bined inner actions, the change is in itself towards discrimi- nation 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 complica- tion, 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 conscious- ness. What is the implication of this law as apply- ing to different grades of men? It is that those having well- developed nervous systems will display a relatively- marked 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 conclu- sions 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 compara- tively-judicial intellect of the civilized man we pass to the intellect of the uncivilized man, sudden in its infer- ences, incapable of balancing evidence, and adhering obsti- nately 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 cul- 582 PHYSICAL SYNTHESIS.
tared 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 rela- tions— that is, in organizing the combinations of ideas into agreement with the combinations of phenomena. And its phy- sical 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 obsti- nately 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 infe- rior 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 heteroge- neous, 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 com- binations 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 deve- lopment of the highest plexuses is the development of ap- pliances 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 emo- tional 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.
584 PHYSICAL SYNTHESIS.
Indeed,, under this, as under other aspects, mental evolu- tion, both, intellectual and emotional, may be measured by the degree of remoteness from primitive reflex action. The form- ation of sudden, irreversible conclusions on the slenderest evidence, is less distant from reflex action than is the form- ation 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 emo- tions into kinds of conduct determined by the joint instiga- tion of their components.
CHAPTER VIIL EVIDENCE FROil FORMAL VARIATIONS.
§ 254. Thus far the evolution of nervous structures, and of their functions, has been considered without reference tojhe varying physiological conditions that affect the pro- cess from moment to moment, as well as from generation to generation. We have spoken as though the physical actions ijy which nervous channels are opened and made more per- meable, equally with those by which the discharges along established channels produce their respective effects, are actions always alike in kind and degree if the stimuli and the structures are alike in kind and degree. But this is not the case. Here we must take note of several circumstances, general and local, which modify the influence of the same outer agent on the same inner part; and observe the cor- respondence between the variations of physical effect and the aceompanying variations of psychical effect.
The better to follow in thought the production of theso variations, let us carry further a comparison before made. When describing how discharges of moleeular*motion go along lines of least resistance/ and by recurring render them lines of less resistance, it was pointed out that in this respect there is an analogy between the flow of molecular m»tion and the flow of a liquid; for a stream, in proportion as it is strong and continued, cuts for itself a large and definite channel ( § 224). That the transfer of molecular motion may be 586 PHYSICAL SYNTHESIS.
properly thus paralleled, we see in tlie case of those forms of molecular motion known as heat and electricity; the con- duction of which through solid bodies, is compared to a flow that takes place more easily through some substances than through others, and which, in bodies having polarized mole- cules, passes with less resistance in some directions than in others.* Reverting, then, to the common hypothesis of a nervous ef fluid " which moves in nerve-" cur- rents " — admitting that though the molecular motion which works nervous effects is not a fluid, and its transfer not a current, they may be conveniently dealt with as though they were; let us consider what variations of special results will arise from incidental variations in the genesis and escape of the nervous fluid. Let us consider the nervous system as an immensely involved set of channels, some wide and allow- ing an easy flow, some narrow and little permeable — some communicating with one another by large openings and others by openings through which nothing passes except under high pressure; but all of them more or less permeable and more or less connected. Let us suppose the aggregate of channels so constituted, to have multitudinous places through which its contents escape and multitudinous places through which there come gushes that increase its contents; and that these places of subtraction and addition are opened in various localities, in various numbers, and in various de- grees— sometimes the subtractions being in excess and sometimes the additions. Let us hence infer a considerable variability of pressure in the fluid filling these ramifying channels — some excessive outflow having now greatly reduced its pressure, and the large inflows having now raised its pressure above the usual height. And lastly, let us draw the necessary corollary that at one time its ebbing streams pass only along the fully open and the more permeable channels; while at a time of high tide its streams find their * See Prof. Tyndall's Heat as a Mode of Motion, Chapter VII EVIDENCE FEOM FORMAL VARIATIONS. 587 ways into less permeable channels,, and, aided by local dis- turbances, escape even through the least permeable channels. Tims symbolizing the physical actions to which the nervous system as a whole is exposed, let us ask how its functions will be affected by changes of physiological con- ditions; and how the accompanying subjective states will be modified.
