Amongst the many sagacious sayings of the patient and profound thinkers
of Germany, not the least noteworthy was Schelling’s affirmation
that the phenomena of instinct are some of the most important of all
phenomena, and capable of serving as a very touch-stone whereby the
value of competing theories of the universe may be effectually tested.
His prescience has been justified by our experience. The greatest
scientific event of the present time is the wide acceptance of the
theory of evolution, and its use as a weapon of offence and defence.
It is used both against the belief that intelligent purpose is, as it
were, incarnate in the living world about us, and also in favor of
a merely mechanical theory of nature. Now it would be difficult to
find a more searching test of that theory’s truth than is supplied
by a careful study of instinct. The essence of that view of nature
which is associated with the name of Professor Haeckel,[1] a negation
of the doctrine of final causes and an assertion of what he calls
“Dysteleology,” that is, the doctrine of the purposelessness of the
organs and organisms which people a purposeless planet. That doctrine
may be called the gospel of the irrationality of the universe, and it
is a doctrine to which a proof of the real existence of such a thing
as “instinct” must necessarily be fatal. Instinct has been defined[2]
as a “special internal impulse, urging animals to the performance of
certain actions which are useful to them or to their kind, but the
use of which they do not themselves perceive, and their performance
of which is a necessary consequence of their being placed in certain
circumstances.” Such an impulse is always understood to be the result
of sensations: actions which take place in response to _unfelt_
stimuli being referred, not to instinct, but to what is termed _reflex
action_. In such action it is commonly supposed that the mechanism of
a living body occasions a prompt responsive muscular movement upon
the occurrence of some unfelt stimulation of the nervous system. The
nervous system, or total mass of nerve-stuff—which is technically
called “nerve-tissue”—in the body of an animal, such as a beast, bird,
reptile, or fish, is composed of two parts or divisions. One of these
divisions consists of a voluminous and continuous mass—the brain and
spinal cord (or spinal marrow), which form what is called the central
part of the nervous system. The second division consists of a multitude
of white threads or cords—the nerves, which form what is called the
peripheral part of the nervous system. Of these nerves one set proceed
forth from the central part of the nervous system to the different
muscles, which they can cause to contract by a peculiar action they
exert upon them, thus producing motion. Another set of nerves proceed
inwards, from the skin to the central part of the nervous system, and
by their peculiar action give rise to various sensations, according as
different influences or stimulations are brought to bear upon the skin
at, or in the vicinity of, their peripheral extremities. Under ordinary
circumstances, different stimulations of the surface of the body convey
an influence inwards, which produces sensation, and give rise to an
outwardly proceeding influence to the muscles, resulting in definite
and appropriate motions.
[1] It is often associated unfairly with the illustrious name of
the late Mr. Darwin. His special views lend themselves indeed to
Haeckelianism, and have been pressed into its service; yet they are by
no means to be identified therewith. As Professor Huxley has pointed
out with his usual lucidity and force, Darwin’s theory can be made to
accord with the most thoroughgoing teleology.
[2] See Todd’s _Cyclopædia of Anatomy and Physiology_, vol. iii. p. 3.
There are cases in which responsive actions take place under very
abnormal conditions—as after a rupture of part of a man’s spinal
cord, or the removal of the whole brain in lower animals, such as the
frog. A man so injured may have utterly lost the power of feeling
any stimulation—pricking, cutting, or burning—of his legs and feet,
the injury preventing the conveyance upwards to the brain of the
influence necessary to ordinary sensation, and stopping short at the
spinal cord below the point of injury. Nevertheless, such a man may
execute movements in response to stimuli just as if he did feel, and
often in an exaggerated manner. He will withdraw his foot if tickled
with a feather just as if he felt the tickling, which he is utterly
incapable of feeling. Similarly a decapitated frog will make with his
hind legs the most appropriate movements to remove any irritating
object applied to the hinder part of its body. Such action is termed
“reflex action,” on the supposition that the influence conveyed inwards
by nerves going from the skin to the spinal cord is reflected back
from that cord to the muscles by the other set of nerves without any
intervention of sensation. This action of the frog may be carried to
a very singular extreme. At the breeding season the male frog tightly
grasps the female behind her arms, and to enable him the more securely
to maintain his hold, a warty prominence is then developed on the inner
side of each of his hands. Now if such a male frog be taken, and not
only decapitated, but the whole hinder part of the body removed also,
so that nothing remains but the fragment of the trunk from which the
two arms with their nerves proceed, and if under these circumstances
the warty prominences be touched, the two arms will immediately
close together like a spring, thus affording a most perfect example
of reflex action. It has been objected by the late Mr. G. H. Lewes
and others that we cannot be sure but that the spinal cord itself
“feels.” But there is often an ambiguity in the use of the term “to
feel.” By it we ordinarily mean a “modification of consciousness;” but
experiences such as those just adverted to, and others in ourselves to
which I shall next advert, show clearly that surrounding agents may
act upon our sense organs without the intervention of anything like
consciousness, and yet produce effects otherwise similar to those which
occur when they do arouse consciousness. Without, then, entering into
any discussion as to whether “sentiency” may or may not be attributed
to the spinal cord, it seems evident that some definite term is
required to denote such affections or modifications of living beings as
those just referred to. Inasmuch as they are affections of creatures
possessing a nervous system, which is the essential organ of sensation,
and as they resemble sensation in their causes and effects though
feeling itself may be absent, they may be provisionally distinguished
as “unfelt sensations.” Such are some of the actions with which
instinct is contrasted, because, unlike instinct, they are not carried
on by the aid of felt sensations, the highest of such insentient action
being reflex action.
