BOOKS.

BAN ON THE SENSES AND THE INTELLECT..

PSYCHOLOGY has been gradually growing into a reasonable study, from which a man of sense may derive pleasure and instruction. Being an inquiry into the nature of mental action,—the organs by which, and the laws according to which, the processes variously called sensation, perception, thought, judgment, emotion, belief, Will, are conducted,—it is beginning to base its results upon a careful examination of facts. It is no fault of psychologists that up to a recent period their acquaintance with the organism by which mental action is carried on has borne a small proportion to the vastness of their speculations on the mode and machinery of that action. The dependence of mind upon bodily organs has never been explicitly denied, but the acknowledgment has faded to lead philosophers to the conclusion that without a thorough know- ledge of the organization all speculations about mind must be purely hypothetical, and were likely to be quite erroneous. But, however strongly they had felt the importance of this dependence, the state of physiological science would have prevented the idea from'bearing its proper fruit. The knowledge of the nervous sys- tem, even in its broad outlines, is a gain of our own times ; and this was but the first step towards a true psychology. We may henceforth expect psychology and physiology to advance pan passu. We welcome Mr. Bain's volume as the most complete descrip- tive treatise that we know of the human organism and its func- tions, so far as psychological distinguished from physiological in- quiry can be benefited by such description. yt le think he has erred in not taking a wider range, and exhibiting mental action and the organs by which it is carried on in the senses and intellect of various grades of animals, from the lowest type of sensitiveness in the contractile muscle of a protozoon, to the marvellous in- stinctive actions of some of the vertebrates, and the unquestionable reasoning faculties of others. It is only thus that a thoroughly scientific conception can be formed of what mental action really is in its moat complex forms. But within his assigned limits Mr. Bain has done his work welL His present volume is only the first half of a treatise which is to embrace the Will and the Emotions in their higher manifestations ; the present volume only treating them in their lower forms, that is, apart from intellect, or so as to involve intellect in the least possible de- gree." The book begins—where all scientific attempts to in- vestigate the mental actions must begin—with an ample de- scription of the nervous system and the muscular machinery it sets in motion. It then proceeds to desoribe the muscular feelings ; the sensations of the organicprocesses; the sensations of the special senses ; the appetites • the instincts, under their several heads of instinctive movements, instinctive expressions of emotion, in- stinctive germs of volition, with the special instinctive activities. The foundation is thus soundly 'laid for the treatment of the pro- oesses and laws of intellect proper, or the power which preserves, recovers, and discriminates states of consciousness after the external stimulus which originally produced them is withdrawn. The laws under which this continuance, reproduction, and discri- mination take place' are stated to be four—two being simple and fundamental, and two complex. They are the law of contiguity, of similarity, of compound association, and of constructive asso- ciation. They are thus described in order. The law of contiguity is, " that actions, sensations, and states of feeling, occurring toge- ther or in close succession, tend to grow together, or cohere in such a way that when any one of them is afterwards presented to the mind, the others are apt to be presented in idea." The law of similarity is, that " present actions, sensations, thoughts, or emo- 'tions' tend to revive their like among previous impressions." The law of compound association is, that " past actions, sensations, thoughts, or emotions, are recalled more easily when associated, either through contiguity or similarity, with more than one pre- sent object or impression." The fourth law is, " that by means of association the mind has the power to form combinations or aggregates different from any that have been presented to it in the course of experience." The discussion and illustration of these four laws occupy about half of the volume, containing in all six hundred pages; of which the first three hundred are employed in the description of the nervous and muscular apparatus which conditions all our impressions of the external world, and fur- nishes all our internal feelings. It is in the space allotted to the physiological department of his subject, and the patient care bestowed upon the description of the organs and the feelings which belong to them, that Mr. Bain's work is distinguished from other psychological treatises. He is, as'it appears to us, a pure sensation- alist, in so far as he derives all the elements of our knowledge from affections of our material organism ; though, as he has yet to treat of the higher manifestations of the Will and the Emotions, such a verdict may be considered as premature. But a touchstone of a psychologist's theory may usually be found in his treatment of the source and explanation of our notions of space and an external material world ; and both these notions Mr. Bain holds to be adequately accounted for by compounding the sensations belonging to the senses of sight and touch with the muscular sense. The real value of the book, however, does not depend upon any theory of the writer. He may be right or wrong in his analysis of this or that complex notion ; he may even .be fundamentally wrong • The Senses and the Intellect. By Alexander Bain, A.M. Published by Parker and Son. in supposing any composition of sensations to be an adequate ac- count of some of our primary beliefs. But his elaborate descrip- tion of the sensations according to -the organs to which they belong—his talent -for bringing clearly, vividly, and definitely before the mind, those subtile shades of feeling which every one experiences, and every one finds it so hard to describe— confer upon his -book, as a mere contribution to the natural history of man, a considerable value and interest. And in his discussion of the four laws under which be arranges the intel- lectual processes, the grasp of thought and ingenuity with which, firmly holding by his law, he traces its operation from the simplest to the most complex results of mental action, recall the elder Mill ; while his wide range of illustration, and his acquaintance -with-the-regions of scientific, literary, and practical activity, render his statements easy for any attentive reader to understand and test. He is not an eloquent nor a very compact writer ; but he is generally lucid, familiar, and unaffected, simply desirous of making his meaning plain, and enforcing his argument by variety of state- ment and illustration,—a thinker earnestly bent upon finding out what is true, and putting his results down in the ordinary lan- guage of cultivated men. There is no pretence of enormous learn- ing, but evident familiarity with leading philosophical systems, and a competent knowledge of the latest indications of physical science, so far as they bear upon the elucidation of man's structure and the conditions under which be exists, feels, and acts. The following description of the general arrangement and functions of the cerebro-spinal system, summing up the scientific details-given in previous paragraphs, -will indicate the intelligible character of the physiological portion of-the work for persons nothabitukted to ,such discussions.

