The principle of direct action of the excited nervous system on the
body, independently of the will and in part of habit—Change of colour
in the hair—Trembling of the muscles—Modified
secretions—Perspiration—Expression of extreme pain—Of rage, great joy,
and terror—Contrast between the emotions which cause and do not cause
expressive movements—Exciting and depressing states of the
mind—Summary.
We now come to our third Principle, namely, that certain actions which
we recognize as expressive of certain states of the mind, are the
direct result of the constitution of the nervous system, and have been
from the first independent of the will, and, to a large extent, of
habit. When the sensorium is strongly excited nerve-force is generated
in excess, and is transmitted in certain directions, dependent on the
connection of the nerve-cells, and, as far as the muscular system is
concerned, on the nature of the movements which have been habitually
practised. Or the supply of nerve-force may, as it appears, be
interrupted. Of course every movement which we make is determined by
the constitution of the nervous system; but actions performed in
obedience to the will, or through habit, or through the principle of
antithesis, are here as far as possible excluded. Our present subject
is very obscure, but, from its importance, must be discussed at some
little length; and it is always advisable to perceive clearly our
ignorance.
The most striking case, though a rare and abnormal one, which can be
adduced of the direct influence of the nervous system, when strongly
affected, on the body, is the loss of colour in the hair, which has
occasionally been observed after extreme terror or grief. One authentic
instance has been recorded, in the case of a man brought out for
execution in India, in which the change of colour was so rapid that it
was perceptible to the eye.[301]
Another good case is that of the trembling of the muscles, which is
common to man and to many, or most, of the lower animals. Trembling is
of no service, often of much disservice, and cannot have been at first
acquired through the will, and then rendered habitual in association
with any emotion. I am assured by an eminent authority that young
children do not tremble, but go into convulsions under the
circumstances which would induce excessive trembling in adults.
Trembling is excited in different individuals in very different degrees
and by the most diversified causes,—by cold to the surface, before
fever-fits, although the temperature of the body is then above the
normal standard; in blood-poisoning, delirium tremens, and other
diseases; by general failure of power in old age; by exhaustion after
excessive fatigue; locally from severe injuries, such as burns; and, in
an especial manner, by the passage of a catheter. Of all emotions, fear
notoriously is the most apt to induce trembling; but so do occasionally
great anger and joy. I remember once seeing a boy who had just shot his
first snipe on the wing, and his hands trembled to such a degree from
delight, that he could not for some time reload his gun; and I have
heard of an exactly similar case with an Australian savage, to whom a
gun had been lent. Fine music, from the vague emotions thus excited,
causes a shiver to run down the backs of some persons. There seems to
be very little in common in the above several physical causes and
emotions to account for trembling; and Sir J. Paget, to whom I am
indebted for several of the above statements, informs me that the
subject is a very obscure one. As trembling is sometimes caused by
rage, long before exhaustion can have set in, and as it sometimes
accompanies great joy, it would appear that any strong excitement of
the nervous system interrupts the steady flow of nerve-force to the
muscles.[302]
The manner in which the secretions of the alimentary canal and of
certain glands—as the liver, kidneys, or mammæ are affected by strong
emotions, is another excellent instance of the direct action of the
sensorium on these organs, independently of the will or of any
serviceable associated habit. There is the greatest difference in
different persons in the parts which are thus affected, and in the
degree of their affection.
The heart, which goes on uninterruptedly beating night and day in so
wonderful a manner, is extremely sensitive to external stimulants. The
great physiologist, Claude Bernard,[303] has shown how the least
excitement of a sensitive nerve reacts on the heart; even when a nerve
is touched so slightly that no pain can possibly be felt by the animal
under experiment. Hence when the mind is strongly excited, we might
expect that it would instantly affect in a direct manner the heart; and
this is universally acknowledged and felt to be the case. Claude
Bernard also repeatedly insists, and this deserves especial notice,
that when the heart is affected it reacts on the brain; and the state
of the brain again reacts through the pneumo-gastric nerve on the
heart; so that under any excitement there will be much mutual action
and reaction between these, the two most important organs of the body.
The vaso-motor system, which regulates the diameter of the small
arteries, is directly acted on by the sensorium, as we see when a man
blushes from shame; but in this latter case the checked transmission of
nerve-force to the vessels of the face can, I think, be partly
explained in a curious manner through habit. We shall also be able to
throw some light, though very little, on the involuntary erection of
the hair under the emotions of terror and rage. The secretion of tears
depends, no doubt, on the connection of certain nerve-cells; but here
again we can trace some few of the steps by which the flow of
nerve-force through the requisite channels has become habitual under
certain emotions.
