PSYCHIC GRADATIONS
Psychological Unity of Organic Nature--Material Basis of the
Soul: Psychoplasm--Scale of Sensation--Scale of Movement--Scale
of Reflex Action--Simple and Compound Reflex Action--Reflex
Action and Consciousness--Scale of Perception--Unconscious and
Conscious Perception--Scale of Memory--Unconscious and Conscious
Memory--Association of Perceptions--Instinct--Primary and Secondary
Instincts--Scale of Reason--Language--Emotion and Passion--The
Will--Freedom of the Will
The great progress which psychology has made, with the assistance
of evolution, in the latter half of the century culminates in the
recognition of _the psychological unity of the organic world_.
Comparative psychology, in co-operation with the ontogeny and phylogeny
of the _psyche_, has enforced the conviction that organic life in all
its stages, from the simplest unicellular protozoon up to man, springs
from the same elementary forces of nature, from the physiological
functions of sensation and movement. The future task of scientific
psychology, therefore, is not, as it once was, the exclusively
subjective and introspective analysis of the highly developed mind
of a philosopher, but the objective, comparative study of the long
gradation by which man has slowly arisen through a vast series of lower
animal conditions. This great task of separating the different steps
in the psychological ladder, and proving their unbroken phylogenetic
connection, has only been seriously attempted during the last ten
years, especially in the splendid work of Romanes. We must confine
ourselves here to a brief discussion of a few of the general questions
which that gradation has suggested.
All the phenomena of the psychic life are, without exception, bound
up with certain material changes in the living substance of the body,
the _protoplasm_. We have given to that part of the protoplasm which
seems to be the indispensable substratum of psychic life the name
of _psychoplasm_ (the "soul-substance," in the monistic sense); in
other words, we do not attribute any peculiar "essence" to it, but
we consider the _psyche_ to be merely _a collective idea of all the
psychic functions of protoplasm_. In this sense the "soul" is merely
a physiological abstraction like "assimilation" or "generation." In
man and the higher animals, in accordance with the division of labor
of the organs and tissues, the psychoplasm is a differentiated part of
the nervous system, the _neuroplasm_ of the ganglionic cells and their
fibres. In the lower animals, however, which have no special nerves
and organs of sense, and in the plants, the psychoplasm has not yet
reached an independent differentiation. Finally, in the unicellular
protists, the psychoplasm is identified either with the whole of the
living protoplasm of the simple cell or with a portion of it. In all
cases, in the lowest as well as the highest stages of the psychological
hierarchy, a certain chemical composition and a certain physical
activity of the psychoplasm are indispensable before the "soul" can
function or act. That is equally true of the elementary psychic
function of the plasmatic sensation and movement of the protozoa,
and of the complex functions of the sense-organs and the brain in the
higher animals and man. The activity of the psychoplasm, which we call
the "soul," is always connected with metabolism.
All living organisms, without exception, are sensitive; they are
influenced by the condition of their environment, and react thereon by
certain modifications in their own structure. Light and heat, gravity
and electricity, mechanical processes and chemical action in the
environment, act as _stimuli_ on the sensitive psychoplasm, and effect
changes in its molecular composition. We may distinguish the following
five chief stages of this sensibility:
I. At the lowest stage of organization the _whole psychoplasm_, as
such, is sensitive, and reacts on the stimuli from without; that is the
case with the lowest protists, with many plants, and with some of the
most rudimentary animals.
II. At the second stage very simple and undiscriminating _sense-organs_
begin to appear on the surface of the organism, in the form of
protoplasmic filaments and pigment spots, the forerunners of the nerves
of touch and the eyes; these are found in some of the higher protists
and in many of the lower animals and plants.
III. At the third stage _specific organs_ of sense, each with a
peculiar adaptation, have arisen by differentiation out of these
rudimentary processes: there are the chemical instruments of smell
and taste, and the physical organs of touch, temperature, hearing,
and sight. The "specific energy" of these sense-organs is not an
original inherent property of theirs, but has been gained by functional
adaptation and progressive heredity.
IV. The fourth stage is characterized by the _centralization_ or
integration of the _nervous system_, and, consequently, of sensation;
by the association of the previously isolated or localized sensations
presentations arise, though they still remain unconscious. That is the
condition of many both of the lower and the higher animals.
