What may be meant by this idea of 'fitness'--which meets us in the
famous phrase that the 'survival of the fittest' in the struggle for
life is the goal of evolution--is a question which brings us at once
to the consideration of the ethical significance of the theory. For
it seems to lay claim to give both an explanation of progress and an
interpretation of what constitutes worth in conduct.




II.

ETHICS AND EVOLUTION.


There are two things which are not always kept distinct,--what may be
called the 'evolution of ethics' and the 'ethics of evolution,' The
former might more correctly be called the evolution of morality,--the
account of the way in which moral customs, moral institutions, and
moral ideas have been developed and have come to take their place in
the life of mankind. Clearly these are all features of human life;
and, if the theory of evolution applies to human life, we must expect
it also to have some contribution to make to this portion of man's
development,--to the growth of the customs, institutions, and ideas
which enter into and make up his morality.

But by the 'ethics of evolution' is meant something more than the
'evolution of ethics' or development of morality. It signifies a
theory which turns the facts of evolution to account in determining