physics. The gold leaves of the electroscope separate, the
pith -balls are attracted towards electrified bodies in spite
of their weight, and are repelled with a rapidity greater
than that which would result merely from their own weight.
And yet these bodies have no more ceased to possess weight
than those masses of iron raised by the powerful mao-nets of
M. Jamin. Etherodynamy in these two ca.ses merely
overcame gravitation and either modified or imitated its
lo TJic Hunicin Species.
Those terrestrial bodies wliicli present no other pheno-
mena than those which can be referred to either gi-avita-
tion or etherod^mamy have, since the time of Linna?us, been
termed Inanimate Bodies. Together they constitute the
Mineral Kingdom. We see that the existence and the
distinction of this gi-oup are perfectly independent of any
hypothesis intended to explain the phenomena.
Two kinds of iihenomena then are characteristic of the
mineral kingdom : p/ie?iome?2(Z of the Keplerian movement
and 'physico-chemical phenomena, -which may be attri-
buted to the action of two forces : gravitation and ethero-
V. The sidereal and mineral kingdoms form the Inorganic
Empire. Passing from it we enter the domain of organised
and living beings. We have already'seen the essential phe-
nomena by which they are distinguished. These phenomena
differ essentially from all those which we have observed in
inanimate bodies. It seems to me, therefore, necessary to
attribute them to a special cause, — to Life.
I know that in the present day any one making use of
this word is readily accused by a great number of physicists
and chemists, and by an entire physiological school, of in-
troducing into science a vague and almost mysterious expres-
sion. There is, however, nothing in it more vague or mys-
terious than in the word gravitation.
It is very true that we do not know what Life is ; but no
more do we know ^vhat the force is that set the stars in
motion and retains them in their orbits. If astronomers
have been right in giving to the force, or iinkmnvn cause,
which gives the worlds their mathematical movements,
naturalists have a perfect right to designate by a special
term that unknown cause which produces filiation, birth
It will bo ajjparcnt that my idea of Life is not tlic same
as it was with many ancient vitalists, that it is no more the
arche of van Ibimont than i\\(i vital principh of liarthez.
Its function appears to mo very ditTerent to that attributed
Empires and Kingdoms of Nature. 1 1
to it by most of our piotlocessors.anJ wliich is .still attributed
to it by some pliy.siol()<,nsts.
Far from merely animating the organs, it is closely asso-
ciated with the furces of whit-li we have already spoken. Li vino-
beings arc heavy, and therefore subject to gravitation ; they
are the seat of numerous and various physico-chemical phe-
nomena -which arc indispensable to their existence and which
must be referred to the action of ctherodynamy. But these
phenomena arc here manifested under the influence of
n not her force. It is for this reason that the results of these
phenomena are often quite ditfereut to those in inanimate
bodies, and that living beings have their special products.
Life is not antagonistic to the inanimate forces, but it governs
and rules their action by its laws. Therefore it makes them
produce tissues, organs and individuals instead of crystals ;
it organises germs, and maintains through space and time,
in spite of the most complex metamorphoses, that luiitij of
definite living forms which we call Species.
If the anti-vitalists would only seriously reflect upon the
matter, they would acknowledge that, considered from this
point of view, there is nothing more mysterious in living
beings than in some of the commonest plienomcna presented
by inanimate bodies. The intervention of Life as a modify-
ing agent of actions purely etherodynamic may be as easily
admitted as that of ctherodynamy itself modifying and over-
coming the action of weight. It is just as strange to see a
piece of iron attracted and supported by a magnet, as to see
carbon, oxygen, hydrogen and nitrogen combine and dispose
themselves so as to form an animal or vegetable cell instead
of any imaginable inorganic composition.
1 have repeatedly, and for many years, maintained the doc-
trine which I have sunmied up here. It seems to me confirmed
in the highest degree by the researches undertaken fur the
elucidation of the problem of which we are treating. The
experiences of M. Bernard in particular, relative to the
action exercised by anajsthetics upon plants as well as upon
animals, makes it impossible for us to doubt for a m.omcnt
12 TIic Unman Species.
the intervention of an agent distinct from pliy.sioo-cliemical
forces in organic beings. In employing the word Life to
designate this agent, I only make use of an established
expression, ■without pretending to go beyond the information
gained from experiment and scientific observation.
