LANGUAGE.
Etymologically the word Language means sign-making by means of the
tongue, _i.e._ articulate speech. But in a wider sense the word is
habitually used to designate sign-making in general, as when we speak
of the “finger-language” of the deaf-and-dumb, the “language of
flowers,” &c. Or, as Professor Broca says, “there are several kinds
of language; every system of signs which gives expression to ideas
in a manner more or less intelligible, more or less perfect, or more
or less rapid, is a language in the general sense of the word. Thus
speech, gesture, dactylology, writing both hieroglyphic and phonetic,
are all so many kinds of language. There is, then, a general faculty of
language which presides over all these modes of expression, and which
may be defined—the faculty of establishing a constant relation between
an idea and a sign, be this a sound, a gesture, a figure, or a drawing
of any kind.”
The best classification of the sundry exhibitions of sign-making
faculty which I have met with, is one that is given by Mr. Mivart in
his _Lessons from Nature_ (p. 83). This classification, therefore, I
will render in his own words.
“We may altogether distinguish six different kinds of language:—
“1. Sounds which are neither articulate nor rational, such as cries of
pain, or the murmur of a mother to her infant.
“2. Sounds which are articulate but not rational, such as the talk of
parrots, or of certain idiots, who will repeat, without comprehending,
every phrase they hear.
“3. Sounds which are rational but not articulate, ejaculations by which
we sometimes express assent to, or dissent from, given propositions.
“4. Sounds which are both rational and articulate, constituting true
speech.
“5. Gestures which do not answer to rational conceptions, but are
merely the manifestations of emotions and feelings.
“6. Gestures which do answer to rational conceptions, and are therefore
‘external,’ but not oral manifestations of the _verbum mentale_.”
To this list of the “Categories of Language” a seventh must be added,
to contain all kinds of written signs; but with such obvious addition
I assent to the classification, as including all the species that
can possibly be included under the genus Language, and therefore as
excluding none.
Now the first thing to be noticed is, that the signs made may be made
either intentionally or unintentionally; and the next is, that the
division of intentional signs may be conveniently subdivided into two
classes—namely, intentional signs which are natural, and intentional
signs which are conventional.
The subdivision of conventional signs may further be split into
those which are due to past associations, and those which are due
to inferences from present experience. A dog which “begs” for food,
or a parrot which puts down its head to be scratched, may do so
merely because past experience has taught the animal that by so
doing it receives the gratification it desires; here is no need for
reason—_i.e._ inference—to come into play. But if the animal has had
no such previous experience, and therefore could not know by special
association that such a particular gesture, or sign, would lead to
such a particular consequence, and if under such circumstances a dog
should see another dog beg, and should imitate the gesture on observing
the result to which it led; or if under such analogous circumstances
a parrot should spontaneously depress its head for the purpose of
making an expressive gesture,—then the sign might strictly be termed a
rational one.
But it is evident that rational signs admit of almost numberless
degrees of complexity and elaboration; so that reason itself does
not present a greater variety of manifestations in this respect than
does the symbolism whereby it is expressed: an algebraical formula is
included in the same category of sign-making as the simplest gesture
whereby we intentionally communicate the simplest idea. Rational signs,
therefore, may be made by gesture, by tone, by articulation, or by
writing—using each of these words in its largest sense.[58]
The following schema may serve to show this classification in a
diagrammatic form—_i.e._ the classification which I have myself
arrived at, and which follows closely the one given by Mr. Mivart.
Indeed, there is no difference at all between the two, save that I have
endeavoured to express the distinction between signs as intentional,
unintentional, natural, conventional, emotional, and intellectual. The
subdivision of the latter into denotative, connotative, denominative,
and predicative, will be explained in Chapter VIII.
[Illustration: LANGUAGE, OR SIGN-MAKING.]
Or, neglecting the unintentional and merely initiative signs as not,
properly speaking, signs at all, every kind of intentional sign may be
represented diagrammatically as in the illustration opposite.