There are also a number of actions which constantly recur in
ourselves, which more or less nearly approximate to reflex action.
Thus the respiratory movements, the various muscular motions by the
aid of which we breathe, are ordinarily performed by us without
advertence, though we can, if we will, perform them with self-conscious
deliberation. It is well also to note that when our mind is entirely
directed upon some external object, or when we are almost in a
state of somnolent unconsciousness, we have but a vague feeling of
our existence—a feeling resulting from the unobserved synthesis
of our sensations of all orders and degrees. This unintellectual
sense of “self” may be conveniently distinguished from intellectual
consciousness as “consentience.” We may also, as everybody knows,
suddenly recollect sights or sounds which were quite unnoticed at the
time we experienced them; yet our very recollection of them proves
that they must, nevertheless, have affected our sensorium. Such
unnoticed modifications of our sense organs may also be provisionally
included in the category of those actions of the lower animals, before
provisionally denominated “unfelt sensations.” It is not, however, with
such inferior activities as reflex and other insentient actions that
instinct is commonly contrasted, but with “reason.” Now “reasonable,”
“consciously intelligent”conduct is understood by all men to mean
conduct in which there is a more or less wise adaptation of means to
ends—a conscious, deliberate adaptation, not one due to accident only.
No one would call an act done blindly a reasonable or intelligent
action on the part of him who did it, however fortunate might be its
result. Instinctive actions, then, hold a middle place between (1)
those which are rational, or truly intelligent, and (2) those in which
sensation has no place. But a great variety of actions of different
kinds occupy this intermediate position, and we must next proceed to
separate off from the others, such actions as may be deemed _truly_
instinctive.
M. Albert Lemoine, who has written the best treatise[3] known to us on
instinct and habit, distinguishes instinctive actions as those which
are neither due to mechanical or chemical causes, nor to intelligence,
experience, or will. They are actions which take place with a general
fixity and precision, are generally present in all the individuals of
each species, and can be perfectly performed the very first time their
action is called for, so that they cannot be due to habit. Instinct, he
very truly says, is more than a want and less than a desire. Instinct
is a certain felt internal stimulus to definite actions which has its
foundation in a certain sense of want, but is not definite feeling of
want of the particular end to be attained. Were that recognised, it
would not be _instinct_, but _desire_. It is but a vague craving to
exercise certain activities the exercise of which conduces to useful
or needful, but unforeseen, end. Instinct often sets in motion organs
quite different from those which feel the prick of want, and which
do not (experience apart) seem to have relation with it. Hunger does
not stimulate to action the organs of digestion which suffer from it,
but excites the limbs and jaws to perform acts by which food may be
obtained and eaten. In examining into instinct, we must be careful not
to omit the consideration of it as it exists in man, since we can know
no creature so well as we can, by the help of language and reflection,
know ourselves and our own species. Nevertheless, it may be well to
begin by calling attention to certain apparently undeniable cases of
instinct in other animals, since in them instinct is much more apparent
and complex than in man, in whom it is indeed reduced to a minimum.
