When we compare the higher forms of religion of civilized nations we

find the same emotional cravings and thought-processes constantly

recurring, and the belief in miracles developing in much the same

way. The three founders of the great monotheistic Mediterranean

religion--Moses, Christ, and Mohammed--were equally regarded as

wonder-working prophets, having direct intercourse with God in virtue

of their special gifts, and transmitting his commands to men in the

shape of laws. The extraordinary authority they enjoy, which has

given so much prestige to the religions they founded, is grounded for

ordinary people on their miraculous powers--the healing of the sick,

the raising of the dead, the expulsion of devils, and so on. If we

examine the miracles of Christ as they are given in the gospels, they

run counter to the laws of nature and rational explanation just in

the same way as the similar miracles of Buddha and Brahma in Hindoo

mythology, or of Mohammed in the Koran. The same must be said of the

belief in the miracle of the bread and wine in the Lord's supper,

and the like. The Creed which was probably drawn up by the leaders

of the Christian communities of the second century, and received its

final and present form in the Church of South Gaul in the fourth

and fifth centuries, has been obligatory for Christians for fifteen

hundred years, and recognized by both Church and State as compulsory.

This Apostles' Creed was also recognized in Luther's catechism to

be fundamental, and is taught in all Protestant and Roman Catholic

schools (though not in the Greek Catholic) as the foundation of

religious instruction. This extraordinary prestige of the Apostles'

Creed, and its great influence on the education of the young, no less

than its glaring inconsistency with rational knowledge, compel us to

devote a few pages to a critical examination of its three articles.

The first article of the Creed deals with creation, and runs: "I

believe in God, the Father Almighty, Creator of heaven and earth."

The modern science of evolution has shown that there never was any

such creation, but that the universe is eternal and the law of

substance all-ruling. God himself is anthropomorphically conceived as

an "Almighty Creator" and the Father of man; heaven (in the sense of

the geocentric system) is imagined as a great blue vault spanning the

earth. The notion of this "personal God" as an intelligent, immaterial

being, creating the material world out of nothing, is wholly irrational

and meaningless. That Luther accepted this childish and scientifically

worthless idea is clear from his commentary on the first article--"What

is that?"

The second article of the Creed deals with the dogma of salvation

in the following words: "I believe in Jesus Christ, his only son,

our Lord, who was conceived of the Holy Ghost, born of the Virgin

Mary, suffered under Pontius Pilate, was crucified, dead, and buried,

descended into hell, on the third day rose again from the dead,

ascended into heaven, sitteth at the right hand of God, the Father

Almighty, whence he will come to judge the living and the dead." As

these dogmas of the second article contain the chief points of the

redemption theory, and are still treasured by millions of educated

people, it is necessary to point out their flagrant opposition to pure

reason. The chief evil of such creeds is that children, who are yet

incapable of reflecting, are forced to learn them by heart. They then

remain unchallenged as revealed truths.

The myth of the conception and birth of Jesus Christ is mere fiction,

and is at the same stage of superstition as a hundred other myths of

other religions. Of the three persons who are mysteriously blended

in the triune God, the son Christ is supposed to be begotten by both

Father and Holy Ghost, parthenogenetically through the Virgin Mary. I

have dealt with the physiology of parthenogenesis in the seventeenth

chapter of the _Riddle_. The curious adventures of Christ after his

death, the descent into hell, resurrection, and ascension, are also

fantastic myths due to the narrow geocentric ideas of an uneducated

people. Troelslund has admirably explained the strong influence they

have had in his interesting book, _The Idea of Heaven and of the

World_.[6] The idea of the "last judgment," with Christ sitting on the

right hand of the Father, as many famous mediæval pictures represent

(notably Michael Angelo's in the Sistine Chapel at the Vatican), is

another outcome of a thoroughly childish and anthropomorphic attitude.

It is remarkable that this second article of the Creed says nothing

about "redemption," which forms its heading [in Germany]. Luther has

dealt with it in his commentary. Christ is believed to have suffered a

painful death, like many thousand other martyrs, for his conviction of

the truth of his faith and teaching--which reminds one of the more than

a hundred thousand men who were done to death by the Inquisition and in

the religious wars of the Middle Ages; but not one of the millions of

ministers who preach on it every Sunday seems to have shown a rational

causal connection of this death with the alleged redemption from sin

and death. The whole of this story of redemption has sprung from the

primitive, obscure, ethical ideas of uneducated races, especially the

crude belief in the propitiatory power of human sacrifice. It has

no practical moral value except for those who believe in personal

immortality--a scientifically untenable dogma. Whoever builds on this

empty promise of a better life beyond may soothe himself with this

hope, and reconcile himself to the thousand ills and defects of this

world. But the man who studies this life as it really is will not

find that the belief in redemption has brought any real improvement.

Want and misery and sin are as prevalent as ever; indeed, our modern

civilization has, in many respects, increased them.

The third and last article of the Apostles' Creed runs: "I believe

in the Holy Ghost, the holy Catholic Church, the communion of

saints, the forgiveness of sins, the resurrection of the body, and

life everlasting." In the curious commentary that Luther made on

this article in his catechism, he said that "man cannot believe

of his own reason in Jesus Christ"--which is very true--but the

Holy Ghost must lead him thereto with his grace; but how the third

person of the Trinity effects this enlightenment and sanctification

he did not explain. What is meant by the "communion of saints" and

the "holy Catholic Church" must be gathered in the light of their

history--especially the history of Romanism. This most powerful and

still influential section of the Christian Church, which especially

claims the title of Catholic and "the one ark of salvation," is really

a most pitiful caricature of pure primitive Christianity. It has, with

consummate skill, succeeded in preaching the beneficent teaching of

Christ in theory and doing just the opposite in practice; we need only

recall the Inquisition, the dark history of the Middle Ages, and the

political hierarchy which still dominates so much of civilization.

However, by far the most important clause in the third article is

the final expression of belief in "the resurrection of the body and

life everlasting." That this greatest "wonder of life" was originally

conceived in a purely material form is evident from thousands of

pictures in which famous painters have realistically depicted the

resurrection of the dead, the aërial flight of the happy souls of the

blessed, and the torments of the damned in hell. It is thus conceived

still by the majority of believers who take eternal life to be an

"enlarged and improved edition" of life here below. This is equally

true of Christian and Mohammedan pictures and of the athanatist ideas

that prevailed in other religions long before Christ was born, even

of the first rudiments of the belief in primitive races. As long as

the geocentric theory prevailed, and the heavens were thought to be a

sort of blue glass bell, illumined by thousands of little stars and

the lamp of the sun, arching like a vault over the flat earth, and

the fires of hell burned in the cellars below, this barbaric notion

of a resurrection of the body and a last judgment could easily be

maintained. But its roots were destroyed when Copernicus refuted the

geocentric theory in 1545; and athanatism became quite untenable when

Darwin shattered the dogma of anthropocentricism. Not only the crude

older materialistic idea of eternal life, but also the refined new

spiritualistic version, has been rendered untenable by the progress of

science in the nineteenth century. I have shown this in the eleventh

chapter of the _Riddle_, which closes with the words: "If we take a

comprehensive glance at all that modern anthropology, psychology,

and cosmology teach with regard to athanatism, we are forced to this

definite conclusion. The belief in the immortality of the human soul

is in hopeless contradiction with the most solid empirical truths of

modern science."[7]

The great influence which has been exercised on civilized nations

by the Christian beliefs, supported by the practical exigencies of

the state, for thousands of years, was chiefly seen in the crude

superstition of the mass of the people. Confessions of faith became

as much a matter of routine as the latest fashion in dress or the

latest custom, etc. But even the majority of the philosophers were

more or less subordinated to the influence. It is true that a few

great thinkers freed themselves by the use of pure reason at an early

date from the prevalent superstition, and framed systems apart from

tradition and the priests. But most philosophers could not rise to

the altitude of these brave Free-thinkers; they remained "school-men"

in the literal sense, dependent on the dictation of authority, the

traditions of the school, and the dogmas of the Church. Philosophy

was the "handmaid" of theology and ecclesiasticism. If we examine the

history of philosophy in this light, we find in it a struggle for

twenty-five hundred years between two great tendencies--the dualism of

the majority (with theological and mystic leanings) and the monism of

the minority (with rationalistic and naturalistic disposition).

Especially notable are those great Free-thinkers of classic antiquity

who taught a monistic view of life in the sixth century before

Christ--the Ionic natural philosophers, Thales, Anaximander, and

Anaximenes; and a little later, Heraclitus, Empedocles, and Democritus.

They made the first thorough attempt to explain the world on rational

principles, independently of all mythological tradition and theological

dogmas. However, these remarkable efforts to found a primitive monism,

which found so finished an expression in the _De rerum natura_ of the

great poet-philosopher, Lucretius Carus (98-54 B.C.), were shortly

thrust out by the spread--through Plato's curious dualism--of the

belief in the immortality of the soul and the transcendental world of

ideas.

The Eleatics, Parmenides and Zeno, had foreshadowed in the fifth

century the division of philosophy into two branches; but Plato and

his pupil Aristotle (in the fourth century B.C.) succeeded in gaining

general acceptance for this dualism and antithesis of physics and

metaphysics. Physics devoted itself on the ground of experience to

the study of the phenomena of things, leaving their real essences (or

noumena) that lay behind the phenomena to metaphysics. These inner

essences are transcendental and inaccessible to empirical research;

they form the metaphysical world of eternal ideas, which is independent

of the real world, and has its highest unity in God, as the Absolute.

The soul, an eternal idea that dwells for a time in the passing human

body, is immortal. This consistent dualism of Plato's system, with

its sharp antithesis of this world and the next, of body and soul, of

world and God, is its chief characteristic. It became all the more

influential when Plato's pupil Aristotle blended it with his empirical

metaphysics, based on ample scientific experience, and pointed out the

idea in the entelechy, or purposively acting principle, of every being;

and especially when Christianity (three hundred years afterwards) found

in this dualism a welcome philosophic support of its own transcendental

tendency.

In the course of the thousand years which historians call the Middle

Ages, and which are usually dated from the fall of the Roman Empire

(476) to the discovery of America (1492), the superstition of civilized

races reached its highest development. The authority of Aristotle was

paramount in philosophy; it was used by the dominant Church for its

own purposes. But the influence of the Christian faith, with all the

gay coloring which the fairy-tales of the Bible added to its structure

of dogmas, was seen much more in practical life. In the foreground of

belief were the three central dogmas of metaphysics, to which Plato had

first given complete expression--the personal God as creator of the

world, the immortality of the soul, and the freedom of the human will.

As Christianity laid the greatest theoretical stress on the first two

dogmas and the greatest practical stress on the third, metaphysical

dualism soon prevailed on all sides. Especially inimical to scientific

inquiry was the Christian contempt of nature and its belittlement

of earthly life in view of the eternal life to come. As long as the

light of philosophical criticism in any form was extinguished, the

flower-garden of religious poetry flourished exceedingly and the idea

of miracle was taken as self-evident. We know what the practical result

of this superstition was from the ghastly history of the Middle Ages,

with its Inquisition, religious wars, instruments of torture, and

drowning of witches. In the face of the current enthusiasm for the

romantic side of mediævalism, the Crusades and Church art, we cannot

lay too much stress on these dark and bloody pages of its chronicles.

An impartial study of the immense progress made by science in the

course of the nineteenth century shows convincingly that the three

central metaphysical dogmas established by Plato have become untenable

for pure reason. Our clear modern insight into the regularity and

causative character of natural processes, and especially our knowledge

of the universal reign of the law of substance, are inconsistent with

belief in a personal God, the immortality of the soul, and the freedom

of the will. If we find this threefold superstition still widely

prevalent, and even retained by academic philosophers as an unshakable

consequence of "critical philosophy," we must trace this remarkable

fact chiefly to the great prestige of Immanuel Kant. His so-called

critical system--really a hybrid product of the crossing of pure reason

with practical superstition--has enjoyed a greater popularity than any

other philosophy, and we must stop to consider it for a moment.

I have described in chapters xiv. and xx. of the _Riddle_ the profound

opposition between my monistic system and Kant's dualistic philosophy.