Now, thus far we have been dealing with matters of fact concerning
which I do not think there can be any question. That is to say, no one
can deny any of the statements which this schema serves to express;
a difference of opinion can only arise when it is asked whether the
sundry faculties (or cases) presented by the schema are developmentally
continuous with one another. To this topic, therefore, we shall now
address ourselves.
First let it be observed that there can be no dispute about one point,
namely, that all the faculties or cases presented by the schema, with
the single exception of the last (No. 7), are common to animals and
men. Therefore we may begin by taking as beyond the reach of question
the important fact that animals do present, in an unmistakable manner,
a _germ_ of the sign-making faculty. But this fact is so important in
its relation to our subject, that I shall here pause to consider the
modes and degrees in which the faculty is exhibited by animals.
* * * * *
Huber says that when one wasp finds a store of honey, “it returns
to the nest and brings off in a short time a hundred other wasps;”
and this statement is confirmed by Dujardin. Again, the very able
observer, F. Müller, writes, in one of his letters to Mr. Darwin, that
he observed a queen bee depositing her eggs in a nest of 47 cells. In
the process she overlooked four of the cells, and when she had filled
the other 43, supposing her work to have been completed, prepared to
retire. “But as she had overlooked the four cells of the new comb, the
workers ran impatiently from this part to the queen, pushing her in an
odd manner with their heads, as they did also the other workers they
met with. In consequence, the queen began again to go round on the two
older combs; but, as she did not find any cell wanting an egg, she
tried to descend, yet everywhere she was pushed back by the workers.
This contest lasted rather a long while, till the queen escaped without
having completed her work. Thus the workers knew how to advise the
queen that something was yet to be done; but they knew not how to show
her where it had to be done.”
[Illustration]
According to De Fravière, Landois, and some other observers, bees
have a number of different notes, or tones, whereby they communicate
information to one another;[59] but there seems to be little doubt
that the means chiefly employed are gestures made with the antennæ.
For example, Huber divided a hive into two chambers by means of a
partition: great excitement prevailed in the half of the hive deprived
of the queen, and the bees set to work to build royal cells for the
creation of a new queen. Huber then divided a hive in exactly the same
manner, with the difference only that the screen, or partition, was
made of trellis work, through the openings of which the bees on either
side could pass their antennæ. Under these circumstances the bees in
the queenless half of the hive exhibited no disturbance, nor did they
construct any royal cells: the bees in the other, or separated, half of
the hive were able to inform them that the queen was safe.
Turning now to ants, the extent to which the power of communicating by
signs is here carried cannot fail to strike us as highly remarkable.
In my work on _Animal Intelligence_ I have given many observations by
different naturalists on this head, the general results of which I will
here render.
When we consider the high degree to which ants carry the principle
of co-operation, it is evident that they must have some means of
intercommunication. This is especially true of the Ecitons, which
so strangely mimic the tactics of military organization. “The army
marches in the form of a rather broad and regular column, hundreds of
yards in length. The object of the march is the capture and plunder of
other insects, &c., for food; and as the well-organized host advances,
its devastating legions set all other terrestrial life at defiance.
From the main column there are sent out smaller lateral columns, the
component individuals of which play the part of scouts, branching off
in various directions, and searching about with the utmost activity for
insects, grubs, &c., over every log, under every fallen leaf, and in
every nook and cranny where there is any chance of finding prey. When
their errand is completed, they return into the main column. If the
prey found is sufficiently small for the scouts themselves to manage,
it is immediately seized, and carried back to the main column; but if
the amount is too large for the scouts to deal with alone, messengers
are sent back to the main column, whence there is immediately
despatched a detachment large enough to cope with the requirements....
