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) Amœboid 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 amœba, 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 (amœboid 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 cœnobium,
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 cœnobia 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 cœnobia 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.