It might naturally be expected to be so reduced in him—if it is a
power serving to bridge over the gulf which exists between such almost
mechanical action as reflex action, and true intelligence—since in
man acts of intelligence, or habits originated through intelligence,
come so constantly into play. But before enumerating cases of animal
instinct, a word should be said as to one character which M. Lemoine
attributes to instinctive action, namely, “consciousness,” This term
is an exceedingly ambiguous one, as it is often referred, not only
to our distinct intellectual perception of our own being and acts,
but also to every state of feeling however rudimentary it may be. I
would therefore avoid the use of so equivocal a term, while fully
admitting that no sensation in any animal is possible without some
subjective psychical state analogous to what I have before denominated
“consentience.” Now, as to the lower animals: birds unquestionably
possess instinctive powers. Chickens, two minutes after they have left
the egg,[4] will follow with their eyes the movements of crawling
insects, and peck at them, judging distance and direction with almost
infallible accuracy. They will instinctively appreciate sounds, readily
running towards an invisible hen hidden in a box, when they hear her
“call.” Some young birds, also, have an innate, instinctive horror of
the sight of a hawk and of the sound of its voice. Swallows, titmice,
tomtits, and wrens, after having been confined from birth, are capable
of flying successfully at once, when liberated, on their wings having
attained the necessary growth to render flight possible. The Duke of
Argyll[5] relates some very interesting particulars about the instincts
of birds, especially of the water ousel, the merganser, and the wild
duck. Even as to the class of beasts I find recorded:[6] “Five young
polecats were found comfortably embedded in dry withered grass; and
in a side hole, of proper dimensions for such a larder, were forty
frogs and two toads, all alive, but merely capable of sprawling a
little. On examination the whole number, toads and all, proved to have
been purposely and dexterously bitten through the brain.” Evidently
the parent polecat had thus provided the young with food which could
be kept perfectly fresh, because alive, and yet was rendered quite
unable to escape. This singular instinct is like others which are yet
more fully developed amongst insects—a class of animals the instincts
of which are so numerous, wonderful, and notorious that it will be,
probably, enough to refer to one or two examples. The female carpenter
bee, in order to protect her eggs, excavates, in some piece of wood,
a series of chambers, in special order with a view to a peculiar mode
of exit for her young: but the young mother can have no conscious
knowledge of the series of actions subsequently to ensue. The female
of the wasp, _sphex_, affords another well-known but very remarkable
example of a complex instinct closely related to that already mentioned
in the case of the polecat. The female wasp has to provide fresh,
living animal food for her progeny, which, when it quits its egg,
quits it in the form of an almost helpless grub, utterly unable to
catch, retain, or kill an active, struggling prey. Accordingly the
mother insect has only to provide and place beside her eggs suitable
living prey, but so to treat it that it may be a helpless, unresisting
victim. That victim may be a mere caterpillar, or it may be a great,
powerful grasshopper, or even that most fierce, active, and rapacious
of insect tyrants, a fell and venomous spider. Whichever it may be, the
wasp adroitly stings it at the spot which induces, or in the several
spots which induce, complete paralysis as to motion, let us hope as to
sensation also. This done, the wasp entombs the helpless being with
its own egg, and leaves it for the support of the future grub. Another
species feeds her young one from time to time with fresh food, visiting
at suitable intervals the nest she has made and carefully covered
and concealed with earth, which she removes and replaces, as far as
necessary, at each visit. If the opening be made ready for her, this,
instead of helping her to get at her young, altogether puzzles her, and
she no longer seems to recognise her young, thus showing how thoroughly
“instinctive” her proceedings are. Other instances of instinct, such as
those of the stag-beetle and emperor moth, I will refer to presently.
But most wonderful, perhaps, of all are the instincts of social
insects, such as bees, where there are not only males and females, but
a large population of practically neuter insects, the special instincts
and peculiarities of which have of course to be transmitted, not
directly by an antecedent set of neuter animals, but by females, the
instincts and peculiarities of which are very different from those of
the neutral portion of their progeny.
[3] _L’Habitude et l’Instinct._ Baillière. Paris. 1875.
[4] As Mr. Spalding has shown. To him I am indebted for the other
facts about young birds given in the text.
[5] _The Unity of Nature_, chap. iii.
[6] See _Magazine of Natural History_, vol. iv. p. 206.
The instincts we have hitherto noticed, and, I may say briefly, the
instincts of animals generally, are destined to subserve two functions,
(1) the preservation and, mainly, the nutrition, of the individual,
and (2) the reproduction of the species. Armed with the facts we have
now noticed, let us turn to consider instinct as it displays itself in
ourselves. As one example, there is the instinct action by which an
infant first sucks the nipple, and then swallows the thence-extracted
nourishment with which its mouth is filled. This action must be
reckoned as instinctive, because it is done directly after birth, when
there has been no time for learning to perform the action; it is one
absolutely necessary for the life of the infant; it is an action which
is definite and precise, similarly performed by all the individuals
of the species, though effected by a very complex mechanism, and is
effected prior to experience. Yet it is not as mechanical as reflex
action, for not only sensation, but consentience, accompanies the act.