A brief consideration of the outward signs of some of the stronger
sensations and emotions will best serve to show us, although vaguely,
in how complex a manner the principle under consideration of the direct
action of the excited nervous system of the body, is combined with the
principle of habitually associated, serviceable movements.
When animals suffer from an agony of pain, they generally writhe about
with frightful contortions; and those which habitually use their voices
utter piercing cries or groans. Almost every muscle of the body is
brought into strong action. With man the mouth may be closely
compressed, or more commonly the lips are retracted, with the teeth
clenched or ground together. There is said to be “gnashing of teeth” in
hell; and I have plainly heard the grinding of the molar teeth of a cow
which was suffering acutely from inflammation of the bowels. The female
hippopotamus in the Zoological Gardens, when she produced her young,
suffered greatly; she incessantly walked about, or rolled on her sides,
opening and closing her jaws, and clattering her teeth together.[304]
With man the eyes stare wildly as in horrified astonishment, or the
brows are heavily contracted. Perspiration bathes the body, and drops
trickle down the face. The circulation and respiration are much
affected. Hence the nostrils are generally dilated and often quiver; or
the breath may be held until the blood stagnates in the purple face. If
the agony be severe and prolonged, these signs all change; utter
prostration follows, with fainting or convulsions.
A sensitive nerve when irritated transmits some influence to the
nerve-cell, whence it proceeds; and this transmits its influence, first
to the corresponding nerve-cell on the opposite side of the body, and
then upwards and downwards along the cerebro-spinal column to other
nerve-cells, to a greater or less extent, according to the strength of
the excitement; so that, ultimately, the whole nervous system maybe
affected.[305] This involuntary transmission of nerve-force may or may
not be accompanied by consciousness. Why the irritation of a nerve-cell
should generate or liberate nerve-force is not known; but that this is
the case seems to be the conclusion arrived at by all the greatest
physiologists, such as Müller, Virchow, Bernard, &c.[306] As Mr.
Herbert Spencer remarks, it may be received as an “unquestionable truth
that, at any moment, the existing quantity of liberated nerve-force,
which in an inscrutable way produces in us the state we call feeling,
MUST expend itself in some direction—MUST generate an equivalent
manifestation of force somewhere;” so that, when the cerebro-spinal
system is highly excited and nerve-force is liberated in excess, it may
be expended in intense sensations, active thought, violent movements,
or increased activity of the glands.[307] Mr. Spencer further maintains
that an “overflow of nerve-force, undirected by any motive, will
manifestly take the most habitual routes; and, if these do not suffice,
will next overflow into the less habitual ones.” Consequently the
facial and respiratory muscles, which are the most used, will be apt to
be first brought into action; then those of the upper extremities, next
those of the lower, and finally those of the whole body.[308]
An emotion may be very strong, but it will have little tendency to
induce movements of any kind, if it has not commonly led to voluntary
action for its relief or gratification; and when movements are excited,
their nature is, to a large extent, determined by those which have
often and voluntarily been performed for some definite end under the
same emotion. Great pain urges all animals, and has urged them during
endless generations, to make the most violent and diversified efforts
to escape from the cause of suffering. Even when a limb or other
separate part of the body is hurt, we often see a tendency to shake it,
as if to shake off the cause, though this may obviously be impossible.
Thus a habit of exerting with the utmost force all the muscles will
have been established, whenever great suffering is experienced. As the
muscles of the chest and vocal organs are habitually used, these will
be particularly liable to be acted on, and loud, harsh screams or cries
will be uttered. But the advantage derived from outcries has here
probably come into play in an important manner; for the young of most
animals, when in distress or danger, call loudly to their parents for
aid, as do the members of the same community for mutual aid.
Another principle, namely, the internal consciousness that the power or
capacity of the nervous system is limited, will have strengthened,
though in a subordinate degree, the tendency to violent action under
extreme suffering. A man cannot think deeply and exert his utmost
muscular force. As Hippocrates long ago observed, if two pains are felt
at the same time, the severer one dulls the other. Martyrs, in the
ecstasy of their religious fervour have often, as it would appear, been
insensible to the most horrid tortures. Sailors who are going to be
flogged sometimes take a piece of lead into their mouths, in order to
bite it with their utmost force, and thus to bear the pain. Parturient
women prepare to exert their muscles to the utmost in order to relieve
their sufferings.