Beings, in which life alone is added to gravitation and
etherodynamy constitute tlie Ver/etahle Kingdom. Now
there is one general fact displayed by this group, the
sisrnificance of which has not, it seems to me, been sufii-
ciently understood. With the exception of certain pheno-
mena of itnconscious irritability which have long been
known in some plants of a superior order, and of facts, pro-
bably of the same class, which have been established chiefly
with reference to some reproductive organs of plants of an
inferior order, every movement wiiich takes place in plants
appears to be produced solely by inanimate forces. The
transfer of matter in particular, which is necessary for the
development and sustenance of every vegetable, belongs to
actions of this kind. Can we believe that these forces, as
they are known to us from innumerable experiments, could,
if left to themselves, have formed an oak, or even raised a
mushroom ? Can we believe that they could have organised
tlie acorn or the spore, and hidden in those minute bodies
the power of reproducing the parent? And yet without
them the vegetable cannot exist. But, in my opinion,
nothing makes their real subordination more apparent than
the importance of their part in the process of execution.
They may be compared to workmen raising an edifice under
the eye of the architect who has made the plan.
Are wc then to conclude that life is an intelligent force,
conscious of the part it plays, and enjoying the dominion it
exercises over the subordinate inanimate forces ? Not at
all. Like these forces, it is ruled by general and fixed laws.
Nevertheless, we do not find in the application of these laws,
and in the results t<j which they lead, the mathematical
precision of the laws and phenomena of gravitation and
etherodynamy. 'J'lieir mode of action merely seems to oscil-
Empii'cs and Kingdoms of Natitrc. 1 3
late between limits which remain impassable. This kind of
liberty, and the bounds imposed upon it, are conspicuous
ill tlio constant diversity of the jiroducts of life, a diversity
wliieli contrasts in so striking a manner with the uniformity
of tlie products of etherodynamy. Crystals, when similar in
composition, and when formed under similar circumstances,
resemble each other perfectly ; but we never find two leaves
exactly alike upon the same tree.
The vegetable kingdom is, tlierefore, characterised by three
kinds of plicnvmena : the Kephi'icm movement, physico-
theviical 2>henomcna, and vital pltenomena, which may be
ascribed to the action of three forces : Gravitation, Ethero-
ihjnamy, and Life.
VI. We find repeated among animals all the phenomena
which we have noticed amongst plants, and, especially in
the highest orders, those movements due to unconscious
irritability, of which examples are presented by plants.
Some eminent men, Lamarck among the number, have even
wished to refer all acts performed by inferior animals to this
order of phenomena. But here the author of La Philoso-
phie Zoolofjique has fallen into an anatomical error, which has
been long since recognised ; and whoever has lived, even for
a short time, by the sea-side, or has followed closely the
habits and actions of worms and zoophytes will certainly
protest against this manner of regarding them.
Pa.ssing from the plant to the animal, the latter executes
movements belonging either to the part or to the whole
which arc perfectly independent of the laws of gravitation
and etherodynamy. The regulating and determining cause
of these movements is evidently within the animal itself. It
is the Will. But the Will itself is intimately connected
with sensibility and consciousness. To everyone who judges
animals by what he finds takes place within himself, personal
experiment and observation prove that the animal feels,
jmhjcs, and ivills, that is to .say rca.ions, and cun.seciuently
This proposition will, I know, be contested by men whose
14 The Human Sj)ca'cs.
learning I profoundly respect, and objections will be made
on all sides. On the one hand the Automatism of Descartes
will be revived in some schools, and will now be supported
by physiology and the experiments of vivisection. I am far
from denying the great interest which is attached to the
latter, and to the phenomena of reflex actions. But the
conclusions which are drawn from them appear to me singu-
larly exaggerated ; Carpenter has rightly opposed them with
personal experiment. I will add that the study of animals
placed far below, and certainly inferior to, the frog, would
doubtless lead to very diftercnt interpretations. Moreover,
Huxley himself admits that animals are probably sensible
and conscious automata. But if they were merely machines
we should be obliged to allow that they performed their
functions as 2/ they felt, judged, and willed.
