\ in so many ways, it helps us to imagine the kind of _re-Jlafion which the highest nervous structures bear to lower Jones. We are enabled by it to understand better how thinking goes on along with,, or apart from,. the perception of external things. It removes the difficulty of conceiving that the centre of compound co-ordination, to which all centripetal nerves bring their impressions and from which issue through centrifugal nerves motor impulses, continues to the last to be the sentient centre. "We see that while this centre is the seat of the sensations aroused by external stimuli, and the place in which these are brought into relation with other sensations similarly aroused; it is also the place in which such feelings and relations are feebly rearoused, in the same combinations and in other combinations, by discharges through the fibres of the overlying cerebral masses. We see, in short, that the medulla oblongata (with its subordinate structures) while played upon through th,e senses by external objects, is w simultaneously played upon by the cerebrum and cerebellum: so producing the thoughtconsciousness that accompanies sense-consciousness. ""™~"~ § 247. One further question to be asked is — ^W^Sifc&SP of viewjjisjm emo^jop? If, recalling the conclusion reached in §§ 213-216, we join with it the above inferences, we shall, I think, get a satisfactory answer.
As said, and tacitly implied, in various places, the coordinating plexus by which any cluster of sensations is made to excite the appropriate muscular actions, must in great measure coincide with other plexuses by which allied clusters of sensations are made to excite allied actions. In proportion as the external things responded to have much in common, and the required motions have much in common, the FUNCTIONS AS BELATED TO THESE STKCCTURES. 569 plexuses that effect the adjustments will have much in common. Not only of the plexuses which effect compound coordinations must this be true: it must "be true also of those which effect doubly-compound co-ordinations. But the' more involved the co-ordinations become the less definite wiH be these agreements; since, along with the progressive compounding of impressions and motions, there necessarily goes multiplication of differences in details. Let us ex- The plexuses which co-ordinate the visual impressions yielded by an apple on the table., with the motor acts required to grasp it and with the ideas of tactual and gustatory sensations it will yield,, are nearly the same as certain plexuses that have before worked together. Those which establish the consciousness of the apple's relative position in space, answer almost exactly to those which have established the consciousness of that relative position in space when occupied by other objects, alike in the experience of the individual and in the experience of antecedent individuals; and those which establish the consciousness of the apple's smoothness, hardness, odour, and taste, as related to its form and colour, are the same within narrow limits as those which have, in previous experiences of the individual, done the like. Along with this agreement of the! plexuses the consciousness is definite. Take now, ' in contrast, the nervous structures excited, and the correlative mental state produced, by an animal that threatens attack — say a fierce dog. It growls, it puts back its ears, it shows its teeth, it advances in an active way. But the motions, the gestures, and the sounds it makes, while they considerably resemble those made by other dogs on other occasions, do not coincide with them by any means closely. Much less do they agree with those made by another animal in a similar mood — say an angr^ bull; though in the rapidity of the approach, in the energy of the movements, in the loudness of the sounds, there is a general similarity. And they differ still more from, the demonstrations made by a furious man; though these, too, fhave in common with them the threatening advance, I the violent actions, and the loud harsh tones. It follows, ;' then, that the co-ordinating plexuses brought into play by 1 perception of an approaching enemy on successive occasions, never coincide in detail, even when the enemy is of the ;same kind; and their non- coincidence is great in proportion as the enemies are of kinds differing in their ^^appearances and modes of action. Let us next consider what happens if the threatened attack becomes an actual attack. There is pain, there is struggling, there are cries, perhaps of anger, perhaps of agony — all implying violent excitements of particular plexuses. But the plexuses excited do not coincide with those before excited by such attacks. The pains do not come from the same injured parts; the struggles are unlike in their combinations; the sounds emitted differ in pitch, or intensity, or order — usually in all of these. So^jbliat though the plexuses Bave inucJi_,JXL. common they have a great deal iiot, in copiaQn^ Mark further that these agreements and disagreements obtain not in the experiences of each individual only, but in the experiences of successive individuals.