On either side of the main column there are constantly running up and
down a few individuals of smaller size and lighter colour than the
other ants, which seem to play the part of officers; for they never
leave their stations, and while running up and down the outsides of the
column, they every now and again stop to touch antennæ with some member
of the rank and file, as if to give instructions. When the scouts
discover a wasps’-nest in a tree, a strong force is sent out from the
main army, the nest is pulled to pieces, and all the larvæ carried to
the rear of the army, while the wasps fly around defenceless against
the invading multitude. Or, if the nest of any other species of ant
is found, a similarly strong force—or perhaps the whole army—is
deflected towards it, and with the utmost energy the innumerable
insects set to work to sink shafts and dig mines till the whole nest
is rifled of its contents. In these mining operations the ants work
with an extraordinary display of organized co-operation; for those low
down in the shafts do not lose time by carrying up the earth which they
excavate, but pass the pellets to those above; and the ants on the
surface, when they receive the pellets, carry them—with an appearance
of forethought which quite staggered Mr. Bates—only just far enough to
insure that they shall not roll back again into the shaft, and, after
depositing them, immediately hurry back for more. But there is not a
rigid (or merely mechanical) division of labour: the work seems to be
performed by intelligent co-operation amongst a host of eager little
creatures; for some of them act at one time as carriers of pellets, and
at another as miners, while all shortly afterwards assume the office of
conveyers of the spoil.”[60]
Mr. Belt writes:—“The Ecitons and most other ants follow each other by
scent, and I believe they can communicate the presence of danger, of
booty, or other intelligence to a distance by the different intensity
or qualities of the odours given off. I one day saw a column running
along the foot of a nearly perpendicular tramway cutting, the side
of which was about six feet high. At one point I noticed a sort of
assembly of about a dozen individuals that appeared in consultation.
Suddenly one ant left the conclave, and ran with great speed up the
perpendicular face of the cutting without stopping.... On gaining
the top of the cutting, the ants entered some brushwood suitable for
hunting. In a very short time the information was communicated to the
ants below, and a dense column rushed up in search of prey.”
Again, Mr. Bates writes:—“When I interfered with the column, or
abstracted an individual from it, news of the disturbance was quickly
communicated to a distance of several yards to the rear, and the
column at that point commenced retreating.”
On arriving at a stream of water, the marching column first endeavours
to find some natural bridge whereby to cross it. Should no such bridge
be found, “they travel along the bank of the river until they arrive
at a flat sandy shore. Each ant now seizes a bit of dry wood, pulls
it into the water and mounts thereon. The hinder rows push the front
ones farther out, holding on to the wood with their feet and to their
comrades with their jaws. In a short time the water is covered with
ants, and when the raft has grown too large to be held together by the
small creatures’ strength, a part breaks itself off, and begins the
journey across, while the ants left on the bank pull the bits of wood
into the water, and work at enlarging the ferry-boat until it breaks
again. This is repeated as long as an ant remains on shore.”[61]
So much, then, to give a general idea of the extent to which
co-operation is exhibited by Ecitons—a fact which must be taken to
depend upon some system of signs. Turning next to still more definite
evidence of communication, Mr. Hague, the geologist, writing to Mr.
Darwin from South America, says that on the mantel-shelf of his
sitting-room there were three vases habitually filled with fresh
flowers. A nest of red ants discovered these flowers, and formed a
line to them, constantly passing upwards and downwards between the
mantel-shelf and the floor, and also between the mantel-shelf and the
ceiling. For several days in succession Mr. Hague frequently brushed
the ants in great numbers from the wall to the floor, but, as they
were not killed, the line again reformed. One day, however, he killed
with his finger some of the ants upon the mantel-shelf. “The effect of
this was immediate and unexpected. As soon as those ants which were
approaching arrived near to where their fellows lay dead and suffering,
they turned and fled with all possible haste. In half an hour the wall
above the mantel-shelf was cleared of ants. During the space of an
hour or two the colony from below continued to ascend until reaching
the lower bevelled edge of the shelf, at which point the more timid
individuals, although unable to see the vase, somehow became aware of
the trouble, and turned without further investigation; while the more
daring advanced hesitatingly just to the upper edge of the shelf, when,
extending their antennæ and stretching their necks, they seemed to peep
cautiously over the edge until they beheld their suffering companions,
when they too turned and followed the others, expressing by their
behaviour great excitement and terror. An hour or two later the path
or trail leading from the lower colony to the vase was entirely free
from ants.... A curious and invariable feature of their behaviour was
that when an ant, returning in fright, met another approaching, the two
would always communicate; but each would pursue its own way, the second
ant continuing its journey to the spot where the first ant had turned
about, and then following that example. For some days after this there
were no ants visible on the wall, either above or below the shelf.