In the appendix to the popular edition, especially, I have pointed out

the glaring contradictions of his system, which other philosophers

have often detected and criticised. Whenever there is question of his

teaching one must ask: "Which Kant do you mean? Kant I., the founder of

the monistic cosmogony, the critical formulator of pure reason; or Kant

II., the author of the dualistic criticism of judgment, the dogmatic

discoverer of practical reason?" These contradictions are partly due

to the psychological metamorphoses which Kant underwent (_Riddle_,

chapter vi.), partly to the perennial conflict between his scientific

bias towards a mechanical explanation of this world and his religious

craving (an outcome of heredity and education) and mystic belief in a

life beyond. This culminates in the distinction between the world of

sense and the world of spirit. The sense world (_mundus sensibilis_)

lies open to our senses and our intellect, and is empirically knowable

within certain limits. But behind it there is the spiritual world

(_mundus intelligibilis_) of which we know, and can know, nothing;

its existence (as the thing in itself) is, however, assured by our

emotional needs. In this transcendental world dwells the power of

mysticism.

It is said to be the chief merit of Kant's system that he first

clearly stated the problem: "How is knowledge possible?" In trying to

solve this problem introspectively, by a subtle analysis of his own

mental activity, he reached the conviction that the most important

and soundest of all knowledge--namely, mathematical--consists of

synthetic _a priori_ judgments, and that pure science is only possible

on condition that there are strict _a priori_ ideas, independent of

all experience, without _a posteriori_ judgments. Kant regarded this

highest faculty of the human mind as innate, and made no inquiry into

its development, its physiological mechanism, and its anatomic organ,

the brain. Seeing the very imperfect knowledge which human anatomy

had of the complicated structure of the brain at the beginning of the

nineteenth century, it was impossible to have at that time a correct

idea of its physiological function.

What seems to us to-day to be an innate capacity, or an _a priori_

quality, of our phronema, is really a phylogenetic result of a long

series of brain-adaptations, formed by _a posteriori_ sense-perceptions

and experiences.

Kant's much-lauded critical theory of knowledge is therefore just as

dogmatic as his idea of "the thing in itself," the unintelligible

entity that lurks behind the phenomena. This dogma is erroneously built

on the correct idea that our knowledge, obtained through the senses, is

imperfect; it extends only so far as the specific energy of the senses

and the structure of the phronema admit. But it by no means follows

that it is a mere illusion, and least of all that the external world

exists only in our ideas. All sound men believe, when they use their

senses of touch and space, that the stone they feel fills a certain

part of space, and this space does really exist. When all men who can

see agree that the sun rises and sets every day, this proves a relative

motion of the two heavenly bodies, and so the real existence of time.

Space and time are not merely necessary forms of intuition for human

knowledge, but real features of things, existing quite independently of

perception.

The increasing recognition of fixed natural laws which accompanied the

growth of science in the nineteenth century was bound to restrict more

and more the blind faith in miracles. There are three chief reasons

why we find this, nevertheless, still so prevalent--the continued

influence of dualistic metaphysics, the authority of the Christian

Church, and the pressure of the modern state in allying itself with

the Church. These three strong bulwarks of superstition are so hostile

to pure reason and the truth it seeks that we must devote special

attention to them. It is a question of the highest interests of

humanity. The struggle against superstition and ignorance is a fight

for civilization. Our modern civilization will only emerge from it in

triumph, and we shall only eliminate the last barbaric features from

our social and political life, when the light of true knowledge has

driven out the belief in miracles and the prejudices of dualism.

The remarkable history of philosophy in the nineteenth century, which

has not yet been written with complete impartiality and knowledge,

shows us in the first place an ever-increasing struggle between the

rising young sciences and the paramount authority of tradition and

dogma. In the first half of the century the various branches of biology

made progress without coming into direct collision with natural

philosophy. The great advance of comparative anatomy, physiology,

embryology, paleontology, the cell-theory, and classification,

provided scientists with such ample material that they attached

little importance to speculative metaphysics. It was otherwise in the

second half of the nineteenth century. Soon after its commencement

the controversy about the immortality of the soul broke out, in

which Moleschott (1852), Büchner, and Carl Vogt (1854) contended for

the physiological dependence of the soul on the brain, while Rudolph

Wagner endeavored to maintain the prevailing metaphysical idea of its

supernatural character. Then Darwin especially initiated in 1859 that

vast reform in biology which brought to light the natural origin of

species and shattered the miracle of creation. When the application

of the theory of descent and the biogenetic law to man was made by

anthropogeny (1874), and his evolution from a series of other mammals

was proved, the belief in the immortality of the soul, the freedom

of the will, and an anthropomorphic deity lost its last support.

Nevertheless, these three fundamental dogmas continued to find favor

in academic philosophy, which mostly followed the paths opened out by

Kant. Most of the representatives of philosophy at the universities

are narrow metaphysicians and idealists, who think more of the fiction

of the "intelligible world" than of the truth of the world of sense.

They ignore the vast progress made by modern biology, especially in

the science of evolution; and they endeavor to meet the difficulties

which it creates for their transcendental idealism by a sort of verbal

gymnastic and sophistry. Behind all these metaphysical struggles there

is still the personal element--the desire to save one's immortality

from the wreck. In this it comes into line with the prevailing

theology, which again builds on Kant. The pitiful condition of modern

psychology is a characteristic result of this state of things. While

the empirical physiology and pathology of the brain have made the

greatest discoveries, the comparative anatomy and histology of the

brain have thrown light on the details of its elaborate structure, and

the ontogeny and phylogeny of the brain have proved its natural origin,

the speculative philosophy of the schools stands aside from it all,

and in its introspective analysis of the functions of the brain will

not hear a word about the brain itself. It would explain the working

of a most complicated machine without paying any attention to its

structure. It is, therefore, not surprising to find that the dualistic

theories established by Kant flourish at our universities as they did

in the Middle Ages.

If the official philosophers, whose formal duty it is to study truth

and natural law, still cling to the belief in miracles in spite of

all the advance of empirical science, we shall not be surprised to

find this in the case of official theology. Nevertheless, the sense of

truth has prompted many unprejudiced and honorable theologians to look

critically at the venerable structure of dogma, and open their minds

to the streaming light of modern science. In the first third of the

nineteenth century a rationalistic section of the Protestant Church

attempted to rid itself of the fetters of dogma and reconcile its

ideas with pure reason. Its chief leader, Schleiermacher, of Berlin,

though an admirer of Plato and his dualist metaphysics, approached

very close to modern pantheism. Subsequent rationalistic theologians,

especially those of the Tübingen school (Baur, Zeller, etc.), devoted

themselves to the historical study of the gospels and their sources and

development, and thus more and more destroyed the base of Christian

superstition. Finally, the radical criticism of David Friedrich

Strauss showed, in his _Life of Jesus_ (1835), the mythological

character of the whole Christian system. In his famous work, _The Old

and New Faith_ (1872), this honorable and gifted theologian finally

abandoned the belief in miracles, and turned to natural knowledge and

the monistic philosophy for the construction of a rational view of

life on the basis of critical experience. This work has lately been

continued by Albert Kalthoff. Moreover, many modern theologians (such

as Savage, Nippold, Pfleiderer, and other liberal Protestants) have

endeavored in various ways to obtain a certain recognition for the

claims of progressive science, and reconcile them with theology, while

discarding the belief in the miraculous. However, these rationalistic

efforts, based on monistic or pantheistic views, are still isolated and

apparently without effect. The great majority of modern theologians

adhere to the traditional teaching of the Church, whose columns and

windows are still everywhere adorned with miracles. While a few liberal

Protestants restrict their faith to the three fundamental dogmas, most

of them still believe in the myths and legends which fill the pages of

the gospels. This orthodoxy is, moreover, encouraged of late by the

conservative and reactionary attitude taken up by many governments on

political grounds.

Most modern governments maintain the connection with the Church in the

idea that the traditional belief in the miraculous is the best security

for their own continuance. Throne and altar must protect and support

each other. However, this conservative-Christian policy meets two

obstacles in an increasing measure. On the one hand, the ecclesiastical

hierarchy is always trying to set its spiritual power above the secular

and make the state serve its own purposes; and, on the other hand, the

modern right of popular representation affords an opportunity to make

the voice of reason heard and oppose the reactionary conservatives

with opportune reforms. The chief rulers and the ministers of public

instruction, who have a great influence in this struggle, generally

favor the teaching of the Church, not out of conviction of its truth,

but because they think knowledge brings unrest, and because docile and

ignorant subjects are easier to rule than educated and independent

citizens. Hence it is that we now hear so much on every occasion, in

speeches from the throne and at banquets, at the opening of churches

and the unveiling of monuments, from able and influential speakers, of

the value of faith. They would give the palm to faith in its struggle

with knowledge. Thus we get this paradoxical situation in educated

countries (such as Prussia), that encouragement is given at once to

modern science and technical training and to the orthodox Church,

which is its deadly enemy. As a rule, it is not stated in these florid

orations to how many and what kind of miracles this precious faith must

extend. Nevertheless, we may yet, in view of the spread of intellectual

reaction in Germany, see it made obligatory for at least all priests,

teachers, and other servants of the state to profess a belief in the

three fundamental mysteries--the triune God of the catechism, the

personal immortality of the soul, and the absolute freedom of the human

will--and even in many of the other miracles which are found in the

gospels, sacred legends, and religious journals of our time.

The refined belief in the miraculous embodied in Kant's practical

philosophy assumed many different forms among his followers, the

Neo-Kantians, approaching sometimes more and sometimes less to the

conventional beliefs. Through a long series of variations, which still

continue to develop, it is gradually passing into the cruder form of

superstition which we find popular to-day as spiritism, and which

provides the basis for what is called occultism. Kant himself, in

spite of his subtle and clear critical faculty, had a decided leaning

to mysticism and positive dogmatism, which showed itself especially

in his later years. He thought a good deal of Swedenborg's idea of

the spirit world forming a universe apart, and compared this to his

_mundus intelligibilis_. Among the natural philosophers of the first

half of the nineteenth century, Schelling (in his later writings),

Schubert (in his _History of the Soul_ and _Observations on the Dark

Side of Science_), and Perty (in his mystic anthropology) especially

investigated the mysterious phenomena of mental action, and sought

to connect them with the physiological functions of the brain on the

one hand and supernatural spiritual agencies on the other. Modern

spook-seeking has no more value than mediæval magic, cabalism,

astrology, necromancy, dream-interpretation, and invocation of the

devil.

We must put at the same stage of superstition the spiritism and

occultism we find mentioned so much in modern literature. There are

always thousands of credulous folk in educated countries who are

taken in by the performances of the spiritists and their media, and

are ready to believe the unbelievable. Spirit-rapping, table-turning,

spirit-writing, the materialization and photographing of deceased

souls, find credit, not only among the uneducated masses, but even

among the most cultured, and sometimes among imaginative scientists.

It has been proved without avail by numbers of impartial observations

and experiments that these occultist performances depend partly on

conscious fraud and partly on careless self-deception. _Mundus vult

decipi_--"the world wishes to be taken in"--as the old saying has it.

This spiritistic fraud is particularly dangerous when it clothes itself

with the mantle of science, makes use of the physiological phenomena

of hypnotism, and even assumes a monistic character. Thus, for

instance, one of the best-known occultist writers, Karl du Prel, has

written, not only a _Philosophy of Mysticism and Studies of Scientific

Subjects_, but also (1888) a _Monistic Psychology_, which is dualistic

from beginning to end. In these popular writings lively imagination

and brilliant presentation are combined with a most flagrant lack of

critical sense and of knowledge of the elements of biology (_cf._

chapter xvi. of the _Riddle_). It seems that the hereditary bias

towards mysticism and superstition is not yet eliminated even from

the educated mind of our time. It is to be explained phylogenetically

by inheritance from prehistoric barbarians and savages, in whom

the earliest religious ideas were wholly dominated by animism and

fetichism.

IV

THE SCIENCE OF LIFE

Object of biology--Relation to the other sciences--General

and special biology--Natural philosophy--Monism:

hylozoism, materialism, dynamism--Naturalism--Nature and

spirit--Physics--Metaphysics--Dualism--Freedom and natural law--God

in biology--Realism--Idealism--Branches of biology--Morphology and

physiology--Anatomy and biogeny--Ergology and perilogy.

The broad realm of science has been vastly extended in the course of

the nineteenth century. Many new branches have established themselves

independently; many new and most fruitful methods of research have

been discovered, and have been applied with the greatest practical

success in furthering the advance of modern thought. But this enormous

expansion of the field of knowledge has its disadvantages. The

extensive division of labor it has involved has led to the growth

of a narrow specialism in many small sections; and in this way the

natural connection of the various provinces of knowledge, and their

relation to the comprehensive whole, have been partly or wholly lost

sight of. The importation of new terms which are used in different

senses by one-sided workers in the various fields of science has caused

a good deal of misunderstanding and confusion. The vast structure

of science tends more and more to become a tower of Babel, in the

labyrinthic passages of which few are at their ease and few any longer

understand the language of other workers. In these circumstances, it

seems advisable, at the commencement of our philosophic study of "the

wonders of life," to form a clear idea of our task. We must carefully

define the place of biology among the sciences, and the relation of

its various branches to each other and to the different systems of

philosophy.