Generation after generation the approach of enemies has exci^ed certain nervous structures in ways much alike in some few general characters, but unlike in multitudinous special characters; and there has followed the excitement of other structures that have similarly agreed in part and disagreed in part. What has resulted? E^^^P^1115 ^as keen inheritedjbo. the form of a well-organized set of connexions in the midst of many less definite connei36ns7"oBsciired by nmMtudmous feeble connexions; ^ndTn^^^jEeriteoT central connexions of "the plexus.first"* excited, are definitely connected Vith the inherited central connexions of the similarlyconstructed plexus that is habitually excited after it. TJia results are these. The conscious- FUNCTIONS AS RELATED TO THESE STRUCT UliES. 571 ne^s of an approaching body making sounds and motions of a certain kind, is followed by a consciousness of painful states, sensory and motor, having no definite localizations. The immediate perception, with the crowd of ideas resulting from preceding similar perceptions, arouses not only ideas of particular pains that have before followed such perceptions in the life of the individual; but through the inherited organization it arouses an indefinable sense of ill — a cloud of dim feelings of suffering that cannot be reduced to form because they have not been personally experienced— -the emotion of fear. And with the primitive form, of fear, thus physically organized and psychically constituted, there are afterwards integrated the higher and more involved forms of fear; all of which have for their central element, ideal feelings of pain or discomfort that are unrealizable and therefore vague.
Respecting emotions it has only to be added that they, like ideas, result from the co-ordinating actions of the erebellum upon over. As the plexuses in these highest nervous centres, by excitmg in distinct ways special sets of plexuses in the inferior centres, call up special sets of ideal feelings and relations j so, by simultaneously exciting in diffused ways the general #ets of plexuses to which these special sets belong, they. call up in vague forms the accompanying general sets of ideal feelings and relations — the emotional background appropriate to the definite conception. In the language of our illustration, we may say I that the superior nervous centres in playing upon the m-4 ferior ones, bring out not only specific chords and cadence of feelings, but, in so doing, arouse reverberating echoes all kindred chords and cadences that have been strucl during an immeasurable past — producing a great volume indefinite tones harmonizing with the definite tonesi* * Let me in passing remark that these views of the respective functions cf the nervous centres, make intelligible various physiological and patholo- § 248. A few remarks are liere called for respecting' the f tenets of the phrenolog^ts.,. It scarcely needs saying that-; the conception above elaborated, implying the constant cooperation of all the leading nervous centres in every thought and emotion, is quite at variance with their theory, as presented by themselves. But it may -be necessary to point out that I do not hence infer the absolute untrath of their theory.
That the contemptuous antagonism they have met with from both psychologists and physiologists is in great measure deserved, must be admitted. They have put forth their body of doctrines as in itself a complete system of Psychology — naturally repelling by this absurdity all students of mental science. At best. Phrenology can be but an appendix to Psychology proper; and one of comparative unimportance, scientifically considered. That those who have carefully investigated the structure and functions of the nervous system, should have long ago turned their backs on Phrenology, is also not to be wondered at; seeing how extremely! loose the phrenologists are in their methods of observation and reasoning, and how obstinately they ignore the adverse evidence furnished by experiment.
Nevertheless, it seems to me that most physiologists have not sufficiently recognized the general truth of which Phrenogical phenomena. We see how it is possible for the cerebrum and cerebellum to be greatly injured, and* indeed wholly shorn away, without destroying thVpower to perform the simpler acts of perception and co-ordination; just as it is possible for the mechanical piano, after the removal of all its tuneboards, to continue responsive to the hands of the musician. Again, the medulla being the seat of all feelings, whether aroused from without or from within, it naturally happens that its undue excitement, in whatever way caused, produces through the vagus nerve like effects on the viscera — it naturally happens that sensations intensely painful or pleasurable, and emotions intensely painful or pleasurable, alike cause fainting, and that fainting «cay be caused even by intense intellectual action. Similarly, it becomes comprehensible why the medulla is so generally the seat of chronic nervous disorders; whether the excess from which they arise be sensational, emotional, or intellect oaL : FUNCTION'S AS R ELATED TO THESE STRUCTURES. 573 logy is jin adumbration. Whoever calmly considers the) question, cannot long resist the conviction that different parts of the cerebrum must, in some way or other, subserve different kinds of mental action. Localization of function is the law of all organization "whatever; and it would be marvellous were there here an exception. If it be admitted that the cerebral hemispheres are the seats of the higher psychical activities; if it be admitted that among these higher psychical activities there are distinctions of kind, which, though not definite, are yet practically recognizable; it cannot be denied, without going in direct opposition to established physiological principles, that these more or less distinct kinds of psychical activity must be carried on in more or less distinct parts of the cerebral hemispheres. To question this is to ignore the truths of nerve-physiology as well as those of physiology in general. It isjgroyed, experi-] mentally, that every bundle of nerve-fibres and every gan-' glion^ hasj^ special.duty; and that each part of every such bundle and every such ganglion has a duty still more special.