Then a few ants from the lower colony began to reappear; but instead
of visiting the vase, which had been the scene of the disaster, they
avoided it altogether, and, following the lower front edge of the shelf
to the tumbler standing near the middle, made their attack upon that
with precisely the same result.”
Lastly, Sir John Lubbock made some experiments with the express purpose
of testing the power of communication by ants. He found that if an ant
discovered a deposit of larvæ outside the nest, she would return to the
nest, and, even though she might have no larvæ to show, was able to
communicate her need of assistance—a number of friends proceeding to
follow her as a guide to the heap of larvæ which she had found.
In one very instructive experiment Sir John arranged three parallel
pieces of tape, each about two and a half feet long: one end of each
piece of tape was attached to the nest, and the other dipped into a
glass vessel. In the glass at the end of one of the tapes he placed a
considerable number of larvæ (300 to 600): in the glass at the end of
another of the pieces he put only two or three larvæ, while the third
glass he left empty. The object of the empty glass was to see whether
any of the ants would come to the glass under such circumstances by
mere accident. He then took two ants, one of which he placed in the
glass with the many larvæ, and the other in the glass with the few.
Each ant took a larva, carried it to the nest, then returned for more,
and so on. After each journey he put another larva in the glass with
the few larvæ, in order to replace the one which had been removed. The
result of the experiment was that during 47½ hours the ants which had
gone to the glass containing numerous larvæ brought 257 friends to
their assistance, while during 53 hours those which had gone to the
glass containing only two or three larvæ brought only 82 friends; and
no single ant came to the glass which contained no larva. Now, as all
the glasses were exposed to similar conditions, and as the roads to the
first two must, in the first instance at all events, have been equally
scented by the passage of ants over them, these results appear very
conclusive as proving some power of definite communication, not only
that larvæ are to be found, but even where the largest store is to be
met with.
As to the means of communication, or method of sign-making, there can
be no doubt that this in ants, as in bees, is mainly gestures made
by the antennæ; but that gestures of other kinds are also employed
is sufficiently well proved by the following observation of the
Rev. Dr. M’Cook. “I have seen an ant kneel down before another and
thrust forward the head, drooping quite under in fact, and lie there
motionless, thus expressing as plainly as sign-language could, her
desire to be cleansed. I at once understood the gesture, and so did the
supplicated ant, for she at once went to work.”
So much, then, for the power of sign-making displayed by the
Hymenoptera. As I have not much evidence of sign-making in any of the
other Invertebrata,[62] I shall pass on at once to the Vertebrata.
Ray observed the different tones used by the common hen, and found
them uniformly significant of different ideas, or emotional states;
therefore we may properly regard this as a system of language, though
of a very rudimentary form. He distinguishes altogether nine or ten
distinct tones, which are severally significant of as many distinct
emotions and ideas—namely, brooding, leading forth the brood, finding
food, alarm, seeking shelter, anger, pain, fear, joy or pride in having
laid an egg. Houzeau, who independently observed this matter, says that
the hen utters at least twelve significant sounds.[63]
Many other cases could be given among Birds, and a still greater number
among Mammals, of vocal tones being used as intentionally significant
of states of feeling and of definite ideas; but to save space I will
only render a few facts in a condensed form.
“In Paraguay, the _Cebus azaræ_ when excited utters at least six
distinct sounds, which excite in other monkeys similar emotions
(Rengger).... It is a more remarkable fact that the dog, since being
domesticated, has learned to bark in at least four or five distinct
tones: ... the bark of eagerness, as in the chase; that of anger, as
well as growling; the yelp, or howl of despair, when shut up; the
baying at night; the bark of joy when starting on a walk with his
master; and the very distinct one of demand or supplication, as when
wishing for a door or window to be opened.”[64]
I may next briefly add allusions to those instances of the use of
signs by mammals which are fully detailed in _Animal Intelligence_.
