III.

Darwin's energetic renewal of the old idea of evolution had its chief

importance in strengthening the conviction of this real continuity in

the world, of continuity in the series of form and events. It was a

great support for all those who were prepared to base their conception

of life on scientific grounds. Together with the recently discovered law

of the conservation of energy, it helped to produce the great realistic

movement which characterises the last third of the nineteenth century.

After the decline of the Romantic movement people wished to have firmer

ground under their feet and reality now asserted itself in a more

emphatic manner than in the period of Romanticism. It was easy for Hegel

to proclaim that "the real" was "the rational," and that "the

rational" was "the real": reality itself existed for him only in the

interpretation of ideal reason, and if there was anything which could

not be merged in the higher unity of thought, then it was only an

example of the "impotence of nature to hold to the idea." But now

concepts are to be founded on nature and not on any system of categories

too confidently deduced a priori. The new devotion to nature had its

recompense in itself, because the new points of view made us see that

nature could indeed "hold to ideas," though perhaps not to those which

we had cogitated beforehand.

A most important question for philosophers to answer was whether the

new views were compatible with an idealistic conception of life and

existence. Some proclaimed that we have now no need of any philosophy

beyond the principles of the conservation of matter and energy and the

principle of natural evolution: existence should and could be definitely

and completely explained by the laws of material nature. But abler

thinkers saw that the thing was not so simple. They were prepared to

give the new views their just place and to examine what alterations the

old views must undergo in order to be brought into harmony with the new

data.

The realistic character of Darwin's theory was shown not only in the

idea of natural continuity, but also, and not least, in the idea of the

cause whereby organic life advances step by step. This idea--the idea of

the struggle for life--implied that nothing could persist, if it had no

power to maintain itself under the given conditions. Inner value

alone does not decide. Idealism was here put to its hardest trial. In

continuous evolution it could perhaps still find an analogy to the inner

evolution of ideas in the mind; but in the demand for power in order to

struggle with outward conditions Realism seemed to announce itself in

its most brutal form. Every form of Idealism had to ask itself seriously

how it was going to "struggle for life" with this new Realism.

We will now give a short account of the position which leading thinkers

in different countries have taken up in regard to this question.

I. Herbert Spencer was the philosopher whose mind was best prepared by

his own previous thinking to admit the theory of Darwin to a place in

his conception of the world. His criticism of the arguments which had

been put forward against the hypothesis of Lamarck, showed that Spencer,

as a young man, was an adherent to the evolution idea. In his

"Social Statics" (1850) he applied this idea to human life and moral

civilisation. In 1852 he wrote an essay on "The Development Hypothesis",

in which he definitely stated his belief that the differentiation of

species, like the differentiation within a single organism, was the

result of development. In the first edition of his "Psychology" (1855)

he took a step which put him in opposition to the older English school

(from Locke to Mill): he acknowledged "innate ideas" so far as to

admit the tendency of acquired habits to be inherited in the course of

generations, so that the nature and functions of the individual are only

to be understood through its connection with the life of the species.

In 1857, in his essay on "Progress", he propounded the law of

differentiation as a general law of evolution, verified by examples from

all regions of experience, the evolution of species being only one of

these examples. On the effect which the appearance of "The Origin of

Species" had on his mind he writes in his "Autobiography": "Up to

that time... I held that the sole cause of organic evolution is the

inheritance of functionally-produced modifications. The "Origin of

Species" made it clear to me that I was wrong, and that the larger part

of the facts cannot be due to any such cause... To have the theory of

organic evolution justified was of course to get further support for

that theory of evolution at large with which... all my conceptions were

bound up." (Spencer, "Autobiography", Vol. II. page 50, London, 1904.)

Instead of the metaphorical expression "natural selection," Spencer

introduced the term "survival of the fittest," which found favour with

Darwin as well as with Wallace.

In working out his ideas of evolution, Spencer found that

differentiation was not the only form of evolution. In its simplest form

evolution is mainly a concentration, previously scattered elements being

integrated and losing independent movement. Differentiation is only

forthcoming when minor wholes arise within a greater whole. And the

highest form of evolution is reached when there is a harmony between

concentration and differentiation, a harmony which Spencer calls

equilibration and which he defines as a moving equilibrium. At the same

time this definition enables him to illustrate the expression "survival

of the fittest." "Every living organism exhibits such a moving

equilibrium--a balanced set of functions constituting its life; and the

overthrow of this balanced set of functions or moving equilibrium is

what we call death. Some individuals in a species are so constituted

that their moving equilibria are less easily overthrown than those of

other individuals; and these are the fittest which survive, or, in Mr

Darwin's language, they are the select which nature preserves." (Ibid.

page 100.) Not only in the domain of organic life, but in all domains,

the summit of evolution is, according to Spencer, characterised by such

a harmony--by a moving equilibrium.

Spencer's analysis of the concept of evolution, based on a great variety

of examples, has made this concept clearer and more definite than

before. It contains the three elements; integration, differentiation and

equilibration. It is true that a concept which is to be valid for all

domains of experience must have an abstract character, and between the

several domains there is, strictly speaking, only a relation of analogy.

