Darwinism In The Strict Sense
It remains for us to consider what is essentially Darwinian in Darwinism,
namely, the theory of natural selection as the determining factor in
evolution. For, given the reality of evolution and descent, and that
transformations from one form to another, from lower to higher, have
really taken place, what was the guiding and impelling factor in
evolution, what forced it forwards and upwards? It is here that the real
lem of Darwinism begins. Only from this point onwards does the
doctrine of evolution, which is not in itself necessarily committed to any
theory of the factors, become definitely Darwinian or anti-Darwinian. And
it is this problem that is mainly concerned in the discussions taking
place to-day as to whether Darwin was right, or whether Darwinism as a
hypothesis has not broken down.
The most characteristic feature of Darwin's theory was "natural
teleology," that is, the explanation of what is apparently full of purpose
and plan in the world, purely as the necessary consequence of very simple
conditions, without purpose or any striving after an aim. He sought to
show that evolution and ascent can be realised through purely "natural"
causes, that this world of life, man included, must have come about, but
not because it was intended so to do. In this sense, indeed, his doctrine
is an attempt to do away with teleology. But in another sense it is so
even more emphatically. The world, and especially the world of life, is
undoubtedly full of what is de facto purposive. The living organism, as
a whole and in every one of its parts, is marvellously adapted to the end
of performing its functions, maintaining its own life and reproducing.
Every single living being is a miracle of inexhaustible adaptations to an
end. Whence came these? They, too, are products, unsought for, unintended,
and yet necessary, and coming about "of themselves," that is without
teleological or any supernatural guiding principles. To eliminate purpose
and the purposive creating and guiding activity of transcendental
principles from interpretations of nature, and to introduce purely
naturalistic principles--"principles of chance," if we understand chance in
this connection not as opposed to necessity, but to plan and purpose--this
is the aim of the Darwinian theory. And it only becomes definitely
anti-theological because it is anti-teleological.
The conclusions which Darwin arrived at as to the factors in the
transformation of species, and in the production of "adaptations," have
been in part supported by the specialists he influenced, in part
strengthened, but in part modified and even reversed, so that a great
crisis has come about in regard to Darwinism in the strict sense--a crisis
which threatens to be fatal to it. We must here attempt to take a general
survey of the state of the question and to define our own position.
Darwin's interpretation is well known. It is the theory of the natural
selection of the best adapted through the struggle for existence, which is
of itself a natural selection, and results in the sifting out of
particular forms and of higher forms. Darwin's thinking follows the course
that all anti-teleological thought has followed since the earliest times.
In bringing forth the forms of life, nature offers, without choice or aim
or intention, a wealth of possibilities. The forms which happen to be best
adapted to the surrounding conditions of life maintain themselves, and
reproduce; the others perish, and are eliminated (survival of the
fittest). Thus arises adaptation at first in the rough, but gradually in
more and more minute detail. This adaptation, brought about by chance,
gives the impression of intelligent creative purpose.
In Darwin this fundamental mode of naturalistic interpretation took, under
the influence of the social-economic theories of Malthus, the special form
of natural selection by means of the struggle for existence, in
association with the assumption of unlimited and fluctuating variability
in the forms of life. All living beings have a tendency to increase in
number without limit. But the means of subsistence and other conditions of
existence do not increase at the same rate; they are relatively constant.
Thus competition must come about. Any organism that is, by fortuitous
variation, more favourably equipped than its fellows maintains itself and
reproduces itself; the less favoured perish. For all things living are
exposed to enemies, to untoward circumstances, and the like. Every
individual favoured above its rivals persists, and can transmit to its
descendants its own more favourable, more differentiated, more highly
equipped character. Thus evolution is begun, and is forced on into the
ever more diverse and ever "higher."
To Darwin this struggle for existence and this selection according to
utility seemed, at any rate, the chief factor in progress. He did, indeed,
make some concessions to the Lamarckian principle that new characters may
be acquired by increased use, and to other "secondary" principles. But
these are of small importance as compared with his main factor.