V. Finally, at the fifth stage, the highest psychic function,
_conscious perception_, is developed by the mirroring of the sensations
in a central part of the nervous system, as we find in man and the
higher vertebrates, and probably in some of the higher invertebrates,
notably the articulata.
All living organisms without exception have the faculty of _spontaneous
movement_, in contradistinction to the rigidity and inertia of
unorganized substances (_e.g._, crystals); in other words, certain
changes of place of the particles occur in the living psychoplasm
from internal causes, which have their source in its own chemical
composition. These active vital movements are partly discovered by
direct observation and partly only known indirectly, by inference from
their effects. We may distinguish five stages of them.
I. At the lowest stage of organic life, in the chromacea, and many
protophyta and lower metaphyta, we perceive only those _movements of
growth_ which are common to all organisms. They are usually so slow
that they cannot be directly observed; they have to be inferred from
their results--from the change in size and form of the growing organism.
II. Many protists, particularly unicellular algæ of the groups of
diatomacea and desmidiacea, accomplish a kind of creeping or swimming
motion by _secretion_, by ejecting a slimy substance at one side.
III. Other organisms which float in water--for instance, many of the
radiolaria, siphonophora, ktenophora, and others--ascend and descend by
altering their _specific gravity_, sometimes by osmosis, sometimes by
the separation or squeezing-out of air.
IV. Many plants, especially the sensitive plants (mimosa) and other
papilionacea, effect movements of their leaves or other organs by
_change of pressure_--that is, they alter the strain of the protoplasm,
and, consequently, its pressure on the enclosing elastic walls of the
cells.
V. The most important of all organic movements are the _phenomena
of contraction_--_i.e._, changes of form at the surface of the
organism, which are dependent on a twofold displacement of their
elements; they always involve two different conditions or phases
of motion--contraction and expansion. Four different forms of this
plasmatic contraction may be enumerated:
(_a_) Amoeboid movement (in rhizopods, blood-cells,
pigment-cells, etc.).
(_b_) A similar flow of protoplasm within enclosed cells.
(_c_) Vibratory motion (ciliary movements) in infusoria,
spermatozoa, ciliated epithelial cells.
(_d_) Muscular movement (in most animals).
The elementary psychic activity that arises from the combination of
sensation and movement is called _reflex_ (in the widest sense),
reflective function, or _reflex action_. The movement--no matter what
kind it is--seems in this case to be the immediate result of the
_stimulus_ which evoked the sensation; it has, on that account, been
called stimulated motion in its simplest form (in the protists). All
living protoplasm has this feature of irritability. Any physical or
chemical change in the environment may, in certain circumstances,
act as a stimulus on the psychoplasm, and elicit or "release" a
movement. We shall see later on how this important physical concept of
"releasing" directly connects the simplest organic reflex actions with
similar mechanical phenomena of movement in the inorganic world (for
instance, in the explosion of powder by a spark, or of dynamite by a
blow). We may distinguish the following seven stages in the scale of
reflex action:
I. At the lowest stage of organization, in the lowest protists, the
stimuli of the outer world (heat, light, electricity, etc.) cause in
the indifferent protoplasm only those indispensable movements of growth
and nutrition which are common to all organisms, and are absolutely
necessary for their preservation. That is also the case in most of the
plants.
II. In the case of many freely moving protists (especially the
amoeba, the heliozoon, and the rhizopod) the stimuli from without
produce on every spot of the unprotected surface of the unicellular
organism external movements which take the form of changes of shape,
and sometimes changes of place (amoeboid movement, pseudopod
formation, the extension and withdrawal of what look like feet); these
indefinite, variable processes of the protoplasm are not yet permanent
organs. In the same way, general organic irritability takes the form
of indeterminate reflex action in the sensitive plants and the lowest
metazoa; in many multicellular organisms the stimuli may be conducted
from one cell to another, as all the cells are connected by fine fibres.
