The mind of man has been a subject of investigation and discussion for thousands of years, and still we know very little of its nature; indeed, it is only during the past century that we have come to recognise that mind is in some mysterious manner related to the grey matter of the bra in, which consists of millions of cells, so-called neurons, whose functions are now being explored in the numerous physiological laboratories of the world. There is one point, however, on which scientists are all agreed : that the brain is the structure through whose medium in all mental operations take place. Only occultists are not of that opinion; yet even they must admit that it requires the services of a medium, through whose brain the higher spiritual phenomena are manifested.

Provided that the grey surface, i. e., the cortex of the brain, be not affected, all the other portions of a man's organisation may become diseased, or separately destroyed, even the spinal cord may become affected, without, the mental manifestations being impaired. We think and feel, rejoice and weep, love and hate, hope and fear, plan and destroy, trust and suspect, all through the agency of the brain-cortex. Its cells record all the events, of whatever nature, which transpire within the sphere of existence of the individual, not merely as concerns the intellectual knowledge acquired, but likewise the emotions passed through and the passions indulged in, and whether we can recollect them or not.

But the brain, besides being an organ of mind, is also the great regulator of all the functions of the body, the ever-active controller of every organ. For this purpose it has a double set of nerves: firstly, the spinal nerves, which in the normal state are more or less under our voluntary control, enabling us to move our muscles and limbs; and, secondly, the so-called sympathetic nerves, which are not under our voluntary dominion, and go to our internal organs as well as our arteries, controlling the-local blood-supply and thus nutrition, and go also to the spinal nerves, thus exerting a brain control over our intentional movements. In this manner—and this is only a rough outline—every organ and every function are represented in the brain, and are so represented that all may be brought into the right relationship and harmony with each other and converted into a vital unity. Thus mind, motion, sensibility, nutrition, repair and drainage have their governing centres in the brain.

It is through this central organisation that every bodily function can be affected by a mental act. Thus certain states of mind are apt to be accompanied by various derangements of the functions of the body. Everyone knows how the receipt of an unpleasant letter may make us lose all appetite for food, and even cause us indigestion or headache, how fear may actually paralyse the muscles, and keep us "rooted to the spot," how sudden shock will sometimes result in instant death, how long-continued grief or mental strain will sap the strength of the body. And it is no Less a fact of observation that when healthy mental states arc substituted for unhealthy ones, the functional derangements of the body tend again to disappear.

On the other hand, it is owing to the same organisation that our mental disposition can be influenced by the bodily functions. Nobody is constantly the same self. Not only is he a different self at different periods of his life and in different circumstances, but also on different days, according to his different bodily states: anguine and optomistic, gloomy and pessimistic, frank and genial, reserved and suspicious, apathetic or energetic. Although bis intellectual powers remain the samehis judgment of the objective world and his relations t inns to it are quite changed, because of the change in his moods and the bodily states which they imply.

Without giving any further illustrations, it will be admitted that there is ample evidence of the inter-action between mind and body, i. e., of the physical effects of mental causes and the mental effects of physical causes. We need not go into details, so long as it is admitted that not only can the body be weakened through the agency of the mind, but it can be- strengthened also by that same agency.

We are not conscious of the various functions of the organic life of the body, which go on in quiet harmony with the nicest adaptations of means to an end throughout its complex mechanism. By a wise providence of Nature we are not conscious of the working of these processes acting between body and mind; we are only conscious of the results, and know nothing of the existence of the machinery, unless it becomes disturbed in one or other of its functions, and the message it then sends to the brain is felt by us as "pain."

It is the subconscious or subliminal mind, from which our feelings arise, which through its instrument, the brain, exercises over the muscular, nervous vasomotor, and circulatory systems and all the functions of the body a control, and raises them to a power which no conscious effort is capable of. Thus great trials in life furnish us often with extraordinary strength, and we accomplish deeds beyond our usual ability.

This leads us to the observation that we are not conscious of any of our feelings until they have actually appeared. All our feelings—love, fear, anger, etc.— arise spontaneously without our knowledge. We can control them only after we have become conscious of them. In both physical and psychical processes, consciousness forms but a small item. Its sphere is only a small circle in the centre of a far wider sphere of action and feeling, of which we are only conscious through its effects.