In the broadest sense in which we can take it, biology is the whole

study of organisms or living beings. Hence not only botany (the science

of plants) and zoology (the science of animals), but also anthropology

(the science of man), fall within its domain. We then contrast with it

all the sciences which deal with inorganic or lifeless bodies, which

we may collectively call abiology (or anorganology); to this belong

astronomy, geology, mineralogy, hydrology, etc. This division of the

two great branches of science does not seem difficult in view of the

fact that the idea of life is sharply defined physiologically by its

metabolism and chemically by its plasm; but when we come to study the

question of abiogenesis (chapter xv.) we shall find that this division

is not absolute, and that organic life has been evolved from inorganic

nature. Moreover, biology and abiology are connected branches of

cosmology, or the science of the world.

While the idea of biology is now usually taken in this broad sense in

most scientific works and made to embrace the whole of living nature,

we often find (especially in Germany) a narrower application of the

term. Many authors (mostly physiologists) understand by it a section of

physiology--namely, the science of the relations of living organisms to

the external world, their habitat, customs, enemies, parasites, etc.

I proposed long ago to call this special part of biology œcology

(the science of home-relations), or bionomy. Twenty years later others

suggested the name of ethology. To call this special study any longer

biology in the narrower sense is very undesirable, because it is the

only name we have for the totality of the organic sciences.

Like every other science, biology has a general and a special part.

General biology contains general information about living nature;

this is the subject of the present study of the wonders of life. We

might also describe it as biological philosophy, since the aim of true

philosophy must be the comprehensive survey and rational interpretation

of all the general results of scientific research. The innumerable

discoveries of detailed facts which observation and experiment give

us, and which are combined into a general view of life in philosophy,

form the subject of empirical science. As the latter, on the side of

the organic world, or as empirical biology, forms the first object of

the science of life, and seeks to effect in the system of nature a

logical arrangement and summary grouping of the countless special forms

of life, this special biology is often wrongly called the science of

classification.

The first comprehensive attempt to reduce to order and unity the

ample biological material which systematic research had accumulated

in the eighteenth century was made by what we call "the older natural

philosophy" at the beginning of the nineteenth century. Reinhold

Treviranus (of Bremen) had made a suggestive effort to accomplish this

difficult task on monistic principles in his _Biology, or Philosophy of

Living Nature_ (1802). Special importance attaches to the year 1809, in

which Jean Lamarck (of Paris) published his _Philosophie Zoologique_,

and Lorentz Oken (of Jena) his _Manual of Natural Philosophy_. I have

fully appreciated the service of Lamarck, the founder of the theory

of descent, in my earlier writings. I have also recognized the great

merit of Lorentz Oken, who not only aroused a very wide interest in

this science by his _General Natural History_, but also put forward

some general observations of great value. His "infamous" theory of a

primitive slime, and the development of infusoria out of it, is merely

the fundamental idea of the theory of protoplasm and the cell which

was long afterwards fully recognized. These and other services of the

older natural philosophy were partly ignored and partly overlooked,

because they went far beyond the scientific horizon of the time, and

their authors to an extent lost themselves in airy and fantastic

speculations. The more scientists confined themselves in the following

half-century to empirical work and the observation and description of

separate facts, the more it became the fashion to look down on all

"natural philosophy." The most paradoxical feature of the situation was

that purely speculative philosophy and idealist metaphysics had a great

run at the same time, and their castles in the air, utterly destitute

of biological foundation, were much admired.

The magnificent reform of biology which Darwin initiated in 1859 by

his epoch-making _Origin of Species_ gave a fresh impulse to natural

philosophy. As this work not only used the rich collection of facts

already made in proof of the theory of descent, but gave it a new

foundation in the theory of selection (Darwinism properly so called),

everything seemed to call for the embodiment of the new conception of

nature in a monistic system. I made the first effort to do this in my

_General Morphology_ (1866). As this found few supporters among my

colleagues, I undertook in my _History of Creation_ (1868) to make

the chief points of the system accessible to the general reader. The

remarkable success of this book (a tenth edition of it appearing in

1902) emboldened me at the end of the nineteenth century to state the

general principles of my monistic philosophy in my _Riddle of the

Universe_. About the same time (1899) there appeared the work of the

Kiel botanist, Johannes Reinke, _The World as Reality_; and two years

afterwards he followed it up with a supplementary volume, _Introduction

to Theoretic Biology_. As Reinke treats the general problems of natural

philosophy from a purely mystic and dualistic point of view, his ideas

are diametrically opposed to my monistic and naturalistic principles.

The history of philosophy describes for us the infinite variety of

ideas that men have formulated during the last three thousand years

on the nature of the world and its phenomena. Überweg has given us,

in his excellent _History of Philosophy_, a thorough and impartial

account of these various systems. Fritz Schultze has published a

clear and compendious "tabulated outline" of them in thirty tables in

his genealogical tree of philosophy, and at the same time shown the

phylogeny of ideas. When we survey this enormous mass of philosophic

systems from the point of view of general biology, we find that we can

divide them into two main groups. The first and smaller group contains

the monistic philosophy, which traces all the phenomena of existence

to one single common principle. The second and larger group, to which

most philosophic systems belong, constitutes the dualistic philosophy,

according to which there are two totally distinct principles in the

universe. These are sometimes expressed as God and the world, sometimes

as the spiritual world and material world, sometimes as mind and

matter, and so on. In my opinion, this antithesis of monism and dualism

is the most important in the whole history of philosophy. All other

systems are only variations of one or the other of these, or a more or

less obscure combination of the two.

The form of monism which I take to be the most complete expression

of the general truth, and which I have advocated in my writings for

thirty-eight years, is now generally called hylozoism. This expresses

the fact that all substance has two fundamental attributes; as matter

(_hyle_) it occupies space, and as force or energy it is endowed with

sensation (_cf._ chapter xix.). Spinoza, who gave the most perfect

expression to this idea in his "philosophy of identity," and most

clearly treated the notion of substance (as the all-embracing essence

of the world), clothes it with two general attributes--extension

and thought. Extension is identical with real space, and thought

with (unconscious) sensation. The latter must not be confused with

conscious human thought; intelligence is not found in substance, but is

a special property of the higher animals and man. Spinoza identifies

his substance with nature and God, and his system is accordingly

called pantheism; but it must be understood that he rejects the

anthropomorphic, personal idea of deity.

A good deal of the infinite confusion that characterizes the conflicts

of philosophers over their systems is due to the obscurity and

ambiguity of many of their fundamental ideas. The words "substance"

and "God," "soul" and "spirit," "sensation" and "matter," are used

in the most different and changing senses. This is especially true

of the word "materialism," which is often wrongly taken to be

synonymous with monism. The moral bias of idealism against _practical_

materialism (or pure selfishness and sensualism) is forthwith

transferred to theoretical materialism, which has nothing to do with

it; and the strictures which are justly urged against the one are

most unjustifiably applied to the other. Hence it is important to

distinguish very carefully between these two meanings of materialism.

Theoretical materialism (or hylonism), as a realistic and monistic

philosophy, is right in so far as it conceives matter and force to be

inseparably connected, and denies the existence of immaterial forces.

But it is wrong when it denies all sensation to matter, and regards

actual energy as a function of dead matter. Thus, in ancient times

Democritus and Lucretius traced all phenomena to the movements of dead

atoms, as did also Holbach and Lamettrie in the eighteenth century.

This view is held to-day by most chemists and physicists. They regard

gravitation and chemical affinity as a mere mechanical movement of

atoms, and this, in turn, as the general source of all phenomena; but

they will not allow that these movements necessarily presuppose a

kind of (unconscious) sensation. In conversation with distinguished

physicists and chemists I have often found that they will not hear a

word about a "soul" in the atom. In my opinion, however, this must

necessarily be assumed to explain the simplest physical and chemical

processes. Naturally I am not thinking of anything like the elaborate

psychic action of man and the higher animals, which is often bound

up with consciousness; we must rather descend the long scale of the

development of consciousness until we reach the simplest protists,

the monera (chapter ix.). The psychic activity of these homogeneous

particles of plasm (for instance, the chromacea) rises very little

above that of crystals; as in the chemical synthesis in the moneron, so

in crystallization we are bound to assume that there is a low degree

of sensation (not of consciousness), in order to explain the orderly

arrangement of the moving molecules in a definite structure.

The prejudice against theoretical materialism (or materialistic monism)

which still prevails so much is partly due to its rejection of the

three central dogmas of dualist metaphysics, and partly to a confusion

of it with hedonism. This practical materialism in its extreme forms

(as Aristippus of Cyrene and the Cyrenaic school, and afterwards

Epicurus, taught it) finds the chief end of life in pleasure--at one

time crude, sensual pleasure, and at others spiritual pleasure. Up to a

certain point, this thirst for happiness and a pleasant and enjoyable

life is innate in every man and higher animal, and so far just; it only

began to be censured as sinful when Christianity directed the thoughts

of men to eternal life, and taught them that their life on earth was

only a preparation for the future. We shall see afterwards, when we

come to weigh the value of life (chapter xvii.), that this asceticism

is unjustifiable and unnatural. But as every legitimate enjoyment can

become wrong by excess, and every virtue be turned into vice, so a

narrow hedonism is to be condemned, especially when it allies itself

with egoism. However, we must point out that this excessive thirst for

pleasure is in no way connected with materialism, but is often found

among idealists. Many convinced supporters of theoretical materialism

(many scientists and physicians, for instance) lead very simple,

blameless lives, and are little disposed to material pleasures. On the

other hand, many priests, theologians, and idealist philosophers, who

preach theoretical idealism, are pronounced hedonists in practice.

In olden times many temples served at one and the same time for the

theoretic worship of the gods and for practical excesses in the way

of wine and love; and even in our day the luxurious and often vicious

lives of the higher clergy (at Rome, for instance) do not fall far

short of the ancient models. This paradoxical situation is due to the

special attractiveness of everything that is forbidden. But it is

utterly unjust to extend the natural feeling against excessive and

egoistic hedonism to theoretical materialism and to monism. Equally

unjust is the habit, still widely spread, of depreciating matter, as

such, in favor of spirit. Impartial biology has taught us of late years

that what we call "spirit" is--as Goethe said long ago--inseparably

bound up with matter. Experience has never yet discovered any spirit

apart from matter.

On the other hand, pure dynamism, now often called energism (and

often spiritualism), is just as one-sided as pure materialism. Just

as the latter takes one attribute of substance, matter, as the one

chief cause of phenomena, dynamism takes its second attribute, force

(_dynamis_). Leibnitz most consistently developed this system among

the older German philosophers; and Fechner and Zöllner have recently

adopted it in part. The latest development of it is found in Wilhelm

Ostwald's _Natural Philosophy_ (1902). This work is purely monistic,

and very ingeniously endeavors to show that the same forces are at

work in the whole of nature, organic and inorganic, and that these may

all be comprised under the general head of energy. It is especially

satisfactory that Ostwald has traced the highest functions of the

human mind (consciousness, thought, feeling, and will), as well as the

simplest physical and chemical processes (heat, electricity, chemical

affinity, etc.), to special forms of energy, or natural force. However,

he is wrong when he supposes that his energism is an entirely new

system. The chief points of it are found in Leibnitz; and other Leipzig

scientists, especially Fechner and Zöllner, had come very close to

similar spiritualistic views--the latter going into outright spiritism.

Ostwald's chief mistake is to take the terms "energy" and "substance"

to be synonymous. Certainly his universal, all-creating energy is, in

the main, the same as the substance of Spinoza, which we have also

adopted in our "law of substance." But Ostwald would deprive substance

of the attribute of matter altogether, and boasts of his _Refutation of

Materialism_ (1895). He would leave it only the one attribute, energy,

and reduce all matter to immaterial points of force. Nevertheless,

as chemist and physicist, he never gets rid of space-filling

substance--which is all we mean by "matter"--and has to treat it and

its parts, the physical molecules and chemical atoms (even if only

conceived as symbols), daily as "vehicles of energy." Ostwald would

reject even these in his pursuit of the illusion of a "science without

hypotheses." As a fact, he is forced every day, like every other exact

scientist, to assume and apply in practice the indispensable idea of

matter, and its separate particles, the molecules and atoms. Knowledge

is impossible without hypotheses.

