Theosophy affirms the existence of supersensuous planes in the Macrocosm, each of which bears its part in the composition of the Microcosm (man), and occultism — or, in other words, advanced science — demonstrates beyond question the intimate relations between them and the material one which is the field of our mundane experiences. Evidence of their existence is also found in a proper understanding of the operations of the mind. These may be broadly classed as imagination, perception, reception, retention, recollection, ratiocination, and impulsion. That this classification is crudely general may be admitted, but it is sufficiently definite for present purposes, which do not include an exhaustive analysis of the infinitely complex functions of the mind, a work in which even so close and careful a reasoner as Raue found himself hampered by the limitations of a volume of almost six hundred pages.
Ultra-materialists — whom it would be better perhaps to call corporealists — affirm that all thought is a product of molecular modes of motion, mere expression of activity in brain-tissue cells, and point to the discernible effects of mental action upon the gray matter of the brain as evidence in support of their hypothesis. This is as correct as it would be to say that the copper of the etcher's plate originates the picture which, in lines and dots, is bitten into its surface by the acid skilfully applied by the artist in conformity to the requirements of the ideal in his mind. The fact of the matter is that the gross matter of which the brain is composed, whether gray or white, great or small in quantity, and much or little convoluted, is of itself as little capable of originating thought, or even sensing an impression, as a stone would be, or the brain itself if the life-principle were separated from it. But within that brain, present in every molecule and even atom of it — yet as far beyond the corporealist's discovery as the conditions of life on Sirius — is the astral brain, which is also matter, but of such tenuity in its atomic constitution that it may not be, in any way, apprehended by our gross senses.
The functions of that astral brain are perception of sensations and their translation to the mind, and the application of the conative forces resultant from such mental cognition to the direction, through the gross brain, of subservient physical impulse. What, then, is the gross brain? Simply a cellular aggregation of molecular matter having such specialized differentiation as enables it to store up, as impressions, the vibrations conveyed to it by the astral brain, holding them as latent vestiges of sensation and, when required, translating them to the lower rate of vibrations appreciable by the denser molecular matter of the body, so becoming the immediate motor force for action. The capacity for development with which it came into being was a matter of Karmic award, being prescribed by its environment, the hereditary influences upon it, and various other circumstances which it is not necessary now to particularize, all having their effect in determining its quality — as the sun, air, soil, and moisture govern the growing plant — but nothing endowing it, in any degree, with the power of starting vibrations, or — in other words — originating thought. Even the primitive forces, the capacity for mere sensory perceptions, do not belong to the gross brain but to the astral brain, in which it is not unreasonable to suppose they inhere as unconsciously-cherished remainders from the exceptionally strong range of impressions naturally resultant from preceding existences, subject to the needs and desires of the corporeal form.
Those who affirm the capacity of gross matter to generate thought assume to find support for their hypotheses in the waste, by mental energy, of the gray tissue of the corporeal brain, but they might as well ascribe to flowing blood the cutting of the vein from which it issues. The waste is an effect, not a cause. All energy is destructive, or, to speak more accurately, is reconstructive, and "the power which builds, unbuilds, and builds again" is ceaselessly at work. Molecular disintegration is hastened by all activity in every sort of tissue, and, if a proper balance is maintained, the work of molecular rearrangement is proportionately hastened by nutrition. Some scientists now affirm that cholesterin — a fatty salt found in the bile, lungs, and brain, and for which until very recently nobody saw any particular use — is the especial nutriment of the grey matter of the brain. Will the corporealists affirm that it is the cholesterin which does the thinking; that an heroic impulse or poetic thought is flattened crystals, insoluble in water but solvable in alcohol and ether, having well defined angles of crystallization and obtainable in quantity from gall-stones? The gentlemen who study mind from the standpoint of matter know a little about the physical brain, but not all, by any means, even of that. Is there one of them who knows the use of the pineal gland — which Descartes affirmed to be "the seat of the soul" — or can account for the gray sand found in it, not present in idiots or infants, scant in old age, and most abundant in middle-age brains of notable mental vigor?
