MONISM 452
INDEX 475
PREFACE
The publication of the present work on _The Wonders of Life_ has been
occasioned by the success of _The Riddle of the Universe_, which I
wrote five years ago. Within a few months of the issue of this study
of the monistic philosophy, in the autumn of 1899, ten thousand copies
were sold. Moreover, the publisher having been solicited on many sides
to issue a popular edition of the work, more than a hundred thousand
copies of this were sold within a year.[1] This extraordinary and--as
far as I was concerned--unexpected success of a philosophical work
which was by no means light reading, and which had no particular charm
of presentation, affords ample proof of the intense interest taken by
even the general reader in the object of the work--the construction of
a rational and solid philosophy of life.
Naturally, the clear opposition of my monistic philosophy, based
as it was on the most advanced and sound scientific knowledge, to
the conventional ideas and to an outworn "revelation," led to the
publication of a vast number of criticisms and attacks. During the
first twelve months more than a hundred reviews and a dozen large
pamphlets appeared, full of the most contradictory strictures and the
most curious observations. One of the ablest of my pupils, Heinrich
Schmidt, gave a summary and criticism of them in his _Der Kampf
um die Welträthsel_, in the autumn of 1900. However, the literary
struggle went on to assume gigantic proportions when twelve different
translations of the _Riddle_ appeared, and led to an ever-increasing
agitation in every educated country of the Old and the New World.
I gave a brief reply to the chief of these attacks in April, 1903,
in the appendix to the popular edition of the _Riddle_. It would be
useless to go further into this controversy and meet the many attacks
that have since been made. It is a question here of that profound
and irreconcilable opposition between knowledge and faith, between
a real knowledge of nature and an alleged "revelation," which has
occupied the thoughtful and inquiring mind for thousands of years.
I base my monistic philosophy exclusively on the convictions which
I have gained during fifty years' close and indefatigable study of
nature and its harmonious working. My dualistic opponents grant only a
restricted value to these experiences; they would subordinate them to
the fantastic ideas which they have reached by faith in a supernatural
world of spirits. An honest and impartial consideration of this
palpable contradiction discovers it to be irreconcilable--_either_
science and experience, or faith and revelation!
For this reason I do not propose to make any further reply to the
opponents of _The Riddle of the Universe_, and I am still less disposed
to take up the personal attacks which some of my critics have thought
fit to make on me. In the course of this controversy I have grown
painfully familiar with the means with which it is sought to silence
the detested free-thinker--misrepresentation, sophistry, calumny, and
denunciation. "Critical" philosophers of the modern Kantist school
vie in this with orthodox theologians. What I have said in this
connection of the theologian Loofs, of Halle, the philologist Dennert,
of Godesberg, and the metaphysician Paulsen, of Berlin, in the appendix
to the cheap German edition of the _Riddle_, applies equally to many
other opponents of the same type. These heated partisans may continue
to attack and calumniate my person as they will; they will not hurt the
sacred cause of truth in which I labor.
Much more interesting to me than these attacks were the innumerable
letters which I have received from thoughtful readers of the _Riddle_
during the last five years, and particularly since the appearance
of a popular edition. Of these I have already received more than
five thousand. At first I conscientiously replied to each of these
correspondents, but I had at length to content myself with sending
a printed slip with the intimation that my time and strength did
not permit me to make an adequate reply. However, though this
correspondence was very exacting, it afforded a very welcome proof of
the lively sympathy of a large number of readers with the aim of the
monistic philosophy, and a very interesting insight into the mental
attitude of the most varied classes of readers. I especially noticed
that the same remarks and questions occurred in many of these five
thousand letters, very often expressed in the same terms. Most of the
inquiries related to biological questions, which I had cursorily and
inadequately touched both in _The Riddle of the Universe_ and _The
History of Creation_. The natural desire to remedy these deficiencies
of my earlier writings and give a general reply to my interrogators was
the immediate cause of the writing of the present work on _The Wonders
of Life_.
I was confirmed in this design by the circumstance that another
scientist, the botanist Johannes Reinke, of Kiel, had published
two works in which he had treated the general problems of natural
philosophy, especially of biology, from a purely dualistic and
teleological point of view; these works were his _Die Welt als That_
(1899) and _Einleitung in die theoretische Biologie_ (1902). As both
these works are well written and present the principles of dualism and
teleology with admirable consistency--as far as this is possible--it
seemed to me that it was desirable to give a thorough exposition of my
own monistic and causative system.
Hence the present work on the wonders of life is, as the title
indicates, a supplementary volume to _The Riddle of the Universe_.
While the latter undertook to make a comprehensive survey of the
general questions of science--as cosmological problems--in the light
of the monistic philosophy, the present volume is confined to the
realm of organic science, or the science of life. It seeks to deal
connectedly with the general problems of biology, in strict accord with
the monistic and mechanical principles which I laid down in 1866 in my
_General Morphology_. In this I laid special stress on the universality
of the law of substance and the substantial unity of nature, which I
have further treated in the second and fourteenth chapters of _The
Riddle of the Universe_.
The arrangement of the vast material for this study of the wonders
of life has been modelled on that of the _Riddle_. I have retained
the division into larger and smaller sections and the synopses of
the various chapters. Thus the whole biological content falls into
four sections and twenty chapters. I should much have liked to add
illustrations in many parts of the text to make the subject plainer,
especially as regards chapters vii., viii., xi., and xvi.; but this
would have led to a considerable increase in the size and price of
the book. Moreover, there are now many illustrated works which will
help the reader to go more fully into the various sections of the
study. Among others, my _History of Creation_ (English translation) and
_Evolution of Man_ (English translation now in course of preparation)
will be found helpful in this way. The German reader will also find
many illustrations to elucidate the text of this book in my recently
completed work, _Kunstformen der Natur_ (10 parts, with 100 tables,
1899-1904).
I had said, in the preface to _The Riddle of the Universe_ in 1899,
that I proposed to close my study of the monistic system with that
work, and that "I am wholly a child of the nineteenth century, and
with its close I draw the line under my life's work." If I now seem
to run counter to this observation, I beg the reader to consider that
this work on the wonders of life is a _necessary_ supplement to the
widely circulated _Riddle of the Universe_, and that I felt bound to
write it in response to the inquiries of so many of my readers. In this
second work, as in the earlier one, I make no pretension to give the
reader a comprehensive statement of my monistic philosophy in the full
maturity it has reached--for me personally, at least--at the close of
the nineteenth century. A subjective theory of the world such as this
can, naturally, never hope to have a complete objective validity. My
knowledge is incomplete, like that of all other men. Hence, even in
this "biological sketch-book," I can only offer studies of unequal
value and incomplete workmanship. There still remains the great design
of embracing all the exuberant phenomena of organic life in one general
scheme and explaining all the wonders of life from the monistic point
of view, as forms of one great harmoniously working universe--whether
you call this Nature or Cosmos, World or God.
The twenty chapters of _The Wonders of Life_ were written
uninterruptedly in the course of four months which I spent at Rapallo,
on the shore of the blue Mediterranean. The quiet life in this tiny
coast-town of the Italian Riviera gave me leisure to weigh again all
the views on organic life which I had formed by many-sided experience
of life and learning since the beginning of my academic studies (1852)
and my teaching at Jena (1861). To this I was stimulated by the
constant sight of the blue Mediterranean, the countless inhabitants
of which had, for fifty years, afforded such ample material for my
biological studies; and my solitary walks in the wild gorges of the
Ligurian Apennines, and the moving spectacle of its forest-crowned
mountain altars, inspired me with a feeling of the unity of living
nature--a feeling that only too easily fades away in the study of
detail in the laboratory. On the other hand, such a situation did not
allow a comprehensive survey of the boundless literature which has been
evoked by the immense advances in every branch of biology. However,
the present work is not intended to be a systematic manual of general
biology. In the revision of the text, on which I was engaged during
the summer at Jena, I had to restrict myself to occasional additions
and improvements. In this I had the assistance of my worthy pupil, Dr.
Heinrich Schmidt, to whom also I am indebted for the careful revision
of the proofs.
When I completed my seventieth year at Rapallo, on February 16th, I
was overwhelmed with a mass of congratulations, letters, telegrams,
flowers, and other gifts, most of which came from unknown readers of
_The Riddle of the Universe_ in all parts of the world. If my thanks
have not yet reached any of them, I beg to tender them in these lines.
But I should be especially gratified if they would regard this work on
the wonders of life as an expression of my thanks, and as a literary
gift in return. May my readers be moved by it to penetrate deeper and
deeper into the glorious work of Nature, and to reach the insight of
our greatest German natural philosopher, Goethe:
"What greater thing in life can man achieve
Than that God-Nature be revealed to him?"
ERNST HAECKEL.
JENA, _June 17, 1904_.
THE WONDERS OF LIFE
THE WONDERS OF LIFE
I
TRUTH
Truth and the riddle of the universe--Experience
and thought--Empiricism and speculation--Natural
philosophy--Science--Empirical science--Descriptive
science--Observation and experiment--History and
tradition--Philosophic science--Theory of knowledge--Knowledge
and the brain--Æstheta and phroneta--Seat of the soul, or
organ of thought: phronema--Anatomy, physiology, ontogeny, and
phylogeny of the phronema--Psychological metamorphoses--Evolution
of consciousness--Monistic and dualistic theories of
knowledge--Divergence of the two ways of attaining the truth.
What is truth? This great question has occupied the more thoughtful of
men for thousands of years, and elicited myriads of attempts to answer
it, myriads of truths and untruths. Every history of philosophy gives a
longer or shorter account of these countless efforts of the advancing
mind of man to attain a clear knowledge of the world and of itself.
Nay, even "world-wisdom" itself, or philosophy in the proper sense
of the word, is nothing but a connected effort to unite the general
results of man's investigation, observation, reflection, and thought,
and bring them to a common focus. Without prejudice and without fear,
philosophy would tear the mantle from "the veiled statue of Sais," and
attain a full vision of the truth. True philosophy, taken in this
sense, may proudly and justly style itself "the queen of the sciences."
When philosophy, as a search for truth in the highest sense, thus
unites our isolated discoveries and seeks to weld them into one unified
system of the world, it comes at length to state certain fundamental
problems, the answer to which varies according to the degree of culture
and the point of view of the inquirer. These final and highest objects
of scientific inquiry have been of late comprehended under the title
of _The Riddle of the Universe_, and I gave this name to the work I
published in 1899, which dealt with them, in order to make its aim
perfectly clear. In the first chapter I dealt briefly with what have
been called "the seven great cosmic problems," and in the twelfth
chapter I endeavored to show that they may all be reduced to one
final "problem of substance," or one great "riddle of the universe."
The general formulation of this problem is effected by blending the
two chief cosmic laws--the chemical law of the constancy of matter
(Lavoisier, 1789), and the physical law of the constancy of force
(Robert Mayer, 1842). This monistic association of the two fundamental
laws, and establishment of the unified law of substance, has met with
a good deal of agreement, but also with some opposition; but the most
violent attacks were directed against my monistic theory of knowledge,
or against the method I followed in seeking to solve the riddle of
the universe. The only paths which I had recognized as profitable
were those of experience and thought--or empirical knowledge and
speculation. I had insisted that these two methods supplemented each
other, and that they alone, under the direction of reason, lead to the
attainment of truth. At the same time I had rejected as false two other
much-frequented paths which purported to lead directly to a profounder
knowledge, the ways of emotion and revelation; both of these are in
opposition to reason, since they demand a belief in miracles.
"All natural science is philosophy, and all true philosophy is natural
science. All true science is natural philosophy." I expressed in
these words the general result of my monistic studies in 1866 (in the
twenty-seventh chapter of my _Generelle Morphologie_). I then laid it
down as the fundamental principle of the monistic system that the unity
of nature and the unity of science follow absolutely from any connected
study of modern philosophic science, and I expressed my conviction
in these terms: "All human science is knowledge based on experience,
or empirical philosophy; or, if the title be preferred, philosophic
empiricism. Thoughtful experience, or thought based on experience, is
the only way and method to be followed in the search for truth." I
endeavored to establish these theses conclusively in the first book
of the _Generelle Morphologie_, which contains (p. 108) a critical
and methodological introduction to this science. Not only are those
methods considered "which must necessarily supplement each other" (I.