Monism is best expressed as hylozoism, in so far as this removes

the antithesis of materialism and spiritualism (or mechanicism and

dynamism), and unites them in a natural and harmonious system. Our

monistic system has been charged with leading to pure naturalism;

one of its most vehement critics, Frederick Paulsen, attaches so

much importance to this stricture that he thinks it as dangerous

as dogmatic clericalism. We may, therefore, usefully consider the

idea of naturalism, and point out in what sense we accept it and

identify it with monism. The key to the position is in our monistic

anthropogeny, our unprejudiced conviction, supported by every branch

of anthropological research, of "man's place in nature," as we have

established it in the first section of the _Riddle_ (chapters ii.-v.).

Man is a purely natural being, a placental mammal of the order of

primates. He was phylogenetically evolved in the course of the

Tertiary Period from a series of the lower primates (directly from

the anthropoid apes, but earlier from the cynocephali and lemures).

Savage man, as we have him to-day in the Veddah or Australian negro, is

physiologically nearer to the apes than to highly civilized men.

Anthropology (in the widest sense) is only a particular branch of

zoology, to which we must assign a special position on account of its

extreme importance. Hence all the sciences which relate to man and his

psychic activity--especially what are called the moral sciences--must

be regarded from our monistic point of view as special branches of

zoology and as natural sciences. Human psychology is inseparably

connected with comparative animal psychology, and this again with

that of the plants and protists. Philology studies in human speech a

complicated natural phenomenon, which depends on the combined action

of the brain-cells of the phronema, the muscles of the tongue, and

the vocal cords of the larynx, as much as the cry of mammals and the

song of birds do. The history of mankind (which we, in our curious

anthropocentric mood, call the history of the world), and its highest

branch, the history of civilization, is connected by modern prehistoric

science directly with the stem-history of the primates and the other

mammals, and indirectly with the phylogeny of the lower vertebrates.

Hence, when we consider the subject without prejudice, we do not find

a single branch of human science that passes the limits of natural

science (in the broadest sense), any more than we find nature herself

to be supernatural.

Just as monism, or naturalism, embraces the totality of science, so on

our principles the idea of nature comprises the whole scientifically

knowable world. In the strict monistic sense of Spinoza the ideas

of God and Nature are synonymous for us. Whether there is a realm

of the supernatural and spiritual beyond nature we do not know. All

that is said of it in religious myths and legends, or metaphysical

speculations and dogmas, is mere poetry and an outcome of imagination.

The imagination of civilized man is ever seeking to produce unified

images in art and science, and when it meets with gaps in these in the

association of ideas it endeavors to fill them with its own creations.

These creations of the phronema with which we fill the gaps in our

knowledge are called _hypotheses_ when they are in harmony with the

empirically established facts, and _myths_ when they contradict the

facts: this is the case with religious myths, miracles, etc. Even

when people contrast mind with nature, this is only a result, as a

rule, of similar superstitions (animism, spiritism, etc.). But when we

speak of man's mind as a higher psychic function, we mean a special

physiological function of the brain, or that particular part of the

cortex of the brain which we call the phronema, or organ of thought.

This higher psychic function is a natural phenomenon, subject, like

all other natural phenomena, to the law of substance. The old Latin

word _natura_ (from _nasci_, to be born) stands, like the corresponding

Greek term _physis_ (from _phyo_--to grow), for the essence of the

world as an eternal "being and becoming"--a profound thought! Hence

physics, the science of the _physis_, is, in the broadest sense of the

word, "natural science."

The extensive division of labor which has taken place in science, on

account of the enormous growth of our knowledge in the nineteenth

century and the rise of many new disciplines, has very much altered

their relations to each other and to the whole, and has even given a

fresh meaning and connotation to the term. Hence by physics, as it is

now taught at the universities, is usually understood only that part of

inorganic science which deals with the molecular relations of substance

and the mechanism of mass and ether, without regard to the qualitative

differences of the elements, which are expressed in the atomic weight

of their smallest particles, the atoms. The study of the atoms and

their affinities and combinations belongs to chemistry. As this

province is very extensive and has its special methods of research,

it is usually put side by side with physics as of equal importance;

in reality, however, it is only a branch of physics--chemistry is

the physics of the atoms. Hence, when we speak of a physico-chemical

inquiry or phenomenon, we might justly describe it briefly as

_physical_ (in the wider sense). Physiology, again, a particularly

important branch of it, is in this sense the physics of living things,

or the physico-chemical study of the living body.

Since Aristotle dealt with the eternal phenomena of nature in the first

part of his works, and called this _physics_, and with their inner

nature in the second part, to which he gave the name of _metaphysics_,

the two terms have undergone many and considerable modifications. If

we restrict the term "physics" to the empirical study of phenomena (by

observation and experiment), we may give the name of metaphysics to

every hypothesis and theory that is introduced to fill up the gaps in

it. In this sense the indispensable theories of physics (such as the

assumption that matter is made up of molecules and atoms and electrons)

may be described as metaphysical; such also is our assumption that all

substance is endowed with sensation as well as extension (matter).

This monistic metaphysics, which recognizes the absolute dominion of

the law of substance in all phenomena, but confines itself to the

study of nature and abandons inquiry into the supernatural, is, with

all its theories and hypotheses, an indispensable part of any rational

philosophy of life. To claim, as Ostwald does, that science must be

free from hypotheses is to deprive it of its foundations. But it is

very different with the current dualistic metaphysics, which holds that

there are two distinct worlds, and which we find in a hundred forms as

philosophic dualism.

If we understand by metaphysics the science of the ultimate ground of

things, springing from the rational demand for causes, it can only

be regarded, from the physiological point of view, as a higher and

late-developed function of the phronema. It could only arise with the

complete development of the brain in civilized man. It is completely

lacking among savages, whose organ of thought rises very little

above that of the most intelligent animals. The laws of the psychic

life of the savage have been closely studied by modern ethnology. It

teaches us that the higher reason is not found in savages, and that

their power of abstract thought and of forming concepts is at a very

low level. Thus, for instance, the Veddahs, who live in the forests

of Ceylon, have not the general idea of trees, though they know and

give names to individual trees. Many savages cannot count up to five;

they never reflect on the ground of their existence or think of the

past or future. Hence it is a great error for Schopenhauer and other

philosophers to define man as a "metaphysical animal," and to seek

a profound distinction between man and the animal in the need for

a metaphysic. This craving has only been awakened and developed by

the progress of civilization. But even in civilized communities it

(like consciousness) is not found in early youth, and only gradually

emerges. The child has to learn to speak and think. In harmony with

our biogenetic law, the child reproduces in the various stages of its

mental development the whole of the gradations which lead from the

savage to the barbarian, and from the barbarian to the half-civilized,

and on to the fully educated man. If this historical development of

the higher human faculties had always been properly appreciated, and

psychology had been faithful to the comparative and genetic methods,

many of the errors of the current metaphysical systems would have been

avoided. Kant would not then have produced his theory of _a priori_

knowledge, but would have seen that all that now seems to be _a priori_

in civilized man was originally acquired by _a posteriori_ experiences

in the long evolution of civilization and science. Here we have the

root of the errors which are distinctive of dualism and the prevailing

metaphysical transcendentalism.

Like all science, biology is _realistic_--that is to say, it regards

its object, the organisms, as really existing things, the features of

which are to an extent knowable through our senses (_sensorium_) and

organ of thought (_phronema_). At the same time, we know that these

cognitive organs, and the knowledge they bring us, are imperfect, and

that there may be other features of organisms that lie beyond our means

of perception altogether. But it by no means follows from this that,

as our idealist opponents say, the organisms (and all other things)

exist only in our mind (in the images in our cortex). Our pure monism

(or hylozoism) agrees with realism in recognizing the unity of being

of each organism, and denying that there is any essential distinction

between its knowable phenomenon and its internal hidden essence (or

noumenon), whether the latter be called, with Plato, the eternal

"idea," or, with Kant, the "thing in itself." Realism is not identical

with materialism, and may even be definitely connected with the very

opposite, dynamism or energism.

As realism generally coincides with monism, so idealism is usually

identical with dualism. The two most influential representatives of

dualism, Plato and Kant, said that there were two totally distinct

worlds. Nature, or the empirical world, is alone accessible to our

experience, while the spiritual or transcendental world is not. The

existence of the latter is known to us only by the emotions or by

practical reason; but we can have no idea of its nature. The chief

error of this theoretical idealism is the assumption that the soul is

a peculiar, immaterial being, immortal and endowed with _a priori_

knowledge. The physiology and ontogeny of the brain (together with the

comparative anatomy and histology of the phronema) prove that the soul

of man is, like that of all other vertebrates, a function of the brain,

and inseparably bound up with this organ. Hence this idealist theory

of knowledge is just as inconsistent with realistic biology as is the

psycho-physical parallelism of Wundt or the psychomonism of more

recent physiologists, which in the end issues in a complete dualism of

body and mind. It is otherwise with _practical_ idealism. When this

presents the symbols or ideals of a personal God, an immortal soul, and

the free-will as ethical stimuli, and uses them for their pedagogical

worth in the education of the young, it may have a good influence for a

time, which is independent of their theoretical untenability.

The many branches of biology which have been developed independently

in the course of the nineteenth century ought to remain in touch

with one another, and co-operate with a clear apprehension of their

task, if they are to attain their high purpose of framing a unified

science embracing the whole field of organic life. Unfortunately, this

common aim is often lost sight of in the specialization of study;

the philosophical task is neglected in favor of the empirical. The

confusion that has ensued makes it desirable to determine the mutual

positions of the various biological disciplines. I went into this

somewhat fully in my academic speech on the development and aim of

zoology in 1869. But as this essay is little known, I will briefly

resume the chief points of it.

In correspondence with the long-established distinction between the

plant and the animal, the two chief branches of biology, zoology

and botany, have developed side by side, and are represented by

two different chairs in the universities. Independently of these,

there arose at the very beginning of scientific activity that field

of inquiry which deals with human life in all its aspects--the

anthropological disciplines and the so-called "mental sciences"

(history, philology, psychology, etc.). Since the theory of descent has

proved man's origin from vertebrate ancestors, and thus anthropology

has been recognized as a part of zoology, we have begun to understand

the inner historic connection between these various branches of

anthropology, and to combine them in a comprehensive science of man.

The immense extent and the great importance of this science have

justified the creation of late years of special chairs of anthropology.

It seems desirable to do the same for the science of the protists, or

unicellular organisms. The cell theory, or cytology, as an elementary

part of anatomy, has to be dealt with in both botany and zoology;

but the lowest unicellular representatives of both kingdoms, the

primitive plants (protophyta) and the primitive animals (protozoa), are

so intimately connected, and throw so great a light, as independent

rudimentary organisms, on the tissue cells in the _histon_, or

multicellular organism, that we must regard as a sign of progress the

recent proposal of Schaudinn to found a special institute and journal

for the science of protists. One very important section of it is

bacteriology.

The practical division of biology, according to the extent of the

organic kingdom, leads us to mark out four chief provinces of research:

protistology (the science of the unicellulars), botany (the science

of plants), zoology (the science of animals), and anthropology (the

science of man). In each of these four fields we may then distinguish

morphology (the science of forms) and physiology (the science of

functions) as the two chief divisions of scientific work. The special

methods and means of observation differ entirely in the two sections.

In morphology the work of description and comparison is the most

important as regards both outer form and inner structure. In physiology

the exact methods of physics and chemistry are especially demanded--the

observation of vital activities and the attempt to discover the

physical laws that govern them. As a correct knowledge of human anatomy

and physiology is indispensable for scientific medicine, and the work

requires a particularly large apparatus, these two sciences have long

been studied separately, and have been handed over to the medical

facility in the division of the academic curriculum.

The broad field of morphology may be divided into anatomy and

biogeny; the one deals with the fully developed, and the other

with the developing, organism. Anatomy, the study of the formed

organism, studies both the external form and the inner structure.

We may distinguish as its two branches the science of structures

(tectology) and the science of fundamental forms (promorphology).

Tectology investigates the features of the structure in the organic

_individual_, and the composition of the body out of various parts

(cells, tissues, and organs). Promorphology describes the real form of

these individual parts and of the whole body, and endeavors to reduce

them mathematically to certain fundamental forms (chapter viii.).