III. Many protists, especially the more highly developed protozoa,
produce on their unicellular body two little organs of the simplest
character--an organ of touch and an organ of movement. Both these
instruments are direct external projections of protoplasm; the
stimulus, which alights on the first, is immediately conducted to
the other by the psychoplasm of the unicellular body, and causes it
to contract. This phenomenon is particularly easy to observe, and
even produce experimentally, in many of the stationary infusoria
(for instance, the _poteriodendron_ among the flagellata, and the
_vorticella_ among the ciliata). The faintest stimulus that touches the
extremely sensitive hairs, or _cilia_, at the free end of the cells,
immediately causes a contraction of a thread-like stalk at the other,
fixed end. This phenomenon is known as a "simple reflex arch."
IV. These phenomena of the unicellular organism of the infusoria lead
on to the interesting mechanism of the neuro-muscular cells, which we
find in the multicellular body of many of the lower metazoa, especially
in the cnidaria (polyps and corals). Each single neuro-muscular cell
is a "unicellular reflex organ"; it has on its surface a sensitive
spot, and a motor muscular fibre inside at the opposite end; the latter
contracts as soon as the former is stimulated.
V. In other cnidaria, notably in the free swimming medusæ--which are
closely related to the stationary polyps--the simple neuro-muscular
cell becomes two different cells, connected by a filament; an external
_sense-cell_ (in the outer skin) and an internal _muscular cell_ (under
the skin). In this _bicellular reflex organ_ the one cell is the
rudimentary organ of sensation, the other of movement; the connecting
bridge of the psychoplasmic filament conducts the stimulus from one to
the other.
VI. The most important step in the gradual construction of the reflex
mechanism is the division into three cells; in the place of the simple
connecting bridge we spoke of there appears a third independent cell,
the _soul-cell_, or ganglionic cell; with it appears also a new psychic
function, _unconscious presentation_, which has its seat in this
cell. The stimulus is first conducted from the sensitive cell to this
intermediate presentative or psychic cell, and then issued from this to
the motor muscular cell as a mandate of movement. These _tricellular
reflex organs_ are preponderantly developed in the great majority of
the invertebrates.
VII. Instead of this arrangement we find in most of the vertebrates
a _quadricellular reflex organ_, two distinct "soul-cells," instead
of one, being inserted between the sensitive cell and the motor cell.
The external stimulus, in this case, is first conducted centripetally
to the sensitive cell (the sensible psychic cell), from this to the
_will-cell_ (the motor psychic cell), and from this, finally, to the
contractile muscular cell. When many such reflex organs combine and new
psychic cells are interposed we have the intricate reflex mechanism of
man and the higher vertebrates.
The important distinction which we make, in morphology and physiology,
between unicellular and multicellular organisms holds good for their
elementary psychic activity, reflex action. In the unicellular
protists (both the plasmodomous primitive plants, or _protophyta_,
and the plasmophagous primitive animals, or _protozoa_) the whole
physical process of reflex action takes place in the protoplasm of
one single cell; their "cell-soul" seems to be a unifying function
of the psychoplasm of which the various phases only begin to be seen
separately when the differentiation of special organs sets in.
The second stage of psychic activity, compound reflex action, begins
with the cenobitic protists (_v.g._, the volvox and the carchesium).
The innumerable social cells, which make up this cell-community
or coenobium, are always more or less connected, often directly
connected by filamentous bridges of protoplasm. A stimulus that alights
on one or more cells of the community is communicated to the rest by
means of the connecting fibres, and may produce a general contraction.
This connection is found, also, in the tissues of the multicellular
animals and plants. It was erroneously believed at one time that the
cells of vegetal tissue were completely isolated from each other, but
we have now discovered fine filaments of protoplasm throughout, which
penetrate the thick membranes of the cells, and maintain a material
and psychological communication between their living plasmic contents.
That is the explanation of the mimosa: when the tread of the passer-by
shakes the root of the plant, the stimulus is immediately conveyed to
all the cells, and causes a general contraction of its tender leaves
and a drooping of the stems.