Empiricism and Philosophy; II. Analysis and Synthesis; III. Induction
and Deduction), but also those "which necessarily exclude each other"
(IV. Dogmatism and Criticism; V. Teleology and Causality, or Vitalism
and Mechanicism; VI. Dualism and Monism). The monistic principles which
I developed there thirty-eight years ago have only been confirmed by
my subsequent labors, and so I may refer the interested reader to
that work. _The Riddle of the Universe_ is in the main an attempt to
introduce to the general reader in a convenient form the chief points
of the monistic system I established. However, the opposition which has
been aroused by the general philosophic observations of the _Riddle_
compels me to give a further explanation of the chief features of my
theory of knowledge.
All true science that deserves the name is based on a collection of
experiences, and consists of conclusions that have been reached by
a rational connection of these experiences. "Only in experience is
there truth," says Kant. The external world is the object that acts
on man's organs of sense, and in the internal sense-centres of the
cortex of the brain these impressions are subjectively transformed into
presentations. The thought-centres, or association centres, of the
cortex (whether or no one distinguishes them from the sense-centres)
are the real organs of the mind that unite these presentations into
conclusions. The two methods of forming these conclusions--induction
and deduction, the formation of arguments and concepts, thought and
consciousness--make up together the cerebral function we call reason.
These long familiar and fundamental truths, the recognition of which
I have described for thirty-eight years as the first condition for
solving the riddle of life, are still far from being generally
appreciated. On the contrary, we find them combated by the extreme
representatives of both tendencies of science. On the one side, the
empirical and descriptive school would reduce the whole task to
experience, without calling in the aid of philosophy; while philosophic
speculation, on the other side, would dispense with experience and
endeavor to construct the world by pure thought.
Starting from the correct principle that all science originally has its
source in experience, the representatives of "experimental science"
affirm that their task consists solely in the exact observation of
"facts" and the classification and description of them, and that
philosophic speculation is nothing more than an idle play of ideas.
Hence this one-sided sensualism, as Condillac and Hume especially
maintained it, affirmed that the whole action of the mind consists in
a manipulation of sense-impressions. This narrow empirical conception
spread very widely during the nineteenth century, particularly in the
second half, among the rapidly advancing sciences; it was favored by
the specialism which grew up in the necessary division of labor. The
majority of scientists are still of opinion that their task is confined
to the exact observation and description of facts. All that goes beyond
this, and especially all far-reaching philosophic conclusions from
their accumulated observations, are regarded by them with suspicion.
Rudolph Virchow strongly emphasized this narrow empirical tendency ten
years ago. In his speech on the foundation of the Berlin University
he explained the "transition from the philosophic to the scientific
age"; he said that the sole aim of science is "the knowledge of
facts, the objective investigation of natural phenomena in detail."
The former politician seemed to forget that he had maintained a
precisely opposite view forty years before (at Würtzburg), and that
his own great achievement, the creation of cellular pathology, was a
philosophic construction--the formation of a new and comprehensive
theory of disease by the combination of countless observations and the
conclusions deduced therefrom.
No science of any kind whatever consists solely in the description of
observed facts. Hence we can only regard it as a pitiful contradiction
in terms when we find biology classed in official documents to-day as
a "descriptive science," and physics opposed to it as an "explanatory
science." As if in both cases we had not, after describing the observed
phenomena, to pass on to trace them to their causes--that is, to
_explain_ them--by means of rational inferences! But it is even more
regrettable to find that one of the ablest scientists of Germany,
Gustav Kirchhoff, has claimed that description is the final and the
highest task of science. The famous discoverer of spectrum analysis
says in his _Lectures on Mathematical Physics and Mechanics_
(1877): "It is the work of science to describe the movements perceived
in Nature, in the most complete and simplest fashion." There is no
meaning in this statement unless we take the word "description" in a
quite unusual sense--unless "complete description" is meant to include
explanation. For thousands of years true science has been, not merely
a simple description of individual facts, but an explanation of them
by tracing them to their causes. It is true that our knowledge of them
is always imperfect, or even hypothetical; but this is equally true
of the description of facts. Kirchhoff's statement is in flagrant
contradiction to his own great achievement, the founding of spectrum
analysis; for the extraordinary significance of this does not lie in
the discovery of the wonderful facts of spectroscopic optics and the
"complete description" of individual spectra, but in the rational
grouping and interpretation of them. The far-reaching conclusions that
he has drawn from them have opened out entirely new paths to physics
and chemistry. Hence Kirchhoff is in as sad a plight as Virchow when
he formulates so precarious a principle. However, these statements of
the two great scientists have done a great deal of harm, as they have
widened still more the deep gulf between science and philosophy. It
may be of some service if a few thousand of the thoughtless followers
of "descriptive science" are persuaded to refrain from attempts at
explanation of facts. But the master-builders of science cannot be
content with the collection of dead material; they must press on to the
knowledge of causes by a rational manipulation of their facts.
The accurate and discriminating observation of facts, supported by
careful experiment, is certainly a great advantage that modern science
has over all earlier efforts to attain the truth. The distinguished
thinkers of classic antiquity were far superior to most modern
scientists and philosophers in regard to judgment and reasoning, or
all the subtler processes of thought; but they were superficial and
unpractised observers, and were barely acquainted with experiment.
In the Middle Ages scientific work degenerated in both its aspects,
as the dominant creed demanded only faith and the recognition of
its supernatural revelation, and depreciated observation. The great
importance of this as a foundation of real knowledge was first
appreciated by Bacon of Verulam, whose _Novum Organon_ (1620) laid down
the principles of scientific knowledge, in opposition to the current
scholasticism derived from Aristotle and his _Organon_. Bacon became
the founder of modern empirical investigation, not only by making
careful and exact observation of phenomena the basis of all philosophy,
but also in demanding the supplementing of this by experiment; by
this experiment he understood the putting of a question to Nature, as
it were, which she must herself answer--a kind of observation under
definite and deliberate conditions.
This more rigorous method of "exact observation," which is hardly
three hundred years old, was very strongly aided by the inventions
which enable the human eye to penetrate into the farthest abysses of
space and the profoundest depths of smaller bodies--the telescope and
microscope. The great improvement in these instruments during the
nineteenth century, and the support given by other recent inventions,
have led to triumphs of observation in this "century of science"
that surpassed all anticipation. However, this very refinement of
the technique of observation has its drawbacks, and has led to many
an error. The effort to obtain the utmost accuracy in _objective_
observation has often led to a neglect of the part which is played by
the _subjective_ mental action of the observer; his judgment and reason
have been depreciated in comparison with the acuteness and clearness
of his vision. Frequently the means has been turned into the end of
knowledge. In the reproduction of the thing observed the objective
photograph, presenting all parts of the object with equal plainness,
has been more valued than the subjective design that reproduces only
what is essential and leaves out what is superfluous; yet the latter
is in many cases (for instance, in histological observation) much more
important and correct than the former. But the greatest fault has been
that many of these "exact" observers have refrained altogether from
reflection and judgment on the phenomena observed, and have neglected
subjective criticism; hence it is that so often a number of observers
of the same phenomenon contradict each other, while each one boasts of
the "exactness" of his observations.
Like observation, experimentation has been wonderfully improved
of late years. The experimental sciences which make most use of
it--experimental physics, chemistry, physiology, pathology, etc.--have
made astounding progress. But it is just as important in the case of
experiment--or observation under artificial conditions--as of simple
observation that it be undertaken and carried out with a sound and
clear judgment. Nature can only give a correct and unambiguous answer
to the question you put it when it is clearly and distinctly proposed.
This is very often not the case, and the experimenter loses himself in
meaningless efforts, with the foolish hope that "something may come
of it." The modern province of experimental or mechanical embryology
is especially marred by these useless and perverse experiments.
Equally foolish is the conduct of those biologists who would transfer
the experiment that is valuable in physiology to the field of
anatomy, where it is rarely profitable. In the modern controversy
about evolution the attempt is frequently made to prove or refute
experimentally the origin of species. It is quite forgotten that the
idea of species is only relative, and that no man of science can give
an absolute definition of it. Nor is it less perverse to attempt to
apply experimentation to historical problems where all the conditions
for a successful application are lacking.
The knowledge which we obtain directly by observation and experiment is
only sound when it refers to present events. We have to turn to other
methods for the investigation of the past--to history and traditions;
and these are less easily accessible. This branch of science has been
investigated for thousands of years, as far as the history of man
and civilization, of peoples and states, and their customs, laws,
languages, and migrations, is concerned. In this, the oral and written
tradition from generation to generation, the ancient monuments, and
documents, and weapons, etc., furnish an abounding empirical material
from which critical judgment can draw a host of conclusions. However,
the door to error lies wide open here, as the documents are usually
imperfect, and the subjective interpretation of them is often no
clearer than their objective validity.
Natural history, properly so called, or the study of the origin and
past history of the universe, the earth, and its organic population,
is much more recent than the history of mankind. Immanuel Kant was
the first to lay the foundations of a mechanical cosmogony in his
remarkable _Natural History of the Heavens_ (1755), and Laplace gave
mathematical shape to his ideas in 1796. Geology, also, or the story of
the evolution of the earth, was not founded until the beginning of the
eighteenth century, and did not assume a definite shape until the time
of Hoff and Lyell (1830). Later still (1866) were laid the foundations
of the science of organic evolution, when Darwin provided a sound
foundation, in his theory of selection, for the theory of descent
which Lamarck had proposed fifty years before.
In sharp contrast to this purely empirical method, which is favored
by most men of science in our day, we have the purely speculative
tendency which is current among our academic philosophers. The great
regard which the critical philosophy of Immanuel Kant obtained during
the nineteenth century has recently been increased in the various
schools of philosophy. As is known, Kant affirmed that only a part of
our knowledge is empirical, or _a posteriori_--that is, derived from
experience; and that the rest of our knowledge (as, for instance,
mathematical axioms) is _a priori_--that is to say, reached by the
deductions of pure reason, independently of experience. This error
led to the further statement that the foundations of science are
metaphysical, and that, though man can attain a certain knowledge
of phenomena by the innate forms of space and time, he cannot grasp
the "thing in itself" that lies behind them. The purely speculative
metaphysics which was built up on Kant's apriorism, and which found its
extreme representative in Hegel, came at length to reject the empirical
method altogether, and insisted that all knowledge is obtained by pure
reason, independently of experience.
Kant's chief error, which proved so injurious to the whole of
subsequent philosophy, lay in the absence of any physiological and
phylogenetic base to his theory of knowledge; this was only provided
sixty years after his death by Darwin's reform of the science of
evolution, and by the discoveries of cerebral physiologists. He
regarded the human mind, with its innate quality of reason, as a
completely formed entity from the first, and made no inquiry into
its historical development. Hence, he defended its immortality as a
practical postulate, incapable of proof; he had no suspicion of the
evolution of man's soul from that of the nearest related mammals.
The curious predisposition to _a priori_ knowledge is really the
effect of the inheritance of certain structures of the brain, which
have been formed in man's vertebrate ancestors slowly and gradually,
by adaptation to an association of experiences, and therefore of
_a posteriori_ knowledge. Even the absolutely certain truths of
mathematics and physics, which Kant described as synthetic judgments _a
priori_, were originally attained by the phyletic development of the
judgment, and may be reduced to constantly repeated experiences and
_a priori_ conclusions derived therefrom. The "necessity" which Kant
considered to be a special feature of these _a priori_ propositions
would be found in all other judgments if we were fully acquainted with
the phenomena and their conditions.
Among the censures which the academic metaphysicians, especially in
Germany, have passed on my _Riddle of the Universe_, the heaviest
is perhaps the charge that I know nothing whatever about the theory
of knowledge. The charge is correct to this extent, that I do _not_
understand the current dualistic theory of knowledge which is based
on Kant's metaphysics; I cannot understand how their introspective
psychological methods--disdaining all physiological, histological, or
phylogenetic foundations--can satisfy the demands of "pure reason." My
monistic theory of knowledge is assuredly very different from this.