Biogeny, or the science of the evolution of organisms, is also divided

into two parts--the science of the individual (ontogeny) and of the

stem or species (phylogeny); each follows its own peculiar methods

and aims, but they are most intimately connected by the biogenetic

law. Ontogeny deals with the development of the individual organism

from the beginning of its existence to death; as embryology it

observes the growth of the individual within the fœtal membranes;

and as metamorphology (or the science of metamorphoses) it follows

the subsequent changes in post-fœtal life (chapter xvi.). The

task of phylogeny is to trace the evolution of the organic stem or

species--that is to say, of the chief divisions in the animal and

plant worlds, which we describe as classes, orders, etc.; in other

words, it traces the genealogy of species. It relies on the facts of

paleontology, and fills up the gaps in this by comparative anatomy and

ontogeny.

The science of the vital phenomena, which we call physiology, is for

the most part the physiology of work, or ergology; it investigates

the functions of the living organism, and has to reduce them as

closely as possible to physical and chemical laws. Vegetable ergology

deals with what are called the vegetative functions, nutrition and

reproduction; animal ergology studies the animal activities of movement

and sensation. Psychology is directly connected with the latter.

But the study of the relations of the organism to its environment,

organic and inorganic, also belongs to physiology in the wider sense;

we call this part of it perilogy, or the physiology of relations. To

this belong chorology, or the science of distribution (also called

biological geography, as it deals with geographical and topographical

distribution), and œcology or bionomy (also recently called

ethology), the science of the domestic side of organic life, of the

life-needs of organisms and their relations to other organisms with

which they live (biocenosis, symbiosis, parasitism).

THIRD TABLE

SYNOPSIS OF THE CHIEF BRANCHES OF BIOLOGY (1869)

BIOLOGY = THE SCIENCE OF LIFE

The four chief branches of systematic biology.

I. Protistology = the science of single cells--unicellular organisms.

II. Botany = the science of plants--tissue plants (metaphyta).

III. Zoology = the science of animals--tissue animals (metazoa).

IV. Anthropology = the science of man--speaking primates.

┌───────────────────────────────────────────────────────────────────────┐

│ A. MORPHOLOGY = THE SCIENCE OF FORMS. │

│ Anatomy and biogeny of organisms. │

├────────────────────────────────────┬──────────────────────────────────┤

│A I. ANATOMY. │A II. BIOGENY. │

│The science of structure. │The science of development. │

│1. TECTOLOGY. │3. PHYLOGENY. │

│The science of structure. │Stem history. │

│Cytology, science of cells. │Paleontology and genealogy. │

│Histology, science of tissues. │Transformism or theory of descent.│

│Organology, science of organs. │Natural classification. │

│Blastology, science of persons. │ ──── │

│Kormology, science of trunks. │ │

│ ──── │4. ONTOGENY. │

│2. PROMORPHOLOGY. │4_a_. Embryology. │

│The science of fundamental │(Development within the │

│forms. Knowledge of the geometrical │fœtal membranes.) │

│ideal forms (mathematically │4_b_. Metamorphology. │

│definable) in relation │(Modification of the organism │

│to the concrete real form of │after fœtal life.) │

│the individual. │ │

└────────────────────────────────────┴──────────────────────────────────┘

┌──────────────────────────────────────────────────────────────────┐

│ B. PHYSIOLOGY = THE SCIENCE OF FUNCTIONS. │

│ Physics and chemistry of the organism. │

├─────────────────────────────┬────────────────────────────────────┤

│B I. ERGOLOGY. │B II. PERILOGY. │

│ Physiology of work. │Physiology of relations. │

│5. Vegetal ergology. │7. Chorology. │

│Physiology of the vegetative │The science of distribution. │

│functions. │Biological geography and topography.│

│5_a_. Trophonomy. │The science of migrations. │

│The science of metabolism. │ │

│5_b_. Gonimatology. │ ──── │

│The science of reproduction. │ │

│ ──── │ │

│6. Animal ergology. │8. ŒCOLOGY. │

│6_a_. Phoronomy. │(or bionomy or ethology). │

│The science of movement. │The science of domestic life. │

│6_b_. Sensonomy. │Biological economy. │

│The science of sensation. │Relations of the organism to │

│6_c_. Psychology. │the environment, and to other │

│ │organisms with which it lives. │

└─────────────────────────────┴────────────────────────────────────┘

V

DEATH

Life and death--Individual death--Immortality

of the unicellulars--Death of the protists and

tissue-organisms--Causes of physiological death--Using up

of the plasma--Regeneration--Biotonus--Perigenesis of the

plastidules: memory of the biogens--Regeneration of protists and

tissue-organisms--Senile debility--Disease--Necrobiosis--The lot

of death--Providence--Chance and fate--Eternal life--Optimism

and pessimism--Suicide and self-redemption--Redemption from

evil--Medicine and philosophy--Maintenance of life--Spartan selection.

Nothing is constant but change! All existence is a perpetual flux

of "being and becoming"! That is the broad lesson of the evolution

of the world, taken as a whole or in its various parts. Substance

alone is eternal and unchangeable, whether we call this all-embracing

world-being Nature, or Cosmos, or God, or World-spirit. The law of

substance teaches us that it reveals itself to us in an infinite

variety of forms, but that its essential attributes, matter and

energy, are constant. All individual forms of substance are doomed

to destruction. That will be the fate of the sun and its encircling

planets, and of the organisms that now people the earth--the fate

of the bacterium and of man. Just as the existence of every organic

individual had a beginning, it will also undeniably have an end. Life

and death are irrevocably united. However, philosophers and biologists

hold very different views as to the real causes of this destiny. Most

of their opinions are at once out of court, because they have not a

clear idea of the nature of life, and so can have no adequate idea of

its termination--death.

The inquiry into the nature of organic life which we instituted

in the second chapter has shown us that it is, in the ultimate

analysis, a chemical process. The "miracle of life" is in essence

nothing but the metabolism of the living matter, or of the plasm.

Recent physiologists, especially Max Verworn and Max Kassowitz, have

pointed out, in opposition to modern vitalism, that "life consists

in a continuous alternation between the upbuild and the decay of the

highly complicated chemical unities of the protoplasm. And if this

conception is admitted, we may rightly say that we know what we mean

by death. If death is the cessation of life, we must mean by that the

cessation of the alternation between the upbuild and the dissolution

of the molecules of protoplasm; and as each of the molecules of

protoplasm must break up again shortly after its formation, we have in

death to deal only with the definite cessation of reconstruction in

the destroyed plasma-molecules. Hence a living thing is not finally

dead--that is to say, absolutely incompetent to discharge any further

vital function--until the whole of its plasma-molecules are destroyed."

In the exhaustive justification with which Kassowitz follows up this

definition in the fifteenth chapter of his _General Biology_, the

natural causes of physiological death are fully described.

Among the numerous and contradictory views of recent biologists on

the nature of death we find many errors and misunderstandings, due

to a lack of clear distinction between the duration of the living

matter in general and that of the individual life-form. This is

particularly noticeable in the contradictory views which have been

elicited by August Weismann's theory (1882) of the immortality of the

unicellulars. I have shown in the eleventh chapter of the _Riddle_ that

it is untenable. But as the distinguished zoologist has again taken

up his theory with energy in his instructive _Lectures on the Theory

of the Descent_ (1902), and has added to it erroneous observations on

the nature of death, I am obliged to return to the point. Precisely

because this interesting work gives most valuable support to the

theory of evolution, and maintains Darwin's theory of selection and

its consequences with great effect, I feel it is necessary to point

out considerable weaknesses and dangerous errors in it. The chief of

these is the important theory of the germ-plasm and the consequent

opposition to the inheritance of acquired characteristics. Weismann

deduces from this a radical distinction between the unicellular and

the multicellular organisms. The latter alone are mortal, the former

immortal; "between the unicellular and the multicellular lies the

introduction of physiological--that is to say, normal--death." We

must say, in opposition to this, that the physiological individuals

(_bionta_) among the protista are just as limited in their duration as

among the histona. But if the chief stress in the question is laid,

not on the individuality of the living matter, but on the continuity

of the metabolic life-movement through a series of generations, it is

just as correct to affirm a partial immortality of the plasm for the

multicellulars as for the unicellulars.

The immortality of the unicellulars, on which Weismann has laid so much

stress, can only be sustained for a small part of the protists even in

his own sense--namely, for those which simply propagate by cleavage,

the chromacea and bacteria among the monera (chapter ix.), the diatomes

and paulotomes among the protophyta, and a part of the infusoria and

rhizopods among the protozoa. Strictly speaking, the individual life is

destroyed when a cell splits into two daughter-cells. One might reply

with Weismann that in this case the dividing unicellular organism

lives on as a whole in its offspring, and that we have no corpse, no

dead remains of the living matter, left behind. But that is not true of

the majority of the protozoa. In the highly developed ciliata the chief

nucleus is lost, and there must be from time to time a conjugation of

two cells and a mutual fertilization of their secondary nuclei, before

there can be any further multiplication by simple cleavage. However,

in most of the sporozoa and rhizopoda, which generally propagate by

spore formation, only one portion of the unicellular organism is used

for this; the other portion dies, and forms a "corpse." In the large

rhizopods (thalamophora and radiolaria) the spore-forming inner part,

which lives on in the offspring, is smaller than the decaying outer

portion, which becomes the corpse.

Weismann's view of the secondary "introduction of physiological death

in the multicellulars" is just as untenable as his theory of the

immortality of the unicellulars. According to this opinion, the death

of the histona--both the metaphyta and metazoa--is a purposive outcome

of adaptation, only introduced by selection when the multicellular

organism has reached a certain stage of complexity of structure, which

is incompatible with its original immortality. Natural selection would

thus kill the immortal and preserve only the mortal; it would interfere

with the multiplication of the immortals in the bloom of their years,

and only use the mortal for rearing posterity. The curious conclusions

which Weismann reached in developing this theory of death, and the

striking contradictions to his own theory of the germ-plasm which

he fell into, have been pointed out by Kassowitz in the forty-ninth

chapter of his _General Biology_. In my opinion, this paradoxical

theory of death has no more basis than the germ-plasm theory he has

ingeniously connected with it. We may admire the subtlety and depth

of the speculations with which Weismann has worked out his elaborate

molecular theory. But the nearer we get to its foundations the less

solid we find them. Moreover, not one of the many supporters of the

theory of germ-plasm has been able to make profitable use of it in the

twenty years since it was first published. On the other hand, it has

had an evil influence in so far as it denied the inheriting of acquired

characters, which I hold, with Lamarck and Darwin, to be one of the

soundest and most indispensable supports of the theory of descent.

In discussing the question of the real causes of death, we confine our

attention to normal or physiological death without considering the

innumerable causes of accidental or pathological death, by illness,

parasites, mishaps, etc. Normal death takes place in all organisms when

the limit of the hereditary term of life is reached. This limit varies

enormously in different classes of organisms. Many of the unicellular

protophyta and protozoa live only a few hours, others several months

or years; many one-year plants and lower animals live only a summer in

our temperate climate, and only a few weeks or months in the arctic

circle or on the snow-covered Alps. On the other hand, the larger

vertebrates are not uncommonly a hundred years old, and many trees live

for a thousand years. The normal span of life has been determined in

all species in the course of their evolution by adaptation to special

conditions, and has then been transmitted to offspring by heredity. In

the latter, however, it is often subject to considerable modifications.

The organism has been compared, on the modern "machine theory" of life,

to an artificially constructed mechanism, or an apparatus in which the

human intelligence has put together various parts for the attainment of

a certain end. This comparison is inapplicable to the lowest organisms,

the monera, which are devoid of such a mechanical structure. In these

primitive "organisms without organs" (chromacea and bacteria) the sole

cause of life is the invisible chemical structure of the plasm and the

metabolism effected by this. As soon as this ceases death takes place

(_cf._ chapter ix.). In the case of all other organisms the comparison

is useful in so far as the orderly co-operation of the various organs

or parts accomplishes a certain task by the conversion of virtual

into active force. But the great difference between the two is that

in the case of the machine the regularity is due to the purposive and

consciously acting will of man, whereas in the case of the organism it

is produced by unconscious natural selection without any design. On

the other hand, the two have another important feature in common in

the limited span of life which is involved in their being used up. A

locomotive, ship, telegraph, or piano, will last only a certain number

of years. All their parts are worn out by long use, and, in spite of

all repairing, become at last useless. So in the case of all organisms,

the various parts are sooner or later worn out and rendered useless;

this is equally true of the organella of the protist and the organs of

the histon. It is true that the parts may be repaired or regenerated;

but sooner or later they cease to be of service, and become the cause

of death.