An important and universal feature of all reflex phenomena is the
absence of consciousness. For reasons which we shall give in the tenth
chapter we only admit the presence of consciousness in man and the
higher animals, not in plants, the lower animals, and the protists;
consequently all stimulated movements in the latter must be regarded
as reflex--that is, all movements which are not _spontaneous_, not the
outcome of internal causes (impulsive and automatic movements).[14]
It is different with the higher animals which have developed a
centralized nervous system and elaborate sense-organs. In these cases
consciousness has been gradually evolved from the psychic reflex
activity, and now conscious, voluntary action appears, in opposition to
the still continuing reflex action below. However, we must distinguish
two different processes, as we did in the question of instinct--primary
and secondary reflex action. Primary reflex actions are those which
have never reached the stage of consciousness in phyletic development,
and thus preserve the primitive character (by heredity from lower
animal forms). Secondary reflex actions are those which were conscious,
voluntary actions in our ancestors, but which afterwards became
unconscious from habit or the lapse of consciousness. It is impossible
to draw a hard and fast line in such cases between conscious and
unconscious psychic function.
Older psychologists (Herbart, for instance) considered "presentation"
to be the fundamental psychic phenomenon, from which all the others are
derived. Modern comparative psychology endorses this view in so far as
it relates to the idea of _unconscious_ presentation; but it considers
_conscious_ presentation to be a secondary phenomenon of mental life,
which is entirely wanting in plants and the lower animals, and is
only developed in the higher animals. Among the many contradictory
definitions which psychologists have given of "presentation," we think
the best is that which makes it consist in an internal picture of the
external object which is given us in sensation--an "idea," in the
broader sense. We may distinguish the following four stages in the
rising scale of presentative function:
I. _Cellular presentation._--At the lowest stages we find presentation
to be a general physiological property of psychoplasm; even in the
simplest unicellular protist sensations may leave a permanent trace in
the psychoplasm, and these may be reproduced by memory. In more than
four thousand kinds of radiolaria, which I have described, every single
species is distinguished by special, hereditary skeletal structure. The
construction of this specific, and often highly elaborate, skeleton
by a cell of the simplest description (generally globular) is only
intelligible when we attribute the faculty of presentation, and,
indeed, of a special reproduction of the plastic "feeling of distance,"
to the constructive protoplasm--as I have pointed out in my _Psychology
of the Radiolaria_.[15]
II. _Histionic presentation._--In the coenobia or cell-colonies of
the social protists, and still better in the tissues of plants and
lower, nerveless animals (sponges, polyps, etc.), we find the second
stage of unconscious presentation, which consists of the common psychic
activity of a number of closely connected cells. If a single stimulus
may, instead of simply spending itself in the reflex movement of an
organ (the leaf of a plant, for instance, or the arm of a polyp),
leave a permanent impression, which can be spontaneously reproduced
later on, we are bound to assume, in explaining the phenomenon, a
histionic presentation, dependent on the psychoplasm of the associated
tissue-cells.
III. _Unconscious presentation in the ganglionic cells._--This
third and higher stage of presentation is the commonest form the
function takes in the animal world; it seems to be a localization of
presentation in definite "soul-cells." In its simplest form it appears
at the sixth stage of reflex action, when the tricellular reflex organ
arises: the seat of presentation is then the intermediate psychic
cell, which is interposed between the sensitive cell and the muscular
cell. With the increasing development of the animal nervous system
and its progressive differentiation and integration, this unconscious
presentation also rises to higher stages.
IV. _Conscious presentation in the cerebral cells._--With the highest
stage of development of the animal organization consciousness arises,
as a special function of a certain central organ of the nervous
system. As the presentations are conscious, and as special parts of
the brain arise for the association of these conscious presentations,
the organism is qualified for those highest psychic functions which
we call thought and reflection, intellect and reason. Although the
tracing of the phyletic barrier between the older, unconscious, and the
younger, conscious, presentation is extremely difficult, we can affirm,
with some degree of probability, that the evolution of the latter from
the former was _polyphyletic_; because we find conscious and rational
thought, not only in the highest forms of the vertebrate stem (man,
mammals, birds, and a part of the lower vertebrates), but also in the
most highly developed representatives of other animal groups (ants
and other insects, spiders and the higher crabs among the articulata,
cephalopods among the mollusca).