As a rule, it is only the result of a mental event that we are conscious of, the actual origin and working remains obscure. Even in the conscious act of perception through our senses, there is a subconscious process of reproduction and influence; hence the liability of all of us at one time or another to be the subjects of hallucination. Indeed, even in the cleverest of us, in the ordinary mental operations of our daily life, there is not so much consciousness as is commonly assumed. Unconsciously and subconsciously, we constantly believe in things which do not exist, or only exist in part. For example, we believe without question in the reality of the perception of our senses, which, however, primarily depend on an edifice of conclusions, with the help of which the sensations are formed. Hence, we are deceived almost regularly by false preceptions.

A sensation, thought, or motion requires to be of a certain magnitude or intensity, and to persist before the mind for a certain time, to make us conscious of it. The mind is constantly receiving impressions, thoughts incessantly passing through it that are unperceived, because they are not of sufficient magnitude or intensity to make themselves felt. If a book is read very quickly, bo that time is not allowed for the sightstimuli to influence the central organ, there is no story of what is reed, because there is no consciousnes of it, and when a speech is too rapid and blurred there is a .similar absence of consciousness and memory because of the want of time and intensity. Yet, though we are not conscious of what we glanced over hurriedly, some passage or other may have registered itself on our brain, and spring up one day like an inspiration, only to disappoint us when we come to know that it is not original.

An act of attention, that is an act of concentration— by which we mean the fixing of the mind intently upon one particular object to the exclusion for the time of all other objects that solicit its notice—is necessary to everyexertion of consciousness. Without some degree of attention no impression of any duration can be made on the mind or laid up in the memory. The remembrance of anything depends upon the clearness and >vividness of the impression originally made by it upon the mind, and this on the degree of attention with which it was regarded. Consciousness has at first an important place in the training of our faculties and the building up of our knowledge. The more consciousness is concentrated upon any new operation, the more readily is it mastered; and the more it is concentrated upon any idea brought before the mind, the better is it impressed upon the memory. But as we acquire facility and skill in the operation and the memory acquires strength, we become less conscious. The great object of education, then, should be to transfer as much as possible of our actions from the conscious to the subconscious region of the mind.

The more we cultivate and train any power of faculty, the more easily and rapidly does it perform its work, the less is consciousness concerned in it, the more work does it accomplish, and the less does it suffer from fatigue. Our mental progress, then, is in the direction of our becoming subconscious, or largely subconscious, of many of our activities.

The more we concentrate our attention on a particular subject, the less we notice other concurrent impressions. For example, in listening to a conversation, we receive impressions not only of the words uttered, but also of the sounds in the air, and of its temperature, of odours, the forms, colours, lights and shades—all associating themselves with the thoughts conveyed—but we exclude all these impressions from our consciousness, although they may be noticed by our subconsciousness.

The more we concentrate on a subject in hand, the less we notice also our internal sensations. Hence, in times of real danger the body may feel no pain, no matter how severe the injury. The universal testimony of soldiers who have been in battle is to the effect that the time when fear is experienced is just before the action commences. When the first gun is fired all fear vanishes, and the soldier often performs feats of the most desperate valour, and evinces the most reckless courage. If wounded, he feels nothing until the battle is over and all excitement is gone.

With the decline of the conscious state we lose our fear of death. It is only in the vigour of youth and manhood, when the conscious state of mind is in the ascendant, that death is looked upon with horror. The aged view its near approach with calm serenity. The convicted murderer, as long as there is hope of pardon, reprieve or escape, Of commutation of the death-penalty, evinces the utmost dread of the scaffold; but when the death-penalty is confirmed, and all hope has fled, his active mind diminishes in strength, and he often evinces the utmost indifference, welcomes the day of his execution, and marches to the scaffold without a tremor. This is regarded by some as courage, whereas the truth is that that merciful provision of Nature which nerves alike the brave man and the coward, steps in to his defence, his objective senses are benumbed, and he submits to the inevitable change without fear and without pain. Even a coward often acts under circumstances of unavoidable danger with the same coolness, and evinces the same presence of mind as the bravest man. The most timid woman under such circumstances will fight like a demon, and display preternatural strength and courage, for the preservation of her own life, or that of her offspring. I know of an officer who trembled in body and limbs on the eve of battle, who could not hold his sword steadily and spilled the glass of wine that was offered him for "good luck," who yet won on that day the Victoria Cross for his extraordinary bravery.