§ 255. Take first the general variations which are seen on contrasting certain mental traits of youth and age.
While waste and repair are rapid, the ramifying set of channels forming the nervous system, receives such a large and perpetual influx at multitudinous points, that it remains well filled notwithstanding the large efflux con- tinuously going on at multitudinous points. The ingoing waves of molecular motion caused by peripheral impres- sions, liberate from moment to moment, in the sensory centres, larger waves,, or, as we may here call them, quick gushes of the ee nervous fluid;" and from the massive plexuses of the higher centres, aroused by combinations of disturbances thns arising, there are added to the contents of the.nervous system still more powerful and continuous gushes. « Considering first the physiological results, we see that the channels of tbe automatic nervous system are filled t© overflowing. The heart pulsates powerfully; the alimentary canal works vigorously; the lungs are well inflated; and every glandular organ receives that continuous discharge which keeps up the peculiar molecular changes carried on in it. Meanwhile the voluntary muscles, receiv- ing their share of this abundant efflux, are all in states of partial tension, so producing attitudes characteristic of vigour; and they are severally ready to contract with great force, and to keep up their contractions for long periods. Among accompanying psychical results, we see that the feelings of both orders are vivid: the" sensations are distinct and the emotions lively. We see 58S PHYSICAL SYNTHESIS.
also — and tliis it is which more especially concerns us hero — that the establishment of relations between feelings is easy, and that the relations when established are relatively permanent. Along whatever lines of nervous- communica- tion are opened, discharges pass that are strong because the pressure is great; whence results a great amount of mole- cular re-arrangement along each line taken by a discharge. A subsequent like discharge passes with comparative facility; making the antecedent state easily produce the consequent state — the terms of the relation are rendered coherent — the memory of it is good.
The converse connexion of phenomena in advanced life, brings out more clearly, by contrast, the law we are contem- plating. In common with the body at large, the nervous system is supplied with poorer blood circulated more slowly, and hence when wasted it is less rapidly repaired. Its channels, therefore, receive from moment to moment feebler gushes of nervous fluid; the general pressure is diminished; and all the various overflowing gushes become less. The physiological results are that the actions of the viscera go on more slowly. Digestion if not positively difficult is a sensible tax; and the propulsion of blood to the surface is no longer active enough to contend with any great loss of heat. Throughout the muscular system, too, the failing nervous discharge is seen; alike in the chronic relaxation of attitude and in the quick following of fatigue upon exertion. Psychically, this state is one in which the feelings aroused are less vivid and the re- lations formed between them less coherent. For reading a strong light is required, taste and smell become less keen, hearing grows dull, and there is apathy in presence of cir- cumstances which yield strong pleasurable emotions to the young. At the same time the comparative want 'of cohesion between impressions is shown in the inability to recollect the names of persons, the times of occurrences, &c. And if we trace out the successive stages of failing memory, we see EVIDENCE 1EOM NORMAL VARIATIONS. 589 fcliafc they follow the order inferable from the hypothesis. Earliest among the related impressions which no longer so cohere that one recalls another, are those made by daily trivialities — those represented in the nervous system by lines through which feeble discharges have but once passed, Interesting statements that are read, and passing events of considerable importance, presently cease to be recallable; though like statements and events which date back to early life are still recallable: the reason being that the channels of nervous communication long ago made by the strong gushes answering to the vivid feelings of youth, remain more permeable than those lately made by the feebler gushes answering to the fainter feelings of age. Passing over many gradations, we conie to incoherences of thought in which the place now inhabited is confounded with places inhabited long ago, and the business of middle life is referred to as though transacted yesterday — inco- herences implying that comparatively permeable channels are now so far deserted that the discharges along them do not arouse the elements of these familiar ideas in their proper relations. And eventually we reach the extreme state, similarly explicable, in which even members of the family, who have been companions through life, cease to be re- cognized.
