nt 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