Thus sucking in man is an instinctive action, while spitting, on the
other hand, is an art. The latter is not necessary to life, and the
power of performing it is slowly acquired by experience, as are also
our powers of walking and feeding ourselves. But the action of sucking
in an adult human being is of course not instinctive; and because the
child learns to walk, it by no means follows that the insect learns to
fly. It is thus plain that actions may be instinctive in one animal and
not in another; or at one period of life in the same animal and not
at another. In a child, however, sucking, deglutition, inspiration,
and expiration are instinctive actions, as are also those by which
the products of excretion are removed from the body. The second class
of instincts, those which ensure the continuance of the race, show
themselves of course, only much later. Yet, long before the little girl
can represent to herself future tributes to her charms, she seeks to
decorate her tiny body with the arts of infant coquetry. Still less
does she look forward to the pains and pleasures of maternity when she
begins to caress and chastise, to soothe and cherish, her first doll,
and fondly presses it to that region whence her future offspring will
draw its nourishment. Again, when the lapse of a few years having made
her a young woman and the boy a youth, they first feel the influence
of love, however ignorant they may be of the physiology of their
race, they will none the less, circumstances permitting, be surely
impelled towards the performance of very definite actions. In the more
refined individuals of the highest races of mankind, the material,
merely animal, consummation of sexual love is most certainly far from
being the one great end distinctly looked forward to by each pair of
lovers. Yet every incident of affectionate intercourse, every tender
glance, every contact of hand or lip, infallibly leads on towards the
one useful end, indispensable to the race, which nature has in view.
Such actions fully merit to be called “instinctive.” Indeed the act of
generation is ministered to in nature by the most manifold, imperious,
general, and inexplicable of all the instincts, and its instinctive
character is the most strongly marked of all. It has emphatically for
its origin a rigorously determined and precise want, partly painful,
partly pleasurable—a mixture of a feeling of privation with a sense of
power. Its end is unknown to the agent, or if known is disregarded, and
in almost all animals it demands the concurrent and reciprocal action
of two diverse organisms. If anyone would deny that it is instinctive
in man, I would advise him to study the sad phenomena connected
therewith which may be observed in our asylums for the insane.
There are other human actions which are sometimes reckoned as
instinctive, such as guarding the eye against injury by suddenly
closing the eyelids. This action, however, appears to be an acquired
art, though the habitual act of winking to keep clean the surface of
the eye may be instinctive. Some other actions, however, not generally
regarded as instinctive, I should be disposed so to regard. Such
are the first _active_ exercises of the senses of seeing, hearing,
smelling, tasting, and feeling (the first “looking,” the first
“listening,” etc.) which the child performs at the very beginning of
its learning to perform them. It would seem, then, as if no one could
deny the existence of such a thing as instinct, and yet it has been
denied, not only in recent times, but centuries ago. Thus Montaigne
sought to explain instinct as but a form of intelligence, while
Descartes taught that it was but mechanism. Condillac regarded it as
the result of individual experience, and Lemarck considered it to be
merely “habit” which had become hereditary. In our own day Darwin has
sought to explain it as partly the result of accidental variations
of activity, which variations have become naturally selected, and
partly the result of intelligent, purposive action which has become
habitual and inherited. Let us consider these attempts at explanation
seriatim. First as to mechanism: This is an hypothesis no one at
present entertains, as everyone now credits animals with sensitivity.
Moreover, instincts are not absolutely invariable, but are modifiable
according to the degree of “intelligence” which animals possess. They
cannot, therefore, be due merely to a mechanism. The attempt to explain
“Instinct” by mere “reflex action” is equivalent to an attempt to
explain a phenomenon by omitting its most striking characteristic. In
“reflex action” we have a sudden response to a stimulus, which response
is more or less purposive as regards the time of its occurrence, but
has no reference to future events to occur long after the faintest
waves of the stimulating action have died out. The very essence of
“instinct,” however, _is_ to provide for a more or less distant future,
often, as we have seen, the future of another generation. It is
essentially _telic_, and directed to a future unforeseen, but generally
useful, end. This explanation, then, is fundamentally and necessarily
inadequate. It is like an explanation of the building of a house, by
“bricks, mortar, bricklayers, and hodmen,” with the omission of all
reference to any influence governing their motions and directing them
towards a common and predetermined end which is not theirs. But though
we cannot _explain_ “instinct” by “reflex action,” there is none the
less a certain obvious affinity between these two forms of animal
activity, and it is in part my object to point out the nature of this
very affinity.
