MAN AND OTHER ANIMALS.
Vertebrate Animals, 35—Succession and Descent of Species,
37—Apes and Man, comparison of structure, 38—Hands and Feet,
42—Hair, 44—Features, 44—Brain, 45—Mind in Lower Animals and
Man, 47.
To understand rightly the construction of the human body, and to compare
our own limbs and organs with those of other animals, requires a thorough
knowledge of anatomy and physiology. It will not be attempted here to
draw up an abstract of these sciences, for which such handbooks should
be studied as Huxley’s _Elementary Physiology_ and Mivart’s _Elementary
Anatomy_. But it will be useful to give a slight outline of the evidence
as to man’s place in the animal world, which may be done without
requiring special knowledge in the reader.
That the bodies of other animals more or less correspond in structure
to our own is one of the lessons we begin to learn in the nursery. Boys
playing at horses, one on all-fours and the other astride on his back,
have already some notion how the imagined horse matches a real one as to
head, eyes, and ears, mouth and teeth, back and legs. If one questions a
country lad sitting on a stile watching the hunters go by, he knows well
enough that the huntsman and his horse, the hounds and the hare they are
chasing, are all creatures built up on the same kind of bony scaffolding
or skeleton, that their life is carried on by means of similar organs,
lungs to breathe with, a stomach to digest the food taken in by the
mouth and gullet, a heart to drive the blood through the vessels, while
the eyes, ears, and nostrils receive in them all in like manner the
impressions of sight, hearing, and smell. Very likely the peasant has
taken all this as a matter of course without ever reflecting on it, and
even more educated people are apt to do the same. Had it come as a new
discovery, it would have set any intelligent mind thinking what must be
the tie or connexion between creatures thus formed as it were on one
original pattern, only varied in different modes for different ends. The
scientific comparison of animals, even when made in the most elementary
way, does at once bring this great problem before our minds. In some
cases, more exact knowledge shows that the first rough comparison of man
and beast may want correction. For instance, when a man’s skeleton and
a horse’s are set side by side, it becomes plain that the horse’s knee
and hock do not answer, as is popularly supposed, to our elbow and knee,
but to our wrist and ankle. The examination of the man’s limb and the
horse’s leads to a further and remarkable conclusion, that the horse’s
fore- and hind-leg really correspond to a man’s arm and leg in which
all the fingers and toes should have become useless and shrunk away,
except one finger and one toe, which are left to be walked upon, with
the nail become a hoof. The general law to be learnt from the series of
skeletons in a natural history museum, is that through order after order
of fishes, reptiles, birds, beasts, up to man himself, a common type or
pattern may be traced, belonging to all animals which are vertebrate,
that is, which have a backbone. Limbs may still be recognised though
their shape and service have changed, and though they may even have
dwindled into remnants, as if left not for use, but to keep up the old
model. Thus, although a perch’s skeleton differs so much from a man’s,
its pectoral and ventral fins still correspond to arms and legs. Snakes
are mostly limbless, yet there are forms which connect them with the
quadrupeds, as for instance, the boa-constrictor’s skeleton shows a pair
of rudimentary hind-legs. The Greenland whale has no visible hind-limbs,
and its fore-limbs are paddles or flippers, yet when dissected, the
skeleton shows not only remnants of what in man would be the leg-bones,
but the flipper actually has within it the set of bones which belong to
the human arm and hand. It is popularly considered that man is especially
distinguished from the lower animals by not having a tail; yet the tail
is plainly to be seen in the human skeleton, represented by the last
tapering vertebræ of the spine.