We thus see that the undirected radiation of nerve-force from the
nerve-cells which are first affected—the long-continued habit of
attempting by struggling to escape from the cause of suffering—and the
consciousness that voluntary muscular exertion relieves pain, have all
probably concurred in giving a tendency to the most violent, almost
convulsive, movements under extreme suffering; and such movements,
including those of the vocal organs, are universally recognized as
highly expressive of this condition.
As the mere touching of a sensitive nerve reacts in a direct manner on
the heart, severe pain will obviously react on it in like manner, but
far more energetically. Nevertheless, even in this case, we must not
overlook the indirect effects of habit on the heart, as we shall see
when we consider the signs of rage.
When a man suffers from an agony of pain, the perspiration often
trickles down his face; and I have been assured by a veterinary surgeon
that he has frequently seen drops falling from the belly and running
down the inside of the thighs of horses, and from the bodies of cattle,
when thus suffering. He has observed this, when there has been no
struggling which would account for the perspiration. The whole body of
the female hippopotamus, before alluded to, was covered with
red-coloured perspiration whilst giving birth to her young. So it is
with extreme fear; the same veterinary has often seen horses sweating
from this cause; as has Mr. Bartlett with the rhinoceros; and with man
it is a well-known symptom. The cause of perspiration bursting forth in
these cases is quite obscure; but it is thought by some physiologists
to be connected with the failing power of the capillary circulation;
and we know that the vasomotor system, which regulates the capillary
circulation, is much influenced by the mind. With respect to the
movements of certain muscles of the face under great suffering, as well
as from other emotions, these will be best considered when we treat of
the special expressions of man and of the lower animals.
We will now turn to the characteristic symptoms of Rage. Under this
powerful emotion the action of the heart is much accelerated,[309] or
it may be much disturbed. The face reddens, or it becomes purple from
the impeded return of the blood, or may turn deadly pale. The
respiration is laboured, the chest heaves, and the dilated nostrils
quiver. The whole body often trembles. The voice is affected. The teeth
are clenched or ground together, and the muscular system is commonly
stimulated to violent, almost frantic action. But the gestures of a man
in this state usually differ from the purposeless writhings and
struggles of one suffering from an agony of pain; for they represent
more or less plainly the act of striking or fighting with an enemy.
All these signs of rage are probably in large part, and some of them
appear to be wholly, due to the direct action of the excited sensorium.
But animals of all kinds, and their progenitors before them, when
attacked or threatened by an enemy, have exerted their utmost powers in
fighting and in defending themselves. Unless an animal does thus act,
or has the intention, or at least the desire, to attack its enemy, it
cannot properly be said to be enraged. An inherited habit of muscular
exertion will thus have been gained in association with rage; and this
will directly or indirectly affect various organs, in nearly the same
manner as does great bodily suffering.
The heart no doubt will likewise be affected in a direct manner; but it
will also in all probability be affected through habit; and all the
more so from not being under the control of the will. We know that any
great exertion which we voluntarily make, affects the heart, through
mechanical and other principles which need not here be considered; and
it was shown in the first chapter that nerve-force flows readily
through habitually used channels,—through the nerves of voluntary or
involuntary movement, and through those of sensation. Thus even a
moderate amount of exertion will tend to act on the heart; and on the
principle of association, of which so many instances have been given,
we may feel nearly sure that any sensation or emotion, as great pain or
rage, which has habitually led to much muscular action, will
immediately influence the flow of nerve-force to the heart, although
there may not be at the time any muscular exertion.
The heart, as I have said, will be all the more readily affected
through habitual associations, as it is not under the control of the
will. A man when moderately angry, or even when enraged, may command
the movements of his body, but he cannot prevent his heart from beating
rapidly. His chest will perhaps give a few heaves, and his nostrils
just quiver, for the movements of respiration are only in part
voluntary. In like manner those muscles of the face which are least
obedient to the will, will sometimes alone betray a slight and passing
emotion. The glands again are wholly independent of the will, and a man
suffering from grief may command his features, but cannot always
prevent the tears from coming into his eyes. A hungry man, if tempting
food is placed before him, may not show his hunger by any outward
gesture, but he cannot check the secretion of saliva.