The evolutionary scale of memory is closely connected with that of
presentation; this extremely important function of the psychoplasm--the
condition of all further psychic development--consists essentially
in the _reproduction of presentations_. The impressions in the
bioplasm, which the stimulus produced as sensations, and which
became presentations in remaining, are revived by memory; they pass
from potentiality to actuality. The latent potential energy of the
psychoplasm is transformed into kinetic energy. We may distinguish
four stages in the upward development of memory, corresponding to the
four stages of presentation.
I. _Cellular memory._--Thirty years ago Ewald Hering showed "memory to
be a general property of organized matter" in a thoughtful work, and
indicated the great significance of this function, "to which we owe
almost all that we are and have." Six years later, in my work on _The
Perigenesis of the Plastidule, or the Undulatory Origin of the Parts
of Life: an Experiment in the Mechanical Explanation of Elementary
Evolutionary Processes_, I developed these ideas, and endeavored
to base them on the principles of evolution. I have attempted to
show in that work that unconscious memory is a universal and very
important function of all _plastidules_; that is, of those hypothetical
molecules, or groups of molecules, which Naegeli has called _micellae_,
others _bioplasts_, and so forth. Only _living_ plastidules, as
individual molecules of the active protoplasm, are reproductive,
and so gifted with memory; that is the chief difference between the
organic and inorganic worlds. It might be stated thus: "Heredity is
the memory of the plastidule, while variability is its comprehension."
The elementary memory of the unicellular protist is made up of the
molecular memory of the plastidules or _micellae_, of which its living
cell-body is constructed. As regards the extraordinary performances
of unconscious memory in these unicellular protists, nothing could be
more instructive than the infinitely varied and regular formation of
their defensive apparatus, their shells and skeletons; in particular,
the diatomes and cosmaria among the protophytes, and the radiolaria
and thalamophora among the protozoa, afford an abundance of most
interesting illustrations. In many thousand species of these protists
the specific form which is inherited is _relatively constant_, and
proves the fidelity of their unconscious cellular memory.
II. _Histionic memory._--Equally interesting examples of the second
stage of memory, the unconscious memory of tissues, are found in the
heredity of the individual organs of plants and the lower, nerveless
animals (sponges, etc.). This second stage seems to be _a reproduction
of the histionic presentations_, that association of cellular
presentations which sets in with the formation of coenobia in the
social protists.
III. In the same way we must regard the third stage, the unconscious
memory of those animals which have a nervous system, as a reproduction
of the corresponding "unconscious presentations" which are stored up
in certain ganglionic cells. In most of the lower animals all memory
is unconscious. Moreover, even in man and the higher animals, to whom
we must ascribe consciousness, the daily acts of unconscious memory
are much more numerous and varied than those of the conscious faculty;
we shall easily convince ourselves of that if we make an impartial
study of a thousand unconscious acts we perform daily out of habit, and
without thinking of them, in walking, speaking, writing, eating, and so
forth.
IV. Conscious memory, which is the work of certain brain-cells in
man and the higher animals, is an "internal mirroring" of very late
development, the highest outcome of the same psychic reproduction of
presentations which were mere unconscious processes in the ganglionic
cells of our lower animal ancestors.
The concatenation of presentations--usually called the association of
ideas--also runs through a long scale, from the lowest to the highest
stages. This, too, is originally and predominantly unconscious
("instinct"); only in the higher classes of animals does it gradually
become conscious ("reason"). The psychic results of this "association
of ideas" are extremely varied; still, a very long, unbroken line of
gradual development connects the simplest unconscious association of
the lowest protist with the elaborate conscious chain of ideas of the
civilized man. The _unity of consciousness_ in man is given as its
highest consequence (Hume, Condillac). All higher mental activity
becomes more perfect in proportion as the normal association extends
to more numerous presentations, and in proportion to the order which
is imposed on them by the "criticism of pure reason." In dreams,
where this criticism is absent, the association of the reproduced
impressions often takes the wildest forms. Even in the work of the
poetic imagination, which constructs new groups of images by varying
the association of the impressions received, and in hallucinations,
etc., they are often most unnaturally arranged, and seem to the
prosaic observer to be perfectly irrational. This is especially true
of supernatural "forms of belief," the apparitions of spiritism,
and the fantastic notions of the transcendental dualist philosophy;
though it is precisely these _abnormal associations_ of "faith" and of
"revelation" that have often been deemed the greatest treasures of the
human mind (cf. chap. xvi.).
