Evolution

Charles Darwin

Charles Darwin

1. Ancient Greek Views

Evolution is not so much a modern discovery as some of its advocates
would have us believe. It made its appearance early in Greek
philosophy, and maintained its position more or less, with the most
diverse modifications, and frequently confused with the idea of
emanation, until the close of ancient thought. The Greeks had, it is
true, no term exactly equivalent to " evolution"; but when Thales
asserts that all things originated from water; when Anaximenes calls
air the principle of all things, regarding the subsequent process as a
thinning or thickening, they must have considered individual beings
and the phenomenal world as, a result of evolution, even if they did
not carry the process out in detail. Anaximander is often regarded as
a precursor of the modem theory of development. He deduces living
beings, in a gradual development, from moisture under the influence of
warmth, and suggests the view that men originated from animals of
another sort, since if they had come into existence as human beings,
needing fostering care for a long time, they would not have been able
to maintain their existence. In Empedocles, as in Epicurus and
Lucretius, who follow in Hs footsteps, there are rudimentary
suggestions of the Darwinian theory in its broader sense; and here
too, as with Darwin, the mechanical principle comes in; the process is
adapted to a certain end by a sort of natural selection, without
regarding nature as deliberately forming its results for these ends.

If the mechanical view is to be found in these philosophers, the
teleological occurs in Heraclitus, who conceives the process as a
rational development, in accordance with the Logos and names steps of
the process, as from igneous air to water, and thence to earth. The
Stoics followed Heraclitus in the main lines of their physics. The
primal principle is, as with him, igneous air. only that this is named
God by them with much greater definiteness. The Godhead has life in
itself, and develops into the universe, differentiating primarily into
two kinds of elements the finer or active, and the coarser or passive.
Formation or development goes on continuously, under the impulse of
the formative principle, by whatever name it is known, until all is
once more dissolved by the ekpyrosis into the fundamental principle,
and the whole process begins over again. Their conception of the
process as analogous to the development of the seed finds special
expression in their term of logos spermatikos. In one point the Stoics
differ essentially from Heraclitus. With them the whole process is
accomplished according to certain ends indwelling in the Godhead,
which is a provident, careful intelligence, while no providence is
assumed in Heraclitus.

Empedocles asserts definitely that the sphairos, as the full
reconciliation of opposites, is opposed, as the superior, to the
individual beings brought into existence by hatred, which are then
once more united by love to the primal essence, the interchange of
world-periods thus continuing indefinitely. Development is to be found
also in the atomistic philosopher Democritus; in a purely mechanical
manner without any purpose, bodies come into existence out of atoms,
and ultimately entire worlds appear and disappear from and to
eternity. Like his predecessors, Deinocritus, deduces organic beings
from what is inorganic-moist earth or slime.

Development, as well as the process of becoming, in general, was
denied by the Eleatic philosophers. Their doctrine, diametrically
opposed to the older thoroughgoing evolutionism, had its influence in
determining the acceptance of unchangeable ideas, or forms, by Plato
and Aristotle. Though Plato reproduces the doctrine of Heraclitus as
to the flux of all things in the phenomenal world, he denies any
continuous change in the world of ideas. Change is permanent only in
so far as the eternal forms stamp themselves upon individual objects.
Though this, as a rule, takes place but imperfectly, the stubborn mass
is so far affected that all works out as far as possible for the best.
The demiurge willed that all should become as far as possible like
himself; and so the world finally becomes beautiful and perfect. Here
we have a development, though the principle which has the most real
existence does not change; the forms, or archetypal ideas, remain
eternally what they are.

In Aristotle also the forms are the real existences, working in matter
but eternally remaining the same, at once the motive cause and the
effectual end of all things. Here the idea of evolution is clearer
than in Plato, especially for the physical world, which is wholly
dominated by purpose. The transition from lifeless to living matter is
a gradual one, so that the dividing-line between them is scarcely
perceptible. Next to lifeless matter comes the vegetable kingdom,
which seems, compared with the inorganic, to have life, but appears
lifeless compared with the organic. The transition from plants to
animals is again a gradual one. The lowest organisms originate from
the primeval slime, or from animal differentiation; there is a
continual progression from simple, undeveloped types to the higher and
more perfect. As the highest stage, the end and aim of the whole
process, man appears; all lower forms are merely unsuccessful attempts
to produce him. The ape is a transitional stage between man and other
viviparous animals. If development has so important a work in
Aristotle's physics, it is not less important in his metaphysics. The
whole transition from potentiality to actuality (from dynamis
toentelecheia) is nothing but a transition from the lower to the
higher, everything striving to assimilate itself to the absolutely
perfect, to the Divine. Thus Aristotle, like Plato, regards the entire
order of the universe as a sort of deification. But the part played in
the development by the Godhead, the absolutely immaterial form, is
less than that of the forms which operate in matter, since, being
already everything,, it is incapable of becoming anything else. Thus
Aristotle, despite his evolutionistic notions, does not take the view
of a thoroughgoing evolutionist as regards the universe; nor do the
Neoplatonists, whose highest principle remains wholly unchanged,
though all things emanate from it.
2. Medieval Views