All these are animals now living. But geology shows that in long-past
ages the earth has been inhabited by species different from those at
present existing, and yet evidently related to them. In the tertiary
period, Australia was distinguished as now by its marsupial or pouched
animals, but these were not of any present species, and mostly far
larger; even the tallest kangaroo now to be seen is a puny creature in
comparison with the enormous extinct diprotodon, whose skull was three
feet long. So in South America there lived huge edentate animals, now
poorly represented by the sloths, anteaters and armadillos, to be seen
in our Zoological Gardens. Elephants are found fossil in the miocene
deposits, but the species were all different from those in Africa and
India now. These are common examples of the great principle now received
by all zoologists, that from remote geological antiquity there have from
time to time appeared on earth new species of animals, so far similar
to those which came before them as to look as if the old types had been
altered to fit new conditions of life, the earlier forms then tending
to die out and disappear. This relation between the older species of
vertebrate animals and the newer species which have supplanted them, is
a matter of actual observation, and beyond dispute. Many zoologists, now
perhaps the majority, go a step farther than this, not only acknowledging
that there is a relation between the new species and the old, but seeking
to explain it by the hypothesis of descent or development, now often
called, from its great modern expounder, the Darwinian theory. The
formation of breeds or varieties of animals being an admitted fact, it
is argued that natural variation under changed conditions of life can go
far enough to produce new species, which by better adaptation to climate
and circumstances may supplant the old. On this theory, the present
kangaroos of Australia, sloths of South America, and elephants of India,
are not only the successors but the actual descendants of extinct ones,
and the fossil bones of tertiary horse-like animals with three-toed and
four-toed feet show what the remote ancestors of our horses were like, in
ages before the unused toes dwindled to the splint-bones which represent
them in the horse’s leg now. According to the doctrine of descent, when
several species of animals living at the same time show close resemblance
in structure, it is inferred that this resemblance must have been
inherited by all from one ancestral species. Now of all the mammalia,
or animals which suckle their young, those whose structure brings them
closest to man are the apes or monkeys, and among these the catarhine or
near-nostrilled apes of the Old World, and among these the group called
anthropoid or manlike, which inhabit tropical forests from Africa to the
Eastern Archipelago. By now comparing their skeletons, it will be seen
that in any scale of nature or scheme of creation these animals must be
placed in somewhat close relation to man. No competent anatomist who has
examined the bodily structure of these apes considers it possible that
man can be descended from any of them, but according to the doctrine
of descent they appear as the nearest existing offshoots from the same
primitive stock whence man also came.
[Illustration: FIG. 5.—Skeletons of apes and man. _a_, gibbon; _b_,
orang; _c_, chimpanzee; _d_, gorilla; _e_, man (after Huxley).]
Professor Huxley’s _Man’s Place in Nature_, in which this anatomical
comparison is made, contains a celebrated drawing which is copied in Fig.
5 as the readiest means of showing how the anthropoid apes correspond
bone for bone with ourselves. At the same time it illustrates some main
points in which their bodily actions are unlike ours. It has been said
that the child first takes on him the dignity of man when he leaves off
going on all-fours. But in fact, standing and walking upright is not a
mere matter of training; it belongs to the arrangement of the human body
being different from that of quadrupeds. The limbs of the dog or cow are
so proportioned as to bring them down on all-fours, and this is to a less
degree the case with the apes, while the head and trunk of the growing
child are lifted toward the erect attitude by the disproportionate growth
of the lower limbs. Though man’s standing upright requires continued
muscular effort, he is so built as to keep his balance more readily
than other animals in this position. It may be noticed from the figure
how in man the opening at the base of the skull (occipital foramen)
through which the spinal cord passes up into the brain, is farther to the
front than in the apes, so that his skull, instead of pitching forward,
is balanced on the top of the atlas vertebra (so called from Atlas
supporting the globe). The figure shows also the S-like curvature of
man’s spine, and how the bony pelvis or basin forms a broad support for
his intestines as he stands upright, in which attitude the feet serve as
bases enabling the legs to carry the trunk. Thus the erect posture, only
imitated with difficult effort by the showman’s performing animals, is to
man easy and unconstrained. Not through great differences of structure,
but by adjustments of bones and muscles, the fore- and hind-limbs of
quadrupeds work in accord, while in man, whose muscular adaptation is
for going on his legs, there is no such reciprocal action between the
legs and arms. Of the monkey tribes, many walk fairly on all-fours as
quadrupeds, with legs bent, arms straightened forward, soles and palms
touching the ground. But the higher manlike apes are adapted by their
structure for a climbing life among the trees, whose branches they grasp
with feet and hands. When the orang-utan takes to the ground he shambles
clumsily along, generally putting down the outer edge of the feet and
the bent knuckles of the hands. The orang and gorilla have the curious
habit of resting on their bent fists, so as to draw their bodies forward
between their long arms, like a cripple between his crutches. The nearest
approach that apes naturally make to the erect attitude, is where the
gibbon will go along on its feet, touching the ground with its knuckles
first on one side and then on the other, or will run some distance with
its arms thrown back above its head to keep the balance, or when the
gorilla will rise on its legs and rush forward to attack. All these modes
of locomotion may be understood from the skeletons in the figure. The
apes thus present interesting intermediate stages between quadruped and
biped. But only man is so formed that, using his feet to carry him, he
has his hands free for their special work.