The antiquated psychology of the Middle Ages (which, however, still
numbers many adherents) considered the mental life of man and that
of the brute to be two entirely different phenomena; the one it
attributed to "reason," the other to "instinct." In harmony with the
traditional story of creation, it was assumed that each animal species
had received a definite, unconscious psychic force from the Creator
at its formation, and that this instinct of each species was just as
unchangeable as its bodily structure. Lamarck proved the untenableness
of this error in 1809 by establishing the theory of Descent, and Darwin
completely demolished it in 1859. He proved the following important
theses with the aid of his theory of selection:
1. The instincts of species show individual differences, and are
just as subject to modification under the law of _adaptation_ as the
morphological features of their bodily structure.
2. These modifications (generally arising from a change of habits) are
partly transmitted to offspring by _heredity_, and thus accumulate and
are accentuated in the course of generations.
3. _Selection_, both artificial and natural, singles out certain of
these inherited modifications of the psychic activity; it preserves the
most useful and rejects the least adaptive.
4. The _divergence_ of psychic character which thus arises leads, in
the course of generations, to the formation of new instincts, just as
the divergence of morphological character gives rise to new species.
Darwin's theory of instinct is now accepted by most biologists; Romanes
has treated it so ably, and so greatly expanded it in his distinguished
work on _Mental Evolution in the Animal World_, that I need merely
refer to it here. I will only venture the brief statement that, in my
opinion, there are instincts in _all_ organisms--in all the protists
and plants as well as in all the animals and in man; though in the
latter they tend to disappear in proportion as reason makes progress at
their expense.
The two chief classes of instincts to be differentiated are the
primary and secondary. Primary instincts are the common lower
impulses which are unconscious and inherent in the psychoplasm
from the commencement of organic life; especially the impulses to
self-preservation (by defence and maintenance) and to the preservation
of the species (by generation and the care of the young). Both these
fundamental instincts of organic life, _hunger_ and _love_, sprang
up originally in perfect unconsciousness, without any co-operation
of the intellect or reason. It is otherwise with the _secondary_
instincts. These were due originally to an intelligent adaptation, to
rational thought and resolution, and to purposive conscious action.
Gradually, however, they became so automatic that this "other nature"
acted unconsciously, and, even through the action of heredity, seemed
to be "innate" in subsequent generations. The consciousness and
deliberation which originally accompanied these particular instincts
of the higher animals and man have died away in the course of the
life of the plastidules (as in "abridged heredity"). The unconscious
purposive actions of the higher animals (for instance, their mechanical
instincts) thus come to appear in the light of innate impulses. We have
to explain in the same way the origin of the "_à priori_ ideas" of man;
they were originally formed empirically by his predecessors.[16]
In the superficial psychological treatises which ignore the mental
activity of animals and attribute to man only a "true soul," we
find him credited also with the exclusive possession of reason and
consciousness. This is another trivial error (still to be found in many
a manual, nevertheless) which the comparative psychology of the last
forty years has entirely dissipated. The higher vertebrates (especially
those mammals which are most nearly related to man) have just as good a
title to "reason" as man himself, and within the limits of the animal
world there is the same long chain of the gradual development of
reason as in the case of humanity. The difference between the reason
of a Goethe, a Kant, a Lamarck, or a Darwin, and that of the lowest
savage, a Veddah, an Akka, a native Australian, or a Patagonian, is
much greater than the graduated difference between the reason of the
latter and that of the most "rational" mammals, the anthropoid apes, or
even the papiomorpha, the dog, or the elephant. This important thesis
has been convincingly proved by the thoroughly critical comparative
work of Romanes and others. We shall not, therefore, attempt to cover
that ground here, nor to enlarge on the distinction between the reason
and the intellect; as to the meaning and limits of these concepts
philosophic experts give the most contradictory definitions, as they do
on so many other fundamental questions of psychology. In general it may
be said that the process of the formation of concepts, which is common
to both these cerebral functions, is confined to the narrower circle of
concrete, proximate associations in the intellect, but reaches out to
the wider circle of abstract, more comprehensive groups of associations
in the work of reason. In the long gradation which connects the reflex
actions and the instincts of the lower animals with the reason of the
highest, intellect precedes the latter. And there is the fact, of
great importance to our whole psychological treatise, that even these
highest of our mental faculties are just as much subject to the laws
of heredity and adaptation as are their respective organs; Flechsig
pointed out in 1894 that the "organs of thought," in man and the higher
mammals, are those parts of the cortex of the brain which lie between
the four inner sense-centres (cf. chapters x. and xi.).