The idea of evolution was not particularly dominant in patristic and
scholastic theology and philosophy, both on account of the dualism
which runs through them as an echo of Plato and Aristotle, and on
account of the generally accepted Christian theory of creation.
However, evolution is not generally denied; and with Augustine (De
civitate dei, xv. 1) it is taken as the basis for a philosophy of
history. Erigena and some of his followers seem to teach a sort of
evolution. The issue of finite beings from God is called analysis or
resolution in contrast to the reverse or deification the return to
God, who once more assimilates all things. God himself, although
denominated the beginning, middle, and end, all in all remains unmixed
in his own essence, transcendent though immanent in the world. The
teaching of. Nicholas of Cusa is similar to Erigena's, though a
certain amount of Pythagoreanism comes in here. The world exhibits
explicitly what the Godhead implicitly contains; the world is an
animated, ordered whole, in which God is everywhere present. Since God
embraces all things in himself, he, unites all opposites: he is the
complicatio omnium contradictoriorum. The idea of evolution thus
appears in Nicholas in a rather pantheistic form, but it is not
logically carried out.

In spite of some obscurities in his conception of the world Giordano
Bruno is a little clearer. According to him God is the immanent first
cause in the universe; there is no difference between matter and form;
matter, which includes in itself forms and ends, is the source of all
becoming and of all actuality. The infinite ether which fills infinite
space conceals within itself the nucleus of all things, and they
proceed from it according to determinate laws, yet in a teleological
manner. Thus the worlds originate not by an arbitrary act, but by an
inner necessity of the divine nature. They are natura naturata, as
distinguished from the operative nature of God, natitra naturans,
which is present in all thin-S as the being- of all that is, the
beauty of all that is fair. As in the Stoic teaching, with which
Bruno's philosophy has much in common, the conception of evolution
comes out clearly both for physics and metaphysics.
3. In Modern Philosophy

Leibniz attempted to reconcile the mechanical-physical and the
teleological views, after Descartes, in his Principia philosophitce,
excluding all purpose, had explained nature both lifeless and living,
as mere mechanism. It is right, however, to point out that Descartes
had a metaphysics above his physics, in which the conception of God
took an important place, and that thus the mechanical notion of
evolution did not really include everything. In Leibnitz the
principles of mechanics and physics are dependent upon the direction
of a supreme intelligence, without which they would be inexplicable to
us. Only by such a preliminary assumption are we able to recognize
that one ordered thing follows upon another continuously. It is in
this sense that the law of continuity is to be understood, which is of
such great importance in Leibnitz. At bottom it is the same as the law
of ordered development. The genera of all beings follow continuously
one upon another, and between the main classes, as between animals and
vegetables, there must be a continuous sequence of intermediate
beings. Here again, however, evolution is not taught in its most
thorough form, since the divine monad, of God, does not come into the
world but transcends it.

Among the German philosophers of the eighteenth century Herder must be
mentioned first of the pioneers of modern evolutionism. He lays down
the doctrine of a continuous development in the unity of nature from
inorganic to organic, from the stone to the plant, from the plant to
the animal, and from the animal to man. As nature develops according
to fixed laws and natural conditions, so does history, which is only a
continuation of the process of nature. Both nature and history labor
to educate man in perfect humanity; but as this is seldom attained, a
future life is suggested. Lessing had dwelt on the education of the
human race as a development to the higher and more perfect. It is only
recently that the significance of Herder, in regard to the conception
and treatment of historic development, has been adequately recognized.
Goethe also followed out the idea of evolution in his zoological and
botanical investigations, with his theory of the metamorphosis of
plants and his endeavor to discover unity in different organisms.
4. In German Idealism

Kant is also often mentioned as having been an early teacher of the
modern theory of descent. It is true he considers the analogy of the
forms which he finds in various classes of organisms a ground for
supposing that they may have come originally from a common source. He
calls the hypothesis that specifically different being have originated
one from the other "a daring adventure of the reason." But he
entertains the thought that in a later epoch "an orang-outang or a
chimpanzee may develop the organs which serve for walking, grasping
objects, and speaking-in short, that lie may evolve the structure of
man, with an organ for the use of reason, which shall gradually
develop itself by social culture." Here, indeed, important ideas of
Darwin were anticipated; but Kant's critical system was such that
development could have no predominant place in it.