[Illustration: FIG. 6.—_a_, hand, _b_, foot, of chimpanzee (after Vogt);
_c_, hand, _d_, foot, of man.]
In comparing man with the lower animals, it is wrong to set down his
pre-eminence entirely to his mind, without noticing the superiority
of his limbs as instruments for practical arts. If one looks at the
illustrations to “Reynard the Fox,” where the artist does his best to
represent the lion holding a sceptre, the she-wolf flirting a fan, or
the fox writing a letter; what he really shows is, how ill adapted the
limbs of quadrupeds are to such actions. Man’s being the “tool-using
animal” is due to his having hands to use the tool as well as mind to
invent it; and only the apes, as most nearly approaching man in their
limbs, can fairly imitate the use of such instruments as a spoon or a
knife. In Fig. 6 the hand and foot of the chimpanzee may be compared with
those of man. Here the ape’s foot _b_, looks so like a hand, that many
naturalists have classed the higher apes under the name of four-handed
animals, or _quadrumana_. In anatomical structure it is a foot, but it is
a prehensile or grasping foot, able to clip or pinch an object by setting
the great toe thumb-wise against the others, which the human foot _d_,
cannot do. It is true that among people who go barefoot the great toe is
not quite so helpless as that of a boot-wearing European. With the naked
foot the savage Australian picks up his spear, and the Hindu tailor holds
his cloth as he squats sewing. The above drawing is purposely taken, not
from the free foot of the savage, but from the European foot cramped
by the stiff leather boot, because this shows in the utmost way the
contrast between ape and man. In the ape, it is seen that both the hands
and feet gain their suitability for a tree-climbing life at the loss of
their suitability for walking on the ground. But man’s upper and lower
extremities have become differentiated or specialised in two opposite
ways, the human foot becoming a stepping-machine with less grasping-power
than the ape-foot, while the human hand comes to excel the ape-hand
as a special organ for feeling, holding, and handling. The figure _c_
shows the longer and freely-acting thumb and the wider flexible palm in
man, the sensitive cushions at our finger-ends also giving us greater
delicacy of touch. It is most instructive to visit the monkey-house at
the Zoological Gardens for the purpose of comparing hands of high and low
kinds. The hand of the marmoset with its five claw-nailed digits, is a
mere grasping instrument hardly capable of handling. Other low monkeys
have the thumbs small and not opposable, that is, their ends do not meet
those of the other fingers, whereas the thumbs of the higher apes are
(as the figure shows) opposable like ours. How far the value of the hand
as a mechanical instrument depends on this opposability, any one may
satisfy himself by using his hand with the thumb stiff. It is plain that
man’s hand, enabling him to shape and wield weapons and tools to subdue
nature to his own ends, is one cause of his standing first among animals.