So there is only analogy between psychical and physical evolution. But

this is no serious objection, because general concepts do not express

more than analogies between the phenomena which they represent. Spencer

takes his leading terms from the material world in defining evolution

(in the simplest form) as integration of matter and dissipation of

movement; but as he--not always quite consistently (Cf. my letter

to him, 1876, now printed in Duncan's "Life and Letters of Herbert

Spencer", page 178, London, 1908.)--assumed a correspondence of mind and

matter, he could very well give these terms an indirect importance for

psychical evolution. Spencer has always, in my opinion with full right,

repudiated the ascription of materialism. He is no more a materialist

than Spinoza. In his "Principles of Psychology" (paragraph 63) he

expressed himself very clearly: "Though it seems easier to translate

so-called matter into so-called spirit, than to translate so-called

spirit into so-called matter--which latter is indeed wholly

impossible--yet no translation can carry us beyond our symbols." These

words lead us naturally to a group of thinkers whose starting-point

was psychical evolution. But we have still one aspect of Spencer's

philosophy to mention.

Spencer founded his "laws of evolution" on an inductive basis, but

he was convinced that they could be deduced from the law of the

conservation of energy. Such a deduction is, perhaps, possible for the

more elementary forms of evolution, integration and differentiation; but

it is not possible for the highest form, the equilibration, which is a

harmony of integration and differentiation. Spencer can no more deduce

the necessity for the eventual appearance of "moving equilibria" of

harmonious totalities than Hegel could guarantee the "higher unities"

in which all contradictions should be reconciled. In Spencer's hands the

theory of evolution acquired a more decidedly optimistic character

than in Darwin's; but I shall deal later with the relation of Darwin's

hypothesis to the opposition of optimism and pessimism.

II. While the starting-point of Spencer was biological or cosmological,

psychical evolution being conceived as in analogy with physical, a group

of eminent thinkers--in Germany Wundt, in France Fouillee, in Italy

Ardigo--took, each in his own manner, their starting-point in psychical

evolution as an original fact and as a type of all evolution, the

hypothesis of Darwin coming in as a corroboration and as a special

example. They maintain the continuity of evolution; they find this

character most prominent in psychical evolution, and this is for them a

motive to demand a corresponding continuity in the material, especially

in the organic domain.

To Wundt and Fouillee the concept of will is prominent. They see the

type of all evolution in the transformation of the life of will from

blind impulse to conscious choice; the theories of Lamarck and Darwin

are used to support the view that there is in nature a tendency to

evolution in steady reciprocity with external conditions. The struggle

for life is here only a secondary fact. Its apparent prominence is

explained by the circumstance that the influence of external conditions

is easily made out, while inner conditions can be verified only

through their effects. For Ardigo the evolution of thought was the

starting-point and the type: in the evolution of a scientific hypothesis

we see a progress from the indefinite (indistinto) to the definite

(distinto), and this is a characteristic of all evolution, as Ardigo has

pointed out in a series of works. The opposition between indistinto and

distinto corresponds to Spencer's opposition between homogeneity and

heterogeneity. The hypothesis of the origin of differences of species

from more simple forms is a special example of the general law of

evolution.

In the views of Wundt and Fouillee we find the fundamental idea of

idealism: psychical phenomena as expressions of the innermost nature of

existence. They differ from the older Idealism in the great stress which

they lay on evolution as a real, historical process which is going on

through steady conflict with external conditions. The Romantic dread

of reality is broken. It is beyond doubt that Darwin's emphasis on the

struggle for life as a necessary condition of evolution has been a very

important factor in carrying philosophy back to reality from the heaven

of pure ideas. The philosophy of Ardigo, on the other side, appears

more as a continuation and deepening of positivism, though the Italian

thinker arrived at his point of view independently of French-English

positivism. The idea of continuous evolution is here maintained in

opposition to Comte's and Mill's philosophy of discontinuity. From Wundt

and Fouillee Ardigo differs in conceiving psychical evolution not as an

immediate revelation of the innermost nature of existence, but only as a

single, though the most accessible example, of evolution.

III. To the French philosophers Boutroux and Bergson, evolution proper

is continuous and qualitative, while outer experience and physical

science give us fragments only, sporadic processes and mechanical

combinations. To Bergson, in his recent work "L'Evolution Creatrice",

evolution consists in an elan de vie which to our fragmentary

observation and analytic reflexion appears as broken into a manifold of

elements and processes. The concept of matter in its scientific form

is the result of this breaking asunder, essential for all scientific

reflexion. In these conceptions the strongest opposition between

inner and outer conditions of evolution is expressed: in the domain of

internal conditions spontaneous development of qualitative forms--in the

domain of external conditions discontinuity and mechanical combination.

We see, then, that the theory of evolution has influenced philosophy

in a variety of forms. It has made idealistic thinkers revise their

relation to the real world; it has led positivistic thinkers to find a

closer connection between the facts on which they based their views; it

has made us all open our eyes for new possibilities to arise through

the prima facie inexplicable "spontaneous" variations which are the

condition of all evolution. This last point is one of peculiar interest.

Deeper than speculative philosophy and mechanical science saw in the

days of their triumph, we catch sight of new streams, whose sources and

laws we have still to discover. Most sharply does this appear in the

theory of mutation, which is only a stronger accentuation of a main

point in Darwinism. It is interesting to see that an analogous

problem comes into the foreground in physics through the discovery

of radioactive phenomena, and in psychology through the assumption

of psychical new formations (as held by Boutroux, William James and

Bergson). From this side, Darwin's ideas, as well as the analogous

ideas in other domains, incite us to renewed examination of our first

principles, their rationality and their value. On the other hand,

his theory of the struggle for existence challenges us to examine the

conditions and discuss the outlook as to the persistence of human life

and society and of the values that belong to them. It is not enough to

hope (or fear?) the rising of new forms; we have also to investigate the

possibility of upholding the forms and ideals which have hitherto been

the bases of human life. Darwin has here given his age the most earnest

and most impressive lesson. This side of Darwin's theory is of peculiar

interest to some special philosophical problems to which I now pass.