Next we may pass in review the two hypotheses that instinct is but
(1) a form of intelligence, or (2) individual experience. As to the
first, I have already given instances of unquestionably instinctive
actions performed by birds as soon as they quit the eggshell, and it
would be but waste of time to argue against the view that the human
infant is guided by intelligent purpose and conscious foresight in
his very first acts of sucking, swallowing, and defecation. Actual
intelligence, therefore, is a radically insufficient explanation,
as also, for the very same reasons, is Condillac’s hypothesis as to
individual experience. About “lapsed intelligence” I will speak later
on. Lemarck’s hypothesis, that instinct is but inherited habit, is
one which is much more worthy of careful consideration than any we
have yet considered. For it may be admitted at once that habits may
be inherited. There are many instances of such inheritance in human
beings, and as regards the lower animals, the barking of dogs may be
taken as an instance of a habit thus perpetuated. In fact “habit,” when
inherited, so simulates instinct, that their confusion is far from
surprising. There is, however, this radical difference between them:
“habit” enables an agent to repeat with facility and precision an act
which has been done before, but “instinct” determines with precision
the first performance of such act. Referring instinct to habit, but
temporarily relieves the difficulty of those who object to instinct,
by putting it a step back. It is impossible to believe that any of the
progenitors of an infant of to-day first acquired, during his or her
lifetime, the habit of sucking, or that the habits of neuter insects
thus arose. But after all, if we _could_ explain “instinct” by “habit,”
should we thereby make the phenomena less mysterious? “Habit” is due
to an internal spontaneity of living things. A living thing no doubt
requires some internal solicitation, in order that it should move, but
when it does move that movement is _its own_. All living organisms tend
to act. With them action is not only their nature, ’tis a want; and,
within limits, their powers and energies increase with action, and
diminish and finally perish through repose. The power of generating any
“habits,” lies in the very first act of the kind an organism performs,
and it is only the first act which owes nothing to habit. If such were
not the case, an act might be performed a thousand times and yet not
generate habit. It is this mysterious internal active tendency which
distinguishes all living organisms from inorganic bodies. The latter
tend simply to persist as they are, and have no relations with the
past or the future. They have, therefore, no relations with time at
all—for the actual present ever evades us. Organisms, on the other
hand, which are permanently more or less changed, through habit, by
every new motion and sensation, have their future prepared by their
past, and thus, as it were, at every present moment they live both
in the past and in the future, a mode of existence which attains its
fullest development in the highest living organism—man, the creature
looking before and after! Thus those who would do away with mystery in
nature would gain little by explaining instinct through habit, though,
as we have seen, the phenomena presented to us by the human infant and
by neuter insects absolutely bar any such explanation. Moreover, the
attempt to explain “instinct” through “inheritance” is a contradiction,
since “inheritance” supposes something already obtained, otherwise it
could not be transmitted. So far, then, from “hereditary transmission”
explaining “instinct,” instinct, in whatever remote ancestor it first
arose, must have been a violation of the law of hereditary transmission.
Now as to “lapsed intelligence:” This hypothesis assumes that a
conscious deliberate, discriminating faculty must have once been
exercised by wasps, bees, ants, and other much more lowly animals,
in the performance of all those actions which are now instinctive.
But could the adult female insect be supposed to foresee the future
needs of her progeny, often so totally different from her own wants?
It would surely be too much to ask us to believe that she could
distinctly recollect all her past experience as a chrysalis and as a
grub from the moment she first quitted the egg. Can we suppose that
the generative acts of male insects, such as bees, could have been due
to deliberate and rational choice, when every such act is necessarily
fatal to him who performs it?