It is not so obvious, but it is true, that his intellectual development
must have been in no small degree gained by the use of his hands. From
handling objects, putting them in different positions, and setting
them side by side, he was led to those simplest kinds of comparing and
measuring which are the first elements of exact knowledge, or science.
Outwardly, the shaggy hair of the apes contrasts with the comparative
nakedness of the human skin. In man as in lower animals, the thatch of
hair indeed forms an effective shelter to the head. The hairy fringe
round the human mouth in the adult male has in some races a strong
growth, as in the European or the native of Australia. But in others, as
the African negro and the so-called American Indian, the scanty face-hair
looks as though it had dwindled to the mere remnant of a fuller growth.
Looked at in this way, the hairy patches on the Englishman’s breast and
limbs, though practically of no importance, are an object of curious
interest to the naturalists who consider them relics from the remote
period when man’s ancestral stock had a fuller hairy covering, whose want
is now supplied by artificial shelter suited to season and climate. It
is interesting to notice that there are some few human beings to be met
with, whose faces and bodies are largely covered with long shaggy hair.
Such a face-covering hides the play of feature—that expressive means of
intercourse between mind and mind. Had the skeletons of apes and man in
our figure been clothed with flesh, we should have seen plainly the signs
of man’s higher organisation in the flexible versatile features, in whose
movements and folds are symbolised the pleasures and pains, the loves
and hates, of every phase of human life. How coarse and clumsy are the
corresponding changes of face in the monkey-tribes, such as the drawing
back of the corners of the mouth and wrinkling of the lower eyelid which
constitute an ape’s smile, or the rise and fall of the baboon’s eyebrow’s
and forehead in anger. The visitor from some other planet, so often
imagined as coming to our earth and forming his judgments by what he
sees, might well discern in the difference between man’s face and the
gorilla’s muzzle some measure of the discrepancy within.
The brain being the instrument or organ of mind, anatomists comparing the
brains of animals have looked for well-marked distinctions between the
less and the more intelligent. In the natural order of Primates, to which
man belongs with the monkeys and lemurs, the series of brains shows a
remarkable rise or development from lower to higher forms. The lemur has
a small and comparatively smooth brain, whereas the high anthropoid apes
have brains which strikingly approach man’s. In fact the lemur has very
little mind in comparison with the sagacious and teachable chimpanzee
or orang-utan. But man’s reason so vastly surpasses that of the highest
apes, that naturalists have wondered at the likeness of their brain to
ours, which is illustrated in the accompanying Fig. 7, representing the
brain of the chimpanzee _a_, and of man _b_, whole on the left to show
the convolutions, and cut across on the right to expose the interior.
To compare their structure the two brains are drawn of the same size,
but in fact the chimpanzee brain is much smaller than the human. It
is one great difference between man and the anthropoid apes, that his
brain exceeds theirs in quantity; in a rough way he has three pounds
of brain to their one. It is seen also that in the ape-brain the lobes
or hemispheres have fewer and simpler windings than the more complex
convolutions of the human brain, which in general outline they resemble.
Now both size and complexity mean mind-power. The lobes of the brain
consist within of the “white matter” with its innumerable fibres carrying
nerve-currents, while the outer coating is formed of the “grey matter,”
containing the brain-corpuscles or cells from which the fibres issue,
and which are centres through which the combinations are made which we
are conscious of as thoughts. As the coating of grey matter follows the
foldings of the brain down into the fissures, it is evident that the
increased complexity of the convolutions, combined with greater actual
size of brain, furnishes man with a vastly more extensive and intricate
thinking-apparatus than the animals nearest below him in the order of
nature.
[Illustration: FIG. 7.—Brain of chimpanzee (_a_) and of man (_b_), seen
from above, showing the cerebral hemispheres, whole on left, in section
on right (after Huxley).]
Having looked at some of the important differences between the bodies of
man and lower animals, we may venture to ask the still harder question,
How far do their minds work like ours? No full answer can be given, yet
there are some well ascertained points to judge by. To begin, it is clear
that the simple processes of sense, will, and action, are carried on in
man by the same bodily machinery as in other high vertebrate animals.
