orld is able to arrive at firm
moral principles. If man, even in his spiritual life and moral action, is a
mere product of nature, originated through descent, and if his whole
spiritual life is fully consumed by these merely mechanical factors, then
all moral principles are also nothing else than inherited customs founded
upon those instincts which in the struggle for existence have proven to be
the most beneficial to man. Then their influence is subject to continual
change, always corresponding to the existing state of human development. As
these moral instincts have displaced the former instincts of the animal
predecessors of man--say, _e.g._, of sharks, of marsupialia, of
lemurides--so they must {380} also expect it any time to be displaced in
turn by new and still more useful instincts. And even in the same period of
the development of mankind, the moral or immoral principles which have
actual authority in each nation or tribe, have their full right of
existence as long as they are not displaced by still more advantageous
instincts. Moral principles in which infanticide, prostitution, and
cannibalism have a place, are inferior to the highest form of Christian
morality only so far as they do not hold their own in the struggle for
existence, when nations having those low views come into collision with
nations of higher moral culture; but in themselves they have full value and
full right, so long as they attain the end of all instincts, and so far as
we can speak of ends at all; in such naturalism, apart from human activity,
the end consists only in the preservation of the individual and the species
in the struggle for existence.

Under these suppositions, moral principles not only lose their objective
and solid consistency in the mass of mankind, but they also become
irrevocably subject to the arbitrariness of the single individual. An
individual who either has not, or asserts that he has not, a determined
moral instinct, or who allows it to be smothered by some other instinct
which in a normal individual is subordinate, but in him stronger, is fully
justified in his immoral action so long as he is successful with it. Every
individual is entirely his own master and his own judge. If man is morally
good, it may be the consequence of an especially happy individual
disposition, or of an especially clear perception, or of happy
circumstances and influences; but it is not the consequence of a free
subordination under the au