Can it be, then, that in the great hemispherical ganglia alone, this specialization of duty does not hold? That there are no conspicuous divisions here is true; but it is also true in other cases where there are undeniable differences of fjp^tion — instance the sginal cjiord^ or one of the great nerve-Indies. Just as there are aggregated together in a f sciatic nerve an immense number of fibres, each of which | has a particular office referring to some one part of the leg,! but all of which have for their joint duty the management off the leg as a whole; so, in any one region of the cerebrum, each fibre may be concluded to have some particular office} which, in common with the particular offices of many neigh-! bouring fibres, is merged in some general office fulfilled by | that region of the cerebrum. Any other hypothesis seems \ to me, on the face of it, untenable. Either there is some arrangement, some organization, in the cerebrum, or there is none. If there is no organization, the cerebrum is a chaotic mass of fibres, incapable of performing any orderly action. If there is some organization, it must consist in that same "physiological division of labour" in which all organization consists; and there is no division of labour* physiological or other,, but what involves the concentration of special kinds of activity in special places.
But to coincide with the doctrine of the phrenologists in its most abstract shape, is by no means to coincide with their I concrete embodiments of it. Indeed, the crudity of their 1 philosophy is such as may well make men who to some extent agree with them, refrain from avowal of their agreement: more especially when they are met by so great an unwillingness to listen to any criticisms on the detailed scheme rashly promulgated as finally settled.
Among fun-damejitaj^ objections to their views,, the first to be set down is demarcations of the faculties. The only localization which the necessities of the case imply, is one of a comparatively Vague kind — one which does not suppose specific limits, but an. insensible shading-off. And this is just the conclusion to which all the preceding investigations point. For as we I have seen that every mental faculty, rightly understood, is I an internal plexus of nervous connexions corresponding to some plexus of relations among external phenomena that are habitually experienced; and as the different plexuses of external relations, in proportion as they ] become complicated, become less definite in their dis- 1 tinctions, so that when we reach those extremely involved ones to which the higher faculties respond there arises a j great overlapping and entanglement of different plexuses; it follows that the answering internal plexuses must be fused together — it must be as impossible to demarkate the internal i nervous aggregations, as it is to demarkate the aggregations ' of external things and actions.
Moreover, I believe the phrenologists to be JSOIiagjii assundry thatjhtere is something specific^ and unalterablejg FUNCTIONS AS RE1ATED TO THESE STRUCTURES. O/O tlie natures of the various faculties. Responding, as faculties do, to particular assemblages of phenomena habitually surrounding any race of organisms, they are only so far fixed and specific as these are fixed and specific. A permanent alteration in one of these assemblages, would in time establish a modified feeling adapted to the modified assemblage. A habit — say of sitting in a particular place in a particukr room, ending in being uncomfortable elsewhere — is nothing* but an incipient emotion answering to that group of outer relations; and if all the successors of the person having this habit were constantly placed in the same relations, the incipient emotion would become an established emotion. So litfcle specific are the faculties that no one of them is quite of the same quality in different persons. Ea,ch mental power is variable to as great an extent as each feature is variable.