How like their organs of sense are, is well illustrated by the anatomist
who dissects a bullock’s eye as a substitute for a man’s, to show how
the picture of the outer world is thrown by the lenses on the retina
or screen, into which spread the end-fibres of the optic nerve leading
into the brain. Not but what the touch, sight, and other senses in the
various orders of animals have their special differences, as where the
eagle’s eyes are focussed to see small objects far beyond man’s range,
while the horse’s eyes are so set in his head that they do not converge
like ours, and he must practically have two pictures of the two sides
of the road to deal with. Such special differences, however, make the
general resemblance all the more striking. Next, the nervous system in
beast and man shows the same common plan, the brain and spinal cord
forming a central nervous organ, to which the sensory nerves convey
the messages of the senses, and from which the motor nerves carry the
currents causing muscular contraction and movement. The involuntary
acts of animals are like our own, as when the sleeping dog draws his
leg back if it is touched, much as his master would do, and when awake,
both man and beast wink when a finger pretends to strike at their eyes.
If we go on to voluntary actions, done with conscious will and thought,
the lower creatures can for some distance keep company with mankind. At
the Zoological Gardens one may sometimes see a handful of nuts divided
between the monkeys inside the bars and the children outside, and it
is instructive to notice how nearly both go through the same set of
movements, looking, approaching, elbowing, grasping, cracking, munching,
swallowing, holding out their hands for more. Up to this level, the
monkeys show all the mental likeness to man that their bodily likeness
would lead us to expect. Now we know that in the scramble, there passes
in the children’s minds a great deal besides the mere sight and feel
of the nuts, and the will to take and eat them. Between the sensation
and action there takes place thought. To describe it simply, the boy
knows a nut by sight, wishes to renew the pleasant taste of former nuts,
and directs his hands and mouth to grasp, crack, and eat. But here are
complicated mental processes. Knowing a nut by sight, or having an idea
of a nut, means that there are grouped together in the child’s mind
memories of a number of past sensations, which have so become connected
by experience that a particular form and colour, feel and weight, lead to
the expectation of a particular flavour. Of what here takes place in the
boy’s mind we can judge, though by no means clearly, from what we know
about our own thoughts and what others have told us about theirs. What
takes place in the monkeys’ minds we can only guess by watching their
actions, but these are so like the human as to be most readily explained
by considering their brain-work also to be like the human, though less
clear and perfect. It seems as though a beast’s idea or thought of an
object may be, as our own, a group of remembered sensations compacted
into a whole. What makes this the more likely is that when part of the
sensations present themselves, the animal seems to judge that the rest
must be there also, much as we ourselves are so apt to do. Thus a dog
will jump upon a scum-covered stream which it takes for dry land, or
when offered a sham biscuit will come for it, turning away when smell
and taste prove that the rest of the idea does not agree with what sight
suggested.