It is firmly and thoroughly based on the splendid advances of modern
physiology, histology, and phytogeny--on the remarkable results of
these empirical sciences in the last forty years, which are entirely
ignored by the prevailing system of metaphysics. It is on the ground of
these experiences that I have adopted the views on the nature of the
human mind which are expounded in the second part of _The Riddle of the
Universe_ (chapters vi.-xi.). The following are the chief points:
1. The soul of man is--objectively considered--essentially similar
to that of all other vertebrates; it is the physiological action or
function of the brain.
2. Like the functions of all other organs, those of the brain are
effected by the cells, which make up the organ.
3. These brain-cells, which are also known as soul-cells, ganglionic
cells, or neurona, are real nucleated cells of a very elaborate
structure.
4. The arrangement and grouping of these psychic cells, the number of
which runs into millions in the brain of man and the other mammals, is
strictly regulated by law, and is distinguished within this highest
class of the vertebrates by several characteristics, which can only be
explained by the common origin of the mammals from one primitive mammal
(or pro-mammal of the Triassic period).
5. Those groups of psychic cells which we must regard as the agents of
the higher mental functions have their origin in the fore-brain, the
earliest and foremost of the five embryonic brain-vesicles; they are
confined to that part of the surface of the fore-brain which anatomists
call the cortex, or gray bed, of the brain.
6. Within the cortex we have localized a number of different mental
activities, or traced them to certain regions; if the latter are
destroyed, their functions are extinguished.
7. These regions are so distributed in the cortex that one part of
them is directly connected with the organs of sense, and receives
and elaborates the impressions from these: these are the inner
sense-centres, or sensoria.
8. Between these central organs of sense lie the intellectual
or thought-organs, the instruments of presentation and thought,
judgment and consciousness, intellect and reason; they are called
the thought-centres, or association-centres, because the various
impressions received from the sense-centres are associated, combined,
and united in harmonious thought by them.[2]
The anatomic distinction between the two regions of the cortex
which we oppose to each other as the internal sense-centres and the
thought or association-centres seems to me of the highest importance.
Certain physiological considerations had for some time suggested
this distinction, but the sound anatomic proof of it has only been
furnished during the last ten years. In 1894 Flechsig showed that
there are four central sense-regions ("internal sense-spheres," or
æstheta) in the gray cortex of the brain, and four thought-centres
("association-centres" or phroneta) between these: the most important
of the latter, from the psychological point of view, is the "principal
brain," or the "great occipito-temporal association-centre." The
anatomic determination of the two "psychic regions" which Flechsig
first introduced was afterwards modified by himself and substantially
altered by others. The distinguished works of Edinger, Weigert,
Hitzig, and others, lead to somewhat discrepant conclusions. But
for the general conception of psychic action, and especially of
the cognitive functions, which interests us at present, it is not
necessary to have this delimitation of the regions. The chief point
holds, that we can to-day anatomically distinguish between the two
most important organs of mental life; that the neurona, which compose
both, differ histologically (or in finer structure) and ontogenetically
(or in origin); and that even chemical differences (or a different
relation to certain coloring matters) may be perceived. We may
conclude from this that the neurona or psychic cells which compose
both organs also differ in their finer structure; there is probably a
difference in the complicated fibrils which extend in the cytoplasm
of both organs, although our coarse means of investigation have not
yet succeeded in detecting this difference. In order to distinguish
properly between the two sets of neurona, I propose to call the
sensory-cells or sense-centres _æsthetal cells_, and the thought-cells
or thought-centres _phronetal cells_. The former are, anatomically and
physiologically, the intermediaries between the external sense-organs
and the internal thought-organs.
To this anatomic delimitation of the internal sense-centres and
thought-organs in the cortex corresponds their physiological
differentiation. The sensorium, or sense-centre, works up the external
sense-impressions that are conveyed by the peripheral sense-organs
and the specific energy of their sensory nerves; the _æstheta_, or
the central sense-instruments that make up the sensorium, and their
organic units, the _æsthetal cells_, prepare the sense-impressions for
thought and judgment in the proper sense. This work of "pure reason" is
accomplished by the _phronema_ of the thought-centres, the _phroneta_
(or the various thought-organs that compose it) and their histological
elements, the phronetal cells, bringing about an association or
combination of the prepared impressions. By this important distinction
we avoid the error of the older sensualism (of Hume, Condillac,
etc.)--namely, that all knowledge depends on sense-action alone. It
is true that the senses are the original source of all knowledge;
but, in order to have real knowledge and thought, the specific task
of reason, the impressions received from the external world by the
sense-organs, and their nerves and centres, must be combined in the
association-centres and elaborated in the conscious thought-centres.
Then there is the important, but frequently overlooked, circumstance
that there is in advance in the phronetal cells of the civilized man
a valuable quality in the shape of inherited potential nerve-energy,
which was originally engendered by the actual sense-action of the
æsthetal cells in the course of many generations.
An impartial and critical study of the action of the brain in
various scientific leaders shows that, as a rule, there is a certain
opposition, or an antagonistic correlation, between the two sections
of the highest mental power. The empirical representatives of science,
or those who are devoted to physical studies, have a preponderant
development of the sensorium, which means a greater disposition and
capacity for the observation of phenomena in detail. On the other hand,
the speculative representatives of what is called mental science and
philosophy, or of metaphysical studies, have the phronema more strongly
developed, which means a preponderant tendency to, and capacity for,
a comprehensive perception of the universal in particulars. Hence it
is that metaphysicians usually look with disdain on "materialistic"
scientists and observers; while the latter regard the play of ideas
of the former as an unscientific and speculative dissipation.
This physiological antagonism may be traced histologically to the
comparative development of the æsthetal and the phronetal cells in
the two cases. It is only in natural philosophers of the first rank,
such as Copernicus, Newton, Lamarck, Darwin, and Johannes Müller, that
both sections are harmoniously developed, and thus the individual is
equipped for the highest mental achievements.
If we take the ambiguous term "soul" (_psyche_ or _anima_) in the
narrower sense of the higher mental power, we may assign as its
"seat" (or, more correctly, its organ), in man and the other mammals,
that part of the cortex which contains the phroneta and is made up
of the phronetal cells; a short and convenient name for this is the
_phronema_. According to our monistic theory, the phronema is the
organ of thought in the same sense in which we consider the eye the
organ of vision, or the heart the central organ of circulation. With
the destruction of the organ its function disappears. In opposition
to this biological and empirically grounded theory, the current
metaphysical psychology regards the brain as the seat of the soul,
only in a very different sense. It has a strictly dualistic conception
of the human soul as a being apart, only dwelling in the brain (like
a snail in its shell) for a time. At the death of the brain it is
supposed to live on, and indeed for all eternity. The immortal soul,
on this theory (which we can trace to Plato), is an immaterial entity,
feeling, thinking, and acting independently, and only using the
material body as a temporary implement. The well-known "piano-theory"
compares the soul to a musician who plays an interesting piece (the
individual life) on the instrument of the body, and then deserts it, to
live forever on its own account. According to Descartes, who insured
the widest acceptance for Plato's dualistic mysticism, the proper
habitation of the soul in the brain--in the music-room--is the pineal
gland, a posterior section of the middle-brain (the second embryonic
cerebral vesicle). The famous pineal gland has lately been recognized
by comparative anatomists as the rudiment of a single organ of vision,
the pineal eye (which is still found in certain reptiles). Moreover,
not one of the innumerable psychologists who seek the seat of the
soul in some part of the body, after the fashion of Plato, has yet
formulated a plausible theory of the connection of mind and body and
the nature of their reciprocal action. On our monistic principles the
answer to this question is very simple, and consonant with experience.
In view of its extreme importance, it is advisable to devote at least a
few lines to the consideration of the phronema in the light of anatomy,
physiology, ontogeny, and phylogeny.
When we conceive the phronema as the real "organ of the soul" in the
strict sense--that is to say, as the central instrument of thought,
knowledge, reason, and consciousness--we may at once lay down the
principle that there is an anatomical unity of organ corresponding
to the physiological and generally admitted unity of thought and
consciousness. As we assign to this phronema a most elaborate
anatomical structure, we may call it the organic apparatus of the
soul, in the same sense in which we conceive the eye as a purposively
arranged apparatus of vision. It is true that we have as yet only made
a beginning of the finer anatomic analysis of the phronema, and are not
yet able to mark off its field decisively from the neighboring spheres
of sense and motion. With the most improved means of modern histology,
the most perfect microscopes and coloring methods, we are only just
beginning to penetrate into the marvellous structure of the phronetal
cells and their complicated grouping. Yet we have advanced far enough
to regard it as the most perfect piece of cell-machinery and the
highest product of organic evolution. Millions of highly differentiated
phronetal cells form the several stations of this telegraphic system,
and thousands of millions of the finest nerve-fibrils represent
the wires which connect the stations with one another and with the
sense-centres on the one hand, and with the motor-centres on the other.
Comparative anatomy, moreover, acquaints us with the long and gradual
development which the phronema has undergone within the higher class
of the vertebrates, from the amphibia and reptiles up to the birds and
mammals, and, within the last class, from the monotremes and marsupials
up to the apes and men. The human brain seems to us to-day to be the
greatest marvel that plasm, or the "living substance," has produced in
the course of millions of years.
The remarkable progress which has been made in the last few decades
in the anatomic and histological investigation of the brain does not
yet, it is true, enable us to make a clear delimitation of the region
of the phronema and its relations to the neighboring sensory and
motor spheres in the cortex. We must, in fact, assume that there is
no sharp distinction in the lower stages of the vertebrate soul; in
the older and phylogenetically more distant stages they were not yet
differentiated. Even now there are still intermediaries between the
æsthetal and phronetal cells. But we may expect with confidence that
further progress in the comparative anatomy of the brain will, with
the aid of embryology, throw more and more light on these complicated
structures. In any case, the fundamental fact is now empirically
established that the phronema (the real organ of the soul) forms a
definite part of the cortex of the brain, and that without it there can
be no reason, no mental life, no thought, and no knowledge.
Since we regard psychology as a branch of physiology, and examine
the whole of the phenomena of mental life from the same monistic
stand-point as all other vital functions, it follows that we can make
no exception for knowledge and reason. In this we are diametrically
opposed to the current systems of psychology, which regard psychology,
not as a natural science, but as a mental science. In the next chapter
we shall see that this position is wholly unjustified. Unfortunately,
this dualistic attitude is shared by a number of distinguished modern
physiologists, who otherwise adopt the monistic principles; they
take the soul to be, in the Cartesian sense, a supernatural entity.
Descartes--a pupil of the Jesuits--only applied his theory to man,
and regarded animals as soulless automata. But the theory is quite
absurd in modern physiologists, who know from innumerable observations
and experiments that the brain, or psychic organ, in man behaves
just as it does in the other mammals, and especially the primates.
This paradoxical dualism of some of our modern physiologists may be
partly explained by the perverse theory of knowledge which the great
authority of Kant, Hegel, etc., has imposed on them; and partly by
a concern for the current belief in immortality, and the dread of
being decried as "materialists" if they abandon it. As I do not share
this belief, I examine and appreciate the physiological work of the
phroneta just as impartially as I deal with the organs of sense or the
muscles. I find that the one is just as much subject as the other to
the law of substance. Hence we must regard the chemical processes in
the ganglionic cells of the cortex as the real factors of knowledge and
all other psychic action. The chemistry of the neuroplasm determines
the vital function of the phronema. The same must be said of its most
perfect and enigmatic function, consciousness. Although this greatest
wonder of life is only directly accessible by the introspective method,
or by the mirroring of knowledge in knowledge, nevertheless the use of
the comparative method in psychology leads us to believe confidently
that the lofty self-consciousness of man differs only in degree, and
not in kind, from that of the ape, dog, horse, and other higher mammals.