Mr. S. Goodbehere tells me of a pony which used to push back the inside
bolt of a gate in its paddock, and neigh for an ass which was loose in
the yard beyond; the ass would then come and push up the outside latch,
thus opening the gate and releasing the pony (p. 333).
With respect to gestures, Mrs. K. Addison wrote me of her
jackdaw—which lived in a garden, and which she usually supplied with a
bath—reminding her that she had forgotten to place the bath, by coming
before her and going through the movements of ablution upon the ground
(p. 316).
Youatt gives the case of a pig which was trained to point game with
great precision (pp. 339, 340), and this, as in the case of the dog,
implies a high development of the sign-making faculty. Every sportsman
must know how well a setter understands its own pointing, _and also the
pointing of other dogs_, as gesture-signs. As regards its own pointing,
if at any distance from the sportsman, the animal will look back to
see if the “point” has been noticed; and, if it has, the point will be
much more “steady” and prolonged than if the animal sees that it has
not been observed. As regards the pointing of other dogs, the “backing”
of one by another means that as soon as one dog sees another dog point
he also stands and points, whether or not he is in a position to scent
the game. In my previous work, while treating of artificial instincts,
I have shown (as Mr. Darwin had previously remarked) that in well-bred
sporting dogs a tendency to “back,” more or less pronounced, is
intuitive. But I have also observed among my own setters that even in
cases where a young dog does not show any innate disposition to “back,”
by working him with other dogs for a short time he soon acquires the
habit, without any other instruction than that which is supplied by his
own observation. I have also noticed that all sporting dogs are liable
to be deceived by the attitude which their companions strike when
defæcating; but this is probably due to their line of sight being so
much lower than that of a man, that slight differences of attitude are
not so perceptible to them as to ourselves.
Major Skinner writes of a large wild elephant which he saw on a
moonlight night coming out of a wood that skirted some water.
Cautiously advancing across the open ground to within a hundred yards
of the water, the animal stood perfectly motionless—the rest of the
herd, still concealed in the wood, being all the while so quiet and
motionless that not the least sound proceeded from them. Gradually,
after three successive advances, halting some minutes after each, he
moved up to the water’s edge, in which however he did not think proper
to quench his thirst, but remained for several minutes listening in
perfect stillness. He then returned cautiously and slowly to the point
at which he had issued from the wood, whence he came back with five
other elephants, with which he proceeded, somewhat less slowly than
before, to within a few yards of the tank, where he posted them as
patrols. He then re-entered the wood and collected the whole herd,
which must have amounted to between eighty and a hundred, and led them
across the open ground, with the most extraordinary composure and
quiet, till they came up to the five sentinels, when he left them for
a moment and again made a reconnaissance at the edge of the tank. At
last, being apparently satisfied that all was safe, he turned back,
and obviously gave the order to advance; “for in a moment,” says
Major Skinner, “the whole herd rushed to the water, with a degree of
unreserved confidence so opposite to the caution and timidity which had
marked their previous movements, that nothing will ever persuade me
that there was not rational and preconcerted co-operation throughout
the whole party”—and so, of course, some definite communication by
signs (p. 401).
With regard to the use of gesture-signs by cats, I have given such
cases as those of their imitating the begging of a terrier on observing
that the terrier received food in answer to this gesture (p. 414);
making a peculiar noise on desiring to have a door opened, which, if
not attended to, was followed up by “pulling one’s dress with its
claws, and then, having succeeded in attracting the desired attention,
it would walk to the street door and stop there, making the same cry
until let out” (p. 414); also of a cat which, on seeing her friend
the parrot “flapping its wings and struggling violently up to its
knees in dough,” ran upstairs after the cook to inform her of the
catastrophe—“mewing and making what signs she could for her to go
down,” till at last “she jumped up, seized her apron, and tried to drag
her down,” so that the cook did go down in time to save the bird from
being smothered. This gesture-sign of pulling at clothing, in order to
induce one to visit a scene of catastrophe, is of frequent occurrence
both in cats and dogs. Several instances are likewise given of cats
jumping on chairs and looking at bells when they want milk (this being
intended as a sign that they desire the bell pulled to call the servant
who brings the milk), placing their paws upon the bell as a still more
emphatic sign, or even themselves ringing the bell (p. 416).