In much the same way, all people who attend to the proceedings of
animals, account for them by faculties more or less like their own. Not
only do creatures of all high orders give unmistakable signs of pleasure
and pain, but our dealings with the brutes go on the ground of their
sharing with us such more complex emotions as fear, affection, anger,
nay, even curiosity, jealousy, and revenge. Some of these show themselves
in bodily symptoms which are quite human, as every one must admit who
has felt the trembling limbs and throbbing heart of a frightened puppy,
or looked at the picture in Darwin’s _Expression of the Emotions_ of
the chimpanzee who has had his fruit taken from him, and displays his
sulkiness by a pout which is a caricature of a child’s. Again, the lower
animals show a well-marked will, which like man’s is not simply wish,
but the resultant or balance of wishes, so that it is possible for two
people calling a dog different ways, or both offering him bones, to
distract his will in a way that reminds us of the philosopher’s imaginary
ass that died of starvation between its hay and its water. As to the
power of memory in brutes, we have all had opportunities of noticing
how lasting and exact it is. Some things which the animals remember may
be explained simply by their ideas becoming associated through habit,
as when the horse betrays its former owner’s ways by stopping at every
public-house; this may only mean that the familiar door suggests to the
beast the memory of rest, and he stops. But to watch a dog dreaming makes
us think that whole trains of ideas from the storehouse of memory are
passing before his consciousness, as in our dreams. A memory in which
such a revival of the past is possible, is a source of experience whence
to extract understanding of the present, and foresight of the future. To
make the memory of what has been, the means of controlling what shall be,
is the great intellectual faculty in man, and in simple and elementary
forms it comes into view among lower creatures. To tell but one of the
innumerable animal stories which show expectation and design founded
on experience. A certain Mr. Cops, who had a young orang-utan, one day
gave it half an orange, put the other half away out of its sight on a
high press, and lay down himself on the sofa, but the ape’s movements
attracting his attention, he only pretended to go to sleep; the creature
came cautiously and satisfied himself of his master being asleep, then
climbed up the press, ate the rest of the orange, carefully hid the peel
among some shavings in the grate, examined the pretended sleeper again,
and then went to lie down on his own bed. Such behaviour is only to be
explained by a train of thought involving something of what in ourselves
we call reason.
To measure the differences between beast and man is really more
difficult than tracing their resemblances. One plain mark of the higher
intellectual rank of man is that he is less dependent on instinct than
the animals which migrate at a fixed season, or build nests of a fixed
and complicated pattern peculiar to their kind. Man has some instincts
plainly agreeing with those of inferior animals, such as the child’s
untaught movements to ward off danger, and the parental affection which
preserves the offspring during the first defenceless period of life.
But if man were possessed by a resistless longing to set off wandering
southward before winter, or to build a shelter of boughs laid in a
particular way, this would be less beneficial to his species than the
use of intelligent judgment adapting his actions to climate, supply of
food, danger from enemies, and a multitude of circumstances differing
from district to district, and changing from year to year. If man’s
remote progenitors had instincts like the beavers’ implanted in the
very structure of their brain, these instincts have long ago fallen
away, displaced by freer and higher reason. Man’s power of accommodating
himself to the world he lives in, and even of controlling it, is
largely due to his faculty of gaining new knowledge. Yet it must not be
overlooked that this faculty is in a less measure possessed by other
animals. We may catch them in the act of learning by experience, which
is indeed one of the most curious sights in natural history, as when
telegraph-wires are set up in a new district, and after the second year
partridges no longer kill themselves by flying against them, or where
in Canada the wily marten baffles the trapper’s ingenuity, finding out
how to get the bait away, even from a new kind of trap, without letting
it fall. The faculty of learning by imitation comes out in the apes
in an almost human way. The anthropoid ape Mafuka, kept lately in the
Zoological Gardens at Dresden, saw how the door of her cage was unlocked,
and not only did it herself, but even stole the key and hid it under her
arm for future use; after watching the carpenter she seized his bradawl
and bored holes with it through the little table she had her meals on; at
her meals she not only filled her own cup from the jug, but, what is more
remarkable, she carefully stopped pouring before it ran over. The death
of this ape had an almost human pathos; when her friend the director of
the gardens came to her, she put her arms round his neck, kissed him
three times, and then lay down on her bed and giving him her hand fell
into her last sleep. One cannot but think that creatures so sagacious
must learn in their wild state. Indeed less clever animals seem to some
extent to teach their young, birds to sing, wolves to hunt, although it
is most difficult for naturalists in such cases to judge what comes by
instinct and what is consciously learnt.