On the other hand, in the name of philosophy and psycho-
logy, I shall be accused of confounding certain intellectual
attributes of the human reason with the exclusively sen^«7a'C
faculties of animals. I shall presently endeavour to answer
this criticism from the standpoint which should never be
(quitted by the naturalist, that, namely, of experiment and
observation. I shall here confine myself to saying that, in
my opinion, the animal is intelligent, and, although a rudi-
mentary being, its intelligence is nevertheless of the same
nature as that of man. It is, moreover, very unecjually
distributed among the animal species ; in this respect there
are many intervening stages between the oyster and the
In atldition to the phenomena which spring from the intelli-
gence and reasoning, we find in animals other imjiulses which
arise from Instinct, a blind impulse, or at least apparently so,
which often is the characteristic of animal species, and with
wiiich each iiulividual is endowed. These two orders of facts
arc very often confounded, but the confusion can bo explained
a.s follows. In the first ])Iaco, instinct has lus its ol)ject the
attainment of a determined and fixe<l result, but in the
multitude of ways and means necessary to attain this result
Empires and Kingdoms of A^afurc. 1 5
a portion whicli is often very largo is due to the intelligence.
'J'lie distinction is not always easy. It will, moreover, be
apparent that I cannot here enter into the details required
by the examination of this question, so entirely foreign to
that which is before us.
Ik'sidc's the acts of intelligence and instinct, phenomena
have been established among animals which are closely
connected with what we call charnder, senilment, or
passion. The familiarity of the terms is in itself a proof
that upon this point ordinary observation has outstripped
All these i)henomena are perfectly new and have no
analogy with those which we have noticed in the preceding
kingdoms. They evidently justify the formation of an
equally important group. The animal Jcingdom is thus
universally admitted, independently of every theory which
attempts to explain its characters.
Facts radically different cannot be attributed to the same
cause. We must admit, then, that the characteristic pheno-
mena of the animal depend upon something different to
those met with in the vegetable or mineral kingdoms. They
are, moreover, united by such intimate relations, that it
would be impossible not to attribute them to a single cause.
From motives already mentioned we will give a name to
this Unhnown Cause, and, making use of an expression
already established, though open, I can see, to more than
one criticism, we will call it the Animal Mind (I'dme
an i male).
Does the animal mind liberate the beings it animates from
the inferior forces ? By no means, for we find them repeated
witii all their characteristics. In order to raise the least of
its organs, the animal must contend with weight ; it cannot
pcrfoi-m the smallest movement without the intervention of
])hysico-chemical phenomena ; it cannot breathe, and, there-
fore, cannot live, without constantly consuming some of its
constituents. In tlie animal, moreover, just as much as in
the plant, the inanimate forces, etherodynamy especially.
i6 The Human Species.
appear in their double character of constancy and of ubiquity
in the accomplishment of phenomena, and of subordination
to life, which governs their action in the animal as in the
Moreover, a large part is reserved for purely vegetative
life in animals of the highest order. The entire organism is
formed without any intervention of the animal mind. Again,
a certain number of organs always escape more or less from
the influence of the latter, and seem to be subject to life
alone. Now these organs are precisely those upon which
nutrition, and consequently the constitution and duration of
the whole, depend. Thus life, which reigned supreme in the
vegetable kingdom, now in its turn, appears in a subordinate
character. We might say that it was essentially entrusted
with the organisation and maintenance of the instruments
of the animal mind.
As to the latter, even where its intervention is most
questioned, it is only revealed to observation by voluntary
movements. Now personal experiment and the faculty of
reasoning, arc necessary to enable us to comprehend the
nature, and appreciate the signification of these movements.