Our monistic conception of the nature and seat of the soul is strongly
confirmed by psychiatry, or the science of mental disease. As an
old medical maxim runs, _Pathologia physiologiam illustrat_--the
science of disease throws light on the sound organism. This maxim is
especially applicable to mental diseases, for they can all be traced to
modifications of parts of the brain which discharge definite functions
in the normal state. The localization of the disease in a definite part
of the phronema diminishes or extinguishes the normal mental function
which is discharged by this section. Thus disease of the speech-centre,
in the third frontal convolution, destroys the power of speech; the
destruction of the visual region (in the occipital convolutions) does
away with the power of sight; the lesion of the temporal convolutions
destroys hearing. Nature herself here conducts delicate experiments
which the physiologist could only accomplish very imperfectly or not at
all. And although we have in this way only succeeded as yet in showing
the functional dependence of a certain part of the mental functions on
the respective parts of the cerebrum, no unprejudiced physician doubts
to-day that it is equally true of the other parts. Each special mental
activity is determined by the normal constitution of the relevant part
of the brain, a section of the phronema. Very striking examples of this
are afforded in the case of idiots and microcephali, the unfortunate
beings whose cerebrum is more or less stunted, and who have accordingly
to remain throughout life at a low stage of mental capacity. These
poor creatures would be in a very pitiable condition if they had a
clear consciousness of it, but that is not the case. They are like
vertebrates from which the cerebrum has been partly or wholly removed
in the laboratory. These may live for a long time, be artificially
fed, and execute automatic or reflex (and in part purposive) motions,
without our perceiving a trace of consciousness, reason, or other
mental function in them.
The embryology of the child-soul has been known in a general way for
thousands of years, and has been an object of keen interest to all
observant parents and teachers; but it was not until about twenty years
ago that a strictly scientific study was made of this remarkable and
important phenomenon. In 1884 Kussmaul published his _Untersuchungen
über das Seelenleben des neugeborenen Menschen_, and in 1882 W. Preyer
published his _Mind of the Child_ [English translation; Dr. J. Sully
has several works on the same subject]. From the careful manuals which
these and other observers have published, it is clear that the new-born
infant not only has no reason or consciousness, but is also deaf, and
only gradually develops its sense and thought-centres. It is only by
gradual contact with the outer world that these functions successively
appear, such as speech, laughing, etc.; later still come the power of
association, the forming of concepts and words, etc. Recent anatomic
observations quite accord with these physiological facts. Taken
together, they convince us that the phronema is undeveloped in the
new-born infant; and so we can no more speak in this case of a "seat of
the soul" than of a "human spirit" as a centre of thought, knowledge,
and consciousness. Hence the destruction of abnormal new-born
infants--as the Spartans practised it, for instance, in selecting the
bravest--cannot rationally be classed as "murder," as is done in even
modern legal works. We ought rather to look upon it as a practice of
advantage both to the infants destroyed and to the community. As the
whole course of embryology is, according to our biogenetic law, an
abbreviated repetition of the history of the race, we must say the same
of psychogenesis, or the development of the "soul" and its organ--the
phronema.
Comparative psychology comes next in importance to embryology as a
means of studying the ancestral history of the soul. Within the ranks
of the vertebrates we find to-day a long series of evolutionary stages
which reach up from the lowest acrania and cyclostoma to the fishes
and dipneusta, from these to the amphibia, and from these again to the
amniota. Among the latter, moreover, the various orders of reptiles and
birds on the one hand, and of mammals on the other, show us how the
higher psychic powers have been developed step by step from the lower.
To this physiological scale corresponds exactly the morphological
gradation revealed by the comparative anatomy of the brain. The most
interesting and important part of this is that which relates to the
highest developed class--the mammals; within this class we find the
same ever-advancing gradation. At its summit are the primates (man, the
apes, and the half-apes), then the carnivora, a part of the ungulates,
and the other placentals. A wide interval seems to separate these
intelligent mammals from the lower placentals, the marsupials and
monotremes. We do not find in the latter the high quantitative and
qualitative development of the phronema which we have in the former;
yet we find every intermediate stage between the two. The gradual
development of the cerebrum and its chief part--the phronema--took
place during the Tertiary period, the duration of which is estimated by
many recent geologists at from twelve to fifteen (at the least three to
five) million years.
As I have gone somewhat fully, in chapters vi.-ix. of the _Riddle_,
into the chief results of the modern study of the brain and its
radical importance for psychology and the theory of knowledge, I
need only refer the reader thereto. There is just one point I may
touch here, as it has been attacked with particular vehemence by my
critics. I had made several allusions to the works of the distinguished
English zoologist, Romanes, who had made a careful comparative study
of mental development in the animal and man, and had continued the
work of Darwin. Romanes partly retracted his monistic convictions
shortly before his death, and adopted mystic religious views. As
this conversion was only known at first through one of his friends,
a zealous English theologian [Dr. Gore], it was natural to retain a
certain reserve. However, it turned out that there had really been
in this case (just as in the case of the aged Baer) one of those
interesting psychological metamorphoses which I have described in
chapter vi. of the _Riddle_. Romanes suffered a good deal from illness
and grief at the loss of friends in his last years. In this condition
of extreme depression and melancholy he fell under mystic influences
which promised him rest and hope by belief in the supernatural. It
is hardly necessary to point out to impartial readers that such a
conversion as this does not shake his earlier monistic views. As in
similar cases where deep emotional disturbance, painful experiences,
and exuberant hope have clouded the judgment, we must still hold that
it is the place of the latter, and not of the emotions or of any
supernatural revelation, to attain a knowledge of the truth. But for
such attainment it is necessary for the organ of mind, the phronema, to
be in a normal condition.[3]
Of all the wonders of life, consciousness may be said to be the
greatest and most astounding. It is true that to-day most physiologists
are agreed that man's consciousness, like all his other mental powers,
is a function of the brain, and may be reduced to physical and chemical
processes in the cells of the cortex. Nevertheless, some biologists
still cling to the metaphysical view that this "central mystery of
psychology" is an insoluble enigma, and not a natural phenomenon.
In face of this, I must refer the reader to the monistic theory of
consciousness which I have given in chapter x. of the _Riddle_, and
must insist that in this case again embryology is the best guide
to a comprehension of the subject. Sight is next to consciousness,
in many respects, as one of the wonders of life. The well-known
embryology of the eye teaches us how sight--the perception of images
from the external world--has been gradually evolved from the simple
sensitiveness to light of the lower animals, by the development of a
transparent lens. In the same way the conscious soul, the internal
mirror of the mind's own action, has been produced as a new wonder of
life out of the unconscious associations in the phronema of our earlier
vertebrate ancestors.
From this thorough and unprejudiced appreciation of the biology of
the phronema it follows that the knowledge of truth, the aim of all
science, is a natural physiological process, and that it must have
its organs like all other psychic functions. These organs have been
revealed to us so fully in the advance of biology during the last
half-century that we may be said to have a generally satisfactory idea
of the natural character of their organization and action, though we
are still far from enjoying a complete anatomical and physiological
insight into their details. The most important acquisition we have
made is the conviction that all knowledge was originally acquired _a
posteriori_ and from experience, and that its first sources are the
impressions made on our organs of sense. Both these--the peripheral
sense-organs--and the phronema, or central psychic organ, are subject
to the law of substance; and the action of the phronema is just as
reducible to chemical and physical processes as the action of the
organs of sense.
In diametrical opposition to our monistic and empirical theory of
knowledge, the prevailing dualistic metaphysics assumes that our
knowledge is only partly empirical and _a posteriori_, and is partly
quite independent of experience and _a priori_, or due to the original
constitution of our "immaterial" mind. The powerful authority of Kant
has lent enormous prestige to this mystic and supernatural view, and
the academic philosophers of our time are endeavoring to maintain it.
A "return to Kant" is held to be the only means of salvation for
philosophy; in my opinion it should be a return to nature. As a fact,
the return to Kant and his famous theory of knowledge is an unfortunate
"crab-walk" on the part of philosophy. Our modern metaphysicians
regard the brain, as Kant did one hundred and twenty years ago, as a
mysterious, whitish-gray, pulpy mass, the significance of which as an
instrument of the mind is very enigmatic and obscure. But for modern
biology the brain is the most wonderful structure in nature, a compound
of innumerable soul-cells or neurona. These have a most elaborate
finer structure, are combined in a vast psychic apparatus by thousands
of interlacing nerve-fibrils, and are thus fitted to accomplish the
highest mental functions.
FIRST TABLE
ANTITHESIS OF THE TWO WAYS OF ATTAINING THE TRUTH
MONISTIC THEORY OF KNOWLEDGE │ DUALISTIC THEORY OF KNOWLEDGE
│
1. Knowledge is a natural process,│ 1. Knowledge is a supernatural
not a miracle. │ process, a miracle.
│
2. Knowledge, as a natural │ 2. Knowledge, as a transcendental
process, is subject to the │ process, is not subject
general law of substance. │ to the law of substance.
│
3. Knowledge is a physiological │ 3. Knowledge is not a physiological,
process, with the brain for │ but a purely spiritual,
its anatomic organ. │ process.
│
4. The part of the human brain │ 4. The part of the human brain
in which knowledge is │ which seems to act as
exclusively engendered │ organ of knowledge is
is a definite and limited │ really only the instrument
part of the cortex, the │ that allows the spiritual
phronema. │ process to appear.
│
5. The organ of knowledge, or │ 5. The organ of knowledge, or
the phronema, consists of │ the phronema (the sum of
the association-centres, │ the association-centres),
and differs by its special │ is merely a part of the
histological structure from │ instrument of mind, like
the neighboring sensory │ the neighboring and correlated
and motor centres in the │ sensory and motor-centres.
cortex, and it is in close │
relation with these. │
│
6. The innumerable cells which │ 6. The innumerable phronetal
make up the phronema--the │ cells, as the microscopic
phronetal cells--are │ elementary parts of the
the elementary organs of │ phronema, are, it is true,
the cognitive process: the │ indispensable instruments
possibility of knowledge │ of the cognitive process,
depends on their normal │ but not its real factors--merely
physical texture and chemical │ finer parts of its
composition. │ instrument.
│
7. The physical process of │ 7. The metaphysical process of
knowledge consists in the │ knowledge consists in the
combination or association │ combination or association
of presentations, the │ of presentations, which are
first sources of which are │ only partly traceable to
the impressions transmitted │ sense-impressions, and are
to the sense-centres. │ partly supersensual, transcendental
│ processes.
│
8. Hence all knowledge originally │ 8. Hence knowledge is of two
comes from experience, │ kinds: empirical and _a
by means of the │ posteriori_ knowledge, obtained
organs of sense; partly │ by experience, and
directly (direct experience, │ transcendental _a priori_
observation, and experiment │ knowledge, independent of
of the present), │ experience. Mathematics
partly indirectly (historical │ especially belongs to the
and indirectly transmitted │ latter class, its axioms
past experiences). │ differing from empirical
All knowledge (even mathematical) │ truths by their absolute
is of empirical │ certainty.
origin and _a posteriori_. │
II
LIFE
Definition of life--Comparison with a flame--Organism and
organization--Machine theory of life--Organisms without organs:
monera--Organization and life of the chromacea--Stages of
organization--Complex organisms--Symbolic organisms--Organic
compounds--Organisms and inorganic bodies compared in regard
to matter, form, and function--Crystalloid and colloid
substances--Life of crystals--Growth of crystals--Waves of
growth--Metabolism--Catalysis--Fermentation--Biogenesis--Vital
force--Old and new vitalism--Palavitalism--Antivitalism--Neovitalism.
As the object of this work is the critical study of the wonders of
life, and a knowledge of the truth concerning them, we must first
of all form a clear idea of the meaning of "life" and "wonder," or
miracle. For thousands of years men have appreciated the difference
between life and death, between living and lifeless bodies; the former
are called organisms, and the latter known as inorganic bodies.
Biology--in the widest sense--is the name of the science which treats
of organisms; we might call the science which deals with the inorganic
"abiology," abiotik, or anorgik. The chief difference between the two
provinces is that organisms accomplish peculiar, periodically repeated,
and apparently spontaneous movements, which we do not find in inorganic
matter. Hence life may be conceived as a special process of movement.