Acts which are at first executed slowly, and with full consciousness and attention, become gradually less and less perceptible as they gain in ease and rapidity by repetition, till they fall below the minimum necessary for consciousness, and become unconscious, or rather subconscious. It is because impressions we have frequently received, thoughts we have often entertained, actions we have many times done, pass through the mind so rapidly that we cease to be conscious of them. In our first attempts to walk, to write, to play on an instrument, or to carry on any other operation, we are intensely conscious of every movement that we make. By degrees, as we acquire more ease and dexterity in their performance we become less and less conscious of them, till we may come to perform them quite unconsciously.

An expert accountant, for example, can sum up almost with a single glance of his eye a long column of figures. He can tell the sum with unerring certainty, while at the same time he is unable to recollect any one of the figures of which that sum is composed; and yet nobody doubts that each of these figures has passed through his mind. It is on account of the rapidity of the process that he is unable to recollect the various steps of it, and only the result appears by a sort of inspiration before consciousness.

Did our actions not become more and more easy of execution, and gain in rapidity by repetition, were we stillas conscious of them as at first, comparatively little could be accomplished in the course of a lifetime.

If in order to walk, we had for ever carefully to consider each step we took, or, in order to write, had always to attend to the formation of each letter—were all our other operations performed as painfully and as consciously as at first—life could scarcely fail to be a burden.

Did everything that exists in the mind exist there consciously, or did every time that an idea occurred to the mind all the other ideas that had at any time been associated with it come along with it, and a selection have to be consciously made of the right one, inconvenience and loss of time could not fail to result. In some persons,habit or lack of proper training, an idea in the mind immediately recalls a number of other ideas having more or less, and sometimes very little, connectionwith it thus distracting the mind with a multitude of thoughts, making the selection of the best a conscious act, producing hesitation and indecision, and causing loss of time. The selection of the right thoughts should be an act of the subconscious mind, and take place, as we say, unconsciously.

Therapidity with which subconscious ideas can pass through the mind is truly marvellous; thus the succession transactions in our dreams is almost inconceivable, insomuch that when we are awakened by the jarring of a door which is opened into our room we sometimes dream a whole history of burglary or fire in the very instant of wakening. We can dream more in a minute than we can act in a day, and the great rapidity of the train of thought in sleep is one of the principal causes why we do not aways recollect what we dream.

All our latent memories are stored in our subconscious mind. Not a millionth part of the mental possession of an educated man exist in his consciousness at any one time. We may forget objects and events—that is to say, we may dismiss them from our consciousness, but they are stored up in our subconsciousness to the end of our. days. We may be able to call them into consciousness when we wish to do so, but at other times the mind is unconscious of their existence. Further, everyone's experience must tell him that there is much in his mind that he cannot always recall when he may wish to do so—much that he can recover only after a laboured search, or that he may search for in vain at the time, but which may occur to him afterwards, when, perhaps, he is not thinking about it. That which has been long forgotten—nay, that which we have often in vain endeavoured to recollect, will sometimes, without any effort of ours, occur to us spontaneously, or some association may revivify it enough to make it flash, after a long oblivion, into consciousness.

I want to write a certain letter on getting home, and in order to remind me of it I make a knot in my handkerchief. The knot and the letter are then associated in my consciousness, and when I see the knot on getting home, the idea of writing the letter rises from subconsciousness into consciousness.

The essence of thinking is that the right ideas occur at the right time. When we write an essay or letter, we often do not know at the time of sitting down to it what we are going to say; but from the moment of taking the pen in hand, our subconscious store of ideas supplies us with the material. We have a name for such momenta—we call them inspired; and thus erroneously gooutside of ourselves for an explanation, instead of finding it deep down in our subconscious self, the germs of which were sown, perchance, far backin our childhood, developed by our surroundings, added to by conditions beyond our control, and not chosen by those who were preparing the material for ourmental development.

There are a multitude of events which are so completely forgotten that no effort of the will can revive them, and that the statement of them calls up no reminiscences which may nevertheless be reproduced with intense vividness under certain physical conditions. Thus persons in the delirium of a fever have been known to speak in a language which they had learned in their childhood, but which for many years hadpassed from their memory; or to repeat with apparent accuracy discourses to which they hadlitened a long time previously, but of which before the fever they had no recollection. They have even been known to repeat accurately long passages from books in foreign tongues, of which they never had any understanding and had no recollections of in health, but which they had casually heard recited many years before.

