Human nature is the same everywhere; the modes only are different.

Never appeal to a man's better nature. He may not have one. Invoking his self interest gives you more leverage.

One of the worst things about life is not how nasty the nasty people are. You know that already. It is how nasty the nice people can be.

Human nature must not be altered in order to have a problem-free world. Man is not just a problem-solving being, as behaviorists would wish us to believe, but a problem-recognizing and -accepting being.

Never can custom conquer nature, for she is ever unconquered.

It's a burden to us even to be human beings-men with our own real body and blood; we are ashamed of it, we think it a disgrace and try to contrive to be some sort of impossible generalized man.

Even the most sadistic and destructive man is human, as human as the saint.

Could we perfect human nature, we might also expect a perfect state of things.

If mankind is naturally good, he is sure going against his nature more and more of the time. It sounds like a bad joke: the paranoids are after us.

It is to the credit of human nature, that, except where its selfishness is brought into play, it loves more readily than it hates.