The arrangement may thus be seen to resemble the course of a-railwe.y train. The variouscentral masses are like so many stations, where tbas train drops a certain number of passengers and takes up others.in.their stead, whilst some are carried through to the final terminus. A system of telegraph wires might be formed to -represent exactly what takes placein the brain. If from a general terminus in London a mass of wires were carried out to proceed towards Liverpool, and if one wire of the mass were to end at each station, while from the same station new wires arose, one for every station further on, a complete and perfectly independent connexion could be kept up between any two stations -along the line. Calling the stations a, b, c, d, e; there would be from a the London terminus, the wires a b, a c, a d, a e; from b would arise be, b d, b e; from a, od, ce ; and from d, de. The mass-of wires found on -the road at a point between a and d, would be a 4. or the one throughgoing wire, b e and bd, cg, and ad; five wires in all, will& would be the ..number sustained throughout. This system of telegraph communication would be, so ,far as appears, the type of nervous communication among the various roassesstrung 'together in the cerebro-spinal axis or centre."

And here is the philosophical application of the facts now ascer- tained in relation to the nervous system and its modes of operk tion.

"The current character of the nerve force leads to a considerable depar- ture from-the common mode of viewing the position of the brain as the organ of mind. We have seen that the cerebrum is a mixed mass of grey and white matter,—the matter of centres, and the matter of conduction. Both are required in any act of the brain known to us. The smallest-cerebral operation includes the transmission of an influence from one centre to another centre, from a centre to an extremity, or the reverse. Hence we cannot sepa- rate the centres from their communicating branches ; and if so, we cannot se- parate the:centres from the other organs of the body that originate or receive nerve stimulus. The organ of mind is not the brain by itself Otis the brain, nerves, muscles, and organs of sense. When the brain is inaction, there is some transmission of nerve power, and the organ that receives er that originated the power is an essential part of the mechanism. A brain bereft of the spinal cord and spinal nerves is dead though-the blood continues to flow to it ; and these nerves, if plucked out of the limbs and other parts where they terminate, would probablynot suffice to sustain the currents as- sociated with mental life.

"It is, therefore, in the present state of our knowledge, an entire mis- conception to talk of a sensorium within the brain, a sanctum sanctorum, or inner chamber, where impressions are poured in and stored up to be repro- duced in a future day. There is no such chamber, -no such mode of recep- tion of outward influence. A stimulus or sensation .acting on the :brain -exhausts itself in the production of a number of transmitted currents qr influences; while the stimulus is alive, these continue, and when these have ceased the impression is exhausted. The revival of the impression is the setting on of the currents anew ; such currents show-themselves in actuating -the bodily members—the voice, the eyes, the features—in productive action, or in mere expression and gesture. The currents may have all degrees of intensity, from the fury of a death-struggle to the languor of a half-sleeping reverie or the fitful flashes of a dream ; but their nature is still the same.

