We may improve every branch of science, every branch of art, everything else relating to the work of human heads and hands; but we can not improve morals by invention or by hypothesis.

Morals are not made, but grow.
Yet, as I have said, there is what may be called a new system of ethics.
But this new system of ethics means nothing more than a new way of understanding the old system of ethics.

By the application of evolutional science to the study of morals, we have been enabled to trace back the whole history of moral ideas to the time of their earliest inception,--to understand the reasons of them, and to explain them without the help of any supernatural theory.

And the result, so far from diminishing our respect for the wisdom of our ancestors, has immensely increased that respect.

There is no single moral teaching common to different civilizations and different religions of an advanced stage of development which we do not find to be eternally true.