Recent study has shown that this is always connected with a particular
chemical substance, _plasm_, and consists essentially in a circulation
of matter, or _metabolism_. At the same time modern science has shown
that the sharp distinction formerly drawn between the organic and the
inorganic cannot be sustained, but that the two kingdoms are profoundly
and inseparably united.
Of all the phenomena of inorganic nature with which the life-process
may be compared, none is so much like it externally and internally as
the flame. This important comparison was made two thousand four hundred
years ago by one of the greatest philosophers of the Ionic school,
Heraclitus of Ephesus--the same thinker who first broached the idea of
evolution in the two words, _Panta rei_--all things are in a state of
flux. Heraclitus shrewdly conceived life as a fire, a real process of
combustion, and so compared the organism to a torch.
Max Verworn has lately employed this metaphor with great effect in his
admirable work on general physiology, and has especially dealt with
the comparison of the individual life-form with the familiar butterfly
shape of the gas-flame. He says:
The comparison of life to a flame is particularly suitable for
helping us to realize the relation between form and metabolism. The
butterfly-shape of a gas-flame has a very characteristic outline.
At the base, immediately above the burner, there is still complete
darkness; over this is a blue and faintly luminous zone; and over
this again the bright flame expands on either side like the wings of
a butterfly. This peculiar form of the flame, with its characteristic
features, which are permanent, as long as we do not interfere with
the gas or the environment, is solely due to the fact that the
grouping of the molecules of the gas and the oxygen at various parts
of the flame is constant, though the molecules themselves change
every moment. At the base of the flame the molecules of the gas are
so thickly pressed that the oxygen necessary for their combustion
cannot penetrate; hence the darkness we find here. In the bluish
zone a few molecules of oxygen have combined with the molecules of
the gas: we have a faint light as the result. But in the body of
the flame the molecules of the gas are so freely combined with the
oxygen of the atmosphere that we have a lively combustion. However,
the exchange of matter (metabolism) between the outpouring gas and
the surrounding air is so regulated that we always find the same
molecules in the same quantity at the same spot. Thus we get the
permanent flame, with all its characteristics. But if we alter the
circulation by lessening the stream of gas, the shape of the flame
changes, because now the disposition of the molecules on both sides
is different. Thus the study of the gas-jet gives us, even in detail,
the features we find in the structure of the cell.
The scientific soundness of this metaphor is all the more notable as
the phrase, "the flame of life," has long been familiar both in poetry
and popular parlance.
In the sense in which science usually employs the word "organism,"
and in which we employ it here, it is equivalent to "living thing" or
"living body." The opposite to it, in the broad sense, is the anorganic
or inorganic body. Hence the word "organism" belongs to physiology,
and connotes essentially the visible life-activity of the body, its
metabolism, nutrition, and reproduction.
However, in most organisms we find, when we examine their structure
closely, that this consists of various parts, and that these parts
are put together for the evident purpose of accomplishing the vital
functions. We call them _organs_, and the manner in which they are
combined, apparently on a definite plan, is their _organization_. In
this respect, we compare the organism to a machine in which some one
has similarly combined a number of (lifeless) parts for a definite
purpose, but according to a preconceived and rationally initiated
design.
The familiar comparison of an organism to a machine has given rise to
very serious errors in regard to the former, and has, of late, been
made the base of false dualistic principles. The modern "machine-theory
of life" which is raised thereon demands an intelligent design and
a deliberate constructing engineer for the origin of the organism,
just as we find in the case of the machine. The organism is then very
freely compared to a watch or a locomotive. In order to secure the
regular working of such a complicated mechanism, it is necessary to
arrange for a perfect co-operation of all its parts, and the slightest
accident to a single wheel suffices to throw it out of gear. This
figure was particularly employed by Louis Agassiz (1858), who saw
"an incarnate thought of the Creator" in every species of animal and
plant. Of late years it has been much used by Reinke in the support of
his theosophic dualism. He described God, or "the world-soul," as the
"cosmic intelligence," but ascribes to this mystic immaterial being
the same attributes that the catechism and the preacher give to the
Creator of heaven and earth. He compares the human intelligence which
the watch-maker has put into the elaborate structure of the watch with
the "cosmic intelligence" which the Creator has put in the organism,
and insists that it is impossible to deduce its purposive organization
from its material constituents. In this he entirely overlooks the
immense difference between the "raw material" in the two cases. The
"organs" of the watch are metallic parts, which fulfil their purpose in
virtue only of their physical properties (hardness, elasticity, etc.).
The organs of the living organism, on the other hand, perform their
functions chiefly in virtue of their chemical composition. Their soft
plasma-body is a chemical laboratory, the highly elaborate molecular
structure of which is the historical product of countless complicated
processes of heredity and adaptation. This invisible and hypothetical
molecular structure must not (as is often done) be confused with the
real and microscopically discoverable structure of the plasm, which
is of great importance in the question of organization. If one is
disposed to assume for this molecular structure a simple chemical
substance, a deliberate design, and an "intelligent natural force"
for cause, one is bound to do the same for powder, and say that the
molecules of charcoal, sulphur, and saltpetre have been purposively
combined to produce an explosion. It is well known that powder was not
made according to a theory, but accidentally discovered in the course
of experiment. The whole of this favorite machine-theory of life, and
the far-reaching dualistic conclusions drawn from it, tumble to pieces
when we study the simplest organisms known to us, the monera; for these
are really organisms without organs--and without organization!
I endeavored in my _Generelle Morphologie_(1866) to draw the attention
of biologists to these simplest and lowest organisms which have no
visible organization or composition from different organs. I therefore
proposed to give them the general title of monera. The more I have
studied these structureless beings--cells without nuclei!--since that
time, the more I have felt their importance in solving the greatest
questions of biology--the problem of the origin of life, the nature
of life, and so on. Unfortunately, these primitive little beings are
ignored or neglected by most biologists to-day. O. Hertwig devotes
one page of his three-hundred-page book on cells and tissues to them;
he doubts the existence of cells without nuclei. Reinke, who has
himself shown the existence of unnucleated cells among the bacteria
(_beggiatoa_), does not say a word about their general significance.
Bütschli, who shares my monistic conception of life, and has given it
considerable support by his own thorough study of plasma-structures
and the artificial production of them in oil and soap-suds, believes,
like many other writers, that the "composition of even the simplest
elementary organism from cell-nucleus and protoplasm" (the primitive
organs of the cell) is indispensable. These and other writers suppose
that the nucleus has been overlooked in the protoplasm of the monera
I have described. This may be true for one section of them; but
they say nothing about the other section, in which the nucleus is
certainly lacking. To this class belong the remarkable _chromacea_
(_phycochromacea_ or _cyanophycea_), and especially the simplest
forms of these, the _chroococcacea_ (_chroococcus_, _aphanocapsa_,
_glœocapsa_, etc.). These plasmodomous (plasma-forming) monera,
which live at the very frontier of the organic and inorganic worlds,
are by no means uncommon or particularly difficult to find; on the
contrary, they are found everywhere, and are easy to observe. Yet they
are generally ignored because they do not square with the prevailing
dogma of the cell.
I ascribe this special significance to the chromacea among all
the monera I have instanced because I take them to be the oldest
phyletically, and the most primitive of all living organisms known
to us. In particular their very simple forms correspond exactly to
all the theoretic claims which monistic biology can make as to the
transition from the inorganic to the organic. Of the chroococcacea,
the chroococcus, glœocapsa, etc., are found throughout the world;
they form thin, usually bluish-green coats or jelly-like deposits on
damp rocks, stones, bark of trees, etc. When a small piece of this
jelly is examined carefully under a powerful microscope, nothing is
seen but thousands of tiny blue-green globules of plasma, distributed
irregularly in the common structureless mass. In some species we can
detect a thin structureless membrane enclosing the homogeneous particle
of plasm; its origin can be explained on purely physical principles
by "superficial energy"--like the firmer surface-layer of a drop of
rain, or of a globule of oil swimming in water. Other species secrete
homogeneous jelly-like envelopes--a purely chemical process. In some
of the chromacea the blue-green coloring matter (_phyocyan_) is stored
in the surface-layer of the particle of plasm, while the inner part
is colorless--a sort of "central body." However, the latter is by no
means a real, chemically and morphologically distinct, nucleus. Such a
thing is completely lacking. The whole life of these simple, motionless
globules of plasm is confined to their metabolism (or _plasmodomism_,
chapter x.) and the resulting growth. When the latter passes a certain
stage, the homogeneous globule splits into two halves (like a drop
of quicksilver when it falls). This simplest form of reproduction is
shared by the chromacea (and the cognate bacteria) with the chromatella
or chromatophora, the green particles of chlorophyll inside ordinary
plant-cells; but these are only parts of a cell. Hence no unprejudiced
observer can compare these unnucleated and independent granules of
plasm with real (nucleated) cells, but must conceive them rather
as _cytodes_. These anatomic and physiological facts may easily be
observed in the chromacea, which are found everywhere. The organism
of the simplest chromacea is really nothing more than a structureless
globular particle of plasm; we cannot discover in them any composition
of different organs (or organella) for definite vital functions. Such a
composition or organization would have no meaning in this case, since
the sole vital purpose of these plasma-particles is self-maintenance.
This is attained in the simplest fashion for the individual by
metabolism; for the species it is effected by self-cleavage, the
simplest conceivable form of reproduction.
Modern histologists have discovered a very intricate and delicate
structure in many of the higher unicellular protists and in many
of the tissue-cells of the higher animals and plants (such as the
nerve-cells). They wrongly conclude that this is universal. In my
opinion, this complication of the structure of the elementary organism
is always a secondary phenomenon, the slow and gradual result of
countless phylogenetic processes of differentiation, initiated by
adaptation and transmitted to posterity by heredity. The earliest
ancestors of all these elaborate nucleated cells were at first simple,
unnucleated cytodes, such as we find to-day in the ubiquitous monera.
We shall see more about them in the ninth and fifteenth chapters.
Naturally, this lack of a visible histological structure in the
plasma-globule of the monera does not exclude the possession of an
invisible molecular structure. On the contrary, we are bound to assume
that there is such a structure, as in all albuminoid compounds, and
especially all plasmic bodies. But we also find this elaborate chemical
structure in many lifeless bodies; some of these, in fact, show a
metabolism similar to that of the simplest organisms. We will return
subsequently to this subject of catalysis. Briefly, the only difference
between the simplest chromacea and inorganic bodies that have catalysis
is in the special form of their metabolism, which we call plasmodomism
(formation of plasm), or "carbon-assimilation." The mere fact that the
chromacea assume a globular form is no sign whatever of a morphological
vital process; drops of quicksilver and other inorganic fluids take the
same shape when the individual body is formed under certain conditions.
When a drop of oil falls into a fluid of the same specific gravity with
which it cannot mix (such as a mixture of water and spirits of wine),
it immediately assumes a globular shape. Inorganic solids usually
take the form of crystals instead. Hence the distinctive feature of
the simplest organism, the plasma-particles of the monera, is neither
anatomic structure nor a certain shape, but solely the physiological
function of plasmodomism--a process of chemical synthesis.
The difference between the monera I have described and any higher
organism is, I think, greater in every respect than the difference
between the organic monera and the inorganic crystals. Nay, even the
difference between the unnucleated monera (as cytodes) and the real
nucleated cells may fairly be regarded as greater still. Even in the
simplest real cell we find the distinction between two different
organella, or "cell-organs," the internal nucleus and the outer
cell-body. The _caryoplasm_ of the nucleus discharges the functions
of reproduction and heredity; the _cytoplasm_ of the cell-body
accomplishes the metabolism, nutrition, and adaptation. Here we have,
therefore, the first, oldest, and most important process of division
of labor in the elementary organism. In the unicellular protists the
organization rises in proportion to the differentiation of the various
parts of the cell; in the tissue-forming histona it rises again in
proportion to the distribution of work (or ergonomy) among the various
organs. Darwin has given us in his theory of selection a mechanical
explanation of the apparent design and purposiveness in this.