"We must thus discard for ever the notion of the sensorium commune, the cerebral closet, as a central seat of mind, or receptacle of sensation and imagery. We may be very far from comprehending the full and exact character of nerve 'force, but the knowledge we have gained is sufficient to destroy the hypothesis that has until lately prevailed as to the materiel processes of perception. Though we have not attained a final understanding of this obscure and complicated machinery, we can at least substitute a more exact view for a less ; and: such is the substitution now demanded of current action for the crude conception of a central receptacle of stored-upimprsa- alone. Our -present insight enables us to say with great probability, no currents, no mind. The transmission of influence along the nerve fibres from place to place, seems the very essence of cerebral action. This transmission, moreover, must not be confined within the limits of the brain : not only could no action be kept up and no sensation received by the brain alone, but it is doubtful if even thought, reminiscence, or the emotions of the past and absent, could be sustained without the more distant communications between the brain and the rest of the body—the organs of sense and of movement. It is true that, between the separate convolutions of the brain, between one hemisphere and another, between the convoluted.hemispheres and the corpora striate, thalami optici, corpora quadrigemina, cerebellum, medulla oblongata, and spinal cord, influence might be imagined to pass and repass without flowing into the active extremities or to the five senses, and might thus con- stitute an isolated cerebral life ; but it is in the highest degree improbable that such isolation does or can exist. Nervous influence, rising in great part in sensation, comes at last to action ' • short of this nothing is done, no end served. However feeble the currents may be, their-natural course is towards the organs accustomed to their sway. Hence the reason for adopting language, as we have done throughout the present chapter, to imply that the brain is only a part of the machinery of mind ; for although a large part of all the circles of mental action lie within the head, other parts equally indispensable extend throughout the-body.'

The foundation of all proper intellectual action is the power we i

possess of revivingiast impressions. Psychology no more

interesting problem then the mode in which this power acts, and the laws it follows. The passage in which Mr. Bain attempts the solution of this problem is somewhat long for quotation, but it is so important in its bearings upon both speculative and practical science, upon both .philosophy and education, that we must find

room for it.

",All the muscular feelings already described, both-the organic feelings of the-muscle and the states produced by exercise in its various forme, can be sustained-for some-time after the physical cause has ceased. All the sensa- tions of the senses can be sustained in like manner, some more and some less easily ; and they can afterwards be revived as ideas bymeans of the asso- ciating forces. What, thee, is the mode of existence of these feelings bereft of their outward support and first cause ? in what particular form do they possess or occupy the mental ' and cerebral system ? This question carries us salar.as see are: able to go,iato the cerebral process of intelligence. It ad- mits of two different answers or assumptions—the one old and widely pre- valent, the other new but better founded. The old notion supposes that the brain is a sort of receptacle of the impressions of sense, where they lie stored up in a chamber quite apart.from the recipient apparatus, to be manifested to the mind when occasion calls. But the modern theory of the brain, ready developed in the Introduction, suggests alotelly different. iew. We have seen that the brain is only one part of the cause of nervous action ; that the completed circles take in the nerves and the extremities of the body-; that nervous action consists of a current passing through these complete w- ales, or-to and fro between the ganglia and the organs of sense and motion ; and that Eibort of a completed course no nervous action exists. The idea eta. cerebral closet is quite incompatible with the real manner of the working of nerve. Seeing, then, that a sensation in the first instance diffuses nerve cur- rents-through the interior of the brain outwards to the organs of expression and movement, the persistence of that sensation after the outward exciting cause is withdrawn can only be a continuance of the same diffusive currents, perhaps less intense, but not otherwise different. The shock re- mainingin the ear and the brain after the firing of artillery must pass through the same circles, and act in the same way, as during the actual sound. We have no -matron for believing that in the self-sustaining condi- tion the impression changes its seat, or passes into some new circles that have the special property of retaining it. Every part actuated after the shock must have.been actuated by the shock, only more powerfully. With this single difference of intensity, the mode of existence of a sensation en- during after the fact, is essentially the same as its mode of existence during the fact; the same organs are occupied, the same current action goes on. We see in the continuance of the attitude and-expression the identical out- ward appearances; and these appearances areprodueed by the course or power being still by the same routes. Moreover, the identity in the inward mode of consciousness implies that the manner of action within the brain is unaltered.