Concerning gesture-signs made by dogs (other than pointing), I may
allude to a terrier which I had, and which when thirsty used to signify
his desire for water by begging before a wash-stand, or any other
object where he knew that water was habitually kept. And Sir John
Lefroy, F.R.S., gave me a similar, though still more striking, case of
his terrier, which it was the duty of a maid-servant to supply with
milk. One morning this servant was engaged on some needlework, and did
not supply the milk. “The dog endeavoured in every possible way to
attract her attention and draw her forth, and at last pushed aside the
curtain of a closet, and, although never having been taught to fetch or
carry, took between his teeth the cup she habitually used, and brought
it to her feet” (p. 466). Another case somewhat similar is given on the
same page.
Again, Mr. A. H. Browning wrote me:—“My attention was called to my dog
appearing in a great state of excitement, not barking (he seldom barks)
but whining, and performing all sorts of antics (in a human subject I
should have said _gesticulating_). The herdmen and myself returned to
the sty; we caught but one pig, and put him back; no sooner had we done
so, than the dog ran after each pig in succession, brought him back to
the sty by the ear, and then went after another, until the whole number
were again housed” (p. 450).
Further, I give an observation of my own (p. 445) on one terrier making
a gesture-sign to another. Terrier A being asleep in my house, and
terrier B lying on a wall outside, a strange dog, C, ran along below
the wall on the public road following a dog-cart. Immediately on seeing
C, B jumped off the wall, ran upstairs to where A was asleep, woke him
up by poking him with his nose in a determined and suggestive manner,
which A at once understood as a sign: he jumped over the wall and
pursued the dog C, although C was by that time far out of sight, round
a bend in the road.
On page 447 I give, on the authority of Dr. Beattie, the case of a
dog which saved his master’s life (who had fallen through the ice,
and was supporting himself with a gun placed across the opening), by
running into a neighbouring village, and pulling a man by the coat in
so significant a manner that he followed the animal and rescued the
gentleman. Many cases more or less similar to this one are recorded in
the anecdote books.
Concerning the use of gesture-signs by monkeys, I give on page 472 the
remarkable case recorded by James Forbes, F.R.S., of a male monkey
begging the body of a female which had just been shot. “The animal,”
says Forbes, “came to the door of the tent, and, finding threats of
no avail, began a lamentable moaning, and by the most expressive
gestures seemed to beg for the dead body. It was given him; he took it
sorrowfully in his arms and bore it away to his expecting companions.
They who were witnesses of this extraordinary scene resolved never
again to fire at one of the monkey race.”
Again, Captain Johnson writes of a monkey which he shot upon a tree,
and which then, as he says, “instantly ran down to the lowest branch of
a tree, as if he were going to fly at me, stopped suddenly, and coolly
put his paw to the part wounded, covered with blood, and held it out
for me to see. I was so much hurt at the time that it has left an
impression never to be effaced, and I have never since fired a gun at
any of the tribe. Almost immediately on my return to the party, before
I had fully described what had passed, a Syer came to inform us that
the monkey was dead. We ordered the Syer to bring it to us; but by the
time he returned the other monkeys had carried the dead one off, and
none of them could anywhere be seen” (p. 475).
And Sir William Hoste records a closely similar case. One of his
officers, coming home after a long day’s shooting, saw a female
monkey running along the rocks, with her young one in her arms. He
immediately fired, and the animal fell. On his coming up, she grasped
her little one close to her breast, and with her other hand pointed
to the wound which the ball had made, and which had entered above her
breast. Dipping her finger in the blood and holding it up, she seemed
to reproach him with having been the cause of her pain, and also of
that of the young one, to which she frequently pointed. “I never,” says
Sir William, “felt so much as when I heard the story, and I determined
never to shoot one of these animals as long as I lived” (p. 476).
