to these becomes an ethical point of view in Nietzsche, the _enfant
terrible_ of modern thought, who maintains that man's life must be
interpreted physiologically only and not spiritually, and who would
replace philanthropy by a boundless egoism.

Influences of the second kind are usually more prominent than the
preceding in the case of the philosophical moralist, and they are
not always avoided by the moralist who boasts his independence of
philosophy. The former influences are more constantly at work: they
supply the facts for all ethical reflexion. Ethical thought is not
so uniformly influenced by the conceptions arrived at in science
or philosophy. But there are certain periods of history in which
conceptions regarding the truth of things--whether arrived at by
scientific methods or not--have had a profound influence upon men's
views of good and evil. At the beginning of our era, for instance, the
view of God and man introduced by Christianity, resulted in a deepened
and, to some extent, in a distinctive morality. Again, at the time of
the Renaissance, the new knowledge and new interests combined with the
weakening of the Church's and of the Empire's authority to bring about
the demand for a revision of the ecclesiastical morality, and led to
some not very successful attempts to find a firmer basis for conduct.

At the present day also it is the case that philosophers of different
schools are for the most part agreed in claiming ethical importance
for their conceptions about reality. In particular, the scientific
thought of the last generation has been reformed under the, influence
of the group of ideas which constitute the theory of evolution. There
is hardly a department of thought which this new doctrine has not
touched; and upon morality its influence may seem to be peculiarly
important and direct. The theory of evolution, as put forward by