The idea of evolution came out more strongly in his German idealistic
successors, especially in Schelling, who regarded nature as a
preliminary stage to mind, and the process of physical development as
continuing in history. The unconscious productions of nature are only
unsuccessful attempts to reflect itself; lifeless nature is an
immature intelligence, so that in its phenomena an intelligent
character appears only unconsciously. Its highest aim, that, of
becoming an object to itself, is only attained in the highest and last
reflection-in man, or in what we call reason, through which for the
first time nature returns perfectly upon itself. All stages of nature
are connected by a common life, and show in their development a
conclusive unity. The course of history as a whole must be conceived
as offering a gradually progressive revelation of the Absolute. For
this he names three periods-that of fate, that of nature, and that of
providence, of which we are now in the second. Schelling's followers
carried the idea of development somewhat further than their master.
This is true especially of Oken, who conceives natural science as the
science of the eternal transformation of God into the world, of the
dissolution of the Absolute into plurality, and of its continuous
further operation in this plurality. The development is continued
through the vegetable and animal kingdoms up to man, who in his art
and science and polity completely establishes the will of nature.
Oken, it is true, conceived man as the sole object of all animal
development, so that the lower stages are only abortive attempts to
produce him-a theory afterward controverted by Ernst von Baer and
Cuvier, the former of whom, standing somewhat in opposition to Darwin,
is of great interest to the student of the history of the theory of
evolution.

Some evolutionistic ideas are found in Krause and Schleiermacher; but
Hegel, with his absolute idealism, is a more notable representative of
them. In his system philosophy is the science of the Absolute, of the
absolute reason developing or unfolding itself. Reason develops itself
first in the abstract element of thought, then expresses itself
externally in nature, and finally returns from this externalization
into itself in mind. As Heraclitus had taught eternal becoming, so
Hegel, who avowedly accepted all the propositions of the Ephesian
philosopher in his logic, taught eternal proceeding. The difference
between the Greek and the German was that the former believed in the
flux of matter, of fire transmuting itself by degrees into all things,
and in nature as the sole existence, outside of which there was
nothing; while the latter conceived the abstract idea or reason as
that which really is or becomes, and nature as only a necessary but
transient phase in the process of development. With Heraclitus
evolution meant the return of all things into the primal principle
followed by a new world-development; with Hegel it was an eternal
process of thought, giving no answer to the question as to the end of
historical development.
5. Darwin's View

While Heraclitus had laid down his doctrine of eternal becoming rather
by intuition than on the ground of experience, and the entire
evolutionary process of Hegel had been expressly conceived as based on
pure thought, Darwin's epoch-making doctrine rested upon a vast mass
of ascertained facts. He was, of course, not the first to lay down the
origin of species one from another as a formal doctrine. Besides those
predecessors of his to whom allusion has already been made, two others
may be mentioned here: his grandfather, Erasmus Darwin, who emphasized
organic variability; and still more Lamarck, who denied the
immutability of species and forms, and claimed to have demonstrated by
observation the gradual development of the animal kingdom. What is new
in Charles Darwin is not his theory of descent, but its confirmation
by the theory of natural selection and the survival of the fittest in
the struggle for existence. Thus a result is brought about which
corresponds as far as possible to a rational end in a purely
mechanical process, without any cooperation of teleological
principles, without any innate tendency in the organisms to proceed to
a higher stage. This theory postulates in the later organisms
deviations from the earlier ones; and that these deviations, in so far
as they are improvements, perpetuate themselves and become generic
marks of differentiation. This, however, imports a difficulty, since
the origin of the first of these deviations is inexplicable. The
differentia of mankind, whom Darwin, led by the force of analogy,
deduces from a species of apes, consists in intellect and moral
qualities, but comes into existence only by degrees. The moral
sensibilities develop from the original social impulse innate in man;
this impulse is an effort to secure not so much individual happiness
as the general welfare.