When we take the idea of regeneration, or the recuperation of parts

that have been rendered useless, in the widest sense, we find it to

be a universal vital function of the greatest importance. The whole

metabolism of the living organism consists in the assimilation of

plasm, or the replacing of the plasma-particles which are constantly

used up by dissimilation (_cf._ chapter x.). Verworn has given the name

of _biogens_ to the hypothetical molecules of living matter--which

I regard with Hering as endowed with memory, and (1875) have called

plastidules. He says: "The biogens are the real vehicles of life.

In their constant decay and reconstruction consists the process of

life, which expresses itself in the great variety of vital phenomena."

The relation of assimilation (the building-up of the biogens) to

dissimilation (the decay of the biogens) may be expressed by a fraction

to which the name _biotonus_ is given A/D. It is of radical importance

in the various phenomena of life. The variations in the size of this

fraction are the cause of all change in the life-expression of every

organism. When the biotone increases, and the metabolism quotient

becomes more than one, we have growth; when, on the other hand, it

falls below one, and the biotone decreases, we have atrophy, and

finally death. New biogens are constructed in _regeneration_. In

_generation_ or reproduction groups of biogens (as germ-plasm) are

released from the parent in consequence of redundant growth, and form

the foundation of new individuals.

The phenomena of regeneration are extremely varied, and have of

late years been made the subject of a good deal of comprehensive

experiment, especially on the side of what is called "mechanical

embryology." Many of these experimental embryologists have drawn

far-reaching conclusions from their somewhat narrow experiments, and

have partly urged them as objections to Darwinism. They imagine that

they have disproved the theory of selection. Most of these efforts

betray a notable lack of general physiological and morphological

knowledge. As they also generally ignore the biogenetic law, and

take no account of the fundamental correlation of embryology and

stem history, we can hardly wonder that they reach the most absurd

and contradictory conclusions. Many examples of this will be found

in the _Archiv für Entwickelungsmechanik_. When, however, we make

a comprehensive survey of the interesting field of regeneration

processes, we discover a continuous series of development from

the simplest repair of plasm in the unicellular protists to the

sexual generation of the higher histona. The sperm-cells and ova

of the latter are redundant growth-products, which have the power

of regenerating the whole multicellular organism. But many of the

higher histona have also the capacity to produce new individuals by

regeneration from detached pieces of tissue, or even single cells.

In the peculiar mode of metabolism and growth which accompanies

these processes of regeneration, the memory of the plastidule, or

the unconscious retentive power of the biogens, plays the chief part

(_cf._ my _Perigenesis of the Plastidule_, 1875). In the most primitive

kinds of the unicellular protists we find the phenomena of death and

regeneration in the simplest form. When an unnucleated moneron (a

chromaceum or bacterium) divides into two equal halves, the existence

of the dividing individual comes to an end. Each half regenerates

itself in the simplest conceivable way by assimilation and growth,

until it, in turn, reaches the size of the parent organism. In the

nucleated cells of most of the protophyta and protozoa it is more

complicated, as the nucleus becomes active as the central organ and

regulator of the metabolism. If an infusorium is cut into two pieces,

only one of which contains the nucleus, this one alone grows into a

complete nucleated cell; the unnucleated portion dies, being unable to

regenerate itself.

In the multicellular body of the tissue-forming organisms we must

distinguish between the partial death of the various cells and the

total death of the whole organism, or cell-state, which they make up.

In many of the lower tissue-plants and tissue-animals the communal

link is very loose and the centralization slight. Odd cells or groups

of cells may be set loose, without any danger to the life of the

whole histon, and grow into new individuals. In many of the algæ

and liverworts (even in the _bryophyllum_, closely related to the

stone-crop, or _sedum_)--as well as in the common fresh-water polyp,

hydra, and other polyps--every bit that is cut off is capable of

growing into a complete individual. But the higher the organization

is developed and the closer the correlation of the parts and their

co-operation in the life of the centralized stock or person, the

slighter we find the regenerative faculty of the several organs. Even

then, however, many used-up cells may be removed and replaced by

regenerated new cells. In our own human organism, as in that of the

higher animals, thousands of cells die every day, and are replaced

by new cells of the same kind, as, for instance, epidermic cells at

the surface of the skin, the cells of the salivary glands or the

mucous lining of the stomach, the blood-cells, and so on. On the other

hand, there are tissues that have little or nothing of this repairing

power, such as many of the nerve-cells, sense-cells, muscle-cells,

etc. In these cases a number of constant cell-individuals remain with

their nucleus throughout life, although a used-up portion of their

cell-body may be replaced by regeneration from the cytoplasm. Thus

our human body, like that of all the higher animals and plants, is a

"cell-state" in another sense. Every day, nay, every hour, thousands

of its citizens, the tissue-cells, pass away, and are replaced by

others that have arisen by cleavage of similar cells. Nevertheless,

this uninterrupted change of our personality is never complete or

general. There is always a solid groundwork of conservative cells, the

descendants of which secure the further regeneration.

Most organisms meet their death through external or accidental

causes--lack of sufficient food, isolation from their necessary

environment, parasites and other enemies, accidents and disease. The

few individuals who escape these accidental causes of death find the

end of life in old age or senility, by the gradual decay of the organs

and dwindling of their functions. The cause of this senility and the

ensuing natural death is determined for each species of organisms by

the specific nature of their plasm. As Kassowitz has lately pointed

out, the senility of individuals consists in the inevitable increase

in the decay of protoplasm and the metaplastic parts of the body

which this produces. Each metaplasm in the body favors the inactive

break-up of protoplasm, and so also the formation of new metaplasms.

The death of the cells follows, because the chemical energy of the

plasm gradually falls off from a certain height, the acme, of life.

The plasm loses more and more the power to replace by regeneration the

losses it sustains by the vital functions. As, in the mental life, the

receptivity of the brain and the acuteness of the senses gradually

decay, so the muscles lose their energy, the bones become fragile, the

skin dry and withered, the elasticity and endurance of the movements

decrease. All these normal processes of senile decay are caused by

chemical changes in the plasm, in which dissimilation gains constantly

on assimilation. In the end they inevitably lead to normal death.

While the gradual decay of the bodily forces and the senile

degeneration of the organs must necessarily cause the death of the

soundest organism in the end, the great majority of men pass away

through illness long before this normal term of life is reached. The

external causes of this are the attacks of enemies and parasites,

accidents, and unfavorable conditions of life. These cause changes

in the tissues and their component cells, which first occasion the

partial death of particular sections, and then the total death of the

whole individual. The modifications of the living matter which produce

disease and premature death are called _necrobioses_. They consist

partly of _histolyses_--that is to say, degeneration of the cells by

atrophy, dissolution, withering (mortification), or colliquation; and

partly of _metaplasmosisms_, or metamorphoses of the plasm--fatty,

mucous, chalky, or amyloid metamorphoses of the cells. It was the great

merit of Rudolph Virchow that he proved, in his epoch-making _Cellular

Pathology_ (1858), that all diseases in man and other organisms may be

reduced to such modifications of the cells which make up the tissues.

Hence disease, with its pain, is a physiological process, a life under

injurious and dangerous conditions. As in all normal vital phenomena,

so in abnormal or pathological, the ultimate ground must be sought in

the physical and chemical processes in the plasm. Pathology is a part

of physiology. This discovery has cut the ground from under the older

notion of disease as a special entity, a devil, or a divine punishment.

The natural physical explanation of death, which has been made possible

by modern physiology and pathology, has shattered, not only all the

old superstitious ideas about disease and death, but also a number of

important metaphysical dogmas which built upon them. Such was, for

instance, the naïve belief in a conscious Providence, controlling

the fate of individuals and determining their death. I do not fail

to appreciate the great subjective value which such a trust in a

protecting Providence has for men amid their countless dangers. We may

envy the childish temper for the confidence and hope which it derives

from this belief. But as we do not seek to have our emotions gratified

by poetic fictions, we are bound to point out that reason cannot detect

the shadow of a proof of the existence and action of this conscious

Providence, or "loving Father in heaven." We read daily in our journals

of accidents and crimes of all kinds that cause the unexpected death

of happy human beings. Every year we read with horror the statistics

of the thousands of deaths from shipwreck and railway accidents,

earthquakes and landslips, wars and epidemics. And then we are asked

to believe in a loving Providence that has decreed the death of each

of these poor mortals! We are asked to console ourselves in face of

the tragedy with the hollow phrases: "God's will be done," or "God's

ways are wonderful." Simple children and dull believers may soothe

themselves with such phrases. They no longer impose on educated people

in the twentieth century, who prefer a full and fearless knowledge of

the truth.

When our monistic and rational conception of death is described as

dreary and hopeless, we may answer that the prevalent dualistic view is

merely an outcome of hereditary habits of thought and mystic training

in early youth. When these are displaced by progressive culture and

science, it will be clear that man has lost nothing, but gained much,

as regards his life on earth. Convinced that there is no eternal life

awaiting him, he will strive all the more to brighten his life on

earth and rationally improve his condition in harmony with that of his

fellows. If it is objected that then everything will depend on mere

"chance," instead of being controlled by a conscious Providence or a

moral order of the world, I must refer the reader for my reply to the

close of the fourteenth chapter of the _Riddle_, where I have dealt

with fate, providence, end, aim, and chance. And if it is further

claimed that our realistic view of life leads to pessimism, there is no

better ground for such an accusation.

I have given, in the eleventh chapter of the _Riddle_, the scientific

reasons which forbid us to accept the personal immortality of the soul.

But as the most vehement attacks have been made on this chapter by

metaphysicians of the prevailing school and by Christian theologians,

I must return to the question here. I am convinced, from numbers of

letters I have received and conversation with educated people of all

classes, that no other dogma is so firmly established and highly valued

as athanatism, or the belief in personal immortality. Most men will not

give up at any price the hope that a better life awaits them beyond

the grave, which will compensate them for all the pain and suffering

they endure here. In the picturing of this future life the mediæval

geocentric idea still forms the chief feature. Troelslund has shown, in

his _Idea of Heaven and of the World_, how this theory still dominates

the metaphysics of the majority of men; in spite of Copernicus and

Laplace, heaven is still for most people the semicircular blue glass

bell that overarches the earth. We still hear the praises of our life

in this heaven sung daily in sermons and speeches and festive orations.

The orator extends his right hand "upward" to the infinite starry

space of heaven, forgetting that the radius of the direction he is

pointing towards changes every second, and in twelve hours reaches the

precisely opposite direction, and becomes "downward." Other believers

endeavor to be still more concrete, and point out definite celestial

bodies as the homes of immortal souls. Modern cosmology, astronomy, and

geology entirely exclude these pretty fictions from science; and modern

psychology, physiology, ontogeny, and phylogeny rigorously refuse an

inch of ground for athanatism.

Optimism regards the world on its good and bright and admirable

side: pessimism looks to the shades and tragedies of life. In some

philosophic and religious systems one or other of these tendencies

is consistently and exclusively worked out; but in most systems the

two are mingled. Pure and consistent realism is generally neither

optimistic nor pessimistic. It takes the world as it is, a unified

whole, the nature of which is neither good nor bad. Dualistic idealism,

however, generally combines the two, and distributes them between

its two worlds; it describes this world as a "vale of tears," and

the next as a glorious city of joy and happiness. This view is a

conspicuous feature in most of the dualistic religions, and has still

a considerable influence, both practically and theoretically, on the

minds of educated people.

The founder of systematic optimism was Gottfried Leibnitz, whose

philosophy sought to achieve an ingenious harmony between divergent

systems, but is really a form of dynamism, or a monism somewhat akin to

the energism of Ostwald. Leibnitz gave a compendious statement of his

system in his _Monadology_ (1714). He taught that the world consists of

an infinite number of monads (which almost correspond to our psychic

atoms), but this pluralism was converted into a monism by making God,

as the central monad, bind all together in a substantial unity. In

his _Theodicy_ (1710) he taught that God (the "all-wise, all-good,

and almighty creator of the world") had with perfect consciousness

created "the best of all possible worlds"; that his infinite goodness,

wisdom, and power are seen everywhere in the pre-established harmony

of things; but that the individual human being, and humanity taken as

a whole, have only a limited capacity for development. The man who

knows the real features of the world, who has honestly confronted the

tragic struggle for life that rules throughout living nature, who has

sympathy for the infinite sum of misery and want of every kind in the

life of men, can scarcely understand how an acute and informed thinker

like Leibnitz could entertain such optimism as this. It would be more

intelligible in the case of a one-sided and nebulous metaphysician like

Hegel, who held that "all that is real is rational and all that is

rational is real."