A case is related by S. T. Coleridge of a young woman of five-and-twenty, who could neither" read nor write and whowas seized with brain fever, during which she continued incessantly talking Latin, Greek and Hebrew in very pompous tones, and with a most distinct enunciation. Sheets of her ravings were taken down from her own mouth, and at last it was found that she had been for some years servant to a Protestant pastor, who was in the habit of walking up and down a passage of his house adjoining the kitchen, and reading aloud to himself portions of his favourite authors. In the books that had belonged to him were found many passages identical with those taken down from the girl's mouth.

The most remarkable cases, however, are those of persons who had been resuscitated from drowning or hanging, and who have reported that they had a sudden revelation of all the events of their past life presented to them with the utmost minuteness and distinctness just before consciousness left them.

Consciousness forms but a small item in the total of physical processes. It is not the essence of mind, but is only incidental to its work. It is not to be regarded as synonymous or co-extensive with mind, for there are ideas and impressions constantly in the mind of which we are totally unconscious. Those who speak of mind and consciousness as co-extensive, and treat the notion of subconscious mind as a gross absurdity, should soberly explain where, during a particular conscious state, all the rest of the mind is; where, in fact, all that furniture beyond the particular piece then in use is stored.

It is not to be supposed, however, that these unconscious or subconscious impressions or thoughts exert no influence upon the mind. The brain being the instrument of the mind, every impression we rethought wo think, as well as every action we do causes some change in that structure, and this is permanent, forming an imperishable record of all that we have experienced, thought, or done in the past. These impressions, thoughts and actions may never again come before our consciousness, yet they will remain in that vast subconscious or subliminal region of the mind, unconsciously moulding and fashioning our subsequent thoughts and actions. Every thought we have entertained, and every act we have done throughout our past life, make their influence felt in the way of building up our present knowledge, or in guiding our everyday actions.

Many things of which we have no recollection that we have even noticed them, innumerable experiences which never attracted our attention, are stored up similarly, and may exercise an influence over us of which we are not conscious. Many minds are moody, morose, melancholy, excitable, irritable, immoral, unbalanced, solely because of the overpowering influence of some picture of a past experience, which remains subconsciously in operation after conscious thought on the occurrence has ceased and the person has apparently forgotten the incident.

What is termed "common-sense" is nothing but a substratum of experiences out of which our judgments flow, while the experiences themselves are hidden away in the subconscious depths of our intellectual nature. Our judgment of things depends on our past experience, the particular instances of which we may be unable to recall, but which undoubtedly have their effect in determining the result at which we arrive.

We all see the same world objectively, but according to our subconscious minds we look through different spectacles, and the scenery suggests to us different ideas. Light, electricity, form, colour, sound are always with us, but they convey a different meaning to all of us, and even to a single person at different times the message suggested may be different according to the mood he happens to be in.

The subconscious elements are the basis of character, and condition conduct to a far greater extent than the view of life that we express, and by which we believe that we are actuated. "When we see the better but follow the worse, when we have acted in a manner wholly opposed to our ultimate interests, the blame must be laid at the door of the subconsciousness.

Education of the conscious self tends to uniformity in all civilised people. The subconscious self, however, which is built up out of that countless multitude of subconscious impressions and their recurrence coming from the surroundings, customs, languages, national types, physical effects of climate, and many other sources, is widely different. They create a subconscious self in every person, and make of him not merely a representative of his times, but produce in him the qualities peculiar to his country, to his nativity, and to the class in society to which he belongs— thus stamping him at once with their limitations and idiosyncrasies. For example, an " educated" Frenchman's opinions—whether he be a merchant, a professional man, or an artisan—may be in no wise different from those of an educated Englishman or of an educated German; he is, as we properly say," a man of the world." But when, for any reason—emotional, for instance, or through depression or illness—his consciousself is weakened or fails him, his subconscious self asserts itself, and the national characteristics appearin spite of "intellectual" culture.

We have, then, two states of mind: the conscious, or objective or supra-liminal; and the subconscious, subjective or sub-liminal—that is the self below the threshold of ordinary consciousness.

As a rule, the conscious state of mind and the subconscious state of mind work together, and there is nodividing line between them; so that we feel that we areonly one personality. Both depend on the organisation of the brain with which we happen to be endowed.