details we are utterly unconscious, yet which we learn to use with such discriminating nicety of adjustment and accomplishment. The discoveries of Golgi and of Ramon y Cajal show us that the brain consists of nerve cells with a number of ramifying fibers connecting each cell and each group of cells with other simple and compound elements of the brain, and sending down connecting fibers to every organ and every part of the body. Dr. Ford Robertson calculates that in an average human brain there are at least three billions of cells. Without knowing anything of their existence, much less anything of the infinite detail of their structure and mode of operation, we have learned to use these for many purposes.
FIG. 3.—SMALL AND MEDIUM-SIZED PYRAMIDAL CELLS OF THE VISUAL CORTEX OF A CHILD TWENTY DAYS OLD. Section taken from the neighborhood of the calcarine fissure. A. plexiform layer; B, layer of the little pyramid; C, layer of the medium-sized pyramid; a, descending axis cylinders; b, ascending or centripetal collaterals; c, stems of the giant pyramidal cells. (Ramon y Cajal.)
(This and the next three illustrations illustrate the complexity of the central nervous system as observed in the very young child where the development does not as yet obscure the interesting details of dentritic branching. They serve to emphasize the much more pronounced condition which develops in the adult.)
Nerve Impulses.—We do not know even how nerve impulses travel. Probably they do so by a mode of vibration, just as heat and light and electricity are transmitted as modes of motion. The similarity that used to be thought to exist between the transmission of nerve impulses and of electrical energy is now known definitely to be only an analogy, and not to represent anything closer. Waves of nervous energy travel at a different rate of speed from electrical waves, and there are other notable differences. Such phases as molecular action, or motion, or vibration are only cloaks for our ignorance, A generation ago Huxley declared that "the forces exerted by living matter are either identical with those existing in the inorganic world or are convertible into them." He instanced nervous energy as the most recondite of all, and yet as being in some way or other associated with the electrical processes of living beings. As Prof, Forel said in his "Hygiene of the Nerves," "the neurokym cannot be a simple physical wave, such as electricity, light or sound; if it were its exceedingly fine weak waves would soon exhaust themselves without causing the tremendous discharges which they actually call forth in the brain."
Law of Avalanche.—How great is the power of the nervous system or the energy of it that may be set loose by some very simple reflex, as suggested by Forel, is illustrated by what Ramon y Cajal calls the Law of Avalanche. A single peripheral nerve ending is represented in many different portions of the brain. An ocular nerve ending, for instance, probably has direct connection with four or more portions of each hemisphere. Each of these portions of the brain has association fibers connecting it with other parts and so the stirring of a single nerve ending may disturb many thousands, perhaps hundreds of thousands, of brain cells; at least it affects them in some way or other. The older psychologists used to insist on the similarity, or analogy, between the cosmos ol the universe and the microcosmos that man is. The English poet of the nineteenth century told us that there is no moving of a flower without the stirring of a star, so intimately connected by the laws of gravitation is the universe. In the microcosm something of this same thing is true and a titillation of even the most trivial nerve ending may produce, in Ramon y Cajal's phrase, "an avalanche" of cell disturbances in the central nervous system which may seriously disturb the whole system.
What is thus true for the brain is true, also, for the cord, and the complexity of spinal cells needs to be seen to be properly realized.
Fig. 4.—SERIES OF SECTIONS SHOWING THE FINE NERVE ENDINGS AND BRANCHINGS OF THE FIRST AND SECOND LAYER OF THE VISUAL CORTEX OF A CHILD FIFTEEN DAYS OLD. A and B, very thick nerve plexus of the layer in which the little pyramids are contained; C,