Nevertheless, persuaded as I am that “lapsed intelligence” will not
explain “instinct” generally, I should be the last to deny that certain
apparently instinctive actions may be so explained, and I fully admit
that intelligent action in ourselves does tend to become practically
though not really instinctive. It is, moreover, very fortunate for
us that such is the case, as thereby we are saved great mental
friction. Our intellect has first to be laboriously applied to learn
what afterwards becomes almost automatic, as the actions of reading,
writing, etc. Sensations and bodily actions having been duly kneaded
together, the intellect becomes free to withdraw and apply itself to
other work—fresh conquests of mere animality—leaving the organism to
carry on automatically the new faculties thus acquired. Were it not for
this power which we have of withdrawing our attention, our intellect
would be absorbed and wasted in the merest routine work, instead of
being set free to appropriate and render practically instinctive, a
continually wider and more important range of deliberate purposive
actions. We come now to the sixth and last attempt to explain instinct,
namely, Mr. Darwin’s attempt. He has recognised the futility of
seeking to explain many instinctive actions in any of the modes we
have yet considered, and he has proposed, as before said, to explain
such residual instinctive phenomena by the play of natural selection,
_i.e._ of the destructive forces of nature upon small, accidental
abnormalities of action on the part of individuals of a species; such
abnormalities, when favorable to the existence of the individual, being
preserved and perpetuated by the destruction of the other individuals
of the same species who adhered to their ancestral tendencies. But
this proposed explanation is not an explanation of the _origin_ of
instincts, but only of the changes and transformations of instincts
already acquired. But putting back the date or modifying the form
of the original instinct, in no way alters the essential nature of
instincts or diminishes its mystery. Let us look at one or two strong
cases of instinct, and see if it is credible that they should be
due to mere accidental, haphazard, minute changes in habits already
acquired. In the first place, there is the wonderful instinct of the
duck, which feigns to have an injured wing, in order to entice a dog
away from the pursuit of her ducklings. Is it conceivable that such an
act was first done by pure accident, and that the descendants of her
who so acted, having inherited the tendency, have been alone selected
and preserved? Again, there is the case of the wasp, sphex, which
stings spiders, caterpillars, and grasshoppers exactly in the spot, or
spots, where their nervous ganglia lie, and so paralyses them. Even
the strongest advocate of the intelligence of insects would not affirm
that the mother sphex has a knowledge of the comparative anatomy of the
nervous system of these very diversely formed insects. According to
the doctrine of natural selection, either an ancestral wasp must have
accidentally stung them each in the right places, and so our sphex of
to-day is the naturally selected descendant of a line of insects which
inherited this lucky tendency to sting different insects differently,
but always in the exact situation of their nervous ganglia; or else
the young of the ancestral sphex originally fed on dead food, but the
offspring of some individuals who happened to sting their prey so
as to paralyse but not kill them, were better nourished and so the
habit grew. But the incredible supposition that the ancestor should
accidentally have acquired the habit of stinging different insects
differently, but always in the right spot, is not eliminated by the
latter hypothesis.
There is, again, the case of neuter insects and the highly complex
instincts of insects living in communities, such as bees, ants,
and termites. The Darwinian theory has the great advantage of only
needing for its support the suggestion of some possible utility in
each case; and as all structures and functions in nature have their
utility, the task is not a difficult one for an ingenious, patient,
and accomplished thinker. Yet Mr. Darwin, with all his ingenuity,
patience, and accomplishments, has been unable to suggest a rational
explanation for the accidental origin of these insect communities with
their marvellously complex instincts. I will confine myself to one more
instance of a highly noteworthy instinct, which no one has in any way
succeeded in explaining. The instance I refer to is that by which an
animal, when an enemy approaches, lies quite quiescent and apparently
helpless, an action often spoken of as “shamming death.” To evade the
force of this remarkable case of instinct, it has been objected that
the disposition of the limbs adopted by insects which thus act, is not
the same as that which the limbs assume when such insects are really
dead, and that all species are not when thus acting equally quiescent.
The first observation, however, does not concern the matter really
at issue. The remarkable thing is not that a helpless insect should
assume the position of its own dead, but that such a creature, instead
of trying to escape, should adopt a mode of procedure utterly hopeless
unless the enemy’s attention is thereby effectually eluded. It is
impossible that this instinct could have been gradually gained by the
elimination of all those individuals who did not practice it, for if
the quiescence, whether absolutely complete or not, were not sufficient
at once to make the creature elude observation, its destruction would
be only the more fully insured by such ineffectual quiescence. The
same argument applies to birds which seem to feign lameness or other
injury. Yet even if we could account for these cases, which as a fact
are as yet entirely unaccounted for, it would not do away with the need
of recognising the real existence and peculiar nature of instinct. It
would not do so on account both of man’s highest and of man’s lowest
instinctive powers. To speak first of the former: as instinct, such
as we have hitherto discovered, is the appointed bridge between mere
organic and intellectual animal life, so there is in man a further
development of instinct, peculiar to him, and serving to bridge over
the gulf between mere intelligent animal faculty and distinctly human
reflective intellectual activity. Such special intellectual instinct
is that which impels man to the external manifestation by voice or
gesture of the mental abstractions which his intellect spontaneously
forms, and which are not formed by the lower animals, which give no
evidence of this power of abstraction. Language could never have been
deliberately invented nor have arisen by a mere accidental individual
variation, for vocal and gesture signs are essentially conventional,
and require more or less comprehension on the part of those to whom
they are addressed as well as on the part of those who use them.