Under a transport of Joy or of vivid Pleasure, there is a strong
tendency to various purposeless movements, and to the utterance of
various sounds. We see this in our young children, in their loud
laughter, clapping of hands, and jumping for joy; in the bounding and
barking of a dog when going out to walk with his master; and in the
frisking of a horse when turned out into an open field. Joy quickens
the circulation, and this stimulates the brain, which again reacts on
the whole body. The above purposeless movements and increased
heart-action may be attributed in chief part to the excited state of
the sensorium,[310] and to the consequent undirected overflow, as Mr.
Herbert Spencer insists, of nerve-force. It deserves notice, that it is
chiefly the anticipation of a pleasure, and not its actual enjoyment,
which leads to purposeless and extravagant movements of the body, and
to the utterance of various sounds. We see this in our children when
they expect any great pleasure or treat; and dogs, which have been
bounding about at the sight of a plate of food, when they get it do not
show their delight by any outward sign, not even by wagging their
tails. Now with animals of all kinds, the acquirement of almost all
their pleasures, with the exception of those of warmth and rest, are
associated, and have long been associated with active movements, as in
the hunting or search for food, and in their courtship. Moreover, the
mere exertion of the muscles after long rest or confinement is in
itself a pleasure, as we ourselves feel, and as we see in the play of
young animals. Therefore on this latter principle alone we might
perhaps expect, that vivid pleasure would be apt to show itself
conversely in muscular movements.
With all or almost all animals, even with birds, Terror causes the body
to tremble. The skin becomes pale, sweat breaks out, and the hair
bristles. The secretions of the alimentary canal and of the kidneys are
increased, and they are involuntarily voided, owing to the relaxation
of the sphincter muscles, as is known to be the case with man, and as I
have seen with cattle, dogs, cats, and monkeys. The breathing is
hurried. The heart beats quickly, wildly, and violently; but whether it
pumps the blood more efficiently through the body may be doubted, for
the surface seems bloodless and the strength of the muscles soon fails.
In a frightened horse I have felt through the saddle the beating of the
heart so plainly that I could have counted the beats. The mental
faculties are much disturbed. Utter prostration soon follows, and even
fainting. A terrified canary-bird has been seen not only to tremble and
to turn white about the base of the bill, but to faint;[311] and I once
caught a robin in a room, which fainted so completely, that for a time
I thought it dead.
Most of these symptoms are probably the direct result, independently of
habit, of the disturbed state of the sensorium; but it is doubtful
whether they ought to be wholly thus accounted for. When an animal is
alarmed it almost always stands motionless for a moment, in order to
collect its senses and to ascertain the source of danger, and sometimes
for the sake of escaping detection. But headlong flight soon follows,
with no husbanding of the strength as in fighting, and the animal
continues to fly as long as the danger lasts, until utter prostration,
with failing respiration and circulation, with all the muscles
quivering and profuse sweating, renders further flight impossible.
Hence it does not seem improbable that the principle of associated
habit may in part account for, or at least augment, some of the
above-named characteristic symptoms of extreme terror.
That the principle of associated habit has played an important part in
causing the movements expressive of the foregoing several strong
emotions and sensations, we may, I think, conclude from considering
firstly, some other strong emotions which do not ordinarily require for
their relief or gratification any voluntary movement; and secondly the
contrast in nature between the so-called exciting and depressing states
of the mind. No emotion is stronger than maternal love; but a mother
may feel the deepest love for her helpless infant, and yet not show it
by any outward sign; or only by slight caressing movements, with a
gentle smile and tender eyes. But let any one intentionally injure her
infant, and see what a change! how she starts up with threatening
aspect, how her eyes sparkle and her face reddens, how her bosom
heaves, nostrils dilate, and heart beats; for anger, and not maternal
love, has habitually led to action. The love between the opposite sexes
is widely different from maternal love; and when lovers meet, we know
that their hearts beat quickly, their breathing is hurried, and their
faces flush; for this love is not inactive like that of a mother for
her infant.
A man may have his mind filled with the blackest hatred or suspicion,
or be corroded with envy or jealousy, but as these feelings do not at
once lead to action, and as they commonly last for some time, they are
not shown by any outward sign, excepting that a man in this state
assuredly does not appear cheerful or good-tempered. If indeed these
feelings break out into overt acts, rage takes their place, and will be
plainly exhibited. Painters can hardly portray suspicion, jealousy,
envy, &c., except by the aid of accessories which tell the tale; and
poets use such vague and fanciful expressions as “green-eyed jealousy.”