*" Yet further, the current impression of phrenologists seems to be that the different parts of the cerebrum in which they locate different faculties, are of themselves competent to produce the manifestations implied by the names they bear. The portion of brain marked (f acquisitiveness," is supposed to be alone concerned in producing the desire of possession. But it is a corollary from foregoing arguments that this desire includes a number of minor desires elsewhere located. As every more complex aggregation of psychical states, is evolved by the union of simpler aggregations previously established — results from the co-ordination and consolidation of these; it follows that that which becomes more especially the seat of this more complex aggregation, or higher feeling, is simply the centre of co-ordination by which all the simpler aggregations are brought into relation. Hence, that particular portion of the cerebrum in which a particular faculty is said to be located^ must be regarded as an agency by which the various actions going on in many other parts of the cerebrum are combined in a particular way. The brain, active throughout, evolves under the co-ordinating plexus that is for tlie time dominant, an aggregate of feelings that is various in quality according to the proportions and arrangements of its components; just as out of the same orchestra, with its many instruments going from moment to moment, are drawn combinations of sounds now grave, now gay, now martial, now pathetic, according to the way in which the actions of its parts are co-ordinated by the composer's score.
Saying nothing of many minor objections to the phrenological doctrine, we conclude that however defensible may be the hypothesis of a localization of faculties, when presented under an abstract form, it is quite indefensible under the form given to it by phrenologists.* * In the first edition of The Principles of Psychology^ the substance of this section was contained in Part IV. — forming the conclnsion to the chapter on " The Feelings."
CHAPTER VII.
PSYCHICAL LAWS AS THUS INTERPRETED.
§ 249. The final stage of the synthetic argument has at length been reached. The task now before us is to comjDarj^ the deductions made in foregoing ^chapters fr.om a ghjBical principle, with the inductively -established, laws of mental action, and to see if the two correspond.
It was pointed out in § 222 that ligence would be fulfilled, and the_grpwth of ^ would Jbe^ explained, if it could he, shown " that when a wayjE^ p£ rnolecuiar transformation passes thjQugh a_g^rs:aas strjuctoe, there^ i§. wrou^it inj}he structure a ^modification t, other "Sings equal, ajsu]^ structure with greater ^cHitj ^pja,,, jts^, grede-It was thereafter infSf ed from established mechanical principles, that a structural change of this kind will occur. And we have since occupied ourselves in tracing up nervous evolution as_an accumulated All that remains is to observe whether the facts of exg^ejrience^.are similarly interpreta]ble — whether the hypothesis is further verified by the agreement of its corollaries with the generalizations of psychologists and with popularly-recognized truths.
§ 250. The congruity between the established laws of association and the several implications of the physical principle laid down, is conspicuous.
; Experience continually sliows us that, other things equal, the connexion formed between two feelings or ideas that:occur together or in succession, is strong when they are.vivid and feeble when they are faint. This truth is deducible from the hypothesis. In proportion to the strength of the discharge passing through a line of un symmetrically placed molecules, will be the amount of fovce expendod in bringing them towards symmetrical arrangement: so enabling them to convey the next discharge with less resistance. Whence it follows that the more vivid the connected feelings the more readily will recurrence of the one? cause recurrence of the other — the closer will be the association between them.
': It is a proposition equally familiar, that repetition of the * relation between two states of consciousness, presentative or representative, strengthens their union. The more fre-\ quently transition from the first to the second occurs, the more coherent they become — the more easily does the antecedent arouse the consequent. This, too, is a corollary from our hypothesis. For the implication of the argument set forth in § 224 is, that of the molecular motion discharged along a line of isomerically- changing molecules unsym metrically arranged, part is passed on by each molecule to the next, while part is absorbed in bringing it towards symmetrical relations with its neighbours. Hence of a subsequent like discharge, more will be passed Oti and less will be absorbed in this re-arrangement: there will be a diminished resistance to the excitement of the one nervous state by the other; and the correlative feelings will become more coherent.