Lastly, as proof that the more intelligent of the lower animals admit
of being _taught the use of signs of the most conventional character_
(or most remote from any natural expression of their feelings and
ideas), I may allude to the recent experiments by Sir John Lubbock
on “teaching animals to converse.” These experiments consisted in
writing on separate and similar cards such words as “bone,” “water,”
“out,” “pet me,” &c., and teaching a dog to bring a card bearing the
word expressive of his want at the time of bringing it. In this way
an association of ideas was established between the appearance of a
certain number and form of written signs, and the meaning which they
severally betokened. Sir John Lubbock found that his dog learnt the
correct use of those signs.[65] Of course in these experiments marks
of any other kind would have served as well as written words; for it
clearly would be absurd to suppose that the dog could read the letters,
so as mentally to construct them into the equivalent of a spoken
word, in any such way as a child would spell b-o-n-e, bone. But, all
the same, these experiments are of great interest as showing that it
falls within the mental capacity of the more intelligent animals to
appreciate the use of signs so conventional as those which constitute
a stage of writing _above_ the drawing of pictures, and _below_ the
employment of an alphabet.
* * * * *
Enough has now been said to prove incontestably that animals present
what I have called the germ of the sign-making faculty. As the main
object of these chapters is to estimate the probability of human
language having arisen by way of a continuous development from this
germ, we may next turn to take a general survey of human language in
its largest sense, or as comprising all the manifestations of the
sign-making faculty.
Referring again to the schema (page 88), it is needless to consider
cases 1 and 2, for evidently these are on a psychological level in man
and animals. Case 3, also, especially in the direction of its branch
4, is to a large extent psychologically equivalent in men and animals:
so far as there is any difference it depends on the higher psychical
nature of man being much more rich in ideas which find their natural
expression in gestures or tones, and which, therefore, are impossible
in brutes. But it will be conceded that here there is nothing to
explain. The fact that man has a mind more richly endowed with ideas
carries with it, as a matter of course, the fact that their natural
expression is more multiplex.
The case, however, is different when we arrive at conventional signs;
for these attain so enormous a development in man as compared with
animals, that the question whether they do not really depend on some
additional mental faculty, distinct in kind, becomes fully admissible.
The first thing, then, we have to notice with regard to conventional
signs as used by man is, that no line of strict demarcation can be
drawn between them and natural signs; the latter shade off into the
former by gradations, which it becomes impossible to detect over large
numbers of individual cases. With respect to tones, for example, it
cannot be said, in many instances, whether this and that modulation,
which is now recognized as expressive of a certain state of feeling,
has always been thus expressive, or has only become so by conventional
habit; although, if we consider the different tones by which different
races of mankind express some of their similar feelings, we may be sure
that in these cases one or other of the differences must be due to
conventional habit—just as in the converse cases, in which all mankind
use the same tones to express the same feelings, we may be sure that
this mode of expression is natural. And so with gestures. Many which at
first sight we should, judging from our own feelings alone, suppose to
be natural—such, for instance, as kissing—are shown by observation
of primitive races to be conventional; while others which we should
probably regard as conventional—such, for instance, as shrugging the
shoulders—are shown by the same means to be natural.[66]
But for our present purposes it is clearly a matter of no consequence
that we should be able to classify all signs as natural or
conventional. For it is certain that animals employ both; and hence
no distinction between the brute and the man can be raised on the
question of the kind of signs which they severally employ as natural
or conventional. This distinction, therefore, may in future be
disregarded, and natural and conventional signs, _if made intentionally
as signs_, I shall consider as identical. For the sake of method,
however, I shall treat the sign-making faculty as exhibited by man in
the order of its probable evolution; and this means that I shall begin
with the most natural, or least conventional, of the systems. This is
the language of tone and gesture.