Analogous considerations apply to the first beginnings of what cannot
be reckoned as merely instinctive activities, but the origins of
which must have been akin to instincts. I refer to the beginnings of
literature, art, science and politics, which were never deliberately
invented. Even men who supposed they were inventing and constructing a
certain new order of things with full purpose and much intelligence,
have really been all the time so dominated by influences beyond their
consciousness, that they really evolved something very different from
what they supposed or intended. This fact has been most instructively
shown by De Tocqueville and Taine with respect to the men who promoted
and carried through the great French Revolution. So much, then, for
man’s highest instinctive powers: but our argument has no need to refer
to them, for a consideration of man’s lowest instinctive powers alone
suffices to show that they cannot be due to “natural selection,” even
when aided by “lapsed intelligence.” Can it be for a moment seriously
maintained that such actions of the infant as those of the sucking,
deglutition, and defecation, or the sexual instincts of later life,
ever arose through the accidental conservation of haphazard variations
of habit in ancestral animals? If it cannot be maintained, as I am
confident it cannot, then it is absolutely impossible successfully to
evade the difficulty of the existence of instinct. However far we may
put back the beginnings of instinct, the question as to its origin
(with its subsequent modifications) ever returns, and indeed with
increased importunity. How did the first sentient creatures obtain and
swallow their food? How did they first come to fecundate their ova
or suitably to deposit them? How did they first effect such movements
as might be necessary for their respiratory processes? Wherever such
phenomena first manifested themselves in sentient organisms, we are
compelled therein to recognise the manifest presence of instinct—the
appointed means (as before said) of bridging over the interval between
the purely vegetative functions and the intelligent activities of
sentient animal life. “Natural selection” is manifestly impotent to
account for the existence of such a faculty as that of “instinct.”
We have already seen that the hypothesis of “lapsed intelligence” is
also impotent to account for it. Thus the most recently attempted
explanation falls altogether to the ground. Nevertheless the theory of
evolution renders it necessary to assume that as new species of animals
were from time to time evolved, so also were new and appropriate
instincts. How then are we to account for the origin of such new
instincts? That a certain mystery attends such origin cannot be denied,
but a parallel mystery attends all other kinds of vital phenomena.
What can be more mysterious than the purely organic functions of
animals? Though not truly instinctive, they are full of unconscious
purpose, and so are akin to instinct. Our nutrition is a process of
self-generation by which the various bodies which constitute our food
become transformed into our own substance. This process is effected by
what is called assimilation, by which process the ultimate substance,
or parenchyma, of our own body and of the bodies transforms part of
what is immediately external to it, into the parenchyma itself. Again,
the process of secretion is, as it were, parallel to the process
of alimentation or nutrition. In secretion, the body extracts from
the blood new substances (the secretions) which do not exist _as
such_ within it. In nutrition, the body extracts from the blood new
substances (the various tissues) which do not exist _as such_ within
it. The blood is not the only source of our nutrition, since it has the
power of replenishing itself. Thus the living particles which form the
ultimate substance of our body exercise a certain power of choice with
respect to the contents of the fluids which come in contact with them.
Such particles are not passive bodies; they are active living agents,
and their action no one has yet really explained. Here, then, are a set
of activities which, if duly pondered over, will be found to be fully
as mysterious and inexplicable in their unconscious teleology as any
phenomena of instinct as ordinarily understood. But there is another
class of organic vital actions which also seem to have a decided
affinity both to reflex action and to instinct, though they are not
to be regarded as actual instances of either of these faculties. The
actions I refer to are those which bring about the repair of injuries
and the reproduction of lost parts. They are like reflex action
inasmuch as they take place in perfect unconsciousness and without the
will having any power over them. They are like instinct inasmuch as
they are directed towards a useful and unforeseen end. In the process
of healing and repair of a wounded part of the body, a fluid, perfectly
structureless substance, is secreted, or poured forth, from the parts
about the wound. In this substance, cells arise and become abundant;
so that the substance, at first structureless, becomes what is called
cellular tissue. Then, by degrees, this structure transforms itself
into vessels, tendons, nerves, bone, and membrane—into some or all
of such parts—according to the circumstances of the case. In a case
of broken bone, the two broken ends of the bone soften, the sharp
edges thus disappearing. Then a soft substance is secreted, and this
becomes at first gelatinous, often afterwards cartilaginous, and,
finally, osseous or bony. But not only do these different kinds of
substance—these distinct tissues—thus arise and develop themselves in
this neutral or, as it is called, “undifferentiated” substance, but
very complex structures, appropriately formed and nicely adjusted for
the performance of complex functions, may also be developed. We see
this in the production of admirably formed joints in parts which were
at first devoid of anything of the kind. I may quote, as an example,
the case of a railway guard, whose arm had been so injured that he
had been compelled to have the elbow with its joint cut out, but who
afterwards developed a new joint almost as good as the old one. In the
uninjured condition the outer bone of the lower arm—the radius—ends
above in a smooth-surfaced cup, which plays against part of the lower
end of the bone of the upper arm, or humerus, while its side also
plays against the side of the other bone of the lower arm, the ulna,
with the interposition of a cartilaginous surface. The radius and ulna
are united to the humerus by dense and strong membranes or ligaments,
which pass between it and them, anteriorly, posteriorly, and on each
side, and are attached to projecting processes, one on each side of
the humerus. Such was the condition of the parts which were removed by
the surgeon. Nine years after the operation the patient died, and Mr.