A further fact finds here, too, its explanation. In the process of connecting mental states, it is observable that the earlier repetitions of the relation between them have greater effects than the later repetitions. For some time, recurrences of a sequence go on appreciably increasing the readiness with which the antecedent excites the consequent; but the rSYCHICAL LAWS AS THUS IXTEEPEETED. 579 increase gradually becomes less and less appreciable. The saying that practice makes perfect is but approximately tru£.. The proficiency gained by practice (as we see plainly in games of skill which furnish definite measures of pf oficiency) augments at first rapidly, then less rapidly, and at length scarcely at all: each individual reaches a limit beyond which repetitions of the nervous changes and concomitant successions pf feelings bring no sensible improvement. The j physical cause is this. "When a wave of molecular motion;, passes* through a line of molecules that are greatly out of symmetrical arrangement, much of it is absorbed in turning them toward symmetrical arrangement. As they approach nearer and nearer to symmetrical arrangement, more and more of the wave passes on— less and less is thus absorbed. But to say that each molecule offers a diminishing resistance to the transfer of the wave, is to say that there is a diminution of the force which tends to bring it into polar re--lations with its neighbours. And since the molecule has inertia and is also restrained by the actions of surrounding molecules, the force available for altering its p6sition bears a continually-decreasing ratio to the forces that maintain its position; until at length the effect of this re-adjusting force becomes insensible.
§ 251. The laws of more complex! mental changes are similarly interpretable. I refer to the phenomena of |ia^it, considered imder those involved forms in wHSfjSie em£ti^^^la^aMle^ng jjart.
It is a familiar fact that a course of action, or a mode of life, originally repugnant, usually, in course of time, gets less repugnant — eventually becoming indifferent or even agreeable. Physiologically considered, a disagreeable course of action is one in which compound feelings have to issue in compound actions, through complex nervous structures that offer considerable resistance. The result is that an extra quantity of feeling (commonly the fear of pain that may 580 PHYSICAL SCTTEESlS.
result from non-performance) has to be evoked before tlie actions can be excited. But since the complex discharges through these complex channels render them gradually more permeable,, it results that the quantity of disagreeable representation of pain required to excite the actions, decreases; and at length the permeability of these channels may become such that the spontaneous now of ordinary feelings suffices — nay, these channels may become needful for the due discharge of ordinary feelings; which otherwise discharge themselves in the purposeless activity we call restlessness.
Where the inherited organization already affords channels for the easy discharge of special feelings in special actions — that is., where there pre-exists an emotion prompting a particular kind of conduct, we see that often-repeated passage of such emotion into such conduct renders less and less resistible its tendency thus to pass. The more frequently the impulse is yielded to, the more difficult becomes restraint of it -, until at length the act it excites follows the feeblest solicitation of the inroulse. Truths of this class, continually illustrated among the lower impulses and illustrated as clearly, though less frequently, among the higher impulses, are corollaries from the same general principle.
§ 252. From this general principle, too, may be derived | an explanation of certain leading traits of developed intellit gence, as distinguished from intelligence which is undeveloped.
We have seen how from the process of nervous evolution as physically caused, it follows that actions become less automatic as they become more complex. When but a single afferent nerve runs to a single ganglion, whence issues ja, solitary efferent nerve to a solitary muscle, there can be no discrimination and no variety of action. When the reflex action becomes compound, responding to more numerous combined outer stimuli by more numerous com- PSYCHICAL LAWS AS THUS INTERPRETED. 5$ I bined inner actions, the change is in itself towards discrimination and variety of action, and opens the way to further changes in the same direction. For, as indicated in §§ 235, 23 7, in proportion as reflex actions increase in complication, there arise more numerous hesitations, both of the kind that habitually precede each established reflex action, and of the kind that accompany the partially^formed reflex actions. Similarly, as we ascend to intelligences in which highly-involved impressions initiate highly-involved kinds of conduct, the automatic and instinctive adjustments bear a continually-decreasing ratio to the mass of adjustments — there is an increasing proportion of actions that take place with deliberation and consciousness, as well as an increase in the amount of deliberation and degree of consciousness. What is the implication of this law as applying to different grades of men? It is that those having well- developed nervous systems will display a relativelymarked premeditation — an habitual representation of more various possibilities of cause, a'nd conduct, an'd consequence — a greater tendency to suspense of judgments and an easier modification of judgments that have been formed. Those having nervous systems less developed, with fewer and simpler sets of connexions among their plexuses, will show less of hesitation — will be prone to premature conclusions that are difficult to change. Unlikenesses of this kind appear when we contrast the larger brained races with the smaller brained races — when from the comparatively-judicial intellect of the civilized man we pass to the intellect of the uncivilized man, sudden in its inferences, incapable of balancing evidence, and adhering obstinately to first impressions. And we may observe a difference similar in kind but smaller in degree between the modes of thought of men and women; for women are the more quick to draw conclusions, and retain more pertinaciously the beliefs once formed.