It would be impossible to name here all those who, in different
countries, have followed in Darwin's footsteps, first in the
biological field and then in those of psychology, ethics, sociology,
and religion. They have carried his teaching further in several
directions, modifying it to some extent and making it fruitful, while
positivism has not seldom come into alliance with it. In Germany Ernst
Haeckel must be mentioned with his biogenetic law, according to which
the development of the individual is an epitome of the history of the
race, and with his less securely grounded notion of the world-ether as
a creative deity. In France Alfred Fouillee worked out a theory of
idea-forces, a combination of Platonic idealism with English (though
not specifically Darwinian) evolutionism. Marie-Jean Guyau understood
by evolution a life led according to the fundamental law that the most
intensive life is also the most extensive. He develops his ethics
altogether from the facts of the social existence of mankind, and his
religion is a universal sociomorphism, the feeling of the unity of man
with the entire cosmos.
6. Spencer's View

The most careful and thorough development of the whole system took
place in England. For a long time it was represented principally by
the work of Herbert Spencer, who had come out for the principle of
evolution even before the publication of Darwin's Origin of Species.
He carries the idea through the whole range of philosophy in his great
System of Synthetic Philosophy and undertakes to show that development
is the highest law of all nature, not merely of the organic. As the
foundation of ill that exists, though itself unknowable and only
revealing itself in material and mental forms, he places a power, the
Absolute, of which we have but an indefinite conception. The
individual processes of the world of phenomena are classed under the
head of evolution, or extension of movement, with which integration of
matter, union into a single whole, is connected, and dissolution or
absorption of movement, which includes disintegration of matter, the
breaking of connection. Both processes go on simultaneously, and
include the history of every existence which we can perceive. In the
course of their development the organisms incorporate matter with
themselves; the plant grows by taking into itself elements which have
previously existed in the form of gases, and the animal by
assimilating elements found in plants and in other animals. The same
sort of integration is observed in social organisms, as when nomadic
families unite into a tribe, or subjects under a prince, and princes
under a king. In like manner integration is evident in the development
of language, of art, and of science, especially philosophy. But as the
individuals unite into a whole, a strongly marked differentiation goes
on at the same time, as in the distinction between the surface and the
interior of the earth, or between various climates. Natural selection
is not considered necessary to account for varying species, but
gradual conditions of life create them. The aim of the development is
to show a condition of perfect balance in the whole; when this is
attained, the development, in virtue of the continuous operation of
external powers, passes into dissolution. Those epochs of development
and of dissolution follow alternately upon each other. This view of
Spencer suggests the hodos ano and hodos kato of Heraclitus, and his
flowing back of individual things into the primal principle.

Similar principles are carried out not only for organic phenomena but
also for mental and social; and on the basis of the theory of
evolution a remarkable combination of intuitionism and empiricism is
achieved. In his principles of sociology Spencer lays down the laws of
hyperorganic evolution, and gives the various stages of human customs
and especially of religious ideas, deducing all religion much too
one-sidedly from ancestor-worship. The belief in an immortal " second
self " is explained by such phenomena as shadows and echoes. The
notion of gods is suppose to arise from the idea of a ghostly life
after death. In his Principles of Ethics he attempts a similar
compromise between intuitionism and empiricism, deducing the
consciousness of duty from innumerable accumulated experiences. The
compelling element in moral actions, originally arising from fear of
religious, civil, or social punishment, disappears with the
development of true morality. There is no permanent opposition between
egoism and altruism, but the latter develops simultaneously with the
former.

Spencer's ethical principles were fruitfully modified, especially by
Sir Leslie Stephen and S. Alexander, though with constant adherence to
the idea of development. While the doctrine of evolution in Huxley and
Tyndall is associated with agnosticism, and thus freed from all
connection with metaphysics, as indeed was the case with Spencer, in
spite of his recognition of the Absolute as the necessary basis for
religion and for thought, in another direction an attempt was made to
combine evolutionism closely with a metaphysics in which the idea of
God was prominent. Thus the evolution theory of Clifford and Romanes
led them to a thoroughgoing monism, and that of J. M. F. Schiller to
pluralism. According to the last-named a personal deity, limited in
power, exists side by side with a multitude of intellectual beings,
who existed before the formation of the world in a chaotic state as
absolutely isolated individuals. The process of world formation begins
with the decision of the divine Spirit to bring a harmony of the
cosmos out of these many existences. Though Spencer's influence in
philosophical development was not so great in Germany as in England,
the idea of development has continued in recent years to exert no
little power. Space forbids more than a mention of Lotze's
teleological idealism; Von Harttmann's absolute monism, in which the
goal of the teleological development of the universe is the reversion
of the will into not-willing; Wundt's metaphysics of the will,
according to which the world is a development, an eternal becoming, in
which nature is a preliminary stage to mind; and Nietzsche's
individualism, the final point of which is the development of the
superman.