In order to have a correct monistic conception of organization, it
is important to distinguish the individuality of the organism in its
various stages of composition. We shall treat this important question,
about which there is a good deal of obscurity and contradiction, in a
special chapter (vii.). It suffices for the moment to point out that
the unicellular beings (protists) are simple organisms both in regard
to morphology and physiology. On the other hand, this is only true in
the physiological sense of the histona, the tissue-forming animals
and plants. From the morphological point of view they are made up of
innumerable cells, which form the various tissues. These histonal
individuals are called sprouts in the plant world and persons in the
animal world. At a still higher stage of organization we have the
trunk or stem (cormus), which is made up of a number of sprouts or
persons, like the tree or the coral-stem. In the fixed animal stems the
associated individuals have a direct bodily connection, and take their
food in common; but in the social aggregations of the higher animals
it is the ideal link of common interest that unites the individuals,
as in swarms of bees, colonies of ants, herds of mammals, etc. These
communities are sometimes called "animal-states." Like human polities,
they are organisms of a higher type.
However, in order to avoid misunderstanding, we must take the word
"organism" in the sense in which most biologists use it--namely, to
designate an individual living thing, the material substratum of which
is plasm or "living substance"--a nitrogenous carbon-compound in a
semi-fluid condition. It leads to a good deal of misunderstanding
when separate functions are called organisms, as is done sometimes
in speaking of the soul or of speech. It would be just as correct to
call seeing or running an organism. It is advisable also in scientific
treatises to refrain from calling inorganic compounds as such
"organisms," as, for instance, the sea or the whole earth. Such names,
having a purely symbolical value, may very well be used in poetry. The
rhythmic wave-movement of the ocean may be regarded as its respiration,
the surge as its voice, and so on. Many scientists (like Fechner)
conceive the whole earth with all its organic and inorganic contents
as a gigantic organism, whose countless organs have been arranged
in an orderly whole by the world-reason (God). In the same way the
physiologist, Preyer, regards the glowing heavenly bodies as "gigantic
organisms, whose breath is, perhaps, the glowing vapor of iron, whose
blood is liquid metal, and whose food may be meteorites." The danger of
this poetic application of the metaphorical sense of organism is very
well seen in this instance, as Preyer builds on it a quite untenable
hypothesis of the origin of life (see chapter xv.).
In the wider sense the word "organic" has long been used in chemistry
as an antithesis to inorganic. By organic chemistry is generally
understood the chemistry of the compounds of carbon, that element being
distinguished from all the others (some seventy-eight in number) by
very important properties. It has, in the first place, the property of
entering into an immense variety of combinations with other elements,
and especially of uniting with oxygen, hydrogen, nitrogen, and sulphur
to form the most complicated albuminoids (see the _Riddle_, chapter
xiv.). Carbon is a biogenetic element of the first importance, as I
explained in my carbon-theory in 1866. It might even be called "the
creator of the organic world." At first these organogenetic compounds
do not appear in the organism in organized form--that is to say, they
are not yet distributed into organs with definite purposes. Such
organization is a result, not the cause, of the life-process.
I have already shown in the fourteenth chapter of the _Riddle_(and at
greater length in the fifteenth chapter of my _History of Creation_)
that the belief in the essential unity of nature, or the monism of
the cosmos, is of the greatest importance for our whole system. I
gave a very thorough justification of this cosmic monism in 1866. In
the fifth chapter of the _Generelle Morphologie_ I considered the
relation of the organic to the inorganic in every respect, pointing
out the differences between them on the one hand, and their points of
agreement in matter, form, and force on the other. Nägeli some time
afterwards declared similarly for the unity of nature in his able
_Mechanisch-physiologische Begründung_ _der Abstammungslehre_(1884).
Wilhelm Ostwald has recently done the same, from the monistic point of
view of his system of energy, in his _Naturphilosophie_, especially in
the sixteenth chapter. Without being acquainted with my earlier work,
he has impartially compared the physico-chemical processes in the
organic and inorganic worlds, partly adducing the same illustrations
from the instructive field of crystallization. He came to the same
monistic conclusions that I reached thirty-six years ago. As most
biologists continue to ignore them, and as, especially, modern vitalism
thrusts these inconvenient facts out of sight, I will give a brief
summary once more of the chief points as regards the matter, form, and
forces of bodies.
Chemical analysis shows that there are no elements present in organisms
that are not found in inorganic bodies. The number of elements that
cannot be further analyzed is now put at seventy-eight; but of these
only the five organogenetic elements already mentioned which combine
to form plasm--carbon, oxygen, hydrogen, nitrogen, and sulphur--are
found invariably in living things. With these are generally (but not
always) associated five other elements--phosphor, potassium, calcium,
magnesium, and iron. Other elements may also be found in organisms; but
there is not a single biological element that is not also found in the
inorganic world. Hence the distinctive features which separate the one
from the other can be sought only in some special form of combination
of the elements. And it is carbon especially, the chief organic
element, that by its peculiar affinity enters into the most diverse and
complicated combinations with other elements, and produces the most
important of all substances, the albuminoids, at the head of which is
the living plasm (_cf._ chapter vi.).
An indispensable condition of the circulation of matter (metabolism)
which we call life is the physical process of osmosis, which is
connected with the variations in the quantity of water in the living
substance and its power of diffusion. The plasm, which is of a spongy
or viscous consistency, can take in dissolved matter from without
(endosmosis) and eject matter from within (exosmosis). This absorptive
property (or "imbibition-energy") of the plasm is connected with the
colloidal character of the albuminoids. As Graham has shown, we may
divide all soluble substances into two groups in respect of their
diosmosis--crystalloids and colloids. Crystalloids (such as soluble
salt and sugar) pass more easily into water through a porous wall
than colloids (such as albumen, glue, gum, caramel). Hence we can
easily separate by dialysis two bodies of different groups which are
mixed in a solution. For this we need a flat bottle with side walls
of india-rubber and bottom of parchment. If we let this vessel float
in a large one containing plenty of water, and pour a mixture of
dissolved gum and sugar into the inner vessel, after a time nearly
all the sugar passes through the parchment into the water, and an
almost pure solution of gum remains in the bottle. This process of
diffusion, or osmosis, plays a most important part in the life of all
organisms; but it is by no means peculiar to the living substance,
any more than the absorptive or viscous condition is. We may even
have one and the same substance--either organic or inorganic--in both
conditions, as crystal or as colloid. Albumen, which usually seems
to be colloidal, forms hexagonal crystals in many plant-cells (for
instance, in the aleuron-granules of the endosperm), and tetrahedric
hœmoglobin-crystals in many animal-cells (as in the blood corpuscles
of mammals). These albuminoid crystals are distinguished by their
capacity for absorbing a considerable quantity of water without losing
their shape. On the other hand, mineral silicon, which appears as
quartz in an immense variety (more than one hundred and sixty) of
crystalline forms, is capable in certain circumstances (as metasilicon)
of becoming colloidal and forming jelly-like masses of glue. This
fact is the more interesting because silicium behaves in other ways
very like carbon, is quadrivalent like it, and forms very similar
combinations. Amorphous (or non-crystalline) silicium (a brown powder)
stands in relation to the black metallic silicon-crystals just as
amorphous carbon does to graphite-crystals. There are other substances
that may be either crystalloid or colloid in different circumstances.
Hence, however important colloidal structure may be for the plasm and
its metabolism, it can by no means be advanced as a distinctive feature
of living matter.
Nor is it possible to assign an absolute distinction between the
organic and the inorganic in respect of morphology any more than of
chemistry. The instructive monera once more form a connecting bridge
between the two realms. This is true both of the internal structure
and the outward form of both classes of bodies--of their individuality
(chapter vii.) and their type (chapter viii.). Inorganic crystals
correspond morphologically to the simplest (unnucleated) forms of the
organic cells. It is true that the great majority of organisms seem to
be conspicuously different from inorganic bodies by the mere fact that
they are made up of many different parts which they use as organs for
definite purposes of life. But in the case of the monera there is no
such organization. In the simplest cases (chromacea, bacteria) they are
structureless, globular, discoid, or rod-shaped plasmic individuals,
which accomplish their peculiar vital function (simple growth and
subdivision) solely by means of their chemical constitution, or their
invisible molecular structure.
The comparison of cells with crystals was made in 1838 by the founders
of the cell-theory, Schleiden and Schwann. It has been much criticised
by recent cytologists, and does not hold in all respects. Still it is
of importance, as the crystal is the most perfect form of inorganic
individuality, has a definite internal structure and outward form,
and obtains these by a regular growth. The external form of crystals
is prismatic, and bounded by straight surfaces which cut each other
at certain angles. But the same form is seen in the skeletons of many
of the protists, especially the flinty shells of the diatomes and
radiolaria; their silicious coverings lend themselves to mathematical
determination just as well as the inorganic crystals. Midway between
the organic plasma-products and inorganic crystals we have the
_bio-crystals_, which are formed by the united plastic action of the
plasm and the mineral matter--for instance, the crystalline flint and
chalk skeletons of many of the sponges, corals, etc. Further, by the
orderly association of a number of crystals we get compound crystal
groups, which may be compared to the communities of protists--for
instance, the branching ice-flowers and ice-trees on the frozen
window. To this regular external form of the crystal corresponds a
definite internal structure which shows itself in their cleavage, their
stratified build, their polar axes, etc.
If we do not restrict the term "life" to organisms properly so-called,
and take it only as a function of plasm, we may speak in a broader
sense of the life of crystals. This is seen especially in their
growth, the phenomenon which Baer regarded as the chief character of
all individual development. When a crystal is formed in a matrix,
this is done by attracting homogeneous particles. When two different
substances, A and B, are dissolved in a mixed and saturated solution,
and a crystal of A is put in the mixture, only A is crystallized out of
it, not B; on the other hand, if a crystal of B is put in, A remains in
solution and B alone assumes the solid crystalline form. We may, in
a certain sense, call this choice _assimilation_. In many crystals we
can detect internally an interaction of their parts. When we cut off
an angle in a forming crystal, the opposite angle is only imperfectly
formed. A more important difference between the growth of crystals and
monera is that the former only grow by _apposition_, or the deposit of
fresh solid matter at their surface; while the monera grow, like all
cells, by _intussusception_, or the taking of new matter into their
interior. But this difference is easily explained by their difference
in consistency, the crystal being solid and the plasm semi-fluid.
Moreover, the difference is not absolute; there are intermediary
stages between apposition and intussusception. A colloid globule
suspended in a salt solution in which it is not dissolved may grow by
intussusception.
It was once the custom to restrict sensation and movement to animals,
but they are now recognized to be present in nearly all living matter.
They are, in fact, not altogether lacking in crystals, as the molecules
move in crystallization in definite directions, and unite according to
fixed laws; they must, therefore, also possess sensation, as we could
not otherwise understand the attraction of the homogeneous particles.
We find in crystallization, as in every chemical process, certain
movements which are unintelligible without sensation--unconscious
sensation, of course. In this respect, also, then, the growth of all
bodies follows the same laws (_cf._ chapters xiii. and xv.).
The growth of a crystal is restricted like the growth of a moneron or
of any cell. If the limit is passed and the conditions remain favorable
to growth, we find an instance of that excessive or _transgressive_
growth which we call reproduction in the case of living individuals.
But we find just the same kind of extension in the inorganic crystal.
Every crystal grows in a supersaturated medium only up to a definite
size, which is determined by its chemical-molecular constitution. When
this limit is reached a number of small crystals appear on the large
one. Ostwald, who has made a thorough comparison of the process of
growth in crystals and monera, especially notices the striking analogy
between a bacterium (a plasmophagous moneron) growing and multiplying
in its nutritive fluid and a crystal in its matrix. When the water
slowly evaporates from a supersaturated solution of Glauber-salt, not
only does a crystal slowly grow in it, but several young crystals
appear on it. The analogy with the bacterium multiplying in its
nutritive fluid can even be followed as far as its permanent forms or
"spores." This quiescent form is assumed by the bacterium if its supply
of food is exhausted; if fresh food is added, the multiplication by
cleavage begins again. In the same way the crystals of Glauber-salt
begin to decay when the solution is evaporated; they lose their crystal
water, but not their power of multiplication. Even the amorphous powder
of the salt causes again the formation of new watery crystals when put
in a supersaturated solution. But the powder loses this property when
it is heated, just as the dormant forms (or spores) of the bacteria
lose their power of germination.