It is only by regarding himself as normal, that man can
judge of the animal, a subject to which I shall presently
Phenomena of four Jcinds are then characteristic of the
Animal Kingdom : 'phenomena of the Keplerian movement;
2>hyiiico-chemical 2^henomena ; vital j^henomena ; and^jAcTio-
mena of voluntary movement; attributable to the action
of 'four forces: gravitation, cthcroch/namy, life, and the
VII. Athough the preceding statements are so much
abridged, I have thought it well to give the condensed
results in the following table :
Empires and Kingdoms of N'atnre. ij
'^Sidereal . .
Mineral . .
Animal . .
( Phenomena of the Kep-
( Icrian movement . .
! Phenomena of tlic Kcp-
lerian movement . .
I Phenomena of the Kcp-
j lerian movement . .
<, Physico-chemical phe-
I Vital phenomena . . .
Phenomena of the Kep-
lerian movement . .
Vital phenomena . .
Phenomena of voluntary
movemeat . . . .
From this table, and the expansions which it siini.s up, rise
the following conclusions.
1. Each kingdom is characterised by a certain number of
phenomena, whose existence is independent of all hypothesis
2. The phenomena increase in number from the sidereal
to the animal kinfjdom.
3. In passing from one kingdom to another, and proceeding
from the simple to the composite, a number of phenomena
appear, which are entirely unknown in the inferior kingdoms.
4. The superior kingdom presents, independently of its
special phenomena, the characteristic phenomena of the
5. Each group of phenomena indicated in the table is
connected with a small number of fundamental phenomena,
which can, in some cases with certainty, in others with more
or less probability, be referred to a single cause.
G. All these causes are equally unknown to us as regards
their nature and mode of action. We know them merely
by phenomena. We can, therefore, make no conjecture as
' 1 8 The Human Species.
to the relations, more or less close, which may exist between
7. We nevertheless give names to these causes for the
sake of convenience, and of facilitating the discussion of tlie
VIII. We can now return to the problem which gave rise
to these expansions, and ask the question : Whether Man
should take his place in the animal kingdom 1 a question
which evidently leads to another : Is man distinguished from
animals by important and characteristic phenomena, abso-
lutely unknown in the latter \ For more than forty years I
have answered this question in the affirmative, and my con-
victions, tested by many controversies, are now stronger
But it is neither in the material disposition, nor in the
action of his physical organism, that we must look for these
phenomena. From this point, of view, man is neither more
nor less than an animal. From an anatomical point of view,
there is less difference between man and the superior order
of apes, than between the latter and the inferior orders.
The microscope reveals equally striking resemblances between
the elements of the human organism and those of the animal
organism ; and chemical analysis leads to the same result.
It was easy to foresee that the action of elements and organs
would be exactly the same in man and beast, and such was
found to be the case.
Passions, sentiments, and characters, establish between
animals and ourselves equally close relations. The animal
loves and hates ; we recognise in it irritability and jealousy ;
unwearying patience, and immutable confidence. In our
domestic species, these differences are more apparent, or
perhaps we only notice them more closely. Who has not
known dogs whicli have been playful or snappish, affectionate
or savage, cowardly or courageous, friendly with everybody,
or exclusive in their affections.
Again, man has true instincts, were it only that of socia-
bility. Faculties, however, of this order, which are so fully
The Human Kingdom. 19
developed in certain animals, in man are evidently very
much reduced in comparison with the intelligence.
The relative development of the latter certainly estab-
lishes an enormous difference between man and animal It
is not, however, the inteixsity of a phenomenon which
gives value to it from our present point of view, but
simply its nature. The question is whether human intelli-
gence and animal intelligence can be considered as of the
As a rule philosophers, psychologists, and theologians, have
replied in the negative, and naturalists in the affirmative.