The primitive forces already spoken of manifest themselves in the earliest moments of an infant's existence and do not cease while life lasts. They all tend towards experience of and repletion with external stimuli which correspond to their nature, and all experiences of sensation thus perceived are recorded in the plastic substance of the molecular brain as vestiges which may be stirred from latency to manifestation either by repetition of the stimuli primarily causing them, by contrasting stimuli, or by a strenuous effort of the mind, consciously or unconsciously applied, as conative vibrations, through the astral medium. Evidently the depth of such latent impressions must be proportioned to the strength and frequency of the experiences of like stimuli of which the vestiges are resultants. Hence it is but natural that the larger number of vestiges accumulated from the lower, or animal, senses — which are most productive of experiences in corporeal life — should eventually predominate in strength over those of the higher or intellectual range. And this affords an explanation of the power of Kama — or animal desire — in controlling our lives, so that a pessimistic good man has been moved to declare that "man is born to evil as the sparks fly upward". It also, if we reflect upon the extensions of this influence, enables us to comprehend the seeming mystery of the formation, during life, of the Kama-rupa, the wholly animal soul which becomes perceptible after death as an objective entity. And it makes apparent why and how men's characters are so often stamped upon their bodily features and forms. All the sensualities and vices that stain men's souls stamp themselves first in deep impressions upon the plastic brain, and thence find expression in the outward form to every part of which that brain extends its influence. It is erroneous to suppose that the brain is all lodged in the cavity of the skull. It is in the spine and the nerve ganglions, and practically throughout all the extensions of the nervous system. Virchow characterized the new-born child as "an almost purely spinal being", and Pfluger's experiments upon frogs demonstrated that consciousness of sensations, capacity to locate them, and power to direct corporeal action were all retained by the unfortunate batrachians upon which he experimented, after their skulls had been emptied of brain matter. The transference of consciousness of a still higher range from the brain to the solar plexus, under certain abnormal nervous conditions, may also be cited as an additional evidence of the diffusion of the specialized matter responsive to astral vibrations. So throughout the entire man runs his gross brain, and coextensive with it his astral brain, energizing it, directing its formative work of giving outward demonstration, in all his physical being, of what he has made of his soul.
Perception of sensations and their retention as vestiges for stimulation of conative force at the command of recollection — which is a mandatory vibration in the mind — may then be said to be powers located in the astral brain and its tool, the gross organ. But beyond these is the higher range of faculties, ratiocination, reception of purely mental impressions — either from purely subjective concepts or by reflection from the mentality of another — and finally the power of impulsion of mental force upon others. All these must necessarily, to be made potential, find translation through the lower rate of the astral medium to the still further diminished rate of the gross brain, if eventual manifestation on the material plane is sought, but not otherwise.
That sensory perception is an attribute of the astral brain and not of the corporeal is sufficiently evidenced by its highest manifestation in the experience of the many who possess the power of "seeing on the astral plane" either normally or under the abnormal stimulus of some phase of hypnotic control. The entities seen by so-called "spiritualistic mediums", and which they mistake for spirits of the dead, are on the astral plane. Charcot, Binet freres, James, and many other investigators have shown the ability of a hypnotee to become a witness of things which were not within the range of physical perception and, being outside the knowledge of any person whose mentality could have reached the subject, could only have been sensed through perception of astral vibrations. And the state of statuvolism, or self-induced trance is simply an excitation of the astral percipiency to an abnormal degree.
These phenomena must not be confused with others, very closely related yet altogether different, in which the compelling force of one mentality exerted upon another is very clearly demonstrated. The mind of every human being, in proportion to its development, possesses individual capacity in ability to reason, to draw deductions from vestiges of perceptions at its command, or impressions of a higher range, and thus to elect for itself between good and evil. It is this which constitutes its moral responsibility and determines its evolutionary progress, whether downward under the domination of its Kamic control or upward to spiritual life. But it is likewise susceptible, in greater or lesser degree, to the vibrations projected upon its plane by other minds, affecting and in some cases even paralyzing that power of ratiocination. This is the case when it is subjected to the will of another mentality exercising upon it hypnotic control, when it is rendered mentally — and it would justly seem — morally irresponsible. It may, on the other hand, if sufficiently forceful to impel such vibrations on the mental plane, in the same way take from others their mentality temporarily and even, to some extent, permanently. Herein lies the awful danger attendant upon the practice of hypnotism, for both the "hypnotist" and the "sensitive".