My personal conviction is that science is concerned wholly with truth, not with ethics.

In a tribal organization, even in time of peace, service to tribe or state predominates over all self seeking; in war, service for the tribe or state becomes supreme, and personal liberty is suspended.

The course of human history is determined, not by what happens in the skies, but what takes place in our hearts.

I am a rank individualist.

Whichever theory we adopt to give a rational explanation of human existence, that theory must take into account and explain the mental nature we see at work in all modern communities.

There are the further difficulties of building a population out of a diversity of races, each at a different stage of cultural evolution, some in need of restraint, many in need of protection; everywhere a bewildering Babel of tongues.

Before the discovery of agriculture mankind was everywhere so divided, the size of each group being determined by the natural fertility of its locality.