Of kindred meaning is the difference between the cultared and the uncultured of the same race and of tlie same sex. The education of the individual (using the word education in its proper sense) is but a carrying further of that process by which intelligence in general has been evolved. It consists in extending and making better the correspondence of inner relations to outer relations— that is, in organizing the combinations of ideas into agreement with the combinations of phenomena. And its physical concomitant must be the formation in the individual of moremultitudinous and more involved connexions of plexuses-The brain of the uncultivated man as compared to that of the cultivated man, must be one in which the routes taken by nervous discharges are -less numerous, less involved, less varied in the resistances they offer — one, therefore, in which the number of ideas that can follow a given antecedent is smaller, and the degrees of strength with which they can present themselves are fewer — one, therefore, in which the possibilities of thought are moi^e limited, and the balancing between alternative conclusions less easy. This is the reason that ignorant people generalize hastily, and adhere obstinately to the erroneous conclusions based on their scanty experiences; while the highly -instructed man is able to keep his judgment undecided — waits for more evidence, contemplates other possible inferences than the one he is inclined to draw, and is ready to abandon or qualify his conviction when he discovers facts at variance with it.
Without going further into detail, it will be obvious that these, and other traits of progressing intelligence, harmonize with the principle that lines of nervous communication are formed b^5 the passage of waves of molecular motion, and become the more permeable the more frequently such waves are repeated,, § 253. Mental evolution in its higher stages shows us a further peculiarity which has the same general nature and admits of the same general interpretation. I refer to PSYCHICAL LAWS AS THUS INTEEPRETED. 583 brought out by comparing the emotional characters of inferior and superior minds.
We have seen that "beginning with simple feelings, rising to clusters of feelings,, afterwards to clusters of these clusters, and so on to aggregates more massive and more heterogeneous, the nervous structures which are their seats advance in complication by the super-posing of new plexuses whereby pre-existing plexuses have their actions co-ordinated. The implication is that the earlier and simpler feelings, being the more directly intermediate between special combinations of external stimuli and special combinations of adapted actions, are the more independent of one another and the more liable to act separately; while as fast as there are evolved those later feelings into which the simpler ones enter as components, there is a decreased tendency for the simpler ones to act separately. In other words, the development of the highest plexuses is the development of appliances by which simpler plexuses of different kinds are simultaneously excited, and the different modes of action which they prompt, simultaneously made nascent. It results, then, that along with advancing evolution of the feelings there will go a diminution of Stfulness and uncertainty of conduct.
An emotional nature not well developed will be relatively impulsive — the liability will be for each passion to display itself quickly and strongly, without check from the rest, and to exhaust itself very soon. While, along with high emotional development there will be little liability to sudden outbursts of feeling — the simultaneous rise of one or more counter-feelings proper to the circumstances, will in most cases retard or qualify the manifestations; but the conduct eventually decided on, prompted by a greater number of feelings severally less excited, will be more persistent. Here, as before, the contrast between the higher and the lower races of men furnishes an illustration j and here, too, as before, a further but less marked illustration is furnished by the contrast between men and women.
Indeed,, under this, as under other aspects, mental evolution, both, intellectual and emotional, may be measured by the degree of remoteness from primitive reflex action. The formation of sudden, irreversible conclusions on the slenderest evidence, is less distant from reflex action than is the formation of deliberate and modifiable conclusions after much evidence has been collected. And, similarly, the quick passage of simple emotions into the particular kinds of conduct they prompt, is less distant from reflex action than is the comparatively-hesitating passage of compound emotions into kinds of conduct determined by the joint instigation of their components.
CHAPTER VIIL EVIDENCE FROil FORMAL VARIATIONS.