The exhaustive comparison of the growth of crystals and monera (as the
simplest forms of unnucleated cells) is important, because it shows
the possibility of tracing the vital function of reproduction--which
had usually been regarded as a quite special "wonder of life"--to
purely physical conditions. The division of the growing individual
into several young ones must necessarily take place when the natural
limit of growth has been passed, and when the chemical composition of
the growing body and the cohesion of its molecules allow no further
enlargement by the assumption of new matter. In order to illustrate
the limit of this transgressive growth by a simple physical example,
Ostwald imagines a ball placed in a small flat basin, built up high on
one side. The ball is in a state of equilibrium in the basin; when it
is lightly pushed aside it always returns to its original position.
But when the push goes beyond a certain point, and the ball is thrust
over the side of the basin, the balance is lost; the ball does not
return, but falls to the ground. The crystal behaves just in the same
way in a supersaturated solution when it exercises its power of forming
new crystals; and it is just the same with the bacterium growing in a
nutritive fluid when it passes the limit of its volume of growth, and
divides into two individuals.
As we can find no morphological and little physiological difference
between the living and non-living, we must look upon metabolism as
the chief characteristic of organic life. This process causes the
conversion of food into plasm; it is determined by the vital force
itself, and is the formation of new living matter. It thus effects
the nutrition and growth of the living being, and therefore its
reproduction, which is merely transgressive growth. As I shall describe
this metabolism fully in the tenth chapter, I will do no more here
than emphasize the fact that this vital process also has analogies in
inorganic chemistry, in the curious process of catalysis, especially
that form of it which we call fermentation.
The distinguished chemist Berzelius discovered in 1810 the
remarkable fact that certain bodies, by their mere presence, apart
from their chemical affinity, set other bodies in decomposition or
composition without being themselves affected. Thus, for instance,
sulphuric acid changes the starch in sugar without undergoing any
alteration itself. Finely ground platinum brought in contact with
hydrogen-superoxide divides it into hydrogen and oxygen. Berzelius
called this process _catalysis_; Mitscherlich, who discovered the
cause of it to be the peculiar surface-action of many bodies, gave
it the name of "contact-action." It was afterwards discovered that
catalysis of this kind is very general, and that a special form of
it--fermentation--plays an important part in the life of organisms.
This special form of contact-action which we call fermentation is
always effected by catalytic bodies of the albuminoid class, and,
in fact, of the group of non-coagulable proteins which are known as
peptones. They have--in however small a quantity--the capacity to
throw into decomposition large masses of organic matter (in the form
of yeast, putrid matter, etc.) without themselves taking part in the
decomposition. When these ferments are free and unorganized they
are called enzyma, in opposition to organized ferments (bacteria,
yeast-fungi, etc.); though the catalytic action of the latter
also consists essentially in the production of enzyma. The recent
investigations of Verworn, Hofmeister, Ostwald, etc., have shown that
these catalyses play everywhere an important part in the life of the
plasm. Many recent chemists and physiologists are of opinion that
plasm is a _colloid catalysator_, and that all the varied activities
of life are connected with this fundamental vital chemistry. Thus
Franz Hofmeister (1901) says in his excellent work on _The Chemical
Organization of the Cell_:
The belief that the agents of the chemical transformation in the
cell are catalysators of a colloid nature is in complete accord
with other facts that have been directly ascertained. What else are
the chemists' ferments but colloid catalysators? The idea that the
ferments are the essential chemical agency in the cell is calculated
to meet the difficulty which arises from the smallness of the cell
in appreciating its chemical processes. However large we suppose the
colloid ferment molecules to be, there is room for millions of them
in the smallest cell.
In the same way Ostwald attributes the greatest significance to
catalysis in connection with the vital processes, and seeks to explain
them on his theory of energy by reference to the duration of chemical
processes. In the discourse "On Catalysis" that he delivered at Hamburg
in 1901 he says:
We must recognize the enzyma as catalysators that arise in the
organism during the life of the cells, and by their action relieve
the living being of the greater part of its duties. Not only are
digestion and assimilation controlled by enzyma from first to last,
but the fundamental vital action of most organisms, the production
of the necessary chemical energy by combustion at the expense of
the oxygen in the air, takes place with the explicit co-operation
of enzyma, and would be impossible without them. Free oxygen is, as
is well known, a very inert body at the temperature of the living
body, and the maintenance of life would be impossible without some
acceleration of its rate of reaction.
In his further observations on catalysis and metabolism he says that
they are both equally subject to the physico-chemical laws of energy.
Max Verworn has given us a very searching analysis of the molecular
process in the catalytic aspect of metabolism in his _Biogen
Hypothesis_ (1903), "a critical and experimental study of the processes
in living matter." He simplifies the catalytic theory of the enzyma
by tracing all the phenomena of life to the catalytic metabolism
of one single chemical compound, the plasm, and regards its active
molecules, the biogens, as the ultimate chemical factors of the vital
process. While the enzyma hypothesis assumes that there are in each
cell a great number of different enzyma which are all co-ordinated,
and each of which only performs its little special work, the biogen
hypothesis deduces all the vital phenomena from one compound, the
biogenetic plasm; and thus the biogen molecules, which increase by
division into parts, are the sole factors of biological catalysis.
Verworn also points out the analogy between this enzymatic process of
metabolism and the inorganic processes of catalysis--for instance,
in the manufacture of English sulphuric acid. A small and constant
quantity of nitromuriatic acid, with the aid of air and water, converts
an unlimited mass of sulphuretted acid into sulphuric acid without
being changed itself; the molecule of the nitromuriatic acid breaks
up steadily by the giving-off of oxygen, and is then restored by the
assumption of oxygen.
The manifold and changeful phenomena of life and their sudden
extinction at death seem to every thoughtful man to be something
so wonderful and so different from all the changes in inorganic
nature that from the very beginning of biological philosophy special
forces were assumed to explain it. This was particularly due to
the remarkable, orderly structure of the organism and the apparent
purposiveness of the vital processes. Hence, in earlier days a
special organic force (_archæus insitus_) was assumed, controlling
the individual life and pressing the "raw forces" of inorganic matter
into its service. In the same way a special formative impulse was
supposed to preside over the wonderful processes of development. When
physiology began to win its independence, about the middle of the
eighteenth century, it explained the peculiar features of organic life
by a specific vital force. The idea was generally received, and Louis
Dumas endeavored thoroughly to establish it at the beginning of the
nineteenth century (_cf._ chapter iii. of the _Riddle_).
As the theory of a vital force, or vitalism, plays an important part
in the study of the wonders of life, has undergone the most curious
modifications in the course of the nineteenth century, and has been
lately revived with great force, we must give a short account of it
in its various forms. The phrase can be interpreted in a monistic
sense, if we understand by it the sum of the forms of energy which
are especially distinctive of the organism, particularly metabolism
and heredity. In this we pass no opinion on their nature, and do
not say that they are specifically different from the forces of
inorganic nature. We might call this monistic conception "physical
vitalism." However, the usual metaphysical vitalism affirms in a
thoroughly dualistic sense that the vital force is a teleological and
super-mechanical principle, is essentially different from the ordinary
forces of nature, and of a transcendental character. The special form
in which this theory of a supernatural vital force has been presented
for the last twenty years is often called Neovitalism; we might call
the older form, by contrast, Palavitalism.
The older idea of the vital force as a special energy could very well
be accepted in the first third of the nineteenth century, and in the
eighteenth, because the physiology of the time was destitute of the
most important aids to the founding of a mechanical theory. There was
then no such thing as the cell-theory or as physiological chemistry;
ontogeny and paleontology were still in their cradles. Lamarck's
theory of descent (1809) had been done to death, like his fundamental
principle: "Life is only an elaborate physical phenomenon." Hence we
can easily understand how physiologists acquiesced in the vitalist
hypothesis up to 1833, and supposed the wonders of life to be enigmatic
phenomena that escaped physical explanation.
But the position of Palavitalism changed in the second third of the
nineteenth century. In 1833 appeared Johannes Müller's classical
_Manual of Human Physiology_, in which the great biologist not only
made a comparative study of the vital phenomena in man and the animals,
but sought to provide a sound basis for it in all its sections by his
own observations and experiments. It is true that Müller retained
to the last (1858) the current idea of a vital force, as the supreme
regulator of all the vital activities. However, he did not regard it
as a metaphysical principle (like Haller, Kant, and their followers),
but as a natural force, subject, like all others, to fixed chemical
and physical laws, and subordinate to the whole. In his comprehensive
study of every single vital function--the organs of sense and the
nervous system, metabolism and the action of the heart, speech and
reproduction--Müller endeavored above all to establish, by close
observation of the facts and careful experiments, the regularity
of the phenomena, and to explain their development by a comparison
of the higher and lower forms. Hence Johannes Müller is wrongly
described--as he has been of late--as a vitalist; he was rather the
first physiologist to provide a physical foundation for the current
metaphysical vitalism. He really gives an indirect proof of the reverse
theory, as E. Dubois-Reymond rightly observed in his brilliant memorial
speech. In the same way Schleiden (1843) cut the ground from under
vitalism in botany. By his cell-theory (1838) he showed the unity of
the multicellular organism to be the resultant of the functions of all
the cells which compose it.
The physical explanation of the vital processes and the rejection
of Palavitalism were general in the last third of the nineteenth
century. This was due most of all to the great advance in experimental
physiology, which Carl Ludwig and Felix Bernard led as regards the
animal body, and Julius Sachs and Wilhelm Preyer for the plant. While
these and other physiologists used the remarkable results of modern
physics and chemistry in the experimental study of the vital functions,
and sought to determine their complicated course in terms of mass and
weight and formulate their discoveries as mathematically as possible,
they brought a great number of the wonders of life under the same
fixed laws that were recognized in the physics and chemistry of the
inorganic world. On the other hand, vitalism met with a powerful
opponent in Charles Darwin, who solved, by his theory of selection,
one of the most obscure biological problems, the constantly repeated
question: How can we give a mechanical explanation of the orderly
structures of the living being? How was this ingenious machine of the
animal or plant body unconsciously produced by natural means, without
supposing that some intelligent artificer or creator had deliberately
designed and produced it?
The further development of Darwin's theory of selection in the last
four decades, and the increasing support which has been given to
the theory of descent in the great advance of ontogeny, phylogeny,
comparative anatomy, and physiology, did much to establish the monistic
conception of life. It took the shape more and more of a definite
anti-vitalism. Hence it is strange to find that in the course of the
last twenty years the old vitalism that everybody had thought dead has
lifted up its head once more, though in a new and modified form.[4]
This modern vitalism comprises two essentially different tendencies.
The partisans of the modern vital force are divided into two groups,
which may be designated the sceptical and the dogmatic. Sceptical
Neovitalism was first formulated by Bunge, of Basle (1887), in the
introduction to his _Manual of Physiological Chemistry_. While he
granted the possibility of a full explanation of one part of the vital
phenomena by mechanical causes, or the physical and chemical forces
of lifeless nature, he rejected it for the other half, especially for
psychic activities. He insists that the latter cannot be explained
mechanically, and that there is nothing analogous to them in inorganic
nature; only a supra-mechanical vital force can produce them, and this
is transcendental and beyond the range of scientific inquiry. Much the
same was said later by Rindfleisch (1888), more recently by Richard
Neumeister in his _Studies of the Nature of Vital Phenomena_ (1903),
and by Oscar Hertwig in the lecture on "The Development of Biology in
the Nineteenth Century," which he delivered at Aachen in 1900.
This sceptical Neovitalism is far surpassed by the dogmatic system,
the chief actual representatives of which are the botanist Johannes
Reinke and the metaphysician Hans Driesch. The vitalist writings of the
latter, which are devoid of any grasp of historical development, have
gained a certain vogue through the extraordinary arrogance of their
author and the obscurity of his mystic and contradictory speculations.