Spenser describes suspicion as “Foul, ill-favoured, and grim, under his
eyebrows looking still askance,” &c.; Shakespeare speaks of envy “as
lean-faced in her loathsome case;” and in another place he says, “no
black envy shall make my grave;” and again as “above pale envy’s
threatening reach.”
Emotions and sensations have often been classed as exciting or
depressing. When all the organs of the body and mind,—those of
voluntary and involuntary movement, of perception, sensation, thought,
&c.,—perform their functions more energetically and rapidly than usual,
a man or animal may be said to be excited, and, under an opposite
state, to be depressed. Anger and joy are from the first exciting
emotions, and they naturally lead, more especially the former, to
energetic movements, which react on the heart and this again on the
brain. A physician once remarked to me as a proof of the exciting
nature of anger, that a man when excessively jaded will sometimes
invent imaginary offences and put himself into a passion, unconsciously
for the sake of reinvigorating himself; and since hearing this remark,
I have occasionally recognized its full truth.
Several other states of mind appear to be at first exciting, but soon
become depressing to an extreme degree. When a mother suddenly loses
her child, sometimes she is frantic with grief, and must be considered
to be in an excited state; she walks wildly about, tears her hair or
clothes, and wrings her hands. This latter action is perhaps due to the
principle of antithesis, betraying an inward sense of helplessness and
that nothing can be done. The other wild and violent movements may be
in part explained by the relief experienced through muscular exertion,
and in part by the undirected overflow of nerve-force from the excited
sensorium. But under the sudden loss of a beloved person, one of the
first and commonest thoughts which occurs, is that something more might
have been done to save the lost one. An excellent observer,[312] in
describing the behaviour of a girl at the sudden death of her father,
says she “went about the house wringing her hands like a creature
demented, saying ‘It was her fault;’ ‘I should never have left him;’
‘If I had only sat up with him,’” &c. With such ideas vividly present
before the mind, there would arise, through the principle of associated
habit, the strongest tendency to energetic action of some kind.
As soon as the sufferer is fully conscious that nothing can be done,
despair or deep sorrow takes the place of frantic grief. The sufferer
sits motionless, or gently rocks to and fro; the circulation becomes
languid; respiration is almost forgotten, and deep sighs are drawn. All
this reacts on the brain, and prostration soon follows with collapsed
muscles and dulled eyes. As associated habit no longer prompts the
sufferer to action, he is urged by his friends to voluntary exertion,
and not to give way to silent, motionless grief. Exertion stimulates
the hear, and this reacts on the brain, and aids the mind to bear its
heavy load.
Pain, if severe, soon induces extreme depression or prostration; but it
is at first a stimulant and excites to action, as we see when we whip a
horse, and as is shown by the horrid tortures inflicted in foreign
lands on exhausted dray-bullocks, to rouse them to renewed exertion.
Fear again is the most depressing of all the emotions; and it soon
induces utter, helpless prostration, as if in consequence of, or in
association with, the most violent and prolonged attempts to escape
from the danger, though no such attempts have actually been made.
Nevertheless, even extreme fear often acts at first as a powerful
stimulant. A man or animal driven through terror to desperation, is
endowed with wonderful strength, and is notoriously dangerous in the
highest degree.
On the whole we may conclude that the principle of the direct action of
the sensorium on the body, due to the constitution of the nervous
system, and from the first independent of the will, has been highly
influential in determining many expressions. Good instances are
afforded by the trembling of the muscles, the sweating of the skin, the
modified secretions of the alimentary canal and glands, under various
emotions and sensations. But actions of this kind are often combined
with others, which follow from our first principle, namely, that
actions which have often been of direct or indirect service, under
certain states of the mind, in order to gratify or relieve certain
sensations, desires, &c., are still performed under analogous
circumstances through mere habit although of no service. We have
combinations of this kind, at least in part, in the frantic gestures of
rage and in the writhings of extreme pain; and, perhaps, in the
increased action of the heart and of the respiratory organs. Even when
these and other emotions or sensations are aroused in a very feeble
manner, there will still be a tendency to similar actions, owing to the
force of long-associated habit; and those actions which are least under
voluntary control will generally be longest retained. Our second
principle of antithesis has likewise occasionally come into play.
Finally, so many expressive movements can be explained, as I trust will
be seen in the course of this volume, through the three principles
which have now been discussed, that we may hope hereafter to see all
thus explained, or by closely analogous principles. It is, however,
often impossible to decide how much weight ought to be attributed, in
each particular case, to one of our principles, and how much to
another; and very many points in the theory of Expression remain
inexplicable.