Pessimism is the direct opposite of systematic optimism. While the

one holds the universe to be the best, the other regards it as the

worst, of all possible worlds. This pessimistic conception has found

expression in the oldest and most popular religions of Asia, Brahmanism

and Buddhism. Both these Hindoo religions were originally pessimistic,

and at the same time atheistic and idealistic. Schopenhauer especially

pointed out this, declaring that they were the most perfect of all

religions, and importing their leading ideas into his own system. He

considers it "a glaring absurdity to attempt to prove this miserable

world the best of all possible ones--this cock-pit of tortured and

suffering beings, who can only survive by destroying one another, in

which the capacity for pain grows with knowledge, and so reaches its

height in man. Truly optimism cuts so sorry a figure in this theatre of

sin, suffering, and death that we should have to regard it as a piece

of sarcasm if Hume had not given us an explanation of its origin (the

wish to flatter God and hope for some result from it). To the palpable

sophistry of Leibnitz, who would prove this world the best of all

possible, we can oppose a strict and honest proof that it is the worst

of all possible." However, neither Schopenhauer nor the most important

of modern pessimists, Edward Hartmann, has drawn the strict practical

conclusion from pessimism. That would be to deny the will to live, and

put an end to suffering by suicide.

The mention of suicide as the logical consequence of pessimism may

serve as an occasion to glance at the curious and contradictory views

that are expressed about it. There are few problems of life (apart

from immortality and the freedom of the will) on which such absurd

and contradictory things have been said even down to our own time.

The theist who regards life as a gift of God may hesitate to reject

or return it--although the offering of one's self as a victim for

other men is considered a high virtue. Most educated people still look

upon suicide as a great sin, and in some countries (such as England)

the attempt is punished by law. In the Middle Ages, when a hundred

thousand men were burned alive for heresy or witchcraft, suicides

were punished by a disgraceful burial. As Schopenhauer says: "Clearly

there is nothing in the world to which a man has a plainer right than

his own life and person. It is simply ridiculous for criminal justice

to deal with suicide." The advance of embryology in the last thirty

years has made it clear that the individual life of a man (and all

other vertebrates) begins at the moment when the male sperm-cell and

the maternal ovum coalesce. In this blind chance plays an important

part, as in so many other important aspects of life--taking "chance"

in the scientific sense, which I have explained in chapter xiv. of

the _Riddle_. Hence, the real cause of personal existence is not the

favor of the Almighty, but the sexual love of one's earthly parents;

very often this consequence of the act of love has been anything but

desired. If, then, the circumstances of life come to press too hard

on the poor being who has thus developed, without any fault of his,

from the fertilized ovum--if, instead of the hoped-for good, there

come only care and need, sickness and misery of every kind--he has the

unquestionable right to put an end to his sufferings by death. Every

religion assents to this under certain conditions, even Christianity

when it says: "If thine eye scandalize thee, cast it from thee." It

is true that the conventional morality condemns suicide under any

circumstances; but the reasons it alleges are ridiculously slight, and

are not improved by having the mantle of religion wrapped about them.

The voluntary death by which a man puts an end to intolerable suffering

is really an act of redemption. We should, therefore, describe it as

self-redemption, and look on it with Christian sympathy, not brand it

pharisaically as "self-murder." As a fact, this contemptuous phrase

has no meaning, since murder is the taking away of a man's life against

his will, while the suicide dies voluntarily. Hence, he usually

deserves our sympathy, not contempt, and certainly not punishment.

Our conventional morality is, as so often happens, full of senseless

contradictions. Modern states have introduced conscription; they demand

that every citizen shall give up his life for his country on command,

and kill as many other men as he can (an admirable commentary on the

Scriptural "Love your enemies") for some political reason or other.

But they never secure to each citizen the means of honorable existence

and free development of his personality--not even the right to work by

which he may maintain himself and his family.

I fully recognize the advance that social politics has made in

improving the conditions of the poorer classes, the promotion of

hygiene and education and the bodily and mental welfare of citizens;

but we are still very far from the attainable ideal of general

prosperity and happiness which reason dictates to every civilized

nation. Misery and want are increasing among the poor, as the division

of labor and over-population increase. Thousands of strong and active

men come to grief every year without any fault of theirs, often

precisely because they were quiet and honest; thousands are hungry

because, with the best will in the world, they cannot find work;

thousands are sacrificed to the heartless demands of our iron age of

machinery with its exacting technical and industrial requirements. On

the other hand, we see thousands of contemptible characters prospering

because they have been able to deceive their fellows by unscrupulous

speculations, or because they have flattered and served the higher

authorities. It is no wonder that the statistics of suicide increase so

much in the more civilized communities. No feeling man who has any real

"Christian love of his neighbor" will grudge his suffering brother the

eternal rest and the freedom from pain which he has obtained by his

self-redemption.

The seventh petition of the Lord's Prayer, which is repeated daily by

millions of Christians, is: "Deliver us from evil." Luther explains

this as a prayer to be saved "from all evil of body and soul" in

this life and the next. When we consider this in the light of our

monistic principles, we have naturally to set aside the superstitious

ideas of the Middle Ages regarding the future life, and deal only

with the petition as regards this life. The number and variety and

gravity of these evils have grown in civilized communities in the

nineteenth century, notwithstanding all the progress we have made in

art and science and the rational reform of our personal and social

life. Civilization has gained infinitely in value by the change we

have made in our conceptions of time and space in this age of steam

and electricity. We can make our domestic and public life much

pleasanter, and avail ourselves of a far greater number of luxuries,

than was possible to our grandfathers a hundred years ago. But all

this has caused a much greater expenditure of nerve-energy. The brain

has to bear a much greater strain, and is worn out earlier, the body

is more stimulated and overworked than it was a hundred years ago.

Many diseases of modern civilization are making appalling progress;

neurasthenia, especially, and other diseases of the nerves, carry off

more victims every year. Our asylums grow bigger and more numerous

every year, and we have sanatoria on every side in which the baited

victim of modern civilization seeks refuge from his evils. Some of

these evils are quite incurable, and the sufferers have to meet a

certain death in terrible pain. Many of these poor creatures look

forward to their redemption from evil and the end of their miserable

lives. The important question arises whether, as compassionate men,

we should be justified in carrying out their wish and ending their

sufferings by a painless death.

This question is of great importance, both in practical philosophy

and in juridical and medical practice, and, as opinions differ very

much on the subject, it seems advisable to deal with it here. I start

from my own personal opinion, that sympathy is not only one of the

noblest and finest functions of the human brain, but also one of

the first conditions of the social life of the higher animals. The

precepts of Christian charity which the gospels rightly place in the

very foreground of morality, were not first discovered by Christ, but

they were successfully urged by him and his followers at a time when

refined selfishness threatened the Roman civilization with decay.

These natural principles of sympathy and altruism had arisen thousands

of years before in human society, and are even found among all the

higher animals that live a social life. They have their first roots

in the sexual reproduction of the lower animals, the sexual love and

the care of the young on which the maintenance of the species depends.

Hence the modern prophets of pure egoism, Friedrich Nietzsche, Max

Stirner, etc., commit a biological error when they would substitute

their morality of the strong for universal charity, and when they

ridicule sympathy as a weakness of character or an ethical blunder

of Christianity. It is just in its insistence on sympathy that the

Christian teaching is most valuable, and this part of its system

will survive long after its dogmas have sunk into oblivion. However,

this lofty duty must not be confined to men, but extended to "our

relations," the higher vertebrates, and, in fact, to all animals whose

brain-organization seems to point to the possession of sensation and

a consciousness of pleasure and pain. Thus, for instance, in the case

of the domestic animals which we use daily in our service, and which

have an undoubted psychic affinity to ourselves, we must take care

to increase their pleasures and mitigate their sufferings. Faithful

dogs and noble horses, with which we have lived for years and which

we love, are rightly put to death and relieved from pain when they

fall hopelessly ill in old age. In the same way we have the right, if

not the duty, to put an end to the sufferings of our fellow-men. Some

severe and incurable disease makes life unbearable for them, and they

ask for redemption from evil. However, medical men hold very different

opinions on the matter, as I have found in conversation with them.

Many experienced physicians, who practise their profession in a spirit

of sympathy and without dogmatic prejudice, have no scruple about

cutting short the sufferings of the incurable by a dose of morphia or

cyanide of potassium when they desire it; very often this painless

end is a blessing both to the invalids and their families. However,

other physicians and most jurists are of opinion that this act of

sympathy is not right, or is even a crime; that it is the duty of the

physician to maintain the life of his patients as long as he can in all

circumstances. I should like to know why.

While I am dealing with this important and--for the medical

conscience--difficult question of social ethics, I may take the

opportunity to consider the general attitude of physicians to the

monistic philosophy. It is now half a century since I visited the

wards in the Julius hospital at Würtzburg as a medical student. It is

true that--happily for me and my patients!--I practised the profession

only for a short time after I had passed my examinations in 1857;

but the thorough acquaintance with the human organism, its anatomic

structure and physiological functions, which I then obtained has been

of incalculable service to me. I owe to it not only the solid empirical

foundation of the special study of my life, zoology, but also the

monistic tendency of my whole system. As the medical training in its

widest sense includes anthropology--and so should include psychology

also--its value for speculative philosophy cannot be exaggerated. The

scholastic metaphysicians who still regard the chairs of philosophy at

our universities as their monopoly would have avoided most of their

dualistic errors if they had had a thorough training in human anatomy,

physiology, ontogeny, and phylogeny. Even pathology, the science of

the diseased organism, is very instructive for the philosopher. The

psychologist especially acquires, by the study of mental disease and

the visiting of the asylum wards, a profound insight into the mental

life which no speculative philosophy could give him. There are few

experienced and thoughtful physicians who retain the conventional

belief in the immortality of the soul and God. What would the immortal

soul do on the other side of eternity when it is already utterly

ruined in this life, or was even born as an idiot? How can a just God

condemn the criminal to the fires of hell when he himself has tainted

the man with an hereditary bias, or has placed him in an environment

in which, seeing the absence of free-will, crime was a necessity for

him? And how can this all-loving God answer for the immeasurable sum of

want and misery, and pain and unhappiness, which he sees accumulated

before him every year in the lives of families and states, cities and

hospitals? It is no wonder that the old saying ran: _Ubi tres medici,

duo sunt athei_ (Of three doctors two are sure to be atheists). One

of my medical colleagues was an old, experienced, and sympathetic

physician who had travelled all over the world, and had then, as

director of a large hospital, been a close witness of the sufferings of

humanity. Religiously educated by pious parents, and endowed with keen

sensitiveness, he was, after long struggles, forced by his medical

studies to part with the faith of his boyhood--like myself, in his

twenty-first year. We were talking about the great mysteries of life

shortly before his death, and he said to me: "I have been unable to

reconcile belief in the immortality of the soul and the freedom of the

will with my psychological experiences, and I have been just as unable

to discover throughout the whole world a single trace of a moral order

or a beneficent providence. If it is true that an intelligent Deity

rules the world, he cannot be a God of love, but an all-powerful demon,

whose constant entertainment is an eternal and merciless play of being

and becoming, building up and destroying." However, we do still find

here and there informed and intelligent physicians who adhere to the

three central dogmas of metaphysics--a proof of the immense power of

dogmatic tradition and religious prejudice.

We must class as a traditional dogma the wide-spread belief that

man is bound under all circumstances to maintain and prolong life,

even when it has become utterly useless--a source of pain to the

incurable and of endless trouble to his friends. Hundreds of thousands

of incurables--lunatics, lepers, people with cancer, etc.--are

artificially kept alive in our modern communities, and their sufferings

are carefully prolonged, without the slightest profit to themselves or

the general body. We have a strong proof of this in the statistics of

lunacy and the growth of asylums and nerve-sanatoria. In Prussia alone

there were 51,048 lunatics cared for in the asylums (six thousand in

Berlin) in 1890; more than one-tenth of them were quite incurable (four

thousand of them suffering from paralysis). In France, in 1871, there

were 49,589 in the asylums (or 13.8 per thousand of the population),

and in 1888 there were 70,443 (or 18.2 per thousand); thus, in the

course of seventeen years, the absolute number of the unsound rose

nearly 30 per cent. (29.6), while the total population only increased

5.6 per cent. In our day the number of lunatics in civilized countries

is, on the average, five-sixths per thousand. If the total population

of Europe is put at three hundred and ninety to four hundred millions,

we have at least two million lunatics among them, and of these more

than two hundred thousand are incurable. What an enormous mass of

suffering these figures indicate for the invalids themselves, and what

a vast amount of trouble and sorrow for their families, what a huge

private and public expenditure! How much of this pain and expense could

be spared if people could make up their minds to free the incurable

from their indescribable torments by a dose of morphia! Naturally

this act of kindness should not be left to the discretion of an

individual physician, but be determined by a commission of competent

and conscientious medical men. So, in the case of other incurables

and great sufferers (from cancer, for instance), the "redemption from

evil" should only be accomplished by a dose of some painless and rapid

poison when they have expressed a deliberate wish (to be afterwards

juridically proved) for this, and under the control of an authoritative

commission.

