THE EMBRYOLOGY OF THE SOUL
Importance of Ontogeny to Psychology--Development of the
Child-Soul--Commencement of Existence of the Individual
Soul--The Storing of the Soul--Mythology of the Origin of
the Soul--Physiology of the Origin of the Soul--Elementary
Processes in Conception--Coalescence of the Ovum and
the Spermatozoon--Cell-Love--Heredity of the Soul from
Parents and Ancestors--Its Physiological Nature as the
Mechanics of the Protoplasm--Blending of Souls (Psychic
Amphigony)--Reversion, Psychological Atavism--The Biogenetic
Law in Psychology--Palingenetic Repetition and Cenogenetic
Modification--Embryonic and Post-Embryonic Psychogeny
The human soul--whatever we may hold as to its nature--undergoes
a continual development throughout the life of the individual.
This ontogenetic fact is of fundamental importance in our monistic
psychology, though the "professional" psychologists pay little or no
attention to it. Since the embryology of the individual is, on Baer's
principle--and in accordance with the universal belief of modern
biologists--the "true torch-bearer for all research into the organic
body," it will afford us a reliable light on the momentous problems of
its psychic activity.
Although, however, this "embryology of the soul" is so important and
interesting, it has hitherto met with the consideration it deserves
only within a very narrow circle. Until recently teachers were almost
the only ones to occupy themselves with a part of the problem;
since their avocation compelled them to assist and supervise the
formation of the psychic activity in the child, they were bound to
take a theoretical interest, also, in the psychogenetic facts that
came under their notice. However, these teachers, for the most part,
both in recent and in earlier times, were dominated by the current
dualistic psychology--in so far as they reflected at all; and they were
totally ignorant of the important facts of comparative psychology, and
unacquainted with the structure and function of the brain. Moreover,
their observations only extended to children in their school-days, or
in the years immediately preceding. The remarkable phenomena which
the individual psychogeny of the child offers in its earliest years,
and which are the joy and admiration of all thoughtful parents, were
scarcely ever made the subject of serious scientific research. Wilhelm
Preyer was the pioneer of this study in his interesting work on _The
Mind of the Child_ (1881). To obtain a perfectly clear knowledge of the
matter, however, we must go further back still; we must commence at the
first appearance of the soul in the impregnated ovum.
The origin of the human individual--body and soul--was still wrapped
in complete mystery at the beginning of the nineteenth century. Caspar
Friedrich Wolff had, it is true, discovered the true character of
embryonic development in 1759, in his _theoria generationis_, and
proved with the confidence of a critical observer that there is a
true _epigenesis_--_i.e._, a series of very remarkable formative
processes--in the evolution of the foetus from the simple ovum. But
the physiologists of the time, with the famous Albert Haller at their
head, flatly refused to entertain these empirical truths, which may be
directly proved by microscopic observation, and clung to the old dogma
of "preformation." This theory assumed that in the human ovum--and in
the egg of all other animals--the organism was already present, or
"preformed," in all its parts; the "evolution" of the embryo consisted
literally in an "unfolding" (_evolutio_) of the folded organs. One
curious consequence of this error was the theory of _scatulation_,
which we have mentioned on p. 55; since the ovary had to be admitted to
be present in the embryo of the woman, it was also necessary to suppose
that the germs of the next generation were already formed in it, and
so on _in infinitum_. Opposed to this dogma of the "Ovulists" was
the equally erroneous notion of the "Animalculists"; the latter held
that the germ was not really in the female ovum, but in the paternal
element, and that the store of succeeding generations was to be sought
in the spermatozoa.
Leibnitz consistently applied this theory of scatulation to the human
soul; he denied that either soul or body had a real development
(_epigenesis_), and said in his _Theodicy_: "Thus I consider that the
souls which are destined one day to become human exist in the seed,
like those of other species; that they have existed in our ancestors
as far back as Adam--that is, since the beginning of the world--in
the forms of organized bodies." Similar notions prevailed in biology
and philosophy until the third decade of the present century, when
the reform of embryology by Baer gave them their death blow. In the
province of psychology, however, they still find many adherents; they
form one group of the many curious mystical ideas which give us a
living illustration of the ontogeny of the soul.
The more accurate knowledge which we have recently obtained, through
comparative ethnology, of the various forms of myths of ancient and
modern uncivilized races, is also of great interest in psychogeny.