Reinke, on the other hand, has presented his transcendental dualism
in clever and attractive form in two works which deserve notice on
account of their consistent dualism. In the first of these, _The World
as Reality_ (1899), Reinke gives us "the outline of a scientific theory
of the universe." The second work (1901) has the title, _Introduction
to Theoretical Biology_. The two works have the same relation to each
other as my _Riddle of the Universe_ and the present supplementary
volume. As our philosophic convictions are diametrically opposed in the
main issues, and as we both think ourselves consistent in developing
them, the comparison of them is not without interest in the great
struggle of beliefs. Reinke is an avowed supporter of dualism, theism,
and teleology. He reduces all the phenomena of life to a supernatural
miracle.
SECOND TABLE
ANTITHESIS OF THE MONISTIC AND DUALISTIC THEORIES OF ORGANIC LIFE
MONISTIC THEORY OF LIFE │ DUALISTIC THEORY OF LIFE
(Biophysics) │ (Vitalism)
│
1. The phenomena of life are │ 1. The phenomena of life are
merely functions of plasm, │ wholly or partly independent
determined by the physical, │ of the plasm, and
chemical, and morphological │ determined by a special
character of the │ immaterial force, the vital
living matter. │ force (_vis vitalis_).
│
2. The energy of the plasm (as │ 2. The energy of the plasm is
the sum-total of the forces │ wholly or partly subject
which are connected with │ to the immaterial vital
the living matter) is subject │ force, which controls and
to the general laws of │ directs the physical and
physics and chemistry. │ chemical forces of the
│ living matter.
│
3. The obvious regularity of the │ 3. The general regularity in the
vital processes and the │ organization and in the
organization they produce │ vital processes it accomplishes
are the outcome of natural │ is the outcome of
evolution; their physiological │ conscious creation; it can
factors (heredity │ only be explained by intelligent
and adaptation) are subject │ immaterial forces
to the law of substance. │ which are not subject to
│ the law of substance.
│
4. All the various functions │ 4. All the various functions of
have thus been mechanically │ organisms have been produced
produced, orderly │ by design, the
structures having been │ historical evolution (or
created by adaptation and │ phyletic transformation)
transmitted to posterity │ being directed to a preconceived
by heredity. │ ideal end.
│
5. Nutrition is a physico-chemical │ 5. Nutrition is an inexplicable
process, the metabolism │ miracle of life, and cannot
of which has an │ be understood by chemical
analogy in inorganic catalysis. │ and physical processes.
│
6. Reproduction is a mechanical │ 6. Reproduction is an inexplicable
consequence of transgressive │ miracle of life,
growth, analogous │ without any analogy in
to the elective multiplication │ inorganic nature.
of crystals. │
│
7. The movement of organisms │ 7. The movement of organisms
is, in every form, not │ is an inexplicable metaphysical
essentially different from │ miracle of life,
the movements of inorganic │ specifically different from
dynamos. │ all inorganic movements.
│
8. Sensation is a general form │ 8. The sensation of organisms
of the energy of substance, │ can only be explained by
not specifically different │ ascribing a soul to them,
in sensitive organisms and │ an immaterial, immortal
irritable inorganic objects │ being that only dwells for
(such as powder, dynamite). │ a time in the body. After
There is no such │ death this spirit lives an
thing as an immaterial │ independent life.
soul. │
III
MIRACLES
Miracle and natural law--Belief in miracles of savages (fetichism),
of semi-civilized (idolatry), of civilized (theism), and of
educated people (dualism)--Religious belief in miracles--Apostles'
Creed--Article relating to creation--Article relating to
redemption--Article relating to immortality--Philosophic belief in
miracles--Academic thinkers and Free-thinkers--Dualism of Plato
and Kant--Belief in miracles in the nineteenth century, in modern
metaphysics, theology, and politics.
In ordinary parlance the word "miracle" means a number of different
things. We say a phenomenon is miraculous or wonderful[5] when we
cannot explain it and trace its causes. But we say a natural object
or a work of art is wonderful when it is unusually beautiful and
imposing--when it passes the ordinary limits of our experience. In this
work I do not take the word in this relative sense, but in the absolute
sense in which a phenomenon is said to transcend the limits of natural
law and lie beyond the range of rational explanation. In this sense
it means the same as "supernatural" or "transcendental." We can know
natural phenomena by our reason and bring them within our cognizance.
The miraculous can only be accepted on faith.
The belief in supernatural miracles is in contradiction to pure reason,
which lays the foundations of all science. Kant, who won so great a
vogue for the term "pure reason," understood by this originally "reason
as independent of experience." The phrase was used in a narrower sense
subsequently to express independence of dogma and prejudice, as the
base of pure and unprejudiced science. In this sense we oppose pure
reason to superstition.
I have dealt in the sixteenth chapter of the _Riddle_ with the
important question of the relations of knowledge and faith. But I
must return to the subject here, as what I said has given rise to a
good deal of misunderstanding and criticism. I by no means claimed,
as my opponents allege, to "know everything," or to have solved every
problem. In fact, I said repeatedly that there are narrow limits to
our knowledge, and always will be. I had also expressly stated that
the irresistible impulse to learn in the intelligent man, or reason's
constant demand to know causes, presses us to fill up the gaps in our
knowledge by faith. But I had at the same time pointed out the contrast
between scientific (natural) and religious (supernatural) faith. The
one leads us to form hypotheses and theories; the other ends in myths
and superstition. Scientific faith fills the gaps in our knowledge
of natural law with temporary hypotheses; but mystic religious faith
contradicts natural law, and transcends its limits in the form of a
belief in miracles.
The great triumph of the progress of science in the nineteenth century,
its theoretical value in the formation of a rational philosophy
of life, and its practical value on the various sides of modern
civilization, consist, above all, in the absolute recognition of fixed
natural laws. That relation of things to each other, which we call
causation, makes it possible for us to understand and explain facts.
We feel that our thirst for a knowledge of the causes of things is
contented when science points out the "sufficient reason" of them. In
the whole province of inorganic cosmology natural law is now generally
recognized to be all-powerful; in astronomy, geology, physics,
and chemistry all phenomena are reduced to fixed laws, and in the
long-run to the all-embracing law of substance, the great law of the
conservation of matter and force (_Riddle_, chapter xii.).
It is otherwise in biology, or the organic section of cosmology. Here
we still find miracles set up in opposition to the law of substance,
and the transgression of natural laws by supernatural forces. The
belief in miracles of this kind, which pure reason calls superstition,
is still very wide-spread--much more prevalent than is usually thought.
For my part, I hold that superstition and unreason are the worst
enemies of the human race, while science and reason are its greatest
friends. Hence it is our duty and task to attack the belief in miracles
wherever we find it, in the interest of the race. We have to prove that
the reign of natural law extends over the whole world of phenomena
as far as we can reach it. A general survey of the history of faith
on the one hand and of science on the other clearly shows that the
advance of the latter has always been accompanied by an increasing
knowledge of fixed natural laws and the shrinking of superstition
into an ever-lessening area. To-day we convince ourselves of this
by an impartial examination of mental culture at the various stages
of civilization. For this purpose I take the four chief stages of
mental development which Fritz Schultze has given in his _Physiology
of Uncivilized Races_, and Alexander Sutherland in his work, _On the
Origin and Growth of the Moral Instinct_: 1, savages; 2, barbarians; 3,
civilized races; 4, educated races (_cf._ chapter i.).
The mental life of savages rises little above that of the higher
mammals, especially the apes, with which they are genealogically
connected. Their whole interest is restricted to the physiological
functions of nutrition and reproduction, or the satisfaction of hunger
and thirst in the crudest animal fashion. Without fixed habitation,
constantly struggling for existence, they live on the raw produce of
nature--fruits, the roots of wild plants, and the animals they fish
in the water or catch on land. Their intelligence moves within the
narrowest bounds, and one can no more (or no less) speak of their
reason than of that of the more intelligent animals. Of art and science
there is no question. Their impulse to discover causes is satisfied
with the simplest association of phenomena which have a merely external
connection, but no intimate relation to each other. Thus arises
their _fetichism_, that irrational trust in fetiches which Fritz
Schultze has traced to four distinct causes: their false estimate of
the value of an object, their anthropomorphic conception of nature,
the imperfect association of their ideas, and the strength of their
emotions, especially hope and fear. Any favorite object, a stone or
a bone, may work miracles as a fetich and exercise all kinds of good
or evil influence, and is therefore honored, feared, and worshipped.
At first the worship was paid to the invisible spirit that dwelt in
the particular object; but it was often transferred afterwards to the
dead object itself. Among the different savage races the belief in
fetiches presents a number of stages, corresponding to the beginnings
of reason. The lowest stage is found in the lowest races, such as the
Veddahs of Ceylon, the Andaman Islanders, Bushmen, and Akkas (of New
Guinea). A somewhat higher stage is met in the middle races (Australian
negroes, Tasmanians, Hottentots, and Tierra del Fuegians); and a still
higher intellectual development is shown by the next group (most of
the Indians of North and South America, the aboriginal inhabitants
of India, etc.). Modern comparative ethnography and evolution and
prehistoric and anthropological research have shown us that our own
ancestors, ten thousand and more years ago, were (like the prehistoric
ancestors of all races of men) savages, and that their earliest belief
in miracles was a crude fetichism.
By barbarians we understand the races that are found between savage
and civilized peoples. They show the first beginnings of civilization,
and are superior to savages chiefly in the possession of agriculture
and the keeping of cattle. They make a provident use of the productive
forces of organic nature, artificially produce large quantities of
food, and are thus enabled by the abundance of food to turn their minds
to other interests. We find that they have the rudiments of art and
science. Their religion does not at first rise much above fetichism,
but soon reaches the stage of animism, lifeless objects in nature
being credited with souls. Worship is no longer paid to favorite dead
objects (stones, bones, etc.), but generally to living things, trees
and animals, and especially to images of gods which have the form
of animals or men, and are believed to possess souls. As demons or
spirits, these have a great influence on the fortunes of men. At first
this soul is conceived to be purely material; it disappears at the
death of the body and lives apart. As the breathing and the beat of the
pulse and heart cease when a man dies, the seat of the soul is thought
to be the lungs, heart, or some other part of the body. The idea of the
immortality of the soul takes on innumerable forms among them, like the
belief in the miracles which are worked by the gods, demons, spirits,
etc. Evolution again points out a long gradation of forms of faith, if
we compare the lower, middle, and higher races.
Civilized races are distinguished from barbaric by the formation of
states with an extensive division of labor. The social organism is
not only larger and more powerful, but is capable of a greater variety
of achievements, the functions of the various states and classes of
workers being more highly differentiated and mutually complementary
(like the cells and tissues in the higher animal body of the metazoa).
Nutrition is easier and more luxurious. Art and science are well
developed. A great advance is seen in regard to religion, the numerous
gods being generally conceived as manlike spirits, and finally
subordinated to a chief god. The belief in miracles flourishes greatly
in poetry; in philosophy it is more and more restricted. In the end,
the working of miracles is limited monotheistically to one god, or to
his priests and other men to whom he communicates the power.
Modern civilization in the narrower sense, as a contrast to the
older civilization, opens, in my opinion, at the beginning of the
sixteenth century. At that time took place some of the greatest
achievements of human thought among civilized peoples, and these
broke the chains of tradition and gave a fresh impetus to progress.
Men's own mental outlook was widened by the system of Copernicus
and the Reformation freed them from the yoke of the papacy. Shortly
before, the discovery of the New World and the circumnavigation of
the globe had convinced men of the rotundity of the earth; geography,
natural history, medicine, and other sciences gained inspiration and
independence; printing and engraving provided an important means of
spreading the new knowledge. This fresh impetus was chiefly of service
to philosophy, which now more and more rejected the dictation of the
Church and superstition; though it was far from casting off the fetters
altogether. This was not generally possible until the nineteenth
century, when empirical science assumed an enormous importance, and in
the ensuing period of speculation the physical conception of the world
gained more and more on the metaphysical. Pure knowledge, thus grounded
on science, entered into sharper conflict than ever with religious
faith. If, as in the preceding cases, we distinguish three stages in
the development of modern civilization, we recognize the progressive
liberation from superstition by scientific knowledge.