"Now if this be the case-with impressions persisting when the cause has ceased, what view are we to adopt concerning impressions reproduced by mental causes alone, or without the aid of the original, as in ordinary recol- lection.? What is the manner of -occupation of the brain with a resuscitated feeling of resistance, a smell, or a amid? There is only one answer so far as I can see. The renewed feeling occupies the very same parts and in the same manner as the original feeling, and no other parts, nor in any other manner that can be assigned. I imagine that if our present -knowledge of the-brain had:been present to the earliest speculators, no other .hypothesis than this would ever have occurred to any one. For where should a past feeling be reimbodied, if not in the same organs as the feeling when present. .1t is-only in this way that its identity can be preserved : a feeling differently embodied must to all intents and purposes be a different feeling, unlesa-we suppose a-duplicate brain-on-which everything past heto be transferred. But such- duplication has- no-proof and _server- no end. .41It is possible, however, to adduce facts that,eet in aetill.clearer light-this seoccupataon of the sentient circles with recovered impressions and feelings. Take find the recovery of feelings of energetic action,' as when reviving the exploits and exertions of -yesterday. It is a notorious circumstance, that if there be much excitement attending their recollection, it is with difficulty .that-we :can prevent ourselveitfrem getting.up tolrepeat them. The rush of jeeling las gone on the old-tracks, and seises the same muscles-, and would go the length of actually stimulating them to a repetition. A child cannot describe anything. that it was engaged in without acting it out to-the-full length-that the circumstances will permit. A dog dreaming sets his feet a-going, and sometimes harks. The suppression of the full stage of perfect resuscitation needs actually an effort of volition, and -we.are often even in- capable of the effort. If the recollection were carried on in a separate sham. bar, of the brain, it would not press in this way :pen thabodily organs-en- gaged in the actual transaction. The truth can only be, that the train of feeling is-reinstated on the same parts as first vibrated to the original stimu- lus and-that recollection -is merely a repetition which does -not usually go quite the same length—which stops short of actual execution. No better example could be furnished than the vocal recollections. When warecall' the impression of a word or a sentence, if we do not speak it out, we feel the twitter of the organs just about to come to that point. The articulating -parts—the larynx, the tongue, the lips—are all sensibly excited : a sup- pressed articulation is in fact-the material of our recollection, theintellectuel manifestation, the idea of speech. Some persons of weak or incontinent nerves can hardly think without -muttering—they talk to-themselves. The excitement of the parts may be very slight ; it may hardly go the length of affecting the muscles in a sensible way ; but in the brain and communicating nerves, it still passes the same rounds in a greatly enfeebled degree. The purposes of intellect can be served even after this extreme enfeeblement of the currents, but their nature mid _their seat have not changed. They have not abandoned the walks of living articulation because they nolonger speak out fully;. they have not taken .refuge in new chambers of the maid. We feel at any moment how easy it is to convert the ideas into utterances.; it is only like making a whisper andiblethe mere addition of mechanical power. The tendency of the idea of an action to produce the fact, shows that the idea already the feet in a weaker form. If the disposition to yawning exists, the-idea anywise brought up will excite the action. The suppressive effort usually accompanying ideas of action, which renders them ideas and not movenients, is too feeble in this case, and the idea is therefore a repetition to-the full of the reality."

In saying that Mr. Bain is a-thorough sensationalist, we indi- cate his opinion on all the leading points of philosophy. The pri- mary finalities of body only differ from the secondary in being more compound-sensations. Externality is the sensation of resist- anoe.to the movement of our muscles • the belief of an external world-simply the conviction, derived from experience, that certain movements of onr muscles will give rise to certain sensations of resistance. He does not, -if we have read his book aright, attempt to meet the difficulty that some of our notions about the external world—the notion of space, for instance—have attaehefl to them a character of universality and necessity; or to explain how it is that a sensation derived from experience can possibly acquire this character of necessity. He does not, in fact, deal with any of the so-called a priori forms of I> I I ption aid thought, the subjective conditions under which all .:u wledge-arises; and as he attempts

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to account for our notion. of apace.by a composition of sensations, we presume that his Gamy of the human mind discards all a priori conditions except the iipecial tendencies of the several organs to take on particular sentient modes. He uses the word " mind " con- stantly; but we should have been glad to hear more distinctly whether this word is adopted only as ageneral expression for the synthesis of the sentient nervous organization, or whether he dis- tinguishes "the indivisible unextended conscioneneas " of the me- taphysicians from the sentient organisation. We are-not alarmed about the orthodoxy of his opinions ; but a distinct statement on these and kindred point/ would add value to his book. However, there is sufficient unquestionable matter in the volume to make us desirous that the _further portion should be published without delay.