The ancient Spartans owed a good deal of their famous bravery, their

bodily strength and beauty, as well as their mental energy and

capacity, to the old custom of doing away with new-born children who

were born weakly or crippled. We find the same custom to-day among

many savage races. When I pointed out the advantages of this Spartan

selection for the improvement of the race in 1868 (chapter vii. of

the _History of Creation_) there was a storm of pious indignation in

the religious journals, as always happens when pure reason ventures

to oppose the current prejudices and traditional beliefs. But I ask:

What good does it do to humanity to maintain artificially and rear the

thousands of cripples, deaf-mutes, idiots, etc., who are born every

year with an hereditary burden of incurable disease? Is it not better

and more rational to cut off from the first this unavoidable misery

which their poor lives will bring to themselves and their families? It

is no use to reply that religion forbids it. Christianity also bids us

give up our life for our brethren, and to cast it from us when it hurts

us--that is to say, when it only causes useless pain to us and our

friends. The truth is, the opposition is only due to sentiment and the

power of conventional morality--that is to say, to the hereditary bias

which is clothed in early youth with the mantle of religion, however

irrational and superstitious be its foundation. Pious morality of this

sort is often really the deepest immorality. "Laws and rights creep on

like an eternal sickness;" this is equally true of the social customs

and morals on which laws and rights are founded. Sentiment should

never be allowed to usurp the place of reason in these weighty ethical

questions. As I pointed out in the first chapter of the _Riddle_,

sentiment is a very amiable, but a very dangerous, function of the

brain. It has no more to do with the attainment of the truth than what

is called revelation. That is well seen in Kant's dualism, for his

_mundus intelligibilis_ is essentially an outcome of his religious

sentimentality

VI

PLASM

Plasm is the universal living substance--Definition of protoplasm,

chemically and morphologically--Physical character--Viscous

condition--Chemical analysis--Colloid character of

albumin--Albuminoid molecules--Elementary structure of plasm--Work

of plasm--Protoplasm and metaplasm--Structures of metaplasm--Frothy

structure--Skeletal structure--Fibrous structure--Granular

structure--Molecular structure--Plasma molecules--Plastidules and

biogens--Micella and biophora--Caryoplasm and cytoplasm--Nuclear

matter--Chromatin and achromin--Nucleolus and centrosoma--Caryotheka

and caryolymph--Cellular matter--Plasma products--Internal plasma

products--External plasma products--Cell membranes--Intercellular

matter--Cuticular matter.

By plasm, in the widest sense of the word, we mean the living matter,

or all bodies that are found to constitute the material foundations

of the phenomena of life. It is usual to give this matter the name

of protoplasm; but this older and historically important designation

has suffered so many changes of meaning through the variety of its

applications that it is better now to use it only in the narrower

sense. Moreover, recent research on protoplasm has been greatly

developed, and several new names have been invented, which are formed

from the word "plasm" with a qualifying prefix. These are special

varieties of the general idea of plasm, or special modifications of the

general matter, such as metaplasm, archiplasm, and so on.

The botanist, Hugo Mohl, who first introduced the name "protoplasm"

in 1846, used it to designate a part of the contents of the ordinary

plant-cell--namely, the viscous matter that Schleiden called

"cell-mucus," which is found on the inner surface of the cell-wall,

and often forms a varying net-work or skeleton in the watery fluid in

the cell, and exhibits characteristic movements. Mohl gave the name of

"primordial skin" to this important wall-layer (the chief element of

the plant-cell), and called the material of it, as being chemically

different from the other parts of the cell, _protoplasm_--that is to

say, the first (_proton_) or earliest formation of the organism. It is

important to notice that Mohl, the author of the name, conceived it in

a purely chemical, not a morphological, sense, like Oscar Hertwig and

other recent cytologists. I intend to retain this early chemical idea

of protoplasm--or, briefly, plasm. It was also taken in this sense by

Max Schultze, who pointed out (in 1860) its extreme significance and

wide distribution in all living cells, and introduced an important

reform of the cell-theory which we will see later.

The mixing of the chemical and the morphological ideas of protoplasm

has been very mischievous in recent biology, and has led to great

confusion. It generally comes from a failure to formulate clearly the

difference between the two essential elements of the modern notion of

the cell--the anatomic distinction between the nucleus and the body

of the cell. The internal nucleus (or _caryon_) had the appearance of

a solid, definite, morphologically distinct constituent of the cell;

the outer and softer mass which we now call the cell-body (_celleus_

or _cytosoma_) seemed to be a formless and only chemically definable

protoplasm. It was only discovered at a later date that the chemical

composition of the nucleus is closely akin to that of the cell-body,

and that we may properly associate the _caryoplasm_ of the one with the

_cytoplasm_ of the other under the general heading of _plasm_. All the

other materials that we find in the living organism are products or

derivatives of the active plasm.

In view of the extraordinary significance which we must assign to the

plasm--as the universal vehicle of all the vital phenomena (or "the

physical basis of life," as Huxley said)--it is very important to

understand clearly all its properties, especially the chemical ones.

This is rendered somewhat difficult from the circumstance that the

plasm is, in most of the organic cells, closely bound up with other

substances--the various plasma products; it can rarely be isolated in

its purity, and can never be had pure in any quantity. Hence we are for

the most part dependent on the imperfect, and often ambiguous, results

of microscopic and microchemical research.

In every case where we have with great difficulty succeeded in

examining the plasm as far as possible and separating it from the

plasma-products, it has the appearance of a colorless, viscous

substance, the chief physical property of which is its peculiar

thickness and consistency. The physicist distinguishes three conditions

of inorganic matter--solid, fluid, and gaseous. Active living

protoplasm cannot strictly be described as either fluid or solid in the

physical sense. It presents an intermediate stage between the two which

is best described as viscous; it is best compared to a cold jelly or

solution of glue. Just as we find the latter substance in all stages

between the solid and the fluid, so we find in the case of protoplasm.

The cause of this softness is the quantity of water contained in the

living matter, which generally amounts to a half of its volume and

weight. The water is distributed between the plasma molecules, or the

ultimate particles of living matter, in much the same way as it is in

the crystals of salts, but with the important difference that it is

very variable in quantity in the plasm. On this depends the capacity

for absorption or imbibition in the plasm, and the mobility of its

molecules, which is very important for the performance of the vital

actions. However, this capacity of absorption has definite limits

in each variety of plasm; living plasm is not soluble in water, but

absolutely resists the penetration of any water beyond this limit.

The chemistry of living matter is the most important and interesting,

but at the same time the most difficult and obscure, part of the whole

of biological chemistry. In spite of the innumerable and careful

investigations which have been made of it by the ablest physiologists

and chemists in the second half of the nineteenth century, we are

still far from a satisfactory solution of this fundamental problem

of biology. This is due partly to the extraordinary difficulty of

isolating pure living plasm and subjecting it to chemical analysis,

and partly to the many errors and misunderstandings that have arisen

through one-sided treatment of the subject, and especially through

confusion of the chemical and morphological features of plasm. We can

thus understand the contradictory views that are still put forward by

distinguished chemists and physiologists, zoologists and botanists.

As I cannot deal here with the very extensive, elaborate, and

contradictory literature of the subject, I must be content to give a

brief summary of the conclusions I have reached by my reading and my

own studies of plasm (begun in 1859).

To begin with, we must clearly understand that protoplasm--in the most

general sense in which we here take it--is a _chemical_ substance, not

a "mixture of different substances," or a "mixture of a small quantity

of solid matter with a good deal of fluid." As Richard Neumeister

very well observes: "We seek the nature of protoplasm in the peculiar

processes which take place in its constituent matter. Protoplasm is

for us a chemical matter, so pronounced, in fact, that the highest

chemical actions that we know of are embodied in it." I must, from my

point of view, entirely reject Oscar Hertwig's conception of living

matter as a "mixture" of a number of chemical elements; because

chemistry applies this phrase to various gases and powdery substances

which are completely indifferent to each other--a property which we

certainly do not find in the constituents of protoplasm. When we speak

of the living matter or protoplasm, the general phrase does not imply

that the substance may not have a distinctive composition in each

particular case. And when we find many biologists still conceiving

protoplasm as a mixture of various substances, the error is generally

due to a confusion of the chemical idea with the morphological, and to

a belief that certain structural features of the plasm are primary,

whereas they are only secondary, products of the vital process itself

in the cell-body.

The older biologists who first introduced the name protoplasm and

studied it carefully recognized that this living matter belonged

to the albuminous (or proteid) group. The many characteristics

which distinguish these nitrogenous carbon-compounds from all

other chemical compounds--their behavior towards acids and bases,

their peculiar color-reaction towards certain salts, their

decomposition-products, etc.--are found in all the plasma-substances,

and in all the other albuminoids. This is quite in agreement with

the results of quantitative analysis. However differently the

various plasma-substances behave in detail, they always exhibit the

same general composition as the other albuminoids out of the five

"organogenetic elements"--namely, in point of weight, fifty-one to

fifty-four per cent. carbon, twenty-one to twenty-three per cent.

oxygen, fifteen to seventeen per cent. nitrogen, six to seven per

cent. hydrogen, and one to two per cent. sulphur. However, there is

a good deal of variety and complication in the way in which the atoms

of these five elements are combined in albumin and their molecules

are grouped. Hence the question of the chemical nature of the

plasma-substances compels us now to look for a moment at the larger

group of albuminoids to which they belong.

The carbon-compounds which we comprise under the chemical title of the

albumins or proteids are the most remarkable, but also, unfortunately,

the least known, of all bodies. The attempt to examine them closely

encounters extraordinary difficulties, greater than in any other group

of chemical compounds. Everybody is familiar with the appearance of

ordinary albumin, from the transparent viscous albumin that surrounds

the yolk in the hen's egg, and which becomes a white, opaque, and solid

mass when it is cooked. However, this special form of albumin, which we

can get so easily in any quantity from the eggs of birds and reptiles,

is only one of the innumerable kinds of albumin, or species of protein,

that are to be found in the bodies of the various animals and plants.

Chemists have hitherto tried in vain to master the chemical structure

of these obscure protein-compounds. They are only rarely to be found in

chemically pure form as crystals. As a rule, they are in the colloid

form, or uncrystallized jelly-like masses, which offer a much greater

resistance than crystals to the passage through a porous medium by

diosmosis (see p. 39). However, although we have not yet succeeded in

penetrating the molecular constitution of the albumins, the laborious

research of chemists has yielded some general results which are of

great importance for our purpose. We have, in the first place, a

general idea of their molecular constitution.

Molecules are the smallest homogeneous parts into which a body can be

divided without altering its chemical character. Hence the molecules of

every chemical compound are made up of two or more atoms of different

kinds. The greater the number of atoms in each compound, the higher

is its molecular weight. The space between the molecules and their

component atoms is filled with imponderable and highly elastic ether.

As even the largest molecules occupy only a very tiny space, and

remain far below the range of the most powerful microscope, all our

ideas of their composition depend on general physical theories and

special chemical hypotheses. Nevertheless, stereochemistry, the modern

science of the molecular structure of chemical compounds, is not only

a perfectly legitimate section of natural philosophy, but it yields

the most important conclusions as to the mutual attractions of the

elements and the invisible movements of the atoms in combining. It

further enables us to calculate approximately the relative size of the

molecules and the number of atoms that are grouped together in them.

However, the albuminoids present the greatest difficulty of all in this

calculation, and their structural features are still very obscure.

Nevertheless, science has reached certain general conclusions, which we

may formulate in the following propositions:

1. The molecule of albumin is unusually large, and therefore its

molecular weight is very high (higher than in most or all other

compounds).

2. The number of atoms composing it is very large (probably much more

than a thousand).

3. The disposition of the atoms and groups of atoms in the albuminous

molecule is very complicated, and at the same time very unstable--that

is to say, very changeable and easily altered.

These characters, which are ascribed to all albuminous bodies by

modern chemistry, hold good of all plasma-substances; and, in fact,

are true in a higher degree of these, as the metabolism of the living

matter causes a constant displacement of the atoms. This is caused,

according to the view of Franz Hofmeister and others, by the formation

of ferments or enzyma--in other words, by catalysators of a colloidal

structure. Verworn has, on physiological grounds, given the name of

biogens to these plasma-molecules.

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