§ 256. Let us consider next certain general psychical variations that accompany differences of bodily constitution. Some of these, of the same natures as the foregoing, we will glance at before passing to some of another nature.
In jjonsequeiLce of specialities of inheritance, specialities of education, and specialities of mode of life,, higfL mental manifestations of certain kinds may go along with wejaJbajess of /body. But classing such cases as^abn(^rmaX^^iations from that constitutional balance which is needful for sifrvival through future generations; and limiting our attention to cases where no monstrosity has been produced by undue 590 PHYSICAL SYNTHESIS.
forcing of the individual or his ancestors; we shall, I think, trace a connexion between abounding physical vigour and power of thinking and feeling, as well as between sluggish- ness of constitution and comparative inertness, intellectual and emotional. On the one hand we have a type of man overflowing with muscular energy that gives supe- riority in sports, games, and feats of strength; who is keenly alive to all orders of gratifications, sensational and emotional; who acquires knowledge easily, and retains it tenaciously; and who, after leaving the academic life throughout which he was marked by these united traits, gains distinction partly because of his mental activity (not necessarily of a high order), and partly because of the strength of constitution which enables him to bear intense and prolonged application. On the other hand we have a type of man whose bodily functions are slow; who from boyhood upwards cares little for active exercises; who even in youth is indifferent to pleasures which others enjoy greatly; who all along finds learning laborious; and who, in after life, lapses into apathetic idleness.
These contrasts between men whose nervous systems work under high pressure and under low pressure re- spectively, I draw less for the purpose of showing their analogy to the contrasts between the young and the old, than for the purpose of drawing attention to accompanying contrasts of another kind. We have seen that when the pressure throughout the nervous system is high, so that any disturbance which facilitates escape along certain channels is followed by a strong gush along those channels, even though they are not very permeable; there is an easy revival of old connexions of ideas and a formation of new connexions that are very coherent. But there is much more than this. Interwoven as the higher nervous plexuses are in such intricate ways, in correspondence with the intricate interweaving of phenomena, it neces- sarily happens that a wave of nervous fluid let into one of EVIDENCE PROM NORMAL VARIATIONS. 591 them, though it escapes most largely along certain most permeable channels,, escapes in part along other channels that are less permeable. The stronger the wave the greater the number of these supplementary discharges; and the further do all the discharges,, larger and smaller, make themselves felt — rushing out into more multitudinous and remote ramifications of the plexuses they enter. Answer- ing to this physical result the psychical result is the pro- duction of ideas that are more numerous, and more distinct, and more discursive. The area of consciousness simul- taneously widens and brightens as the pressure of the nervous fluid increases; so that while its near and central elements become clearer,, elements more distant from the centre come into view. Between the two types of constitution above described,, we see such mental differ- ences as are hence to be inferred. The man whose nervous system works under high pressure shows us an abundance of ideas. He has always something to say; and instantly finds words fit for the occasion. All the proximate bearings of a situation or an event quickly occur to him; and out of the several courses which almost simultaneously suggest them- selves,, he takes the appropriate one. He thus shows what we call "presence of mind;" and habitually trusting1 with success to the fertility of his resources, he has courage in facing difficulties. In the man whose nervous system works at low pressure, thoughts come slowly in single file instead of rapidly in a column formed of many almost. abreast. The various possible causes and consequences of each act dawn upon him gradually one by one, and some of them not at all; so that the occasion has passed before he has had time to adjust himself to it. Finding *chat he is consequently unable to cope with men who have " their wits about them/' he leaves the crowded thoroughfares of life and takes to its quiet byeways. * § 257. That general physical causes entail such general 592 PHYSICAL SYNTHESIS.
psychical differences, we see not only on contrasting the minds of the young and old as well as those of the con- stitutionally vivacious and the constitutionally sluggish, but also on contrasting the exalted and depressed constitu- tional states of the same individual.