Still, it would take us too far from our purpose if we were to enter
into it with any fulness here; we must refer the reader to Adalbert
Svoboda's excellent work on _Forms of Faith_ (1897). In respect of
their scientific and poetical contents, we may arrange all pertinent
_psychogenetic myths_ in the following five groups:
I. The myth of transmigration.--The soul lived formerly in the body of
another animal, and passed from this into a human body. The Egyptian
priests, for instance, taught that the human soul wandered through all
the species of animals after the death of the body, returning to a
human frame after three thousand years of transmigration.
II. The myth of the in-planting of the soul.--The soul existed
independently in another place--a psychogenetic store, as it were (in a
kind of embryonic slumber or latent life); it was taken out by a bird
(sometimes represented as an eagle, generally as a white stork), and
implanted in the human body.
III. The myth of the creation of the soul.--God creates the souls,
and keeps them stored--sometimes in a pond (living in the form of
_plankton_), according to other myths in a tree (where they are
conceived as the fruit of a phanerogam); the Creator takes them from
the pond or tree, and inserts them in the human germ during the act of
conception.
IV. The myth of the scatulation of the soul (the theory of Leibnitz
which we have given above).
V. The myth of the division of the soul (the theory of Rudolph Wagner
[1855] and of other physiologists).--In the act of procreation a
portion is detached from both the (immaterial) souls of the parents;
the maternal contribution passes in the ovum, the paternal in the
spermatozoa; when these two germinal cells coalesce, the two psychic
fragments that accompany them also combine to form a new (immaterial)
soul.
Although the poetic fancies we have mentioned as to the origin of
the individual human soul are still widely accepted, their purely
mythological character is now firmly established. The deeply
interesting and remarkable research which has been made in the course
of the last twenty-five years into the more minute processes of the
impregnation and germination of the ovum has made it clear that these
mysterious phenomena belong entirely to the province of cellular
physiology (cf. p. 48). Both the female element, the ovum, and the male
fertilizing body, the sperma or spermatozoa, are _simple cells_. These
living cells possess a certain sum of physiological properties to which
we give the title of the "cell-soul," just as we do in the permanently
unicellular protist (see p. 48). Both germinal cells have the faculty
of movement and sensation. The young ovum, or egg-cell, moves after
the manner of an amoeba; the minute spermatozoa, of which there are
millions in every drop of the seminal fluid, are ciliated cells, and
swim about as freely in the sperm, by means of their lashes or _cilia_,
as the ordinary ciliated infusoria (the flagellata).
When the two cells meet as a result of copulation, or when they are
brought into contact through artificial fertilization (in the fishes,
for instance), they attract each other and become firmly attached. The
main cause of this cellular attraction is a chemical sensitive action
of the protoplasm, allied to smell or taste, which we call "erotic
chemicotropism"; it may also be correctly (both in the chemical and
the romantic sense) termed "cellular affinity" or "sexual cell-love."
A number of the ciliated cells in the sperm swim rapidly towards the
stationary egg-cell and seek to penetrate into it. As Hertwig showed in
1875, as a rule only one of the suitors is fortunate enough to reach
the desired goal. As soon as this favored spermatozoon has pierced
into the body of the ovum with its head (the nucleus of the cell), a
thin mucous layer is detached from the ovum which prevents the further
entrance of spermatozoa. The formation of this protective membrane
was only prevented when Hertwig kept the ovum stiff with cold by
lowering the temperature, or benumbed it with narcotics (chloroform,
morphia, nicotine, etc.); then there was "super-impregnation" or
"poly-spermy"--a number of sperm-threads pierced into the body of
the unconscious ovum. This remarkable fact proved that there is a
low degree of "cellular instinct" (or, at least, of specific, lively
sensation) in the sexual cells just as effectively as do the important
phenomena that immediately follow in their interior. Both nuclei--that
of the ovum and of the spermatozoon--attract each other, approach, and,
on contact, completely fuse together. Thus from the impregnated ovum
arises the important new cell which we call the "stem-cell" (_cytula_),
from the repeated segmentation of which the whole polycellular organism
is evolved.
The psychological information which is afforded by these remarkable
facts of impregnation, which have only been properly observed
during the last twenty-five years, is supremely important; its vast
significance has hitherto been very far from appreciated. We shall
condense the main conclusions of research in the following five theses:
I. Each human individual, like every other higher animal, is a single
simple cell at the commencement of his existence.
II. This "stem-cell" (cytula) is formed in the same manner in all
cases--that is, by the blending or copulation of two separate cells of
diverse origin, the female ovum and the male spermatozoon.
