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.

Hand it to him, and he will turn away. Take it from him, and he quickly runs after it.

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.

Gentlemen, let us suppose that man is not stupid. (Indeed one cannot refuse to suppose that, if only from the one consideration, that, if man is stupid, then who is wise?) But if he is not stupid, he is monstrously ungrateful! Phenomenally ungrateful. In fact, I believe that the best definition of man is the ungrateful biped.

The fall of man is written in too legible characters not to be understood: Those that deny it, by their denying, prove it.

Human Nature is the only science of man; and yet has been hitherto the most neglected.