The higher grade of development of ideas, of intellect and reason,
which raises man so much above the brute, is intimately connected with
the rise of language. Still here also we have to recognize a long chain
of evolution which stretches unbroken from the lowest to the highest
stages. Speech is no more an exclusive prerogative of man than reason.
In the wider sense, it is a common feature of all the higher gregarious
animals, at least of all the articulata and the vertebrates, which live
in communities or herds; they need it for the purpose of understanding
each other and communicating their impressions. This is effected either
by touch or by signs, or by sounds having a definite meaning. The
song of the bird or of the anthropoid ape (_hylobates_), the bark of
the dog, the neigh of the horse, the chirp of the cricket, the cry of
the cicada, are all specimens of animal speech. Only in man, however,
has that articulate conceptual speech developed which has enabled his
reason to attain such high achievements. Comparative philology, one
of the most interesting sciences that has arisen during the century,
has shown that the numerous elaborate languages of the different
nations have been slowly and gradually evolved from a few simple
primitive tongues (Wilhelm Humboldt, Bopp, Schleicher, Steinthal, and
others). August Schleicher, of Jena, in particular, has proved that
the historical development of language takes place under the same
phylogenetic laws as the evolution of other physiological faculties
and their organs. Romanes (1893) has expanded this proof, and amply
demonstrated that human speech, also, differs from that of the brute
only in _degree_ of development, not in essence and kind.
The important group of psychic activities which we embrace under the
name of "emotion" plays a conspicuous part both in theoretical and
practical psychology. From our point of view they have a peculiar
importance from the fact that we clearly see in them the direct
connection of cerebral functions with other physiological functions
(the beat of the heart, sense-action, muscular movement, etc.);
they, therefore, prove the unnatural and untenable character of
the philosophy which would essentially dissociate psychology from
physiology. All the external expressions of emotional life which we
find in man are also present in the higher animals (especially in the
anthropoid ape and the dog); however varied their development may be,
they are all derived from the two elementary functions of the _psyche_,
sensation and motion, and from their combination in reflex action and
presentation. To the province of sensation, in a wide sense, we must
attribute the feeling of _like_ and _dislike_ which determines the
emotion; while the corresponding _desire_ and _aversion_ (love and
hatred), the effort to attain what is liked and avoid what is disliked,
belong to the category of movement. "Attraction" and "repulsion"
seem to be the sources of _will_, that momentous element of the soul
which determines the character of the individual. The _passions_,
which play so important a part in the psychic life of man, are but
intensifications of emotion. Romanes has recently shown that these also
are common to man and the brute. Even at the lowest stage of organic
life we find in all the protists those elementary feelings of like
and dislike, revealing themselves in what are called their _tropisms_,
in the striving after light and darkness, heat or cold, and in their
different relations to positive and negative electricity. On the other
hand, we find at the highest stage of psychic life, in civilized man,
those finer shades of emotion, of delight and disgust, of love and
hatred, which are the mainsprings of civilization and the inexhaustible
sources of poetry. Yet a connecting chain of all conceivable gradations
unites the most primitive elements of feeling in the psychoplasm of the
unicellular protist with the highest forms of passion that rule in the
ganglionic cells of the cortex of the human brain. That the latter are
absolutely amenable to physical laws was proved long ago by the great
Spinoza in his famous _Statics of Emotion_.