III. Each of these sexual cells has its own "cell-soul"--that is, each
is distinguished by a peculiar form of sensation and movement.
IV. At the moment of conception or impregnation, not only the
protoplasm and the nuclei of the two sexual cells coalesce, but also
their "cell-souls"; in other words, the potential energies which are
latent in both, and inseparable from the matter of the protoplasm,
unite for the formation of a new potential energy, the "germ-soul" of
the newly constructed stem-cell.
V. Consequently each personality owes his bodily and spiritual
qualities to both parents; by heredity the nucleus of the ovum
contributes a portion of the maternal features, while the nucleus of
the spermatozoon brings a part of the father's characteristics.
By these empirical facts of conception, moreover, the further fact of
extreme importance is established, that every man, like every other
animal, _has a beginning of existence_; the complete copulation of
the two sexual cell-nuclei marks the precise moment when not only the
body, but also the "soul," of the new stem-cell makes its appearance.
This fact suffices of itself to destroy the myth of the immortality
of the soul, to which we shall return later on. It suffices, too, for
the destruction of the still prevalent superstition that man owes
his personal existence to the favor of God. Its origin is rather to
be attributed solely to the "eros" of his parents, to that powerful
impulse that is common to all polycellular animals and plants,
and leads to their nuptial union. But the essential point in this
physiological process is not the "embrace," as was formerly supposed,
or the amorousness connected therewith; it is simply the introduction
of the spermatozoa into the vagina. This is the sole means, in the
land-dwelling animals, by which the fertilizing element can reach the
released ova (which usually takes place in the uterus in man). In the
case of the lower aquatic animals (fishes, mussels, medusæ, etc.) the
mature sexual elements on both sides are simply discharged into the
water, and their union is let to chance; they have no real copulation,
and so they show none of those higher psychic "erotic" functions which
play so conspicuous a part in the life of the higher animals. Hence
it is, also, that all the lower, non-copulating animals are wanting
in those interesting organs which Darwin has called "secondary sexual
characters," and which are the outcome of sexual selection: such are
the beard of man, the antlers of the stag, the beautiful plumage of
the bird of paradise and of so many other birds, together with other
distinctions of the male which are absent in the female.
Among the above theses as to the physiology of conception the
inheritance of the psychic qualities of the two parents is of
particular importance for psychological purposes. It is well known that
every child inherits from both his parents peculiarities of character,
temperament, talent, acuteness of sense, and strength of will. It
is equally well known that even psychic qualities are often (if not
always) transmitted from grandparents by heredity--often, in fact,
a man resembles his grandparents more than his parents in certain
respects; and that is true both of bodily and mental features. All
the chief laws of heredity which I first formulated in my _General
Morphology_, and popularized in my _Natural History of Creation_, are
just as valid and universal in their application to psychic phenomena
as to bodily structure--in fact, they are frequently more striking and
conspicuous in the former than in the latter.
However, the great province of heredity, to the inestimable importance
of which Darwin first opened our eyes in 1859, is thickly beset with
obscure problems and physiological difficulties. We dare not claim,
even after forty years of research, that all its aspects are clear
to us. Yet we have done so much that we can confidently speak of
heredity as a _physiological function_ of the organism, which is
directly connected with the faculty of generation; and we must reduce
it, like all other vital phenomena, to exclusively physical and
chemical processes, to the _mechanics of the protoplasm_. We now know
accurately enough the process of impregnation itself; we know that in
it the nucleus of the spermatozoon contributes the qualities of the
male parent, and the nucleus of the ovum gives the qualities of the
mother, to the newly born stem-cell. The blending of the two nuclei is
the "physiological moment" of heredity; by it the personal features of
both body and soul are transmitted to the new individual. These facts
of ontogeny are beyond the explanation of the dualistic and mystic
psychology which still prevails in the schools; whereas they find a
perfectly simple interpretation in our monistic philosophy.