This opposition can be easily understood. The former make
the human mind, considered as an indivisible whole, their
principal study, and attribute to it all our faculties. Unable
to deny the similarity, external at least, between certain
animal and human acts, and yet being anxious to clearly
distinguish man from the brute, they have given to the acts
different interpretations as they have been performed by one
or the other. Naturalists have regarded the phenomena
more closely without thinking of anything else, and when
they have seen the animal behave in the same manner as
they themselves would have done under the given circum-
stances, they have concluded that the motives of the action
must ])e fundamentally the same. I must ask permission to
remain a naturalist, and to recall some facts, and regard
them from this point of view.
The theologians themselves allow that the animal pos-
sesses sensation, formation and association of images, im-
agination, and passion (R. P. de BonniotJ, They allow
that the animal feels the relation of fitness or of unfitness
between sensible objects and his own senses ; that it experi-
ences sensible attractions and repulsions, and acts perfectly
in consequence, and that in this sense the animal reasons
and judges (I'Abbe A. Lecomte). Therefore, they add, we
cannot doubt but that the animal possesses a principle
superior to that of mere matter, and we may even give it
the name of mind (R. P. Bonniot). But in spite of all,
20 The HiLinan Species.
theologians and philosophers maintain that the animal cannot
be intelligent, because it has neither innate sense, conscious-
ness nor reason.
Let us leave for a moment the last term, with which the
idea of phenomena which we shall presently discuss, is
connected in the mind of our opponents. Is it true that
animals are wanting in innate sense, and are not conscious of
their actions ? Upon what facts of observation does this
opinion rest? We each one of us feel that we possess this
sense, that we enjoy this faculty. By means of speech we
can convey to another the results of our personal experience.
But this source of information is wanting when we come to
deal with animals. Neither in them nor in ourselves are
innate sense and consciousness revealed to the outer world
by any special characteristic movement. It is, therefore,
only by interpreting these movements, and by judging from
ourselves, that we can form an idea of the motives from
which the animal acts.
Proceeding in this manner, it seems to me impossible to
refuse to allow animals a certain amount of consciousness of
their actions. Doubtless, they do not form such an exact
estimate of them, as even an illiterate man can do. But we
may be very certain that when a cat is trying to catch
sparrows on level ground, and creeps along the hollows,
availing herself of every tuft of grass however small, she
knows what she is about, just as well as the hunter who
glides in a crouching attitude from one bush to another.
We may be equally sure that kittens and puppies when they
fight, growl and bite without hurting each other, know very
well that they are playing and not in earnest.
I must here beg permission to relate the remembrance of
my struggles with a mastiff of pure breed, and which had
attained its full size, remaining, however, very young in
character. We were very good friends, and often played
together. As soon as ever I assumed an attitude of defence
before him, he would leap upon me with every appearance
of fury, seizing in his mouth the arm which I had used
The Hnman Kiiigdo7n. 21
as a sliielJ. He might have marked my arm deeply at
the first onset, but he never pressed it in a manner that
could inflict the slightest pain. I often seized him by his
lower jaw with my hand, but he never used his teeth so
as to bite me. And yet the next moment the same teeth
would indent a piece of wood, I tried to tear away from
This animal evidently knew what it was doing when it
feigned the passion precisely o'p'posite to that which it really
felt; when, even in the excitement of play, it retained
sufficient mastery over its movements to avoid hurting me.
In reality it played a part in a comedy, and we cannot act
without being conscious of it.
It is useless for me to insist upon many other facts which
I could bring forward, and I refer my reader to the works of
those naturalists who have studied the question, especially
those of F. Cuvier. But the more I reflect upon it, the
more is my conviction confirmed that man and animals
think and reason in virtue of a faculty which is common to
both, and which is only far more developed in the latter
than in the former.
What I have just said of the intelligence I do not hesitate
to say also of language, the highest manifestation of the
intelligence. It is true that man alone possesses speech, that
is to say the articulate voice. But two classes of animals
possess voice. With us it is, again, only a high degree of
perfection, nothing radically new. In both cases the sounds,
produced by the air which is thrown into vibration by the
voluntary movements accorded to the larynx, convey im-
pressions and personal thoughts which are understood by
individuals of the same species. The mechanism of the