Most persons have had experience of a general prostra- tion during which pleasures are accepted apathetically, while thinking is a fatigue and the effort to recollect un- familiar things repugnant; and along with this diminished cohesion of ideas there is a diminished number of them — instead of coming in a continuous crowd they come as a train of stragglers. Conversely, there is an exceptional invigoration, often traceable to some favourable combination of conditions, physical and social (as an excur- sion along with intimate friends) in which the mental mani- festations are unusually vivid and abundant. Every thought is clearly and quickly seized; apt expressions come to the mouth without hesitation; illustrations are ready on the instant; long-forgotten anecdotes recur; and out of the flood of ideas, now so broad and swift, there are readily formed those complex combinations of likeness and differ- ence which constitute wit, even by those who ordinarily are not witty.
Clearly these opposite deviations from the mean state, are, like the others, interpretable as caused by relatively low pressure, and relatively high pressure, throughout the nervous system.
§ 258. One other variation of constitutional state, occur- ring daily, presents us with a series of similar effects similarly produced.
The diminution of nervous efflux which, reaching a certain point, shows itself in an increasing quietude, lapsing into sleep, is accompanied by a descending series of psychical activities conforming to the general principle set forth. When drowsiness begins, there is first a failure of the EVIDENCE FRCB1 NORMAL VARIATIONS.
feebler and more complex connexions of ideas, as well as a decreased quantity of ideas. Thought leaves its remoter and less-beaten tracks, and confines its excursions to the more familiar tracks — common-place remarks and allusions take the place of wit and speculation. Gradually becoming limited to a still narrower range, consciousness is by-and-bye made up of little else than those almost automatic interpre- tations of the impressions received from things around which constitute recognitions of them. And at length when the circulation has fallen to the requisite degree, and low tide of the nervous efflux has been reached, even the place and the persons are no longer known.
The dreams that occur during the ensuing sleep present traits of like meaning. For sleep-consciousness, while differing from waking consciousness mainly in being inde- pendent of, and uncorrected by, impressions received through the senses, differs also as the consciousness of the old does from that of the young, or that of the inert from that of the vivacious. Its elements are less coherent and less abundant. An ordinary dream is so faint that it is not recallable unless thought of just after waking; and then only a few of its closing scenes are recallable. Even these are not coherent over any considerable space; but through some accidental associations each new act or occurrence leads off into quite another series of acts and occurrences — there is a perpetual wandering away from what was just before thought or intended. Meanwhile, the narrowing of the area of consciousness is shown in the absence of those multi- tudinous collateral thoughts which the successive scenes are fitted to arouse, and in the consequent acceptance* of these scenes without any sense of their absurdity. To dream of flying and not to suspect any illusion, implies that thought is limited to a narrow train of simple ideas; and tha^ there aro not aroused any remembrances of those antagonistic experiences and of those general conceptions framed on them, which are implied by scepticism and disbelief.
594 PHYSICAL SYNTHESIS.
A verification meets us when we compare tlie dr earns ac- companying quiet circulation of the blood,, with the dreams accompanying excited circulation — either through the system as a whole or through the brain only. For under conditions implying a higher rate of molecular change,, and consequently of nervous discharge, than is usual during sleep, the dreams become both more vivid and more rational. Many acts are performed in succession with a view to some desired end; and the earlier members of the series do not wholly disappear from consciousness as the later arise. At the same time the things done, the means used, the difficulties overcome, are less incongruous with waking experience; because of the greater excursiveness of thought, and the consequent accompaniment of criticism on the main current of ideas.
§ 259. Another class of facts offer a kindred problem which admits of a kindred solution. I refer to the psychical variations that accompany variations not in the state of the organism as a whole but in the states of its different parts.