The main force used in the evolving world of humanity has hitherto been applied in the form of war.

Human nature, as manifested in tribalism and nationalism, provides the momentum of the machinery of human evolution.

We shall never understand the ethical system taught by Jesus unless we realize that he was a Jew, not only by birth, but that he lived and taught as a Jew; the Sermon on the Mount was addressed to his distracted fellow nationals.

There are very few men and women in whom a Universalist feeling is altogether lacking; its prevalence suggests that it must be part of our inborn nature and have a place in Nature's scheme of evolution.

No tribe unites with another of its own free will.

Reason has not tamed desire: it is as strong as ever.

The discovery of agriculture was the first big step toward a civilized life.