The notion of _will_ has as many different meanings and definitions
as most other psychological notions--presentation, soul, mind, and
so forth. Sometimes will is taken in the widest sense as a _cosmic
attribute_, as in the "World as will and presentation" of Schopenhauer;
sometimes it is taken in its narrowest sense as an _anthropological
attribute_, the exclusive prerogative of man--as Descartes taught, for
instance, who considered the brute to be a mere machine, without will
or sensation. In the ordinary use of the term, _will_ is derived from
the phenomenon of voluntary movement, and is thus regarded as a psychic
attribute of most animals. But when we examine the will in the light of
comparative physiology and evolution, we find--as we do in the case of
sensation--that it is a universal property of living psychoplasm. The
automatic and the reflex movements which we observe everywhere, even
in the unicellular protists, seem to be the outcome of inclinations
which are inseparably connected with the very idea of life. Even in the
plants and lowest animals these inclinations, or tropisms, seem to be
the joint outcome of the inclinations of all the combined individual
cells.
But when the "tricellular reflex organ" arises (page 115), and a third
independent cell--the "psychic," or "ganglionic," cell--is interposed
between the sense-cell and the motor cell, we have an independent
elementary organ of will. In the lower animals, however, this will
remains _unconscious_. It is only when consciousness arises in the
higher animals, as the subjective mirror of the objective, though
internal, processes in the neuroplasm of the psychic cells, that the
will reaches that highest stage which likens it in character to the
human will, and which, in the case of man, assumes in common parlance
the predicate of "liberty." Its free dominion and action become more
and more deceptive as the muscular system and the sense-organs develop
with a free and rapid locomotion, entailing a correlative evolution of
the brain and the organs of thought.
The question of the liberty of the will is the one which has more than
any other cosmic problem occupied the time of thoughtful humanity,
the more so that in this case the great philosophic interest of the
question was enhanced by the association of most momentous consequences
for practical philosophy--for ethics, education, law, and so forth.
Emil du Bois-Reymond, who treats it as the seventh and last of his
"seven cosmic problems," rightly says of the question: "Affecting
everybody, apparently accessible to everybody, intimately involved in
the fundamental conditions of human society, vitally connected with
religious belief, this question has been of immeasurable importance
in the history of civilization. There is probably no other object
of thought on which the modern library contains so many dusty folios
that will never again be opened." The importance of the question is
also seen in the fact that Kant put it in the same category with the
questions of the immortality of the soul and belief in God. He called
these three great questions the indispensable "postulates of practical
reason," though he had already clearly shown them to have no reality
whatever in the light of _pure_ reason.
The most remarkable fact in connection with this fierce and confused
struggle over the freedom of the will is, perhaps, that it has been
theoretically rejected, not only by the greatest critical philosophers,
but even by their extreme opponents, and yet it is still affirmed to
be self-evident by the majority of people. Some of the first teachers
of the Christian Churches--such as St. Augustine and Calvin--rejected
the freedom of the will as decisively as the famous leaders of pure
materialism, Holbach in the eighteenth and Büchner in the nineteenth
century. Christian theologians deny it, because it is irreconcilable
with their belief in the omnipotence of God and in predestination. God,
omnipotent and omniscient, saw and willed all things from eternity--he
must, consequently, have predetermined the conduct of man. If man, with
his free will, were to act otherwise than God had ordained, God would
not be all-mighty and all-knowing. In the same sense Leibnitz, too,
was an unconditional determinist. The monistic scientists of the last
century, especially Laplace, defended determinism as a consequence of
their mechanical view of life.
The great struggle between the determinist and the indeterminist,
between the opponent and the sustainer of the freedom of the will,
has ended to-day, after more than two thousand years, completely in
favor of the determinist. The human will has no more freedom than that
of the higher animals, from which it differs only in degree, not in
kind. In the last century the dogma of liberty was fought with general
philosophic and cosmological arguments. The nineteenth century has
given us very different weapons for its definitive destruction--the
powerful weapons which we find in the arsenal of comparative physiology
and evolution. We now know that each act of the will is as fatally
determined by the organization of the individual and as dependent on
the momentary condition of his environment as every other psychic
activity. The character of the inclination was determined long ago
by _heredity_ from parents and ancestors; the determination to each
particular act is an instance of _adaptation_ to the circumstances of
the moment wherein the strongest motive prevails, according to the laws
which govern the statics of emotion. Ontogeny teaches us to understand
the evolution of the will in the individual child. Phylogeny reveals
to us the historical development of the will within the ranks of our
vertebrate ancestors.