The physiological fact which is most material for a correct appreciation
of individual psychogeny is the _continuity_ of the _psyche_ through
the rise and fall of generations. A new individual comes into
existence at the moment of conception; yet it is not an independent
entity, either in respect of its mental or its bodily features, but
merely the product of the blending of the two parental factors, the
maternal egg-cell and paternal sperm-cell. The cell-souls of these
two sexual cells combine in the act of conception for the formation
of a new cell-soul, just as truly as the two cell-nuclei, which are
the material vehicles of this psychic potential energy, unite to form
a new nucleus. As we now see that the individuals of one and the same
species--even sisters born of the same parents--always show certain
differences, however slight, we must assume that these variations
were already present in the chemical plasmatic constitution of the
generative cells themselves.[17]
These facts alone would suffice to explain the infinite variety of
individual features, of soul and of bodily form, that we find in the
organic world. As an extreme, but one-sided, consequence of them, there
is the theory of Weismann, which considers the _amphimixis_, or the
blending of the germ-plasm in sexual generation, to be the universal
and the sole cause of individual variability. This exclusive theory,
which is connected with his theory of the continuity of the germ-plasm,
is, in my opinion, an exaggeration. I am convinced, on the contrary,
that the great laws of _progressive heredity_ and of the correlative
_functional adaptation_ apply to the soul as well as to the body. The
new characteristics which the individual has acquired during life may
react to some extent on the molecular texture of the germ-plasm in
the egg-cell and sperm-cell, and may thus be transferred to the next
generation by heredity in certain conditions (naturally, only in the
form of latent energy).
Although in the soul-blending at the moment of conception only
the latent forces of the two parent souls are transmitted by the
coalescence of the erotic cell-nuclei, still it is possible that the
hereditary psychic influence of earlier, and sometimes very much
older, generations may be communicated at the same time. For the laws
of _latent heredity_ or atavism apply to the soul just as validly as
to the anatomical organization. We find these remarkable phenomena of
reversion in a very simple and instructive form in the alternation of
generations of the polyps and medusæ. Here we see two very different
generations alternate so regularly that the first resembles the third,
fifth, and so on; while the second (very different from the preceding)
is like the fourth, sixth, etc. (_Natural History of Creation_). We do
not find such alternation of generations in man and the higher animals
and plants, in which, owing to continuous heredity, each generation
resembles the next; nevertheless, even in these cases we often meet
with phenomena of reversion, which must be reduced to the same law of
latent heredity.
Eminent men often take more after their grandparents than their parents
even in the finer shades of psychic activity--in the possession of
certain artistic talents or inclinations, in force of character, and
in warmth of temperament; not infrequently there is a striking feature
which neither parents nor grandparents possessed, but which may be
traced a long way back to an older branch of the family. Even in
these remarkable cases of atavism the same laws of heredity apply to
the _psyche_ and to the physiognomy, to the personal quality of the
sense-organs, muscles, skeleton, and other parts of the body. We can
trace them most clearly in the reigning dynasties and in old families
of the nobility, whose conspicuous share in the life of the State has
given occasion to a more careful historical picture of the individuals
in the chain of generations--for instance, in the Hohenzollerns, the
princes of Orange, the Bourbons, etc., and in the Roman Cæsars.
The causal-nexus of _biontic_ (individual) and _phyletic_ (historical)
evolution, which I gave in my _General Morphology_ as the supreme law
at the root of all biogenetic research, has a universal application to
psychology no less than to morphology. I have fully treated the special
importance which it has with regard to man, in both respects, in the
first chapter of my _Anthropogeny_. In man, as in all other organisms,
"the embryonic development is an epitome of the historical development
of the species. This condensed and abbreviated recapitulation is the
more complete in proportion as the original _epitomized development_
(_palingenesis_) is preserved by a constant heredity; on the other
hand, it falls off from completeness in proportion as the later
_disturbing development_ (_cenogenesis_) is accentuated by varying
adaptation."
While we apply this law to the evolution of the soul, we must lay
special stress on the injunction to keep _both_ sides of it critically
before us. For, in the case of man, just as in all the higher animals
and plants, such appreciable perturbations of type (or _cenogeneses_)
have taken place during the millions of years of development that
the original simple idea of _palingenesis_, or "epitome of history,"
has been greatly disturbed and altered. While, on the one side, the
_palingenetic_ recapitulation is preserved by the laws of like-time
and like-place heredity, it is subject to an essential _cenogenetic_
change, on the other hand, by the laws of abbreviated and simplified
heredity. That is clearly seen in the embryonic evolution of the
psychic organs, the nervous system, the muscles, and the sense-organs.
But it applies in just the same manner to the psychic functions, which
are absolutely dependent on the normal construction of these organs.
Their evolution is subject to great cenogenetic modification in man
and all other viviparous animals, precisely because the complete
development of the embryo occupies a longer time within the body of
the mother. But we have to distinguish two periods of individual
psychogeny: (1) the embryonic, and (2) the post-embryonic development
of the soul.