Philosophers have tried to draw a hard and fast line between the animal
and human mind. The most celebrated of these attempts is Locke’s, where
in his _Essay concerning Human Understanding_ he lays it down that beasts
indeed have ideas, but are without man’s faculty of forming abstract
or general ideas. Now it is true that we have learnt to reason with
abstract ideas, such as solidity and fluidity, quantity and quality,
vegetable and animal, courage and cowardice; and that there is not the
least reason to suppose that such abstractions are formed by dogs or
apes. But though the faculty of thus abstracting and generalising is
one which rises to the highest flights of philosophic thought, it must
be borne in mind that it begins in easy mental acts which seem quite
possible to animals. Abstraction is noticing what several thoughts have
in common, and neglecting their differences; thus a general idea is
obtained by not attending too closely to particulars. The simplest form
of this is when only one sense at a time is attended to, as in Locke’s
example of the idea of whiteness, as being that which chalk, snow, and
milk, agree in. But, to judge by animals’ actions, they also will attend
to one sense at a time, as where a bull is excited by anything red. And
it is most interesting to watch animals comparing a new object with
their recollections or ideas of previous ones, practically recognising
in it what is already familiar, and expecting it to behave like other
individuals of its class. Cats or monkeys do not require to be shown the
use of a fresh rug or cushion, when it is at all like the old one it is
put in place of, and the “dog of the regiment” will accept any man in the
uniform as a master, whether he has seen him before or not. Thus, the
very simplicity of animal thought foreshadows the results of man’s higher
abstraction and generalisation. Let us now read a few lines farther in
Locke, and we shall see why he concludes that animals have not the power
of forming abstract ideas. It is, he says, because they have no use of
words or other general signs. But this itself is an easier point and far
more worth arguing, than the hard question whether brutes have abstract
ideas. In fact the power of speech gives about the clearest distinction
that can be drawn between the action of mind in beast and man. It is far
more satisfactory than another division attempted by philosophers who
lay it down that while other animals have consciousness, man alone has
self-consciousness, that is, he not only feels and thinks, but is aware
of himself as feeling and thinking. Man, we know, is capable of this
self-consciousness, which is cultivated by his being able to talk about
himself as he does about other persons; but it has never been proved that
animals, who we know are not apt to mistake their own bodies for anything
outside, have no consciousness of themselves. When we study the rules of
sign-making and language, we really have some means of contrasting the
animals with ourselves. Evidently it is by means of language that the
human mind has been able to work out and mark the high abstract ideas we
deal with so easily; without words, how could we have reached results of
combined and compared thought such as momentum, plurality, righteousness?
The great mental gap between us and the animals we study is well measured
by the difference between their feeble beginnings in calling one another
and knowing when they are called, and man’s capacity for perfect speech.
It is not merely that the highest anthropoid apes have no speech; they
have not the brain-organisation enabling them to acquire even its
rudiments. Man’s power of using a word, or even a gesture, as the symbol
of a thought and the means of conversing about it, is one of the points
where we most plainly see him parting company with all lower species, and
starting on his career of conquest through higher intellectual regions.
In the comparison of man with other animals the standard should naturally
be the lowest man, or savage. Put the savage is possessed of human
reason and speech, while his brain-power, though it has not of itself
raised him to civilization, enables him to receive more or less of
the education which transforms him into a civilized man. To show how
man may have advanced from savagery to civilization is a reasonable
task, worked out to some extent in the later chapters of this volume.
But there is no such evidence available for crossing the mental gulf
that divides the lowest savage from the highest ape. On the whole, the
safest conclusion warranted by facts is that the mental machinery of the
lower animals is roughly similar to our own, up to a limit. Beyond this
limit the human mind opens out into wide ranges of thought and feeling
which the beast-mind shows no sign of approaching. If we consider man’s
course of life from birth to death, we see that it is, so to speak,
founded on functions which he has in common with lower beings. Man,
endowed with instinct and capable of learning by experience, drawn by
pleasure and driven by pain, must like a beast maintain his life by food
and sleep, must save himself by flight, or fight it out with his foes,
must propagate his species and care for the next generation. Upon this
lower framework of animal life is raised the wondrous edifice of human
language, science, art, and law.