It will, of course, be understood that directly or indirectly, soon or late, every advance in the sciences of human nature will contribute to our success in controlling human nature and changing it to the advantage of the common weal.

Human beings are accustomed to think of intellect as the power of having and controlling ideas and of ability to learn as synonymous with ability to have ideas. But learning by having ideas is really one of the rare and isolated events in nature.

To the intelligent man with an interest in human nature it must often appear strange that so much of the energy of the scientific world has been spent on the study of the body and so little on the study of the mind.

Every so often, we pass laws repealing human nature.

Nothing in human nature is so God-like as the disposition to do good to our fellow-creatures.

Lincoln was a supreme politician. He understood politics because he understood human nature.