Syme had the opportunity of dissecting the arm, which in the meantime
had served the poor man perfectly well, he having been in the habit of
swinging himself by it from one carriage to another, while the train
was in motion, quite as easily and securely as with the other arm.
On examination, Mr. Syme found that the amputated end of the radius
had formed a fresh polished surface, and played both on the humerus
and the ulna, a material something like cartilage being interposed.
The ends of the bones of the forearm were locked in by two processes
projecting downwards from the humerus, and also strong lateral and
still stronger anterior and posterior ligaments again bound them fast
to the last-named bone.[7] It would be easy to bring forward a number
of more or less similar cases. The amount of reproduction of lost parts
which may take place in many of the lower animals is astonishing. Thus
the tails of lizards, if broken off, will grow again, and the limbs of
newts will be reproduced, with their bones, muscles, blood-vessels, and
nerves. Even the eye and the lower jaw have been seen to be reproduced
in the last-named animals. If certain worms be cut in two, each half
will become a perfect animal, the head producing a new tail, and the
tail a new head; and a worm called a _nais_ has been cut into as many
as twenty-five parts with a like result. But the most remarkable animal
for its power of repairing injuries is the fresh-water hydra, almost
any fragment of which will, under favorable circumstances, grow into a
new and entire fresh animal. It is also a notorious and very noteworthy
fact that, in both man and the lower animals, the processes of repair
take place the more readily the younger the age of the injured
individual may be. But these unconscious but practically teleological
processes of repair, are often preceded by actions which everyone would
call instinctive.
[7] See Mr. Timothy Holmes’s _System of Surgery_, 3rd edit. vol. iii.
p. 746.
There is yet another class of organic vital actions to which I must
advert, which are at once utterly unconscious, while the fact that
they are directed to a distinct end is indisputable; in fact they are
purposive in the very highest degree that any unconscious actions can
be purposive. They are the actions of true reproduction, and they
come before us naturally here, since a consideration of the process
of remedial reproduction in the individual, naturally leads us on
to the consideration _of the reproduction of the species itself_.
In the cases of the frog and the butterfly, everyone knows that the
creature which comes forth from the egg is very different from the
parent. Animals, in fact, mostly attain their adult condition by
passing through a series of development changes; only as a rule that
series is not abruptly interrupted by plainly marked pauses, as it is
in the frog and butterfly, and, therefore, such changes, instead of
being obvious, are only to be detected with difficulty and through
patient research. Almost every animal thus goes through a series of
very remarkable changes during its individual process of development
or, as it is called, during its “ontogeny.” This process, in its
perfect unconsciousness, is like reflex action, but it is far more
wonderful, since in the earliest stages even nerve-tissue is absent and
has itself to be formed. In the accuracy of its direction towards a
useful end, it is the very counterpart of the most developed instinct;
nor, if the impulses by which adult individuals are led to seek and
to perform those processes which give rise to the embryo, are to
be called instinctive, is it easy to see how the analogical use of
the term “instinctive” can be refused to that impulse by which each
developing embryo is led to go through those processes which give
rise to the adult. The action of each organism during its individual
development may be compared, and has evidently much affinity with, the
processes of nutrition and the repair and reproduction of parts lost
through some injury. These processes of nutrition and repair have also
evidently a close relation to reflex action and reflex action has also
a close affinity to instinctive action. Instead, however, of explaining
“instinct” by “reflex action,” I would rather explain reflex action,
processes of nutrition, processes of repair, processes of individual
development, by instinct—using this term in a wide analogical sense.
For we know the wonderful action and nature of instinct as it exists
in our own human activity, standing, as it were, at the head of the
various unconsciously intelligent vital processes. These processes
seem to me to be all diverse manifestations of what is fundamentally
one kind of activity. Of these manifestations, instinctive action is
the best type, because by it we can, to a certain extent, understand
the others, whereas none of the others enable us to understand
instinct.—_Fortnightly Review._