I. _Embryonic Psychogeny._--The human foetus, or embryo, normally
takes nine months (or two hundred and seventy days) to develop in
the uterus. During this time it is entirely cut off from the outer
world, and protected, not only by the thick muscular wall of the womb,
but also by the special foetal membranes (_embryolemmata_) which
are common to all the three higher classes of vertebrates--reptiles,
birds, and mammals. In all the classes of amniotes these membranes
(the _amnion_ and the _serolemma_) develop in just the same fashion.
They represent the protective arrangements which were acquired by
the earliest reptiles (_proreptilia_), the common parents of all the
amniotes, in the Permian period (towards the end of the palæozoic
age), when these higher vertebrates accustomed themselves to live on
land and breathe the atmosphere. Their ancestors, the amphibia of the
Carboniferous period, still lived and breathed in the water, like their
earlier predecessors, the fishes.
In the case of these older and lower vertebrates that lived in the
water, the embryonic development had the palingenetic character in
a still higher degree, as is the case in most of the fishes and
amphibia of the present day. The familiar tadpole and the larva of
the salamander or the frog still preserve the structure of their
fish-ancestors in the first part of their life in the water; they
resemble them, likewise, in their habits of life, in breathing by
gills, in the action of their sense-organs, and in other psychic
organs. Then, when the interesting metamorphosis of the swimming
tadpole takes place, and when it adapts itself to a land-life, the
fish-like body changes into that of a four-footed, crawling amphibium;
instead of the gill-breathing in the water comes an exclusive
breathing of the atmosphere by means of lungs, and, with the changed
habits of life, even the psychic apparatus, the nervous system, and
the sense-organs reach a higher degree of construction. If we could
completely follow the psychogeny of the tadpole from beginning to end,
we should be able to apply the biogenetic law in many ways to its
psychic evolution. For it develops in direct communication with the
changing conditions of the outer world, and so must quickly adapt its
sensation and movement to these. The swimming tadpole has not only the
structure but the habits of life of a fish, and only acquires those of
a frog in its metamorphosis.
It is different with man and all the other amniotes; their embryo is
entirely withdrawn from the direct influence of the outer world, and
cut off from any reciprocal action therewith, by enclosure in its
protective membranes. Besides, the special care of the young on the
part of the amniotes gives their embryo much more favorable conditions
for the cenogenetic abbreviation of the palingenetic evolution. There
is, in the first place, the excellent arrangement for the nourishment
of the embryo; in the reptiles, birds, and monotremes (the oviparous
mammals) it is effected by the great yellow nutritive yelk, which is
associated with the egg; in the rest of the mammals (the marsupials and
placentals) it is effected by the mother's blood, which is conducted to
the foetus by the blood-vessels of the yelk-sac and the allantois.
In the case of the most highly developed placentals this elaborate
nutritive arrangement has reached the highest degree of perfection by
the construction of a placenta; hence in these classes the embryo is
fully developed before birth. But its soul remains during all this time
in a state of embryonic slumber, a state of repose which Preyer has
justly compared to the hibernation of animals. We have a similar long
sleep in the chrysalis stage of those insects which undergo a complete
metamorphosis--butterflies, bees, flies, beetles, and so forth. This
sleep of the pupa, during which the most important formations of
organs and tissues take place, is the more interesting from the fact
that the preceding condition of the free larva (caterpillar, grub, or
maggot) included a highly developed psychic activity, and that this is,
significantly, lower than the stage which is seen afterwards (when the
chrysalis sleep is over) in the perfect, winged, sexually mature insect.
Man's psychic activity, like that of most of the higher animals, runs
through a long series of stages of development during the individual
life. We may single out the five following as the most important of
them:
I. The soul of the new-born infant up to the birth of self-consciousness
and the learning of speech.
II. The soul of the boy or girl up to puberty (_i.e._, until the
awakening of the sexual instinct).
III. The soul of the youth or maiden up to the time of sexual
intercourse (the "idealist" period).
IV. The soul of the grown man and the mature woman (the period of
full maturity and of the founding of families, lasting until about
the sixtieth year for the man and the fiftieth for the woman--until
_involution_ sets in).
V. The soul of the old man or woman (the period of degeneration).
Man's psychic life runs the same evolution--upward progress, full
maturity, and downward degeneration--as every other vital activity in
his organization.